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在进化生物学中，自然发生，或通俗地称为生命起源（OoL），<ref>{{cite book| last1 = Oparin| first1 = Aleksandr Ivanovich| author-link1 = Alexander Oparin| translator1-last = Morgulis| translator1-first = Sergius| year = 1938| title = The Origin of Life| url = https://books.google.com/books?id=Jv8psJCtI0gC| series = Phoenix Edition Series| edition = 2| location = Mineola, New York| publisher = Courier Corporation| publication-date = 2003| isbn = 978-0486495224| access-date = 2018-06-16}}</ref><ref name=Pereto /><ref name="AST-20151218">Compare: {{cite journal |author= Scharf, Caleb |title= A Strategy for Origins of Life Research |date= 18 December 2015 |journal= [[Astrobiology (journal)|Astrobiology]] |volume= 15 |issue= 12 |pages= 1031–1042 |doi= 10.1089/ast.2015.1113 |display-authors= etal |pmid= 26684503 |pmc= 4683543|bibcode= 2015AsBio..15.1031S | quote = What do we mean by the origins of life (OoL)? [...] Since the early 20th century the phrase OoL has been used to refer to the events that occurred during the transition from non-living to living systems on Earth, i.e., the origin of terrestrial biology (Oparin, 1924; Haldane, 1929). The term has largely replaced earlier concepts such as abiogenesis (Kamminga, 1980; Fry, 2000).}}</ref>是生命从非生命物质（如简单的有机化合物）中产生的自然过程。 <ref name=Oparin>{{harvnb|Oparin|1953|p=vi}}</ref><ref name=Pereto>{{cite journal|last= Peretó |first= Juli |year= 2005 |title= Controversies on the origin of life |url= http://www.im.microbios.org/0801/0801023.pdf |journal= [[International Microbiology]] |volume= 8 |issue= 1 |pages= 23–31 |pmid= 15906258 |accessdate= 2015-06-01 |url-status= dead |archiveurl= https://web.archive.org/web/20150824074726/http://www.im.microbios.org/0801/0801023.pdf |archivedate= 24 August 2015 |quote = Ever since the historical contributions by Aleksandr I. Oparin, in the 1920s, the intellectual challenge of the origin of life enigma has unfolded based on the assumption that life originated on Earth through physicochemical processes that can be supposed, comprehended, and simulated; that is, there were neither miracles nor spontaneous generations.}}</ref><ref>{{cite journal |last1= Warmflash |first1= David |last2= Warmflash |first2= Benjamin |date= November 2005 |title= Did Life Come from Another World? |journal= [[Scientific American]] |volume= 293 |issue= 5 |pages= 64–71 |doi= 10.1038/scientificamerican1105-64|pmid= 16318028 |bibcode= 2005SciAm.293e..64W | quote = According to the conventional hypothesis, the earliest living cells emerged as a result of chemical evolution on our planet billions of years ago in a process called abiogenesis.}}</ref><ref>{{harvnb|Yarus|2010|p=47}}</ref>虽然这一过程的细节仍未可知，但主流的科学假说认为，从非生命实体到生命实体的转变不是一个单一的事件，而是一个复杂度逐渐增加的进化过程，其中包括分子的自复制、自组装、自催化和细胞膜的出现。<ref>{{cite journal|url=http://www.biocommunication.at/pdf/publications/biosystems_2016.pdf |title=Crucial steps to life: From chemical reactions to code using agents|journal=Biosystems|volume=140|pages=49–57|doi=10.1016/j.biosystems.2015.12.007|pmid=26723230|year=2016|last1=Witzany|first1=Guenther}}</ref><ref name="AB-20141208">{{cite web |last= Howell |first= Elizabeth |title= How Did Life Become Complex, And Could It Happen Beyond Earth? |url= https://www.astrobio.net/origin-and-evolution-of-life/life-become-complex-happen-beyond-earth/ |date= 8 December 2014 |work= [[Astrobiology Magazine]] |accessdate= 14 February 2018 }}</ref><ref name="EA-20150420">{{Cite book |last= Tirard |first= Stephane |title= Abiogenesis – Definition|date= 20 April 2015 |doi= 10.1007/978-3-642-27833-4_2-4 |journal= Encyclopedia of Astrobiology|pages= 1 | quote = Thomas Huxley (1825–1895) used the term abiogenesis in an important text published in 1870. He strictly made the difference between spontaneous generation, which he did not accept, and the possibility of the evolution of matter from inert to living, without any influence of life. [...] Since the end of the nineteenth century, evolutive abiogenesis means increasing complexity and evolution of matter from inert to living state in the abiotic context of evolution of primitive Earth. |isbn= 978-3-642-27833-4 }}</ref>虽然自然发生的发生在科学家中是没有争议的，但其可能的机制我们却不甚了解。关于自然发生如何发生，有几种原理和假说。<ref>{{Cite book |title=Rethinking evolution: the revolution that's hiding in plain sight  |last=Levinson |first=Gene |publisher=World Scientific |year=2020 |isbn=978-1786347268 |url=https://rethinkingevolution.com/}}</ref>

在进化生物学中，自然发生，或通俗地称为生命起源（OoL），<ref>{{cite book| last1 = Oparin| first1 = Aleksandr Ivanovich|translator1-last = Morgulis| translator1-first = Sergius| year = 1938| title = The Origin of Life| url = https://books.google.com/books?id=Jv8psJCtI0gC| series = Phoenix Edition Series| edition = 2| location = Mineola, New York| publisher = Courier Corporation| publication-date = 2003| isbn = 978-0486495224| access-date = 2018-06-16}}</ref><ref name=Pereto /><ref name="AST-20151218">Compare: {{cite journal |author= Scharf, Caleb |title= A Strategy for Origins of Life Research |date= 18 December 2015 |journal= Astrobiology|volume= 15 |issue= 12 |pages= 1031–1042 |doi= 10.1089/ast.2015.1113 |display-authors= etal |pmid= 26684503 |pmc= 4683543|bibcode= 2015AsBio..15.1031S | quote = What do we mean by the origins of life (OoL)? [...] Since the early 20th century the phrase OoL has been used to refer to the events that occurred during the transition from non-living to living systems on Earth, i.e., the origin of terrestrial biology (Oparin, 1924; Haldane, 1929). The term has largely replaced earlier concepts such as abiogenesis (Kamminga, 1980; Fry, 2000).}}</ref>是生命从非生命物质（如简单的有机化合物）中产生的自然过程。 <ref name=Oparin>{{harvnb|Oparin|1953|p=vi}}</ref><ref name=Pereto>{{cite journal|last= Peretó |first= Juli |year= 2005 |title= Controversies on the origin of life |url= http://www.im.microbios.org/0801/0801023.pdf |journal= International Microbiology|volume= 8 |issue= 1 |pages= 23–31 |pmid= 15906258 |accessdate= 2015-06-01 |url-status= dead |archiveurl= https://web.archive.org/web/20150824074726/http://www.im.microbios.org/0801/0801023.pdf |archivedate= 24 August 2015 |quote = Ever since the historical contributions by Aleksandr I. Oparin, in the 1920s, the intellectual challenge of the origin of life enigma has unfolded based on the assumption that life originated on Earth through physicochemical processes that can be supposed, comprehended, and simulated; that is, there were neither miracles nor spontaneous generations.}}</ref><ref>{{cite journal |last1= Warmflash |first1= David |last2= Warmflash |first2= Benjamin |date= November 2005 |title= Did Life Come from Another World? |journal= Scientific American |volume= 293 |issue= 5 |pages= 64–71 |doi= 10.1038/scientificamerican1105-64|pmid= 16318028 |bibcode= 2005SciAm.293e..64W | quote = According to the conventional hypothesis, the earliest living cells emerged as a result of chemical evolution on our planet billions of years ago in a process called abiogenesis.}}</ref><ref>{{harvnb|Yarus|2010|p=47}}</ref>虽然这一过程的细节仍未可知，但主流的科学假说认为，从非生命实体到生命实体的转变不是一个单一的事件，而是一个复杂度逐渐增加的进化过程，其中包括分子的自复制、自组装、自催化和细胞膜的出现。<ref>{{cite journal|url=http://www.biocommunication.at/pdf/publications/biosystems_2016.pdf |title=Crucial steps to life: From chemical reactions to code using agents|journal=Biosystems|volume=140|pages=49–57|doi=10.1016/j.biosystems.2015.12.007|pmid=26723230|year=2016|last1=Witzany|first1=Guenther}}</ref><ref name="AB-20141208">{{cite web |last= Howell |first= Elizabeth |title= How Did Life Become Complex, And Could It Happen Beyond Earth? |url= https://www.astrobio.net/origin-and-evolution-of-life/life-become-complex-happen-beyond-earth/ |date= 8 December 2014 |work= Astrobiology Magazine|accessdate= 14 February 2018 }}</ref><ref name="EA-20150420">{{Cite book |last= Tirard |first= Stephane |title= Abiogenesis – Definition|date= 20 April 2015 |doi= 10.1007/978-3-642-27833-4_2-4 |journal= Encyclopedia of Astrobiology|pages= 1 | quote = Thomas Huxley (1825–1895) used the term abiogenesis in an important text published in 1870. He strictly made the difference between spontaneous generation, which he did not accept, and the possibility of the evolution of matter from inert to living, without any influence of life. [...] Since the end of the nineteenth century, evolutive abiogenesis means increasing complexity and evolution of matter from inert to living state in the abiotic context of evolution of primitive Earth. |isbn= 978-3-642-27833-4 }}</ref>虽然自然发生的发生在科学家中是没有争议的，但其可能的机制我们却不甚了解。关于自然发生如何发生，有几种原理和假说。<ref>{{Cite book |title=Rethinking evolution: the revolution that's hiding in plain sight  |last=Levinson |first=Gene |publisher=World Scientific |year=2020 |isbn=978-1786347268 |url=https://rethinkingevolution.com/}}</ref>

1952年经典的[[Miller-Urey实验 Miller–Urey experiment]]和类似的研究表明，大多数氨基酸，即所有生物体中使用的蛋白质的化学成分，可以在旨在复制早期地球的条件下从无机化合物中合成。科学家们提出了各种可能引发这些反应的外部能量来源，包括闪电和辐射。其他方法（“新陈代谢优先”假说）则侧重于了解早期地球化学系统中的催化作用如何提供自复制所需的前体分子。<ref name="Ralser 2014">{{cite journal |last1= Keller |first1= Markus A. |last2= Turchyn |first2= Alexandra V. |last3= Ralser |first3= Markus |date= 25 March 2014 |title= Non‐enzymatic glycolysis and pentose phosphate pathway‐like reactions in a plausible Archean ocean |journal= [[Molecular Systems Biology]] |volume= 10 |issue= 725 |page= 725 |doi= 10.1002/msb.20145228 |pmc= 4023395 |pmid= 24771084}}</ref>

1952年经典的[[Miller-Urey实验 Miller–Urey experiment]]和类似的研究表明，大多数氨基酸，即所有生物体中使用的蛋白质的化学成分，可以在旨在复制早期地球的条件下从无机化合物中合成。科学家们提出了各种可能引发这些反应的外部能量来源，包括闪电和辐射。其他方法（“新陈代谢优先”假说）则侧重于了解早期地球化学系统中的催化作用如何提供自复制所需的前体分子。<ref name="Ralser 2014">{{cite journal |last1= Keller |first1= Markus A. |last2= Turchyn |first2= Alexandra V. |last3= Ralser |first3= Markus |date= 25 March 2014 |title= Non‐enzymatic glycolysis and pentose phosphate pathway‐like reactions in a plausible Archean ocean |journal= Molecular Systems Biology |volume= 10 |issue= 725 |page= 725 |doi= 10.1002/msb.20145228 |pmc= 4023395 |pmid= 24771084}}</ref>

另一种有[[生源论假说 panspermia hypothesis]]<ref name="USRA-2010">{{cite conference|last=Rampelotto|first=Pabulo Henrique|date=26 April 2010|title=Panspermia: A Promising Field of Research|url=http://www.lpi.usra.edu/meetings/abscicon2010/pdf/5224.pdf|url-status=live|conference=Astrobiology Science Conference 2010|location=Houston, TX|publisher=[[Lunar and Planetary Institute]]|page=5224|bibcode=2010LPICo1538.5224R|archiveurl=https://web.archive.org/web/20160327005016/http://www.lpi.usra.edu//meetings/abscicon2010/pdf/5224.pdf|archivedate=27 March 2016|accessdate=2014-12-03|conference-url=http://www.lpi.usra.edu/meetings/abscicon2010/}} Conference held at League City, TX</ref>推测，微生物通过未知的机制在地球以外产生，并通过太空尘埃<ref name="ARX-20171106">{{cite journal |last= Berera |first= Arjun |title= Space dust collisions as a planetary escape mechanism |journal= Astrobiology |date= 6 November 2017 |arxiv= 1711.01895 |bibcode= 2017AsBio..17.1274B |doi= 10.1089/ast.2017.1662 |pmid= 29148823 |volume= 17 |issue= 12 |pages= 1274–1282|s2cid= 126012488 }}</ref>和流星体传播到早期地球。<ref name="SA-20180110">{{cite journal|last1=Chan|first1=Queenie H.S.|date=10 January 2018|title=Organic matter in extraterrestrial water-bearing salt crystals|journal=[[Science Advances]]|volume=4|page=eaao3521|bibcode=2018SciA....4O3521C|doi=10.1126/sciadv.aao3521|pmc=5770164|pmid=29349297|number=1, eaao3521}}</ref>众所周知，太阳系和星际空间中存在复杂的有机分子，这些分子可能为地球上生命的发展提供了起始物质。<ref name="Ehrenfreund2010" /><ref name="Science 2015">{{cite news|url=http://news.sciencemag.org/chemistry/2015/04/organic-molecules-found-circling-nearby-star?rss=1|title=Organic molecules found circling nearby star|last=Perkins|first=Sid|date=8 April 2015|work=[[Science (journal)|Science]]|accessdate=2015-06-02|publisher=[[American Association for the Advancement of Science]]|location=Washington, DC|type=News}}</ref><ref>{{cite news|url=http://www.rsc.org/chemistryworld/2015/04/meteorites-may-have-delivered-chemicals-started-life-earth|title=Chemicals formed on meteorites may have started life on Earth|last=King|first=Anthony|date=14 April 2015|work=[[Chemistry World]]|accessdate=2015-04-17|archiveurl=https://web.archive.org/web/20150417142723/http://www.rsc.org/chemistryworld/2015/04/meteorites-may-have-delivered-chemicals-started-life-earth|archivedate=17 April 2015|url-status=live|publisher=[[Royal Society of Chemistry]]|location=London|type=News}}</ref><ref>{{cite journal|last1=Saladino|first1=Raffaele|last2=Carota|first2=Eleonora|last3=Botta|first3=Giorgia|last4=Kapralov|first4=Mikhail|last5=Timoshenko|first5=Gennady N.|last6=Rozanov|first6=Alexei Y.|last7=Krasavin|first7=Eugene|last8=Di Mauro|first8=Ernesto|display-authors=3|date=13 April 2015|title=Meteorite-catalyzed syntheses of nucleosides and of other prebiotic compounds from formamide under proton irradiation|journal=[[Proceedings of the National Academy of Sciences of the United States of America|Proc. Natl. Acad. Sci. U.S.A.]]|volume=112|issue=21|pages=E2746–E2755|bibcode=2015PNAS..112E2746S|doi=10.1073/pnas.1422225112|pmc=4450408|pmid=25870268}}</ref>

另一种有[[生源论假说 panspermia hypothesis]]<ref name="USRA-2010">{{cite conference|last=Rampelotto|first=Pabulo Henrique|date=26 April 2010|title=Panspermia: A Promising Field of Research|url=http://www.lpi.usra.edu/meetings/abscicon2010/pdf/5224.pdf|url-status=live|conference=Astrobiology Science Conference 2010|location=Houston, TX|publisher=Lunar and Planetary Institute|page=5224|bibcode=2010LPICo1538.5224R|archiveurl=https://web.archive.org/web/20160327005016/http://www.lpi.usra.edu//meetings/abscicon2010/pdf/5224.pdf|archivedate=27 March 2016|accessdate=2014-12-03|conference-url=http://www.lpi.usra.edu/meetings/abscicon2010/}} Conference held at League City, TX</ref>推测，微生物通过未知的机制在地球以外产生，并通过太空尘埃<ref name="ARX-20171106">{{cite journal |last= Berera |first= Arjun |title= Space dust collisions as a planetary escape mechanism |journal= Astrobiology |date= 6 November 2017 |arxiv= 1711.01895 |bibcode= 2017AsBio..17.1274B |doi= 10.1089/ast.2017.1662 |pmid= 29148823 |volume= 17 |issue= 12 |pages= 1274–1282}}</ref>和流星体传播到早期地球。<ref name="SA-20180110">{{cite journal|last1=Chan|first1=Queenie H.S.|date=10 January 2018|title=Organic matter in extraterrestrial water-bearing salt crystals|journal=Science Advances|volume=4|page=eaao3521|bibcode=2018SciA....4O3521C|doi=10.1126/sciadv.aao3521|pmc=5770164|pmid=29349297|number=1, eaao3521}}</ref>众所周知，太阳系和星际空间中存在复杂的有机分子，这些分子可能为地球上生命的发展提供了起始物质。<ref name="Ehrenfreund2010" /><ref name="Science 2015">{{cite news|url=http://news.sciencemag.org/chemistry/2015/04/organic-molecules-found-circling-nearby-star?rss=1|title=Organic molecules found circling nearby star|last=Perkins|first=Sid|date=8 April 2015|work=Science |accessdate=2015-06-02|publisher=American Association for the Advancement of Science|location=Washington, DC|type=News}}</ref><ref>{{cite news|url=http://www.rsc.org/chemistryworld/2015/04/meteorites-may-have-delivered-chemicals-started-life-earth|title=Chemicals formed on meteorites may have started life on Earth|last=King|first=Anthony|date=14 April 2015|work=Chemistry World|accessdate=2015-04-17|archiveurl=https://web.archive.org/web/20150417142723/http://www.rsc.org/chemistryworld/2015/04/meteorites-may-have-delivered-chemicals-started-life-earth|archivedate=17 April 2015|url-status=live|publisher=Royal Society of Chemistry|location=London|type=News}}</ref><ref>{{cite journal|last1=Saladino|first1=Raffaele|last2=Carota|first2=Eleonora|last3=Botta|first3=Giorgia|last4=Kapralov|first4=Mikhail|last5=Timoshenko|first5=Gennady N.|last6=Rozanov|first6=Alexei Y.|last7=Krasavin|first7=Eugene|last8=Di Mauro|first8=Ernesto|display-authors=3|date=13 April 2015|title=Meteorite-catalyzed syntheses of nucleosides and of other prebiotic compounds from formamide under proton irradiation|journal=Proceedings of the National Academy of Sciences of the United States of America|volume=112|issue=21|pages=E2746–E2755|bibcode=2015PNAS..112E2746S|doi=10.1073/pnas.1422225112|pmc=4450408|pmid=25870268}}</ref>

地球仍然是宇宙中已知的唯一一个孕育生命的地方，<ref name="NASA-1990">{{cite web |url= https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900013148.pdf |title= Extraterrestrial Life in the Universe |last= Graham |first= Robert W. |date= February 1990 |place= [[Glenn Research Center|Lewis Research Center]], Cleveland, Ohio |publisher= [[NASA]] |type= NASA Technical Memorandum 102363 |accessdate= 2015-06-02 |url-status= live |archiveurl= https://web.archive.org/web/20140903100534/http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900013148.pdf |archivedate= 3 September 2014}}</ref><ref>{{harvnb|Altermann|2009|p=xvii}}</ref> 来自地球的化石证据为大多数关于自然发生论的研究提供了信息。地球的年龄是45.5亿年；<ref name="USGS1997">{{cite web |url= http://pubs.usgs.gov/gip/geotime/age.html |title= Age of the Earth |date= 9 July 2007 |publisher= [[United States Geological Survey]] |accessdate= 2006-01-10 |url-status= live |archiveurl= https://web.archive.org/web/20051223072700/http://pubs.usgs.gov/gip/geotime/age.html |archivedate= 23 December 2005}}</ref><ref>{{harvnb|Dalrymple|2001|pp= 205–221}}</ref><ref>{{cite journal |last1= Manhesa |first1= Gérard |last2= Allègre |first2= Claude J. |authorlink2= Claude Allègre |last3= Dupréa |first3= Bernard |last4= Hamelin |first4= Bruno |date= May 1980 |title= Lead isotope study of basic-ultrabasic layered complexes: Speculations about the age of the earth and primitive mantle characteristics |journal= [[Earth and Planetary Science Letters]] |volume= 47 |issue= 3 |pages= 370–382 |bibcode= 1980E&PSL..47..370M |doi= 10.1016/0012-821X(80)90024-2 }}</ref>地球上最早的无可争议的生命证据至少可以追溯到35亿年前，<ref name="Origin1">{{cite journal |last1= Schopf |first1= J. William |authorlink1= J. William Schopf |last2= Kudryavtsev |first2= Anatoliy B. |last3= Czaja |first3= Andrew D. |last4= Tripathi |first4= Abhishek B. |date= 5 October 2007 |title= Evidence of Archean life: Stromatolites and microfossils |journal= [[Precambrian Research]] |volume= 158 |pages= 141–155 |issue= 3–4 |doi= 10.1016/j.precamres.2007.04.009 |bibcode= 2007PreR..158..141S }}</ref><ref name="Origin2">{{cite journal |last= Schopf |first= J. William |date= 29 June 2006 |title= Fossil evidence of Archaean life |journal= [[Philosophical Transactions of the Royal Society B]] |volume= 361 |issue= 1470 |pages= 869–885 |doi= 10.1098/rstb.2006.1834 |pmid= 16754604 |pmc=1578735}}</ref><ref name="RavenJohnson2002">{{harvnb|Raven|Johnson|2002|p=68}}</ref>也可能还要追溯到早至始太古代（36-40亿年前之间）。2017年，科学家在西澳大利亚的皮尔巴拉古地台发现的34.8亿岁的硅华和其他相关矿藏(通常在温泉和间歇泉附近发现) 中发现了陆地上早期生命的可能证据。<ref name="PO-20170509">{{cite news |author= Staff |title= Oldest evidence of life on land found in 3.48-billion-year-old Australian rocks |url= https://phys.org/news/2017-05-oldest-evidence-life-billion-year-old-australian.html |date= 9 May 2017 |work= [[Phys.org]] |accessdate= 13 May 2017 |url-status= live |archiveurl= https://web.archive.org/web/20170510013721/https://phys.org/news/2017-05-oldest-evidence-life-billion-year-old-australian.html |archivedate= 10 May 2017}}</ref><ref name="NC-20170509">{{cite journal |last1= Djokic |first1= Tara |last2= Van Kranendonk |first2= Martin J. |last3= Campbell |first3= Kathleen A. |last4= Walter |first4= Malcolm R. |last5= Ward |first5= Colin R. |title= Earliest signs of life on land preserved in ca. 3.5 Gao hot spring deposits |date= 9 May 2017 |journal= [[Nature Communications]] |doi= 10.1038/ncomms15263 |pmid= 28486437 |pmc= 5436104 |volume= 8 |page= 15263 |bibcode= 2017NatCo...815263D}}</ref><ref name="PNAS-2017">{{cite journal |last1= Schopf |first1= J. William |last2= Kitajima |first2= Kouki |last3= Spicuzza |first3= Michael J. |last4= Kudryavtsev |first4= Anatolly B. |last5= Valley |first5= John W. |title= SIMS analyses of the oldest known assemblage of microfossils document their taxon-correlated carbon isotope compositions |date= 2017 |journal= [[Proceedings of the National Academy of Sciences of the United States of America|PNAS]] |doi= 10.1073/pnas.1718063115 |pmid= 29255053 |pmc= 5776830 |volume= 115 |issue= 1 |pages= 53–58|bibcode= 2018PNAS..115...53S }}</ref><ref name="WU-20171218">{{cite web |last= Tyrell |first= Kelly April |title= Oldest fossils ever found show life on Earth began before 3.5 billion years ago |url= https://news.wisc.edu/oldest-fossils-ever-found-show-life-on-earth-began-before-3-5-billion-years-ago/ |date= 18 December 2017 |work= [[University of Wisconsin-Madison]] |accessdate= 18 December 2017 }}</ref>然而，许多发现表明，地球上的生命可能出现得更早。截至2017年，加拿大魁北克省的岩石中37.7亿至42.8亿年前的深海热液喷口沉淀物内的微化石（化石微生物）可能蕴藏着地球上最古老的生命记录，这表明生命在冥古宙44亿年前海洋形成后不久就开始了。<ref name="NAT-20170301">{{cite journal |last1= Dodd |first1= Matthew S. |last2= Papineau |first2= Dominic |last3= Grenne |first3= Tor |last4= Slack |first4= John F. |last5= Rittner |first5= Martin |last6= Pirajno |first6= Franco |last7= O'Neil |first7= Jonathan |last8= Little |first8= Crispin T.S. |title= Evidence for early life in Earth's oldest hydrothermal vent precipitates |url= http://eprints.whiterose.ac.uk/112179/ |journal= [[Nature (journal)|Nature]] |date= 1 March 2017 |volume= 543 |issue= 7643 |pages= 60–64 |doi= 10.1038/nature21377 |pmid= 28252057 |accessdate= 2 March 2017 |bibcode= 2017Natur.543...60D |url-status= live |archiveurl= https://web.archive.org/web/20170908201821/http://eprints.whiterose.ac.uk/112179/ |archivedate= 8 September 2017|doi-access= free }}</ref><ref name="NYT-20170301">{{cite news |last= Zimmer |first= Carl |authorlink= Carl Zimmer |title= Scientists Say Canadian Bacteria Fossils May Be Earth's Oldest |url= https://www.nytimes.com/2017/03/01/science/earths-oldest-bacteria-fossils.html |date= 1 March 2017 |work= [[The New York Times]] |accessdate= 2 March 2017 |url-status= live |archiveurl= https://web.archive.org/web/20170302042424/https://www.nytimes.com/2017/03/01/science/earths-oldest-bacteria-fossils.html |archivedate= 2 March 2017}}</ref><ref name="BBC-20170301">{{Cite news |last= Ghosh |first= Pallab |title= Earliest evidence of life on Earth found |url= https://www.bbc.co.uk/news/science-environment-39117523 |publisher= [[BBC News]] |date= 1 March 2017 |accessdate= 2 March 2017 |url-status= live |archiveurl= https://web.archive.org/web/20170302002134/http://www.bbc.co.uk/news/science-environment-39117523 |archivedate= 2 March 2017|work= BBC News }}</ref><ref name="4.3b oldest">{{cite news |last1= Dunham |first1= Will |title= Canadian bacteria-like fossils called oldest evidence of life |url= http://ca.reuters.com/article/topNews/idCAKBN16858B?sp=true |date= 1 March 2017 |agency= [[Reuters]] |accessdate= 1 March 2017 |url-status= live |archiveurl= https://web.archive.org/web/20170302114728/http://ca.reuters.com/article/topNews/idCAKBN16858B?sp=true |archivedate= 2 March 2017}}</ref><ref>{{cite news|title=Researchers uncover 'direct evidence' of life on Earth 4 billion years ago|url= http://dw.com/p/2YUnT|accessdate= 5 March 2017|publisher= Deutsche Welle}}</ref>

地球仍然是宇宙中已知的唯一一个孕育生命的地方，<ref name="NASA-1990">{{cite web |url= https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900013148.pdf |title= Extraterrestrial Life in the Universe |last= Graham |first= Robert W. |date= February 1990 |place= Glenn Research Center, Cleveland, Ohio |publisher= NASA |type= NASA Technical Memorandum 102363 |accessdate= 2015-06-02 |url-status= live |archiveurl= https://web.archive.org/web/20140903100534/http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900013148.pdf |archivedate= 3 September 2014}}</ref><ref>{{harvnb|Altermann|2009|p=xvii}}</ref> 来自地球的化石证据为大多数关于自然发生论的研究提供了信息。地球的年龄是45.5亿年；<ref name="USGS1997">{{cite web |url= http://pubs.usgs.gov/gip/geotime/age.html |title= Age of the Earth |date= 9 July 2007 |publisher= United States Geological Survey |accessdate= 2006-01-10 |url-status= live |archiveurl= https://web.archive.org/web/20051223072700/http://pubs.usgs.gov/gip/geotime/age.html |archivedate= 23 December 2005}}</ref><ref>{{harvnb|Dalrymple|2001|pp= 205–221}}</ref><ref>{{cite journal |last1= Manhesa |first1= Gérard |last2= Allègre |first2= Claude J.|last3= Dupréa |first3= Bernard |last4= Hamelin |first4= Bruno |date= May 1980 |title= Lead isotope study of basic-ultrabasic layered complexes: Speculations about the age of the earth and primitive mantle characteristics |journal= Earth and Planetary Science Letters|volume= 47 |issue= 3 |pages= 370–382 |bibcode= 1980E&PSL..47..370M |doi= 10.1016/0012-821X(80)90024-2 }}</ref>地球上最早的无可争议的生命证据至少可以追溯到35亿年前，<ref name="Origin1">{{cite journal |last1= Schopf |first1= J. William |last2= Kudryavtsev |first2= Anatoliy B. |last3= Czaja |first3= Andrew D. |last4= Tripathi |first4= Abhishek B. |date= 5 October 2007 |title= Evidence of Archean life: Stromatolites and microfossils |journal= Precambrian Research |volume= 158 |pages= 141–155 |issue= 3–4 |doi= 10.1016/j.precamres.2007.04.009 |bibcode= 2007PreR..158..141S }}</ref><ref name="Origin2">{{cite journal |last= Schopf |first= J. William |date= 29 June 2006 |title= Fossil evidence of Archaean life |journal= Philosophical Transactions of the Royal Society B |volume= 361 |issue= 1470 |pages= 869–885 |doi= 10.1098/rstb.2006.1834 |pmid= 16754604 |pmc=1578735}}</ref><ref name="RavenJohnson2002">{{harvnb|Raven|Johnson|2002|p=68}}</ref>也可能还要追溯到早至始太古代（36-40亿年前之间）。2017年，科学家在西澳大利亚的皮尔巴拉古地台发现的34.8亿岁的硅华和其他相关矿藏(通常在温泉和间歇泉附近发现) 中发现了陆地上早期生命的可能证据。<ref name="PO-20170509">{{cite news |author= Staff |title= Oldest evidence of life on land found in 3.48-billion-year-old Australian rocks |url= https://phys.org/news/2017-05-oldest-evidence-life-billion-year-old-australian.html |date= 9 May 2017 |work= Phys.org |accessdate= 13 May 2017 |url-status= live |archiveurl= https://web.archive.org/web/20170510013721/https://phys.org/news/2017-05-oldest-evidence-life-billion-year-old-australian.html |archivedate= 10 May 2017}}</ref><ref name="NC-20170509">{{cite journal |last1= Djokic |first1= Tara |last2= Van Kranendonk |first2= Martin J. |last3= Campbell |first3= Kathleen A. |last4= Walter |first4= Malcolm R. |last5= Ward |first5= Colin R. |title= Earliest signs of life on land preserved in ca. 3.5 Gao hot spring deposits |date= 9 May 2017 |journal= Nature Communications|doi= 10.1038/ncomms15263 |pmid= 28486437 |pmc= 5436104 |volume= 8 |page= 15263 |bibcode= 2017NatCo...815263D}}</ref><ref name="PNAS-2017">{{cite journal |last1= Schopf |first1= J. William |last2= Kitajima |first2= Kouki |last3= Spicuzza |first3= Michael J. |last4= Kudryavtsev |first4= Anatolly B. |last5= Valley |first5= John W. |title= SIMS analyses of the oldest known assemblage of microfossils document their taxon-correlated carbon isotope compositions |date= 2017 |journal= Proceedings of the National Academy of Sciences of the United States of America |doi= 10.1073/pnas.1718063115 |pmid= 29255053 |pmc= 5776830 |volume= 115 |issue= 1 |pages= 53–58|bibcode= 2018PNAS..115...53S }}</ref><ref name="WU-20171218">{{cite web |last= Tyrell |first= Kelly April |title= Oldest fossils ever found show life on Earth began before 3.5 billion years ago |url= https://news.wisc.edu/oldest-fossils-ever-found-show-life-on-earth-began-before-3-5-billion-years-ago/ |date= 18 December 2017 |work= University of Wisconsin-Madison |accessdate= 18 December 2017 }}</ref>然而，许多发现表明，地球上的生命可能出现得更早。截至2017年，加拿大魁北克省的岩石中37.7亿至42.8亿年前的深海热液喷口沉淀物内的微化石（化石微生物）可能蕴藏着地球上最古老的生命记录，这表明生命在冥古宙44亿年前海洋形成后不久就开始了。<ref name="NAT-20170301">{{cite journal |last1= Dodd |first1= Matthew S. |last2= Papineau |first2= Dominic |last3= Grenne |first3= Tor |last4= Slack |first4= John F. |last5= Rittner |first5= Martin |last6= Pirajno |first6= Franco |last7= O'Neil |first7= Jonathan |last8= Little |first8= Crispin T.S. |title= Evidence for early life in Earth's oldest hydrothermal vent precipitates |url= http://eprints.whiterose.ac.uk/112179/ |journal= Nature |date= 1 March 2017 |volume= 543 |issue= 7643 |pages= 60–64 |doi= 10.1038/nature21377 |pmid= 28252057 |accessdate= 2 March 2017 |bibcode= 2017Natur.543...60D |url-status= live |archiveurl= https://web.archive.org/web/20170908201821/http://eprints.whiterose.ac.uk/112179/ |archivedate= 8 September 2017|doi-access= free }}</ref><ref name="NYT-20170301">{{cite news |last= Zimmer |first= Carl |title= Scientists Say Canadian Bacteria Fossils May Be Earth's Oldest |url= https://www.nytimes.com/2017/03/01/science/earths-oldest-bacteria-fossils.html |date= 1 March 2017 |work= The New York Times|accessdate= 2 March 2017 |url-status= live |archiveurl= https://web.archive.org/web/20170302042424/https://www.nytimes.com/2017/03/01/science/earths-oldest-bacteria-fossils.html |archivedate= 2 March 2017}}</ref><ref name="BBC-20170301">{{Cite news |last= Ghosh |first= Pallab |title= Earliest evidence of life on Earth found |url= https://www.bbc.co.uk/news/science-environment-39117523 |publisher= BBC News |date= 1 March 2017 |accessdate= 2 March 2017 |url-status= live |archiveurl= https://web.archive.org/web/20170302002134/http://www.bbc.co.uk/news/science-environment-39117523 |archivedate= 2 March 2017|work= BBC News }}</ref><ref name="4.3b oldest">{{cite news |last1= Dunham |first1= Will |title= Canadian bacteria-like fossils called oldest evidence of life |url= http://ca.reuters.com/article/topNews/idCAKBN16858B?sp=true |date= 1 March 2017 |agency= Reuters|accessdate= 1 March 2017 |url-status= live |archiveurl= https://web.archive.org/web/20170302114728/http://ca.reuters.com/article/topNews/idCAKBN16858B?sp=true |archivedate= 2 March 2017}}</ref><ref>{{cite news|title=Researchers uncover 'direct evidence' of life on Earth 4 billion years ago|url= http://dw.com/p/2YUnT|accessdate= 5 March 2017|publisher= Deutsche Welle}}</ref>

相比之下，德克·舒尔茨-马库奇 Dirk Schulze-Makuch和路易斯·欧文 Louis Irwin在他们的书中花了整整第一章来讨论这个问题。<ref “Schulze-Makuch”>{{cite book| last1 = Schulze-Makuch | first1 = Dirk | last2 = Irwin

相比之下，德克·舒尔茨-马库奇 Dirk Schulze-Makuch和路易斯·欧文 Louis Irwin在他们的书中花了整整第一章来讨论这个问题。<ref “Schulze-Makuch”>{{cite book| last1 = Schulze-Makuch | first1 = Dirk | last2 = Irwin | first2 = Louis N. | year = 2018| edition = 3 | title = Life in the Universe. Expectations and Constraints | location= New York | publisher = Springer  }}</ref>

| first2 = Louis N. | year = 2018| edition = 3 | title = Life in the Universe. Expectations and Constraints | location= New York | publisher = Springer  }}</ref>

 

 

尽管如此，美国宇航局目前对生命的定义是，生命是“一种能够进行达尔文进化的自我维持的化学系统”。<ref name="NASA-20210306">{{cite news |last=Voytek |first=Mary a. |title=About Life Detection |url=https://astrobiology.nasa.gov/research/life-detection/about/ |date=6 March 2021 |work=NASA |access-date=8 March 2021 }}</ref><ref name="NG-20201214">{{cite news |last=Marshall |first=Michael |title=He may have found the key to the origins of life. So why have so few heard of him? - Hungarian biologist Tibor Gánti is an obscure figure. Now, more than a decade after his death, his ideas about how life began are finally coming to fruition. |url=https://www.nationalgeographic.com/science/2020/12/he-may-have-found-the-key-to-origins-of-life-tibor-ganti-chemoton/ |date=14 December 2020 |work=National Geographic Society |access-date=8 March 2021 }}</ref><ref name="SPC-20130801">{{cite news |last=Mullen |first=Lesle |title=Defining Life: Q&A with Scientist Gerald Joyce |url=https://www.space.com/22210-life-definition-gerald-joyce-interview.html |date=1 August 2013 |work=Space.com |access-date=8 March 2021 }}</ref><ref name="NYT-20210226">{{cite news |last=Zimmer |first=Carl |title=The Secret Life of a Coronavirus - An oily, 100-nanometer-wide bubble of genes has killed more than two million people and reshaped the world. Scientists don't quite know what to make of it. |url=https://www.nytimes.com/2021/02/26/opinion/sunday/coronavirus-alive-dead.html |date=26 February 2021 |access-date=8 March 2021 }}</ref>更简单地说，生命是“可以自我繁殖并按照生存要求进化的物质”。<ref name="ETSU-2012a">{{cite web |last=Luttermoser |first=Donald G. |title=ASTR-1020: Astronomy II Course Lecture Notes Section XII |url=http://faculty.etsu.edu/lutter/courses/astr1020/a1020chap12.pdf |date=2012 |work=East Tennessee State University |archive-url=https://web.archive.org/web/20170707114650/http://faculty.etsu.edu/lutter/courses/astr1020/a1020chap12.pdf |access-date=8 March 2021 |archive-date=7 July 2017 }}</ref><ref name="ETSU-2012b">{{cite web |last=Luttermoser |first=Donald G. |title=Physics 2028: Great Ideas in Science: The Exobiology Module |url=http://faculty.etsu.edu/lutter/courses/phys2028/p2028exobnotes.pdf |date=2012 |work=East Tennessee State University |archive-url=https://web.archive.org/web/20160412201815/http://faculty.etsu.edu/lutter/courses/phys2028/p2028exobnotes.pdf |access-date=8 March 2021 |archive-date=12 April 2016 }}</ref><ref name="ETSU-2012c">{{cite web |last=Luttermoser |first=Donald G. |title=Lecture Notes for ASTR 1020 - Astronomy II with Luttermoser at East Tennessee (ETSU) |url=http://www.koofers.com/files/notes-gyw4cx4ar4/ |date=2012 |work=East Tennessee State University|archive-url=https://web.archive.org/web/20120502172318/http://www.koofers.com/files/notes-gyw4cx4ar4/ |access-date=8 March 2021 |archive-date=2 May 2012 }}</ref>

====发酵====

====发酵====

[[File:010 small subunit-1FKA.gif|thumb|upright=1.25|嗜热细菌核糖体30S亚基的分子结构。 <ref name="Venki">{{cite journal |last1=Wimberly |first1=Brian T. |last2=Brodersen |first2=Ditlev E. |last3=Clemons |first3=William M. Jr. |last4=Morgan-Warren |first4=Robert J. |last5=Carter |first5=Andrew P. |last6=Vonrhein |first6=Clemens |last7=Hartsch |first7=Thomas |last8=Ramakrishnan |first8=V. |authorlink8=Venkatraman Ramakrishnan |display-authors=3 |date=21 September 2000 |title=Structure of the 30S ribosomal subunit |journal=Nature |volume=407 |issue=6802 |pages=327–339 |doi=10.1038/35030006 |pmid=11014182|bibcode=2000Natur.407..327W |s2cid=4419944 }}</ref>蛋白质显示为蓝色，单个RNA链显示为橙色。 ]]

[[File:010 small subunit-1FKA.gif|thumb|upright=1.25|嗜热细菌核糖体30S亚基的分子结构。 <ref name="Venki">{{cite journal |last1=Wimberly |first1=Brian T. |last2=Brodersen |first2=Ditlev E. |last3=Clemons |first3=William M. Jr. |last4=Morgan-Warren |first4=Robert J. |last5=Carter |first5=Andrew P. |last6=Vonrhein |first6=Clemens |last7=Hartsch |first7=Thomas |last8=Ramakrishnan |first8=V. |display-authors=3 |date=21 September 2000 |title=Structure of the 30S ribosomal subunit |journal=Nature |volume=407 |issue=6802 |pages=327–339 |doi=10.1038/35030006 |pmid=11014182|bibcode=2000Natur.407..327W}}</ref>蛋白质显示为蓝色，单个RNA链显示为橙色。 ]]

RNA世界假说描述了一个具有自我复制和催化能力的RNA，但没有DNA或蛋白质的早期地球。<ref name="NYT-20140925-CZ">{{cite news |last=Zimmer |first=Carl |date=25 September 2014 |title=A Tiny Emissary From the Ancient Past |url=https://www.nytimes.com/2014/09/25/science/a-tiny-emissary-from-the-ancient-past.html |newspaper=The New York Times |location=New York |accessdate=2014-09-26 |url-status=live |archiveurl=https://web.archive.org/web/20140927022738/http://www.nytimes.com/2014/09/25/science/a-tiny-emissary-from-the-ancient-past.html |archivedate=27 September 2014}}</ref> 现在普遍认为现在地球上的生命起源于一个RNA世界，尽管基于RNA的生命可能并不是最早存在的生命。<ref name="RNA">*{{cite journal |last1=Copley |first1=Shelley D. |last2=Smith |first2=Eric |last3=Morowitz |first3=Harold J. |authorlink3=Harold J. Morowitz |date=December 2007 |title=The origin of the RNA world: Co-evolution of genes and metabolism |url=http://tuvalu.santafe.edu/~desmith/PDF_pubs/Copley_BOG.pdf |journal=Bioorganic Chemistry |volume=35 |issue=6 |pages=430–443 |doi=10.1016/j.bioorg.2007.08.001 |pmid=17897696 |accessdate=2015-06-08 |quote=The proposal that life on Earth arose from an RNA world is widely accepted. |url-status=live |archiveurl=https://web.archive.org/web/20130905070129/http://tuvalu.santafe.edu/~desmith/PDF_pubs/Copley_BOG.pdf |archivedate=5 September 2013}}这个结论是由许多独立的证据得出的，例如观察到RNA是翻译过程的核心，并且小RNA可以催化生命所需的所有化学基团和信息转移。核糖体的结构被称为 "确凿的证据 smoking gun"，因为它表明核糖体是一个核酶，其核心是RNA，并且在催化肽键形成的活性位点18埃以内没有氨基酸侧链。<ref name="Robertson2012">{{cite journal |last1=Robertson |first1=Michael P. |last2=Joyce |first2=Gerald F. |author-link2=Gerald Joyce |date=May 2012 |title=The origins of the RNA world |journal=Cold Spring Harbor Perspectives in Biology |volume=4 |issue=5 |page=a003608 |doi=10.1101/cshperspect.a003608  |pmc=3331698 |pmid=20739415 }}</ref><ref>{{cite journal |last1=Fox |first1=George.E. |date=9 June 2010 |title=Origin and evolution of the ribosome |journal=Cold Spring Harbor Perspectives in Biology |volume=2 |issue=9(a003483) |page=a003483 |doi=10.1101/cshperspect.a003483 |pmid=20534711|pmc=2926754 |doi-access=free }}</ref> 尽管如此，在 2021 年 3 月，研究人员报告的证据表明，转移 RNA 的初步形式可能是生命早期发展中的复制分子本身。<ref name="EL-20210302">{{cite journal |last1=Kühnlein |first1=Alexandra |last2=Lanzmich |first2=Simon A. |last3=Brun |first3=Dieter |title=tRNA sequences can assemble into a replicator |doi=10.7554/eLife.63431 |date=2 March 2021 |journal=[[eLife]] |volume=10 |pmid=33648631 |pmc=7924937 |doi-access=free }}</ref><ref name="STD-20210403">{{cite news |last=Maximilian |first=Ludwig |title=Solving the Chicken-and-the-Egg Problem – "A Step Closer to the Reconstruction of the Origin of Life" |url=https://scitechdaily.com/solving-the-chicken-and-the-egg-problem-a-step-closer-to-the-reconstruction-of-the-origin-of-life/ |date=3 April 2021 |work=[[SciTech (magazine)|SciTechDaily]] |access-date=3 April 2021 }}</ref>

RNA世界假说描述了一个具有自我复制和催化能力的RNA，但没有DNA或蛋白质的早期地球。<ref name="NYT-20140925-CZ">{{cite news |last=Zimmer |first=Carl |date=25 September 2014 |title=A Tiny Emissary From the Ancient Past |url=https://www.nytimes.com/2014/09/25/science/a-tiny-emissary-from-the-ancient-past.html |newspaper=The New York Times |location=New York |accessdate=2014-09-26 |url-status=live |archiveurl=https://web.archive.org/web/20140927022738/http://www.nytimes.com/2014/09/25/science/a-tiny-emissary-from-the-ancient-past.html |archivedate=27 September 2014}}</ref> 现在普遍认为现在地球上的生命起源于一个RNA世界，尽管基于RNA的生命可能并不是最早存在的生命。<ref name="RNA">*{{cite journal |last1=Copley |first1=Shelley D. |last2=Smith |first2=Eric |last3=Morowitz |first3=Harold J. |date=December 2007 |title=The origin of the RNA world: Co-evolution of genes and metabolism |url=http://tuvalu.santafe.edu/~desmith/PDF_pubs/Copley_BOG.pdf |journal=Bioorganic Chemistry |volume=35 |issue=6 |pages=430–443 |doi=10.1016/j.bioorg.2007.08.001 |pmid=17897696 |accessdate=2015-06-08 |quote=The proposal that life on Earth arose from an RNA world is widely accepted. |url-status=live |archiveurl=https://web.archive.org/web/20130905070129/http://tuvalu.santafe.edu/~desmith/PDF_pubs/Copley_BOG.pdf |archivedate=5 September 2013}}这个结论是由许多独立的证据得出的，例如观察到RNA是翻译过程的核心，并且小RNA可以催化生命所需的所有化学基团和信息转移。核糖体的结构被称为 "确凿的证据 smoking gun"，因为它表明核糖体是一个核酶，其核心是RNA，并且在催化肽键形成的活性位点18埃以内没有氨基酸侧链。<ref name="Robertson2012">{{cite journal |last1=Robertson |first1=Michael P. |last2=Joyce |first2=Gerald F. |date=May 2012 |title=The origins of the RNA world |journal=Cold Spring Harbor Perspectives in Biology |volume=4 |issue=5 |page=a003608 |doi=10.1101/cshperspect.a003608  |pmc=3331698 |pmid=20739415 }}</ref><ref>{{cite journal |last1=Fox |first1=George.E. |date=9 June 2010 |title=Origin and evolution of the ribosome |journal=Cold Spring Harbor Perspectives in Biology |volume=2 |issue=9(a003483) |page=a003483 |doi=10.1101/cshperspect.a003483 |pmid=20534711|pmc=2926754 |doi-access=free }}</ref> 尽管如此，在 2021 年 3 月，研究人员报告的证据表明，转移 RNA 的初步形式可能是生命早期发展中的复制分子本身。<ref name="EL-20210302">{{cite journal |last1=Kühnlein |first1=Alexandra |last2=Lanzmich |first2=Simon A. |last3=Brun |first3=Dieter |title=tRNA sequences can assemble into a replicator |doi=10.7554/eLife.63431 |date=2 March 2021 |journal=eLife|volume=10 |pmid=33648631 |pmc=7924937 |doi-access=free }}</ref><ref name="STD-20210403">{{cite news |last=Maximilian |first=Ludwig |title=Solving the Chicken-and-the-Egg Problem – "A Step Closer to the Reconstruction of the Origin of Life" |url=https://scitechdaily.com/solving-the-chicken-and-the-egg-problem-a-step-closer-to-the-reconstruction-of-the-origin-of-life/ |date=3 April 2021 |work=SciTechDaily |access-date=3 April 2021 }}</ref>

RNA世界的概念是由亚历山大·里奇Alexander Rich在1962年首次提出的<ref>{{cite journal |last1=Neveu |first1=Marc |last2=Kim |first2=Hyo-Joong |last3=Benner |first3=Steven A. |date=22 April 2013 |title=The 'Strong' RNA World Hypothesis: Fifty Years Old |journal=Astrobiology |volume=13 |issue=4 |pages=391–403 |bibcode=2013AsBio..13..391N |doi=10.1089/ast.2012.0868 |pmid=23551238 |ref=harv}}</ref> ，而这个术语则是由沃尔特·吉尔伯特Walter Gilbert在1986年创造的。<ref name="Cech2012">{{cite journal |last=Cech |first=Thomas R. |authorlink=Thomas Cech |date=July 2012 |title=The RNA Worlds in Context |journal=Cold Spring Harbor Perspectives in Biology |volume=4 |issue=7 |page=a006742 |doi=10.1101/cshperspect.a006742 |pmc=3385955 |pmid=21441585}}</ref><ref>{{cite journal |last=Gilbert |first=Walter |authorlink=Walter Gilbert |date=20 February 1986 |title=Origin of life: The RNA world |journal=Nature |volume=319 |issue=6055 |page=618 |bibcode=1986Natur.319..618G |doi=10.1038/319618a0 |s2cid=8026658 }}</ref> 在2020年3月，天文学家户谷友则 Tomonori Totani提出了一种统计方法，用于解释初始的活性RNA分子是如何在宇宙大爆炸后某个时间随机产生的。<ref name="UT-20200310">{{cite news |last=Gough |first=Evan |title=Life Could be Common Across the Universe, Just Not in Our Region |url=https://www.universetoday.com/145304/life-could-be-common-across-the-universe-just-not-in-our-region/ |date=10 March 2020 |work=[[Universe Today]] |accessdate=15 March 2020 }}</ref><ref name="SR-20200203">{{cite journal |last=Totani |first=Tomonori |title=Emergence of life in an inflationary universe |date=3 February 2020 |journal=[[Scientific Reports]] |volume=10 |number=1671 |pages=1671 |doi=10.1038/s41598-020-58060-0 |pmid=32015390 |pmc=6997386 |arxiv=1911.08092 |bibcode=2020NatSR..10.1671T |doi-access=free }}</ref>

RNA世界的概念是由亚历山大·里奇Alexander Rich在1962年首次提出的<ref>{{cite journal |last1=Neveu |first1=Marc |last2=Kim |first2=Hyo-Joong |last3=Benner |first3=Steven A. |date=22 April 2013 |title=The 'Strong' RNA World Hypothesis: Fifty Years Old |journal=Astrobiology |volume=13 |issue=4 |pages=391–403 |bibcode=2013AsBio..13..391N |doi=10.1089/ast.2012.0868 |pmid=23551238 |ref=harv}}</ref> ，而这个术语则是由沃尔特·吉尔伯特Walter Gilbert在1986年创造的。<ref name="Cech2012">{{cite journal |last=Cech |first=Thomas R. |date=July 2012 |title=The RNA Worlds in Context |journal=Cold Spring Harbor Perspectives in Biology |volume=4 |issue=7 |page=a006742 |doi=10.1101/cshperspect.a006742 |pmc=3385955 |pmid=21441585}}</ref><ref>{{cite journal |last=Gilbert |first=Walter |date=20 February 1986 |title=Origin of life: The RNA world |journal=Nature |volume=319 |issue=6055 |page=618 |bibcode=1986Natur.319..618G |doi=10.1038/319618a0}}</ref> 在2020年3月，天文学家户谷友则 Tomonori Totani提出了一种统计方法，用于解释初始的活性RNA分子是如何在宇宙大爆炸后某个时间随机产生的。<ref name="UT-20200310">{{cite news |last=Gough |first=Evan |title=Life Could be Common Across the Universe, Just Not in Our Region |url=https://www.universetoday.com/145304/life-could-be-common-across-the-universe-just-not-in-our-region/ |date=10 March 2020 |work=Universe Today |accessdate=15 March 2020 }}</ref><ref name="SR-20200203">{{cite journal |last=Totani |first=Tomonori |title=Emergence of life in an inflationary universe |date=3 February 2020 |journal=Scientific Reports |volume=10 |number=1671 |pages=1671 |doi=10.1038/s41598-020-58060-0 |pmid=32015390 |pmc=6997386 |arxiv=1911.08092 |bibcode=2020NatSR..10.1671T |doi-access=free }}</ref>

===系统发育和最后的普遍共同祖先 Phylogeny and LUCA===

===系统发育和最后的普遍共同祖先 Phylogeny and LUCA===

====孰先孰后：蛋白质还是核酸？====

====孰先孰后：蛋白质还是核酸？====

蛋白质合成的进化的可能前体包括合成短肽辅因子的机制或形成RNA复制的机制。祖先的核糖体很可能完全由RNA组成，尽管有些作用已经被蛋白质取代了。关于这个主题的主要剩余问题包括确定核糖体进化的选择性力量和确定遗传密码是如何产生的。<ref name="Noller2012">{{cite journal |last=Noller |first=Harry F. |authorlink=Harry F. Noller |date=April 2012 |title=Evolution of protein synthesis from an RNA world. |journal=Cold Spring Harbor Perspectives in Biology |volume=4 |issue=4 |page=a003681 |doi=10.1101/cshperspect.a003681 |pmc=3312679 |pmid=20610545}}</ref>

蛋白质合成的进化的可能前体包括合成短肽辅因子的机制或形成RNA复制的机制。祖先的核糖体很可能完全由RNA组成，尽管有些作用已经被蛋白质取代了。关于这个主题的主要剩余问题包括确定核糖体进化的选择性力量和确定遗传密码是如何产生的。<ref name="Noller2012">{{cite journal |last=Noller |first=Harry F. |date=April 2012 |title=Evolution of protein synthesis from an RNA world. |journal=Cold Spring Harbor Perspectives in Biology |volume=4 |issue=4 |page=a003681 |doi=10.1101/cshperspect.a003681 |pmc=3312679 |pmid=20610545}}</ref>

尤金·库宁 Eugene Koonin 说，

尤金·库宁 Eugene Koonin 说，

====灾难性翻译错误====

====灾难性翻译错误====

霍夫曼 Hoffmann已经证明，早期容易出错的翻译机制可以稳定地抵御曾被设想为对生命起源有问题的那种错误灾难，被称为 "奥格尔悖论 Orgel's paradox"。<ref>{{cite journal |last=Hoffmann |first=Geoffrey W. |authorlink=Geoffrey W. Hoffmann |date=25 June 1974 |title=On the origin of the genetic code and the stability of the translation apparatus |journal=[[Journal of Molecular Biology]] |volume=86 |issue=2 |pages=349–362 |doi=10.1016/0022-2836(74)90024-2 |pmid=4414916}}</ref><ref>{{cite journal |last=Orgel |first=Leslie E. |date=April 1963 |title=The Maintenance of the Accuracy of Protein Synthesis and its Relevance to Ageing |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=49 |issue=4 |pages=517–521 |bibcode=1963PNAS...49..517O |doi=10.1073/pnas.49.4.517  |pmc=299893 |pmid=13940312}}</ref><ref>{{cite journal |last=Hoffmann |first=Geoffrey W. |title=The Stochastic Theory of the Origin of the Genetic Code |date=October 1975 |journal=[[Annual Review of Physical Chemistry]] |volume=26 |pages=123–144 |bibcode=1975ARPC...26..123H |doi=10.1146/annurev.pc.26.100175.001011 }}</ref>

霍夫曼 Hoffmann已经证明，早期容易出错的翻译机制可以稳定地抵御曾被设想为对生命起源有问题的那种错误灾难，被称为 "奥格尔悖论 Orgel's paradox"。<ref>{{cite journal |last=Hoffmann |first=Geoffrey W. |date=25 June 1974 |title=On the origin of the genetic code and the stability of the translation apparatus |journal=Journal of Molecular Biology |volume=86 |issue=2 |pages=349–362 |doi=10.1016/0022-2836(74)90024-2 |pmid=4414916}}</ref><ref>{{cite journal |last=Orgel |first=Leslie E. |date=April 1963 |title=The Maintenance of the Accuracy of Protein Synthesis and its Relevance to Ageing |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=49 |issue=4 |pages=517–521 |bibcode=1963PNAS...49..517O |doi=10.1073/pnas.49.4.517  |pmc=299893 |pmid=13940312}}</ref><ref>{{cite journal |last=Hoffmann |first=Geoffrey W. |title=The Stochastic Theory of the Origin of the Genetic Code |date=October 1975 |journal=Annual Review of Physical Chemistry|volume=26 |pages=123–144 |bibcode=1975ARPC...26..123H |doi=10.1146/annurev.pc.26.100175.001011 }}</ref>

====同手性====

====同手性====

同手性是指由手性单元组成的某些材料的几何均匀性。手性是指不可重叠的三维形态，它们是彼此的镜像，就像左手和右手一样。生物体使用的分子具有相同的手性（"利手性"）：几乎没有例外，<ref>{{harvnb|Chaichian|Rojas|Tureanu|2014|pp=353–364}}</ref>氨基酸是左旋的，而核苷酸和糖类是右旋的。手性分子可以合成，但在没有手性源或手性催化剂的情况下，它们是以两种对映体以50/50的混合物（称为外消旋混合物）形成的。已知从外消旋起始原料产生非外消旋混合物的机制包括：非对称物理定律，如弱电相互作用；非对称环境，如圆偏振光、石英晶体或地球自转引起的环境，外消旋合成过程中的统计波动，<ref name="Plasson2007">{{cite journal |last1=Plasson |first1=Raphaël |last2=Kondepudi |first2=Dilip K. |last3=Bersini |first3=Hugues |last4=Commeyras |first4=Auguste |last5=Asakura |first5=Kouichi |display-authors=3 |date=August 2007 |title=Emergence of homochirality in far-from-equilibrium systems: Mechanisms and role in prebiotic chemistry |journal=[[Chirality (journal)|Chirality]] |volume=19 |issue=8 |pages=589–600 |doi=10.1002/chir.20440 |pmid=17559107}} "Special Issue: Proceedings from the Eighteenth International Symposium on Chirality (ISCD-18), Busan, Korea, 2006"</ref>以及自发的对称性破缺。<ref name="jafarpour2017">{{cite journal |last1=Jafarpour |first1=Farshid |last2=Biancalani |first2=Tommaso |last3=Goldenfeld |first3=Nigel |year=2017 |title=Noise-induced symmetry breaking far from equilibrium and the emergence of biological homochirality |journal=Physical Review E |volume=95 |issue=3 |pages=032407 |doi=10.1103/PhysRevE.95.032407|pmid=28415353 |bibcode=2017PhRvE..95c2407J |url=http://dspace.mit.edu/bitstream/1721.1/109170/1/PhysRevE.95.032407.pdf }}</ref><ref name="jafarpour2015">{{cite journal |last1=Jafarpour |first1=Farshid |last2=Biancalani |first2=Tommaso |last3=Goldenfeld |first3=Nigel |year=2015 |title=Noise-induced mechanism for biological homochirality of early life self-replicators |journal=Physical Review Letters |volume=115 |issue=15 |pages=158101 |doi=10.1103/PhysRevLett.115.158101|pmid=26550754 |arxiv=1507.00044 |bibcode=2015PhRvL.115o8101J |s2cid=9775791 }}</ref><ref name="frank1953">{{cite journal |last1=Frank |first1=F.C. |year=1953 |title=On spontaneous asymmetric synthesis |journal=Biochimica et Biophysica Acta |volume=11 |issue=4 |pages=459–463 |doi=10.1016/0006-3002(53)90082-1|pmid=13105666 }}</ref>

同手性是指由手性单元组成的某些材料的几何均匀性。手性是指不可重叠的三维形态，它们是彼此的镜像，就像左手和右手一样。生物体使用的分子具有相同的手性（"利手性"）：几乎没有例外，<ref>{{harvnb|Chaichian|Rojas|Tureanu|2014|pp=353–364}}</ref>氨基酸是左旋的，而核苷酸和糖类是右旋的。手性分子可以合成，但在没有手性源或手性催化剂的情况下，它们是以两种对映体以50/50的混合物（称为外消旋混合物）形成的。已知从外消旋起始原料产生非外消旋混合物的机制包括：非对称物理定律，如弱电相互作用；非对称环境，如圆偏振光、石英晶体或地球自转引起的环境，外消旋合成过程中的统计波动，<ref name="Plasson2007">{{cite journal |last1=Plasson |first1=Raphaël |last2=Kondepudi |first2=Dilip K. |last3=Bersini |first3=Hugues |last4=Commeyras |first4=Auguste |last5=Asakura |first5=Kouichi |display-authors=3 |date=August 2007 |title=Emergence of homochirality in far-from-equilibrium systems: Mechanisms and role in prebiotic chemistry |journal=Chirality |volume=19 |issue=8 |pages=589–600 |doi=10.1002/chir.20440 |pmid=17559107}} "Special Issue: Proceedings from the Eighteenth International Symposium on Chirality (ISCD-18), Busan, Korea, 2006"</ref>以及自发的对称性破缺。<ref name="jafarpour2017">{{cite journal |last1=Jafarpour |first1=Farshid |last2=Biancalani |first2=Tommaso |last3=Goldenfeld |first3=Nigel |year=2017 |title=Noise-induced symmetry breaking far from equilibrium and the emergence of biological homochirality |journal=Physical Review E |volume=95 |issue=3 |pages=032407 |doi=10.1103/PhysRevE.95.032407|pmid=28415353 |bibcode=2017PhRvE..95c2407J |url=http://dspace.mit.edu/bitstream/1721.1/109170/1/PhysRevE.95.032407.pdf }}</ref><ref name="jafarpour2015">{{cite journal |last1=Jafarpour |first1=Farshid |last2=Biancalani |first2=Tommaso |last3=Goldenfeld |first3=Nigel |year=2015 |title=Noise-induced mechanism for biological homochirality of early life self-replicators |journal=Physical Review Letters |volume=115 |issue=15 |pages=158101 |doi=10.1103/PhysRevLett.115.158101|pmid=26550754 |arxiv=1507.00044 |bibcode=2015PhRvL.115o8101J}}</ref><ref name="frank1953">{{cite journal |last1=Frank |first1=F.C. |year=1953 |title=On spontaneous asymmetric synthesis |journal=Biochimica et Biophysica Acta |volume=11 |issue=4 |pages=459–463 |doi=10.1016/0006-3002(53)90082-1|pmid=13105666 }}</ref>

一旦建立，手性将被选择。<ref>{{cite journal |last=Clark |first=Stuart |authorlink=Stuart Clark (author) |date=July–August 1999 |title=Polarized Starlight and the Handedness of Life |journal=[[American Scientist]] |volume=87 |issue=4 |page=336 |bibcode=1999AmSci..87..336C |doi=10.1511/1999.4.336}}</ref>群体中的一个小偏差（对映体过量）可以通过不对称自催化放大成一个大的偏差，如在Soai反应中。<ref>{{cite journal |last1=Shibata |first1=Takanori |last2=Morioka |first2=Hiroshi |last3=Hayase |first3=Tadakatsu |last4=Choji |first4=Kaori |last5=Soai |first5=Kenso |display-authors=3 |date=17 January 1996 |title=Highly Enantioselective Catalytic Asymmetric Automultiplication of Chiral Pyrimidyl Alcohol |journal=Journal of the American Chemical Society |volume=118 |issue=2 |pages=471–472 |doi=10.1021/ja953066g }}</ref>在不对称自催化中，催化剂是一个手性分子，这意味着手性分子正在催化自己的生产。最初的对映体过量，例如可以通过偏振光产生，然后允许更丰富的对映体超过其他对映体。<ref name="Soai2001">{{cite journal |last1=Soai |first1=Kenso |last2=Sato |first2=Itaru |last3=Shibata |first3=Takanori |year=2001 |title=Asymmetric autocatalysis and the origin of chiral homogeneity in organic compounds |journal=The Chemical Record |volume=1 |issue=4 |pages=321–332 |doi=10.1002/tcr.1017 |pmid=11893072}}</ref>

一旦建立，手性将被选择。<ref>{{cite journal |last=Clark |first=Stuart |date=July–August 1999 |title=Polarized Starlight and the Handedness of Life |journal=American Scientist|volume=87 |issue=4 |page=336 |bibcode=1999AmSci..87..336C |doi=10.1511/1999.4.336}}</ref>群体中的一个小偏差（对映体过量）可以通过不对称自催化放大成一个大的偏差，如在Soai反应中。<ref>{{cite journal |last1=Shibata |first1=Takanori |last2=Morioka |first2=Hiroshi |last3=Hayase |first3=Tadakatsu |last4=Choji |first4=Kaori |last5=Soai |first5=Kenso |display-authors=3 |date=17 January 1996 |title=Highly Enantioselective Catalytic Asymmetric Automultiplication of Chiral Pyrimidyl Alcohol |journal=Journal of the American Chemical Society |volume=118 |issue=2 |pages=471–472 |doi=10.1021/ja953066g }}</ref>在不对称自催化中，催化剂是一个手性分子，这意味着手性分子正在催化自己的生产。最初的对映体过量，例如可以通过偏振光产生，然后允许更丰富的对映体超过其他对映体。<ref name="Soai2001">{{cite journal |last1=Soai |first1=Kenso |last2=Sato |first2=Itaru |last3=Shibata |first3=Takanori |year=2001 |title=Asymmetric autocatalysis and the origin of chiral homogeneity in organic compounds |journal=The Chemical Record |volume=1 |issue=4 |pages=321–332 |doi=10.1002/tcr.1017 |pmid=11893072}}</ref>

克拉克 Clark认为，同手性可能始于外太空，因为对默奇森 Murchison陨石上氨基酸的研究表明，L-丙氨酸的出现频率是其D形式的两倍多，L-谷氨酸是其D形式的三倍多。各种手性晶体表面也可以作为手性单体单元可能集中和组装成大分子的场所。<ref>{{harvnb|Hazen|2005|p=184}}</ref><ref name=Meierhenrich>{{cite book|last1=Meierhenrich|first1=Uwe|title=Amino acids and the asymmetry of life caught in the act of formation|date=2008|publisher=Springer|location=Berlin|isbn=978-3540768869|pages=76–79}}</ref>在陨石上发现的化合物表明，生命的手性来源于非生物合成，因为陨石上的氨基酸表现出左手旋偏向，而糖类则主要表现出右手旋偏向，这与在生物体中发现的相同。<ref name=StarStuff>{{cite journal |last=Mullen |first=Leslie |date=5 September 2005 |title=Building Life from Star-Stuff |url=http://www.astrobio.net/news-exclusive/building-life-from-star-stuff/ |journal=[[Astrobiology Magazine]] |accessdate=2015-06-15 |url-status=live |archiveurl=https://web.archive.org/web/20150714084344/http://www.astrobio.net/news-exclusive/building-life-from-star-stuff/ |archivedate=14 July 2015}}</ref>

克拉克 Clark认为，同手性可能始于外太空，因为对默奇森 Murchison陨石上氨基酸的研究表明，L-丙氨酸的出现频率是其D形式的两倍多，L-谷氨酸是其D形式的三倍多。各种手性晶体表面也可以作为手性单体单元可能集中和组装成大分子的场所。<ref>{{harvnb|Hazen|2005|p=184}}</ref><ref name=Meierhenrich>{{cite book|last1=Meierhenrich|first1=Uwe|title=Amino acids and the asymmetry of life caught in the act of formation|date=2008|publisher=Springer|location=Berlin|isbn=978-3540768869|pages=76–79}}</ref>在陨石上发现的化合物表明，生命的手性来源于非生物合成，因为陨石上的氨基酸表现出左手旋偏向，而糖类则主要表现出右手旋偏向，这与在生物体中发现的相同。<ref name=StarStuff>{{cite journal |last=Mullen |first=Leslie |date=5 September 2005 |title=Building Life from Star-Stuff |url=http://www.astrobio.net/news-exclusive/building-life-from-star-stuff/ |journal=Astrobiology Magazine|accessdate=2015-06-15 |url-status=live |archiveurl=https://web.archive.org/web/20150714084344/http://www.astrobio.net/news-exclusive/building-life-from-star-stuff/ |archivedate=14 July 2015}}</ref>

===有第一颗恒星的早期宇宙===

===有第一颗恒星的早期宇宙===

在宇宙大爆炸发生后不久，大约140亿年前，宇宙中存在的化学元素只有氢、氦和锂，这是周期表中最轻的三种元素。这些元素逐渐聚集在一起，形成了恒星。这些早期的恒星质量大、寿命短，通过恒星核合成产生更重的元素。碳是目前宇宙中含量第四丰富的化学元素（仅次于氢、氦、氧），主要形成于白矮星，尤其是那些大于两个太阳质量的白矮星。<ref name="INV-20200706">{{cite news|last=Rabie|first=Passant|date=6 July 2020|title=Astronomers Have Found The Source Of Life In The Universe|work=[[Inverse (website)|Inverse]]|url=https://www.inverse.com/science/carbon-from-white-dwarfs|accessdate=7 July 2020}}</ref><ref name="NA-20200706">{{cite journal|author=Marigo, Paola|display-authors=et al.|date=6 July 2020|title=Carbon star formation as seen through the non-monotonic initial–final mass relation|url=https://www.nature.com/articles/s41550-020-1132-1|journal=[[Nature Astronomy]]|volume=152|arxiv=2007.04163|doi=10.1038/s41550-020-1132-1|bibcode=2020NatAs.tmp..143M|accessdate=7 July 2020|s2cid=220403402}}</ref>

在宇宙大爆炸发生后不久，大约140亿年前，宇宙中存在的化学元素只有氢、氦和锂，这是周期表中最轻的三种元素。这些元素逐渐聚集在一起，形成了恒星。这些早期的恒星质量大、寿命短，通过恒星核合成产生更重的元素。碳是目前宇宙中含量第四丰富的化学元素（仅次于氢、氦、氧），主要形成于白矮星，尤其是那些大于两个太阳质量的白矮星。<ref name="INV-20200706">{{cite news|last=Rabie|first=Passant|date=6 July 2020|title=Astronomers Have Found The Source Of Life In The Universe|work=Inverse|url=https://www.inverse.com/science/carbon-from-white-dwarfs|accessdate=7 July 2020}}</ref><ref name="NA-20200706">{{cite journal|author=Marigo, Paola|display-authors=et al.|date=6 July 2020|title=Carbon star formation as seen through the non-monotonic initial–final mass relation|url=https://www.nature.com/articles/s41550-020-1132-1|journal=Nature Astronomy|volume=152|arxiv=2007.04163|doi=10.1038/s41550-020-1132-1|bibcode=2020NatAs.tmp..143M|accessdate=7 July 2020}}</ref>

当这些恒星达到其生命周期的终点时，它们在整个宇宙中喷射出这些较重的元素，其中包括碳和氧。这些较重的元素使得新的物体得以形成，包括岩质行星和其他天体。<ref>{{Cite web | url=https://wmap.gsfc.nasa.gov/universe/uni_life.html |title = WMAP- Life in the Universe}}</ref>

当这些恒星达到其生命周期的终点时，它们在整个宇宙中喷射出这些较重的元素，其中包括碳和氧。这些较重的元素使得新的物体得以形成，包括岩质行星和其他天体。<ref>{{Cite web | url=https://wmap.gsfc.nasa.gov/universe/uni_life.html |title = WMAP- Life in the Universe}}</ref>

===地球的出现===

===地球的出现===

地球，形成于45亿年前，起初是不适合任何生物体生存的。根据对地质学时间尺度的大量观察和研究，人们认为冥古代地球曾有过一个次级大气层，是通过小行星撞击物所积累的岩石脱气而形成的。起初，人们认为地球的大气层由氢化合物——甲烷、氨和水蒸气组成，生命就是在这种有利于有机分子形成的还原性条件下开始的。根据后来的模型，通过对古代矿物的研究提出，冥古代晚期的大气层主要由水蒸气、氮气和二氧化碳组成，还有少量的一氧化碳、氢气和硫化合物。<ref>{{cite journal |last=Kasting |first=James F. |authorlink=James Kasting |date=12 February 1993 |title=Earth's Early Atmosphere |url=http://wwwdca.iag.usp.br/www/material/fornaro/ACA410/Kasting%201993_EarthEarlyAtmos.pdf |journal=Science |volume=259 |issue=5097 |pages=920–926 |doi=10.1126/science.11536547 |pmid=11536547 |bibcode=1993Sci...259..920K |s2cid=21134564 |accessdate=2015-07-28 |ref=harv |url-status=dead |archiveurl=https://web.archive.org/web/20151010074651/http://wwwdca.iag.usp.br/www/material/fornaro/ACA410/Kasting%201993_EarthEarlyAtmos.pdf |archivedate=10 October 2015}}</ref>在地球形成过程中，地球失去了其初始质量的很大一部分，原行星盘中较重的岩石元素组成的核仍然存在。<ref>{{harvnb|Fesenkov|1959|p=9}}</ref>因此，地球缺乏在大气层中容纳任何氢分子的引力，并且在冥古代迅速失去了它，以及大部分的原始惰性气体.。二氧化碳在水中形成的溶液被认为使海洋呈微酸性，使海洋的pH值约为5.5。<ref>{{Cite journal|last=Morse|first=John|date=September 1998|title=Hadean Ocean Carbonate Geochemistry|journal=Aquatic Geochemistry|volume=4|issue=3/4|pages=301–319|doi=10.1023/A:1009632230875|bibcode=1998MinM...62.1027M|s2cid=129616933}}</ref> 当时的大气层被描述为 "巨大的、高产的露天化学实验室。"它可能与今天火山释放的混合气体相似，它仍然支持一些非生物化学。<ref name="Follmann2009" />

地球，形成于45亿年前，起初是不适合任何生物体生存的。根据对地质学时间尺度的大量观察和研究，人们认为冥古代地球曾有过一个次级大气层，是通过小行星撞击物所积累的岩石脱气而形成的。起初，人们认为地球的大气层由氢化合物——甲烷、氨和水蒸气组成，生命就是在这种有利于有机分子形成的还原性条件下开始的。根据后来的模型，通过对古代矿物的研究提出，冥古代晚期的大气层主要由水蒸气、氮气和二氧化碳组成，还有少量的一氧化碳、氢气和硫化合物。<ref>{{cite journal |last=Kasting |first=James F. |date=12 February 1993 |title=Earth's Early Atmosphere |url=http://wwwdca.iag.usp.br/www/material/fornaro/ACA410/Kasting%201993_EarthEarlyAtmos.pdf |journal=Science |volume=259 |issue=5097 |pages=920–926 |doi=10.1126/science.11536547 |pmid=11536547 |bibcode=1993Sci...259..920K |accessdate=2015-07-28 |ref=harv |url-status=dead |archiveurl=https://web.archive.org/web/20151010074651/http://wwwdca.iag.usp.br/www/material/fornaro/ACA410/Kasting%201993_EarthEarlyAtmos.pdf |archivedate=10 October 2015}}</ref>在地球形成过程中，地球失去了其初始质量的很大一部分，原行星盘中较重的岩石元素组成的核仍然存在。<ref>{{harvnb|Fesenkov|1959|p=9}}</ref>因此，地球缺乏在大气层中容纳任何氢分子的引力，并且在冥古代迅速失去了它，以及大部分的原始惰性气体.。二氧化碳在水中形成的溶液被认为使海洋呈微酸性，使海洋的pH值约为5.5。<ref>{{Cite journal|last=Morse|first=John|date=September 1998|title=Hadean Ocean Carbonate Geochemistry|journal=Aquatic Geochemistry|volume=4|issue=3/4|pages=301–319|doi=10.1023/A:1009632230875|bibcode=1998MinM...62.1027M}}</ref> 当时的大气层被描述为 "巨大的、高产的露天化学实验室。"它可能与今天火山释放的混合气体相似，它仍然支持一些非生物化学。<ref name="Follmann2009" />

===海洋的出现===

===海洋的出现===

海洋可能最早出现在冥古宙，即地球形成后的2亿年，在一个100 C的高温的还原性环境中，pH值约为5.8，迅速上升到中性。.<ref>{{cite journal |last1=Morse |first1=John W. |last2=MacKenzie |first2=Fred T. |author-link2=Fred T. Mackenzie (scientist) |year=1998 |title=Hadean Ocean Carbonate Geochemistry |journal=Aquatic Geochemistry |volume=4 |issue=3–4 |pages=301–319 |doi=10.1023/A:1009632230875 |bibcode=1998MinM...62.1027M |s2cid=129616933 }}</ref>这一假设已经得到了来自澳大利亚西部纳里尔山变质石英岩的4.404 Gyo锆石晶体的年代测定的支持。这一设想已经得到了来自澳大利亚西部的皮尔巴拉的杰克高地的纳瑞耶山的变质石英岩的44.04亿年前的锆石晶体的年代测定的支持，它提供了地球形成后1.5亿年前内存在海洋和大陆地壳的证据。<ref name="Wilde2001">{{cite journal |last1=Wilde |first1=Simon A. |last2=Valley |first2=John W. |last3=Peck |first3=William H. |last4=Graham |first4=Colin M. |date=11 January 2001 |title=Evidence from detrital zircons for the existence of continental crust and oceans on the Earth 4.4&nbsp;Gyr ago |url=http://www.geology.wisc.edu/~valley/zircons/Wilde2001Nature.pdf |journal=[[Nature (journal)|Nature]] |volume=409 |issue=6817 |pages=175–178 |doi=10.1038/35051550 |pmid=11196637 |access-date=2015-06-03 |url-status=live |archive-url=https://web.archive.org/web/20150605132344/http://www.geology.wisc.edu/~valley/zircons/Wilde2001Nature.pdf |archive-date=5 June 2015|bibcode=2001Natur.409..175W |s2cid=4319774 }}</ref>尽管可能增加了火山活动，并存在许多较小的构造 "板块"，但有人认为，在44-43亿年之间，地球是一个水世界，几乎没有大陆地壳，大气层极度动荡，水圈受到来自T金牛座阶段的太阳的强烈的紫外线(UV)照射、宇宙辐射和持续的天体撞击。<ref name="rise.2006">{{cite journal |last1=Rosing |first1=Minik T. |last2=Bird |first2=Dennis K. |last3=Sleep |first3=Norman H. |last4=Glassley |first4=William |last5=Albarède |first5=Francis |author-link5=Francis Albarède |display-authors=3 |date=22 March 2006 |title=The rise of continents – An essay on the geologic consequences of photosynthesis |url= https://www.researchgate.net/publication/223066196|journal=[[Palaeogeography, Palaeoclimatology, Palaeoecology]] |volume=232 |issue=2–4 |pages=99–113 |doi=10.1016/j.palaeo.2006.01.007  |access-date=2015-06-08 |url-status=live |archive-url=https://web.archive.org/web/20150714073656/http://www.researchgate.net/profile/Francis_Albarede/publication/223066196_The_rise_of_continentsAn_essay_on_the_geologic_consequences_of_photosynthesis/links/00b7d51766c442f58b000000.pdf |archive-date=14 July 2015|bibcode=2006PPP...232...99R }}</ref>由于地核和地幔之间的重力分选导致的内部加热会引起大量的地幔对流，这可能导致比现在存在的更小、更活跃的构造板块。

海洋可能最早出现在冥古宙，即地球形成后的2亿年，在一个100 C的高温的还原性环境中，pH值约为5.8，迅速上升到中性。.<ref>{{cite journal |last1=Morse |first1=John W. |last2=MacKenzie |first2=Fred T. |year=1998 |title=Hadean Ocean Carbonate Geochemistry |journal=Aquatic Geochemistry |volume=4 |issue=3–4 |pages=301–319 |doi=10.1023/A:1009632230875 |bibcode=1998MinM...62.1027M }}</ref>这一假设已经得到了来自澳大利亚西部纳里尔山变质石英岩的4.404 Gyo锆石晶体的年代测定的支持。这一设想已经得到了来自澳大利亚西部的皮尔巴拉的杰克高地的纳瑞耶山的变质石英岩的44.04亿年前的锆石晶体的年代测定的支持，它提供了地球形成后1.5亿年前内存在海洋和大陆地壳的证据。<ref name="Wilde2001">{{cite journal |last1=Wilde |first1=Simon A. |last2=Valley |first2=John W. |last3=Peck |first3=William H. |last4=Graham |first4=Colin M. |date=11 January 2001 |title=Evidence from detrital zircons for the existence of continental crust and oceans on the Earth 4.4&nbsp;Gyr ago |url=http://www.geology.wisc.edu/~valley/zircons/Wilde2001Nature.pdf |journal=Nature|volume=409 |issue=6817 |pages=175–178 |doi=10.1038/35051550 |pmid=11196637 |access-date=2015-06-03 |url-status=live |archive-url=https://web.archive.org/web/20150605132344/http://www.geology.wisc.edu/~valley/zircons/Wilde2001Nature.pdf |archive-date=5 June 2015|bibcode=2001Natur.409..175W}}</ref>尽管可能增加了火山活动，并存在许多较小的构造 "板块"，但有人认为，在44-43亿年之间，地球是一个水世界，几乎没有大陆地壳，大气层极度动荡，水圈受到来自T金牛座阶段的太阳的强烈的紫外线(UV)照射、宇宙辐射和持续的天体撞击。<ref name="rise.2006">{{cite journal |last1=Rosing |first1=Minik T. |last2=Bird |first2=Dennis K. |last3=Sleep |first3=Norman H. |last4=Glassley |first4=William |last5=Albarède |first5=Francis |display-authors=3 |date=22 March 2006 |title=The rise of continents – An essay on the geologic consequences of photosynthesis |url= https://www.researchgate.net/publication/223066196|journal=Palaeogeography, Palaeoclimatology, Palaeoecology |volume=232 |issue=2–4 |pages=99–113 |doi=10.1016/j.palaeo.2006.01.007  |access-date=2015-06-08 |url-status=live |archive-url=https://web.archive.org/web/20150714073656/http://www.researchgate.net/profile/Francis_Albarede/publication/223066196_The_rise_of_continentsAn_essay_on_the_geologic_consequences_of_photosynthesis/links/00b7d51766c442f58b000000.pdf |archive-date=14 July 2015|bibcode=2006PPP...232...99R }}</ref>由于地核和地幔之间的重力分选导致的内部加热会引起大量的地幔对流，这可能导致比现在存在的更小、更活跃的构造板块。

===晚期重型轰炸===

===晚期重型轰炸===

冥古代的环境对现代生命将是非常危险的。与直径达500公里的大型物体频繁碰撞，足以在撞击后的几个月内使地球成为不毛之地，并使海洋汽化，热蒸汽与岩石蒸汽混合，成为足以完全覆盖地球的高空云层。几个月后，这些云层的高度会开始降低，但在接下来的大约一千年里，云层的底部仍会升高。在那之后，低海拔地区就会开始下雨。在接下来的两千年里，雨水会慢慢地拉低云层的高度，使海洋只有在撞击事件发生3000年后才恢复到原来的深度。<ref>{{cite journal |last1=Sleep |first1=Norman H. |last2=Zahnle |first2=Kevin J. |authorlink2=Kevin J. Zahnle |last3=Kasting |first3=James F. |last4=Morowitz |first4=Harold J. |authorlink4=Harold J. Morowitz |display-authors=3 |date=9 November 1989 |title=Annihilation of ecosystems by large asteroid impacts on early Earth |journal=Nature |volume=342 |issue=6246|pages=139–142 |url=https://www.researchgate.net/publication/11809063|bibcode=1989Natur.342..139S |doi=10.1038/342139a0 |pmid=11536616|s2cid=1137852 }}</ref>

冥古代的环境对现代生命将是非常危险的。与直径达500公里的大型物体频繁碰撞，足以在撞击后的几个月内使地球成为不毛之地，并使海洋汽化，热蒸汽与岩石蒸汽混合，成为足以完全覆盖地球的高空云层。几个月后，这些云层的高度会开始降低，但在接下来的大约一千年里，云层的底部仍会升高。在那之后，低海拔地区就会开始下雨。在接下来的两千年里，雨水会慢慢地拉低云层的高度，使海洋只有在撞击事件发生3000年后才恢复到原来的深度。<ref>{{cite journal |last1=Sleep |first1=Norman H. |last2=Zahnle |first2=Kevin J. |last3=Kasting |first3=James F. |last4=Morowitz |first4=Harold J. |display-authors=3 |date=9 November 1989 |title=Annihilation of ecosystems by large asteroid impacts on early Earth |journal=Nature |volume=342 |issue=6246|pages=139–142 |url=https://www.researchgate.net/publication/11809063|bibcode=1989Natur.342..139S |doi=10.1038/342139a0 |pmid=11536616}}</ref>

传统上认为，在42.8亿<ref name="NAT-20170301" /><ref name="NYT-20170301" /> 年前到38亿年前之间的时期，巨行星轨道的变化可能造成了小行星和彗星<ref>{{cite journal |last1=Gomes |first1=Rodney |last2=Levison |first2=Hal F. |authorlink2=Harold F. Levison |last3=Tsiganis |first3=Kleomenis |last4=Morbidelli |first4=Alessandro |authorlink4=Alessandro Morbidelli (astronomer) |date=26 May 2005 |title=Origin of the cataclysmic Late Heavy Bombardment period of the terrestrial planets |journal=Nature |volume=435 |issue=7041 |pages=466–469 |bibcode=2005Natur.435..466G |doi=10.1038/nature03676 |pmid=15917802|doi-access=free }}</ref>对月球和其他内行星（水星、火星，大概还有地球和金星）的猛烈轰击。如果生命在那之前出现的话，这很可能会使这个星球反复成为不毛之地。<ref name="Follmann2009" />从地质学上来说，冥古代地球会比历史上任何其他时间都要活跃得多。对陨石的研究表明，放射性同位素，如半衰期为7.17 千年的铝-26和半衰期为12.5亿年的钾-40，这些主要产生于超新星的同位素更为常见<ref>{{harvnb|Davies|2007|pp=61–73}}</ref> 。由于地核和地幔之间的重力分选而产生的内部加热会引起大量的地幔对流，其结果可能是产生了比现在更小、更活跃的构造板块。

传统上认为，在42.8亿<ref name="NAT-20170301" /><ref name="NYT-20170301" /> 年前到38亿年前之间的时期，巨行星轨道的变化可能造成了小行星和彗星<ref>{{cite journal |last1=Gomes |first1=Rodney |last2=Levison |first2=Hal F. |last3=Tsiganis |first3=Kleomenis |last4=Morbidelli |first4=Alessandro date=26 May 2005 |title=Origin of the cataclysmic Late Heavy Bombardment period of the terrestrial planets |journal=Nature |volume=435 |issue=7041 |pages=466–469 |bibcode=2005Natur.435..466G |doi=10.1038/nature03676 |pmid=15917802|doi-access=free }}</ref>对月球和其他内行星（水星、火星，大概还有地球和金星）的猛烈轰击。如果生命在那之前出现的话，这很可能会使这个星球反复成为不毛之地。<ref name="Follmann2009" />从地质学上来说，冥古代地球会比历史上任何其他时间都要活跃得多。对陨石的研究表明，放射性同位素，如半衰期为7.17 千年的铝-26和半衰期为12.5亿年的钾-40，这些主要产生于超新星的同位素更为常见<ref>{{harvnb|Davies|2007|pp=61–73}}</ref> 。由于地核和地幔之间的重力分选而产生的内部加热会引起大量的地幔对流，其结果可能是产生了比现在更小、更活跃的构造板块。

这种毁灭性的环境事件之间的时间段，为早期环境中可能的生命起源提供了时间窗口。如果深海热液环境是生命起源的场所，那么自然发生可能早在40-42亿年前就发生了。如果地点在地球表面，那么自然发生只能发生在37-40亿年前之间。<ref>{{cite journal |last1=Maher |first1=Kevin A. |last2=Stevenson |first2=David J. |date=18 February 1988 |title=Impact frustration of the origin of life |journal=Nature |volume=331 |issue=6157 |pages=612–614 |bibcode=1988Natur.331..612M |doi=10.1038/331612a0 |pmid=11536595|s2cid=4284492 }}</ref>

这种毁灭性的环境事件之间的时间段，为早期环境中可能的生命起源提供了时间窗口。如果深海热液环境是生命起源的场所，那么自然发生可能早在40-42亿年前就发生了。如果地点在地球表面，那么自然发生只能发生在37-40亿年前之间。<ref>{{cite journal |last1=Maher |first1=Kevin A. |last2=Stevenson |first2=David J. |date=18 February 1988 |title=Impact frustration of the origin of life |journal=Nature |volume=331 |issue=6157 |pages=612–614 |bibcode=1988Natur.331..612M |doi=10.1038/331612a0 |pmid=11536595}}</ref>

对这些来源的有机物的产生的估计表明，在35亿年前之前，早期大气层内的晚期重型轰炸使可获得的有机物的数量与陆地来源产生的有机物数量相当。<ref>{{cite journal |last1=Chyba |first1=Christopher |authorlink=Christopher Chyba |last2=Sagan |first2=Carl |authorlink2=Carl Sagan |date=9 January 1992 |title=Endogenous production, exogenous delivery and impact-shock synthesis of organic molecules: an inventory for the origins of life |journal=Nature |volume=355 |issue=6356 |pages=125–132 |bibcode=1992Natur.355..125C |doi=10.1038/355125a0 |pmid=11538392|s2cid=4346044 }}</ref><ref>{{cite journal |last1=Furukawa |first1=Yoshihiro |last2=Sekine |first2=Toshimori |last3=Oba |first3=Masahiro |last4=Kakegawa |first4=Takeshi |last5=Nakazawa |first5=Hiromoto |display-authors=3 |date=January 2009 |title=Biomolecule formation by oceanic impacts on early Earth |journal=Nature Geoscience |volume=2 |issue=1 |pages=62–66 |bibcode=2009NatGe...2...62F |doi=10.1038/NGEO383}}</ref>

对这些来源的有机物的产生的估计表明，在35亿年前之前，早期大气层内的晚期重型轰炸使可获得的有机物的数量与陆地来源产生的有机物数量相当。<ref>{{cite journal |last1=Chyba |first1=Christopher |last2=Sagan |first2=Carl |date=9 January 1992 |title=Endogenous production, exogenous delivery and impact-shock synthesis of organic molecules: an inventory for the origins of life |journal=Nature |volume=355 |issue=6356 |pages=125–132 |bibcode=1992Natur.355..125C |doi=10.1038/355125a0 |pmid=11538392}}</ref><ref>{{cite journal |last1=Furukawa |first1=Yoshihiro |last2=Sekine |first2=Toshimori |last3=Oba |first3=Masahiro |last4=Kakegawa |first4=Takeshi |last5=Nakazawa |first5=Hiromoto |display-authors=3 |date=January 2009 |title=Biomolecule formation by oceanic impacts on early Earth |journal=Nature Geoscience |volume=2 |issue=1 |pages=62–66 |bibcode=2009NatGe...2...62F |doi=10.1038/NGEO383}}</ref>

== 生命的最早证据：古生物学==

== 生命的最早证据：古生物学==

 

[[File:Stromatolites.jpg|left|thumb|冰川国家公园锡耶组 Siyeh Formation的前寒武纪叠层石。2002年的一项研究表明，这些35亿岁的岩层中含有蓝藻微生物化石。这表明它们是地球上最早的生命形式之一的证据。]]  

[[File:Stromatolites.jpg|left|thumb|[[Precambrian]] [[stromatolite]]s in the Siyeh Formation, [[Glacier National Park (U.S.)|Glacier National Park]].

A 2002 study suggested that these 3.5 Gyo (billion year old) [[Geologic formation|formations]] contain fossilized [[cyanobacteria]] [[microorganism|microbes]]. This suggests they are evidence of one of the [[Earliest known life forms|earliest life forms]] on [[Earth]]. 冰川国家公园锡耶组 Siyeh Formation的前寒武纪叠层石。2002年的一项研究表明，这些35亿岁的岩层中含有蓝藻微生物化石。这表明它们是地球上最早的生命形式之一的证据。]]  

 

 

[[File:Stromatolites in Sharkbay.jpg|thumb|鲨鱼湾中的石笋]]

[[File:Stromatolites in Sharkbay.jpg|thumb|鲨鱼湾中的石笋]]

人们在格陵兰岛西南部37亿岁的变质沉积岩中发现了生物来源的石墨<ref name="NG-20131208">{{cite journal |last1=Ohtomo |first1=Yoko |last2=Kakegawa |first2=Takeshi |last3=Ishida |first3=Akizumi |last4=Nagase |first4=Toshiro |last5=Rosing |first5=Minik T. |display-authors=3 |date=January 2014 |title=Evidence for biogenic graphite in early Archaean Isua metasedimentary rocks |journal=[[Nature Geoscience]] |volume=7 |issue=1 |pages=25–28 |bibcode=2014NatGe...7...25O |doi=10.1038/ngeo2025 }}</ref> ，在西澳大利亚距今34.8亿年前的砂岩中发现了微生物垫层化石<ref name="AP-20131113">{{cite news |last=Borenstein |first=Seth |date=13 November 2013 |title=Oldest fossil found: Meet your microbial mom |url=http://apnews.excite.com/article/20131113/DAA1VSC01.html |work=[[Excite]] |location=Yonkers, NY |publisher=[[Mindspark Interactive Network]] |agency=[[Associated Press]] |accessdate=2015-06-02 |url-status=live |archiveurl=https://web.archive.org/web/20150629230719/http://apnews.excite.com/article/20131113/DAA1VSC01.html |archivedate=29 June 2015}}</ref><ref name="AST-20131108">{{cite journal |last1=Noffke |first1=Nora |last2=Christian |first2=Daniel |last3=Wacey |first3=David |last4=Hazen |first4=Robert M. |authorlink4=Robert Hazen |date=16 November 2013 |title=Microbially Induced Sedimentary Structures Recording an Ancient Ecosystem in the ''ca.'' 3.48 Gyo Dresser Formation, Pilbara, Western Australia |journal=[[Astrobiology (journal)|Astrobiology]] |volume=13 |issue=12 |pages=1103–1124 |bibcode=2013AsBio..13.1103N |doi=10.1089/ast.2013.1030 |pmc=3870916 |pmid=24205812}}</ref>。在格陵兰岛西南部伊苏亚上地壳带附近的阿基利亚岛的岩石中发现了早期生命的证据，这些可追溯到37亿年前的证据中发现了生源碳同位素<ref name="NYT-20160831">{{cite news |last=Wade |first=Nicholas |title=World's Oldest Fossils Found in Greenland |url=https://www.nytimes.com/2016/09/01/science/oldest-fossils-on-earth.html |date=31 August 2016 |work=[[The New York Times]] |accessdate=31 August 2016 |url-status=live |archiveurl=https://web.archive.org/web/20160831185959/http://www.nytimes.com/2016/09/01/science/oldest-fossils-on-earth.html |archivedate=31 August 2016}}</ref><ref>{{harvnb|Davies|1999}}</ref> 。在伊苏亚上地壳带的其他地方，被困在石榴石晶体内的石墨包裹体与生命的其他元素相连：氧、氮和可能以磷酸盐形式存在的磷，为37亿年前的生命提供了进一步的证据<ref>{{Cite journal |last1=Hassenkam|first1=T. |last2=Andersson |first2=M.P. |last3=Dalby|first3=K.N. |last4=Mackenzie |first4=D.M.A.|last5=Rosing |first5=M.T. |title=Elements of Eoarchean life trapped in mineral inclusions |journal=Nature |doi=10.1038/nature23261 |pmid=28738409 |volume=548|issue=7665|pages=78–81 |year=2017 |bibcode=2017Natur.548...78H|s2cid=205257931 }}</ref> 。在西澳大利亚皮尔巴拉地区的斯特雷利池，在一个化石滩的含黄铁矿砂岩中发现了早期生命的令人信服的证据，它显示了圆形的管状细胞，在没有氧气的情况下通过光合作用氧化硫。2015年对西澳大利亚的锆石的进一步研究表明，生命很可能在至少41亿年前就存在于地球上。<ref name="AP-20151019">{{cite news |last=Borenstein |first=Seth |title=Hints of life on what was thought to be desolate early Earth |url=https://apnews.com/e6be2537b4cd46ffb9c0585bae2b2e51 |date=19 October 2015 |work=AP News |publisher=[[Associated Press]] |accessdate=9 October 2018}}</ref><ref name="PNAS-20151014-pdf">{{cite journal |last1=Bell |first1=Elizabeth A. |last2=Boehnike |first2=Patrick |last3=Harrison |first3=T. Mark |last4=Mao |first4=Wendy L. |display-authors=3 |date=19 October 2015 |title=Potentially biogenic carbon preserved in a 4.1 billion-year-old zircon|journal=Proc. Natl. Acad. Sci. U.S.A. |doi=10.1073/pnas.1517557112|pages=14518–14521 |pmid=26483481 |pmc=4664351 |volume=112 |issue=47 |bibcode=2015PNAS..11214518B}} Early edition, published online before print.</ref><ref name="UCLA-20151019">{{cite web |last1=Wolpert |first1=Stuart |title=Life on Earth likely started at least 4.1 billion years ago – much earlier than scientists had thought |url=http://newsroom.ucla.edu/releases/life-on-earth-likely-started-at-least-4-1-billion-years-ago-much-earlier-than-scientists-had-thought |date=19 October 2015 |publisher=[[ULCA]] |accessdate=20 October 2015 |url-status=live |archiveurl=https://web.archive.org/web/20151020164038/http://newsroom.ucla.edu/releases/life-on-earth-likely-started-at-least-4-1-billion-years-ago-much-earlier-than-scientists-had-thought |archivedate=20 October 2015}}</ref>

人们在格陵兰岛西南部37亿岁的变质沉积岩中发现了生物来源的石墨<ref name="NG-20131208">{{cite journal |last1=Ohtomo |first1=Yoko |last2=Kakegawa |first2=Takeshi |last3=Ishida |first3=Akizumi |last4=Nagase |first4=Toshiro |last5=Rosing |first5=Minik T. |display-authors=3 |date=January 2014 |title=Evidence for biogenic graphite in early Archaean Isua metasedimentary rocks |journal=Nature Geoscience |volume=7 |issue=1 |pages=25–28 |bibcode=2014NatGe...7...25O |doi=10.1038/ngeo2025 }}</ref> ，在西澳大利亚距今34.8亿年前的砂岩中发现了微生物垫层化石<ref name="AP-20131113">{{cite news |last=Borenstein |first=Seth |date=13 November 2013 |title=Oldest fossil found: Meet your microbial mom |url=http://apnews.excite.com/article/20131113/DAA1VSC01.html |work=Excite|location=Yonkers, NY |publisher=Mindspark Interactive Network|agency=Associated Press |accessdate=2015-06-02 |url-status=live |archiveurl=https://web.archive.org/web/20150629230719/http://apnews.excite.com/article/20131113/DAA1VSC01.html |archivedate=29 June 2015}}</ref><ref name="AST-20131108">{{cite journal |last1=Noffke |first1=Nora |last2=Christian |first2=Daniel |last3=Wacey |first3=David |last4=Hazen |first4=Robert M. |date=16 November 2013 |title=Microbially Induced Sedimentary Structures Recording an Ancient Ecosystem in the ''ca.'' 3.48 Gyo Dresser Formation, Pilbara, Western Australia |journal=Astrobiology |volume=13 |issue=12 |pages=1103–1124 |bibcode=2013AsBio..13.1103N |doi=10.1089/ast.2013.1030 |pmc=3870916 |pmid=24205812}}</ref>。在格陵兰岛西南部伊苏亚上地壳带附近的阿基利亚岛的岩石中发现了早期生命的证据，这些可追溯到37亿年前的证据中发现了生源碳同位素<ref name="NYT-20160831">{{cite news |last=Wade |first=Nicholas |title=World's Oldest Fossils Found in Greenland |url=https://www.nytimes.com/2016/09/01/science/oldest-fossils-on-earth.html |date=31 August 2016 |work=The New York Times |accessdate=31 August 2016 |url-status=live |archiveurl=https://web.archive.org/web/20160831185959/http://www.nytimes.com/2016/09/01/science/oldest-fossils-on-earth.html |archivedate=31 August 2016}}</ref><ref>{{harvnb|Davies|1999}}</ref> 。在伊苏亚上地壳带的其他地方，被困在石榴石晶体内的石墨包裹体与生命的其他元素相连：氧、氮和可能以磷酸盐形式存在的磷，为37亿年前的生命提供了进一步的证据<ref>{{Cite journal |last1=Hassenkam|first1=T. |last2=Andersson |first2=M.P. |last3=Dalby|first3=K.N. |last4=Mackenzie |first4=D.M.A.|last5=Rosing |first5=M.T. |title=Elements of Eoarchean life trapped in mineral inclusions |journal=Nature |doi=10.1038/nature23261 |pmid=28738409 |volume=548|issue=7665|pages=78–81 |year=2017 |bibcode=2017Natur.548...78H}}</ref> 。在西澳大利亚皮尔巴拉地区的斯特雷利池，在一个化石滩的含黄铁矿砂岩中发现了早期生命的令人信服的证据，它显示了圆形的管状细胞，在没有氧气的情况下通过光合作用氧化硫。2015年对西澳大利亚的锆石的进一步研究表明，生命很可能在至少41亿年前就存在于地球上。<ref name="AP-20151019">{{cite news |last=Borenstein |first=Seth |title=Hints of life on what was thought to be desolate early Earth |url=https://apnews.com/e6be2537b4cd46ffb9c0585bae2b2e51 |date=19 October 2015 |work=AP News |publisher=Associated Press |accessdate=9 October 2018}}</ref><ref name="PNAS-20151014-pdf">{{cite journal |last1=Bell |first1=Elizabeth A. |last2=Boehnike |first2=Patrick |last3=Harrison |first3=T. Mark |last4=Mao |first4=Wendy L. |display-authors=3 |date=19 October 2015 |title=Potentially biogenic carbon preserved in a 4.1 billion-year-old zircon|journal=Proc. Natl. Acad. Sci. U.S.A. |doi=10.1073/pnas.1517557112|pages=14518–14521 |pmid=26483481 |pmc=4664351 |volume=112 |issue=47 |bibcode=2015PNAS..11214518B}} Early edition, published online before print.</ref><ref name="UCLA-20151019">{{cite web |last1=Wolpert |first1=Stuart |title=Life on Earth likely started at least 4.1 billion years ago – much earlier than scientists had thought |url=http://newsroom.ucla.edu/releases/life-on-earth-likely-started-at-least-4-1-billion-years-ago-much-earlier-than-scientists-had-thought |date=19 October 2015 |publisher=ULCA|accessdate=20 October 2015 |url-status=live |archiveurl=https://web.archive.org/web/20151020164038/http://newsroom.ucla.edu/releases/life-on-earth-likely-started-at-least-4-1-billion-years-ago-much-earlier-than-scientists-had-thought |archivedate=20 October 2015}}</ref>

== 20世纪60年代以前的概念演变史：生物学 Conceptual history until the 1960s: biology ==

== 20世纪60年代以前的概念演变史：生物学 Conceptual history until the 1960s: biology ==

泛种论假说并不试图解释生命最初是如何起源的，而只是将起源转移到另一颗行星或彗星上。原始生命的地外起源的优点是，生命不需要在它出现的每个星球上形成，而是在一个单一的位置，然后通过彗星和/或陨石撞击在银河系周围传播到其他恒星系统。<ref name="NYT-20160912">{{cite news |last=Chang |first=Kenneth |title=Visions of Life on Mars in Earth's Depths |url=https://www.nytimes.com/2016/09/13/science/south-african-mine-life-on-mars.html |date=12 September 2016 |work=[[The New York Times]] |accessdate=12 September 2016 |url-status=live |archiveurl=https://web.archive.org/web/20160912225220/http://www.nytimes.com/2016/09/13/science/south-african-mine-life-on-mars.html |archivedate=12 September 2016}}</ref> 泛种论假说的证据很少，但它在对南极洲发现的火星陨石的研究和对极端微生物在外太空测试中生存的研究中找到了一些支持。<ref>{{cite journal |last=Clark |first=Stuart |date=25 September 2002 |title=Tough Earth bug may be from Mars |url=https://www.newscientist.com/article/dn2844 |journal=New Scientist |accessdate=2015-06-21 |url-status=live |archiveurl=https://web.archive.org/web/20141202003401/http://www.newscientist.com/article/dn2844 |archivedate=2 December 2014}}</ref><ref name="Gerda Horneck">{{cite journal |last1=Horneck |first1=Gerda |last2=Klaus |first2=David M. |last3=Mancinelli |first3=Rocco L. |date=March 2010 |title=Space Microbiology |journal=[[Microbiology and Molecular Biology Reviews]] |volume=74 |issue=1 |pages=121–156 |doi=10.1128/MMBR.00016-09  |pmc=2832349 |pmid=20197502|bibcode=2010MMBR...74..121H }}</ref><ref name="Rabbow">{{cite journal |last1=Rabbow |first1=Elke |last2=Horneck |first2=Gerda |last3=Rettberg |first3=Petra |last4=Schott |first4=Jobst-Ulrich |last5=Panitz |first5=Corinna |last6=L'Afflitto |first6=Andrea |last7=von Heise-Rotenburg |first7=Ralf |last8=Willnecker |first8=Reiner |last9=Baglioni |first9=Pietro |last10=Hatton |first10=Jason |last11=Dettmann |first11=Jan |last12=Demets |first12=René |last13=Reitz |first13=Günther |display-authors=3 |date=December 2009 |title=EXPOSE, an Astrobiological Exposure Facility on the International Space Station – from Proposal to Flight |journal=Origins of Life and Evolution of Biospheres |volume=39 |issue=6 |pages=581–598 |bibcode=2009OLEB...39..581R |doi=10.1007/s11084-009-9173-6|pmid=19629743|s2cid=19749414 }}</ref><ref>{{cite journal |last1=Onofri |first1=Silvano |last2=de la Torre |first2=Rosa |last3=de Vera |first3=Jean-Pierre |last4=Ott |first4=Sieglinde |last5=Zucconi |first5=Laura |last6=Selbmann |first6=Laura |last7=Scalzi |first7=Giuliano |last8=Venkateswaran |first8=Kasthuri J. |last9=Rabbow |first9=Elke |last10=Sánchez Iñigo |first10=Francisco J. |last11=Horneck |first11=Gerda |display-authors=3 |date=May 2012 |title=Survival of Rock-Colonizing Organisms After 1.5 Years in Outer Space |journal=Astrobiology |volume=12 |issue=5 |pages=508–516 |bibcode=2012AsBio..12..508O |doi=10.1089/ast.2011.0736 |pmid=22680696}}</ref>

泛种论假说并不试图解释生命最初是如何起源的，而只是将起源转移到另一颗行星或彗星上。原始生命的地外起源的优点是，生命不需要在它出现的每个星球上形成，而是在一个单一的位置，然后通过彗星和/或陨石撞击在银河系周围传播到其他恒星系统。<ref name="NYT-20160912">{{cite news |last=Chang |first=Kenneth |title=Visions of Life on Mars in Earth's Depths |url=https://www.nytimes.com/2016/09/13/science/south-african-mine-life-on-mars.html |date=12 September 2016 |work=The New York Times|accessdate=12 September 2016 |url-status=live |archiveurl=https://web.archive.org/web/20160912225220/http://www.nytimes.com/2016/09/13/science/south-african-mine-life-on-mars.html |archivedate=12 September 2016}}</ref> 泛种论假说的证据很少，但它在对南极洲发现的火星陨石的研究和对极端微生物在外太空测试中生存的研究中找到了一些支持。<ref>{{cite journal |last=Clark |first=Stuart |date=25 September 2002 |title=Tough Earth bug may be from Mars |url=https://www.newscientist.com/article/dn2844 |journal=New Scientist |accessdate=2015-06-21 |url-status=live |archiveurl=https://web.archive.org/web/20141202003401/http://www.newscientist.com/article/dn2844 |archivedate=2 December 2014}}</ref><ref name="Gerda Horneck">{{cite journal |last1=Horneck |first1=Gerda |last2=Klaus |first2=David M. |last3=Mancinelli |first3=Rocco L. |date=March 2010 |title=Space Microbiology |journal=Microbiology and Molecular Biology Reviews|volume=74 |issue=1 |pages=121–156 |doi=10.1128/MMBR.00016-09  |pmc=2832349 |pmid=20197502|bibcode=2010MMBR...74..121H }}</ref><ref name="Rabbow">{{cite journal |last1=Rabbow |first1=Elke |last2=Horneck |first2=Gerda |last3=Rettberg |first3=Petra |last4=Schott |first4=Jobst-Ulrich |last5=Panitz |first5=Corinna |last6=L'Afflitto |first6=Andrea |last7=von Heise-Rotenburg |first7=Ralf |last8=Willnecker |first8=Reiner |last9=Baglioni |first9=Pietro |last10=Hatton |first10=Jason |last11=Dettmann |first11=Jan |last12=Demets |first12=René |last13=Reitz |first13=Günther |display-authors=3 |date=December 2009 |title=EXPOSE, an Astrobiological Exposure Facility on the International Space Station – from Proposal to Flight |journal=Origins of Life and Evolution of Biospheres |volume=39 |issue=6 |pages=581–598 |bibcode=2009OLEB...39..581R |doi=10.1007/s11084-009-9173-6|pmid=19629743}}</ref><ref>{{cite journal |last1=Onofri |first1=Silvano |last2=de la Torre |first2=Rosa |last3=de Vera |first3=Jean-Pierre |last4=Ott |first4=Sieglinde |last5=Zucconi |first5=Laura |last6=Selbmann |first6=Laura |last7=Scalzi |first7=Giuliano |last8=Venkateswaran |first8=Kasthuri J. |last9=Rabbow |first9=Elke |last10=Sánchez Iñigo |first10=Francisco J. |last11=Horneck |first11=Gerda |display-authors=3 |date=May 2012 |title=Survival of Rock-Colonizing Organisms After 1.5 Years in Outer Space |journal=Astrobiology |volume=12 |issue=5 |pages=508–516 |bibcode=2012AsBio..12..508O |doi=10.1089/ast.2011.0736 |pmid=22680696}}</ref>

2020年8月，科学家报告称，根据在国际空间站上进行的研究，发现来自地球的细菌，特别是对环境危害有很强抵抗力的耐辐射球菌，可以在外太空存活3年。<ref name="CNN-20200826">{{cite news |last=Strickland |first=Ashley |title=Bacteria from Earth can survive in space and could endure the trip to Mars, according to new study |url=https://www.cnn.com/2020/08/26/world/earth-mars-bacteria-space-scn/index.html |date=26 August 2020 |work=[[CNN News]] |accessdate=26 August 2020 }}</ref><ref name="FM-20200826">{{cite journal |author=Kawaguchi, Yuko |display-authors=et al. |title=DNA Damage and Survival Time Course of Deinococcal Cell Pellets During 3 Years of Exposure to Outer Space |date=26 August 2020 |journal=[[Frontiers in Microbiology]] |volume=11 |page=2050 |doi=10.3389/fmicb.2020.02050 |pmid=32983036 |pmc=7479814 |s2cid=221300151 |doi-access=free }}</ref>

2020年8月，科学家报告称，根据在国际空间站上进行的研究，发现来自地球的细菌，特别是对环境危害有很强抵抗力的耐辐射球菌，可以在外太空存活3年。<ref name="CNN-20200826">{{cite news |last=Strickland |first=Ashley |title=Bacteria from Earth can survive in space and could endure the trip to Mars, according to new study |url=https://www.cnn.com/2020/08/26/world/earth-mars-bacteria-space-scn/index.html |date=26 August 2020 |work=CNN News |accessdate=26 August 2020 }}</ref><ref name="FM-20200826">{{cite journal |author=Kawaguchi, Yuko |display-authors=et al. |title=DNA Damage and Survival Time Course of Deinococcal Cell Pellets During 3 Years of Exposure to Outer Space |date=26 August 2020 |journal=Frontiers in Microbiology|volume=11 |page=2050 |doi=10.3389/fmicb.2020.02050 |pmid=32983036 |pmc=7479814 |doi-access=free }}</ref>

====生命起源于宇宙大爆炸之后，并已遍布整个宇宙====

====生命起源于宇宙大爆炸之后，并已遍布整个宇宙====

一种极端的推测是生命的生物化学可能早在大爆炸后1700万年就开始了，在一个适宜居住的时期，生命可能存在于整个宇宙中。<ref name="IJA-2014October_ARXIV-20131202">{{cite journal|last=Loeb|first=Abraham|authorlink=Abraham (Avi) Loeb|date=2014|title=The habitable epoch of the early universe|journal=[[International Journal of Astrobiology]]|volume=13|issue=4|pages=337–339|arxiv=1312.0613|bibcode=2014IJAsB..13..337L|citeseerx=10.1.1.748.4820|doi=10.1017/S1473550414000196|s2cid=2777386}}</ref><ref name="NYT-20141202">{{cite news|url=https://www.nytimes.com/2014/12/02/science/avi-loeb-ponders-the-early-universe-nature-and-life.html|title=Much-Discussed Views That Go Way Back|last=Dreifus|first=Claudia|date=2 December 2014|newspaper=[[The New York Times]]|accessdate=2014-12-03|archiveurl=https://web.archive.org/web/20141203010758/http://www.nytimes.com/2014/12/02/science/avi-loeb-ponders-the-early-universe-nature-and-life.html|archivedate=3 December 2014|url-status=live|location=New York|page=D2|authorlink=Claudia Dreifus}}</ref>

一种极端的推测是生命的生物化学可能早在大爆炸后1700万年就开始了，在一个适宜居住的时期，生命可能存在于整个宇宙中。<ref name="IJA-2014October_ARXIV-20131202">{{cite journal|last=Loeb|first=Abraham|date=2014|title=The habitable epoch of the early universe|journal=International Journal of Astrobiology|volume=13|issue=4|pages=337–339|arxiv=1312.0613|bibcode=2014IJAsB..13..337L|citeseerx=10.1.1.748.4820|doi=10.1017/S1473550414000196}}</ref><ref name="NYT-20141202">{{cite news|url=https://www.nytimes.com/2014/12/02/science/avi-loeb-ponders-the-early-universe-nature-and-life.html|title=Much-Discussed Views That Go Way Back|last=Dreifus|first=Claudia|date=2 December 2014|newspaper=The New York Times|accessdate=2014-12-03|archiveurl=https://web.archive.org/web/20141203010758/http://www.nytimes.com/2014/12/02/science/avi-loeb-ponders-the-early-universe-nature-and-life.html|archivedate=3 December 2014|url-status=live|location=New York|page=D2|}}</ref>

====生命从火星带入地球的泛种论====

====生命从火星带入地球的泛种论====

卡尔·齐默 Carl Zimmer推测，火星早期的化学条件，包括最初生成RNA所需的硼，钼和氧的存在，可能比地球早期更好。<ref name="NYT-20130912">{{cite news |last=Zimmer |first=Carl |date=12 September 2013 |title=A Far-Flung Possibility for the Origin of Life |url=https://www.nytimes.com/2013/09/12/science/space/a-far-flung-possibility-for-the-origin-of-life.html |newspaper=The New York Times |location=New York |accessdate=2015-06-15 |url-status=live |archiveurl=https://web.archive.org/web/20150708122622/http://www.nytimes.com/2013/09/12/science/space/a-far-flung-possibility-for-the-origin-of-life.html |archivedate=8 July 2015}}</ref><ref name="NS-20130829">{{cite journal |last=Webb |first=Richard |date=29 August 2013 |title=Primordial broth of life was a dry Martian cup-a-soup |url=https://www.newscientist.com/article/dn24120-primordial-broth-of-life-was-a-dry-martian-cupasoup.html |journal=New Scientist  |accessdate=2015-06-16 |url-status=live |archiveurl=https://web.archive.org/web/20150424181341/http://www.newscientist.com/article/dn24120-primordial-broth-of-life-was-a-dry-martian-cupasoup.html |archivedate=24 April 2015}}</ref><ref>{{cite journal |author1=Wentao Ma |author2=Chunwu Yu |author3=Wentao Zhang |author4=Jiming Hu |display-authors=3 |date=November 2007 |title=Nucleotide synthetase ribozymes may have emerged first in the RNA world |journal=[[RNA (journal)|RNA]] |volume=13 |issue=11 |pages=2012–2019 |doi=10.1261/rna.658507  |pmc=2040096 |pmid=17878321}}</ref>如果是这样，起源于火星的适合生命的分子可能后来会通过流星喷射迁移到地球。

卡尔·齐默 Carl Zimmer推测，火星早期的化学条件，包括最初生成RNA所需的硼，钼和氧的存在，可能比地球早期更好。<ref name="NYT-20130912">{{cite news |last=Zimmer |first=Carl |date=12 September 2013 |title=A Far-Flung Possibility for the Origin of Life |url=https://www.nytimes.com/2013/09/12/science/space/a-far-flung-possibility-for-the-origin-of-life.html |newspaper=The New York Times |location=New York |accessdate=2015-06-15 |url-status=live |archiveurl=https://web.archive.org/web/20150708122622/http://www.nytimes.com/2013/09/12/science/space/a-far-flung-possibility-for-the-origin-of-life.html |archivedate=8 July 2015}}</ref><ref name="NS-20130829">{{cite journal |last=Webb |first=Richard |date=29 August 2013 |title=Primordial broth of life was a dry Martian cup-a-soup |url=https://www.newscientist.com/article/dn24120-primordial-broth-of-life-was-a-dry-martian-cupasoup.html |journal=New Scientist  |accessdate=2015-06-16 |url-status=live |archiveurl=https://web.archive.org/web/20150424181341/http://www.newscientist.com/article/dn24120-primordial-broth-of-life-was-a-dry-martian-cupasoup.html |archivedate=24 April 2015}}</ref><ref>{{cite journal |author1=Wentao Ma |author2=Chunwu Yu |author3=Wentao Zhang |author4=Jiming Hu |display-authors=3 |date=November 2007 |title=Nucleotide synthetase ribozymes may have emerged first in the RNA world |journal=RNA |volume=13 |issue=11 |pages=2012–2019 |doi=10.1261/rna.658507  |pmc=2040096 |pmid=17878321}}</ref>如果是这样，起源于火星的适合生命的分子可能后来会通过流星喷射迁移到地球。

=== 自然发生 ===

=== 自然发生 ===

<blockquote>  

<blockquote>  

To question this [spontaneous generation], is to question Reason, Sense, and Experience: If he doubts of this, let him go to ''[[Egypt|Ægypt]]'', and there he will find the fields swarming with mice begot of the mud of ''[[Nile|Nylus]]'', to the great calamity of the Inhabitants.<ref>{{cite journal |last=Balme |first=D.M. |authorlink=David Mowbray Balme |year=1962 |title=Development of Biology in Aristotle and Theophrastus: Theory of Spontaneous Generation |journal=[[Phronesis (journal)|Phronesis]] |volume=7 |issue=1–2 |pages=91–104 |doi=10.1163/156852862X00052}}</ref><ref>{{harvnb|Ross|1652}}</ref>

To question this [spontaneous generation], is to question Reason, Sense, and Experience: If he doubts of this, let him go to ''Egypt'', and there he will find the fields swarming with mice begot of the mud of ''Nile'', to the great calamity of the Inhabitants.

 

质疑这个自然发生，就是质疑理性、感觉和经验。如果他怀疑这一点，让他去埃及， 在那里，他将会发现田野里到处都是由尼罗斯的泥土生出的老鼠，给当地居民带来了巨大的灾难。<ref>{{cite journal |last=Balme |first=D.M. |year=1962 |title=Development of Biology in Aristotle and Theophrastus: Theory of Spontaneous Generation |journal=Phronesis ]] |volume=7 |issue=1–2 |pages=91–104 |doi=10.1163/156852862X00052}}</ref><ref>{{harvnb|Ross|1652}}</ref>

</blockquote>  

</blockquote>  

# 从分子到细胞的演变

# 从分子到细胞的演变

Bernal认为，进化始于第一和第二阶段之间。Bernal认为第三阶段是最困难的阶段，在这一阶段，生物反应被纳入细胞的边界之后。现代对细胞膜自组装方式的研究，以及对各种基质中微孔的研究，可能是理解独立自主生活细胞发展的关键一步。<ref>{{cite journal |last= Martin |first= William F. |authorlink= William F. Martin |date= January 2003 |title= On the origins of cells: a hypothesis for the evolutionary transitions from abiotic geochemistry to chemoautotrophic prokaryotes, and from prokaryotes to nucleated cells |journal=Phil. Trans. R. Soc. Lond. A |volume= 358 |issue= 1429 |pages= 59–83 |doi= 10.1098/rstb.2002.1183 |pmid=12594918 |pmc=1693102}}</ref><ref>{{cite journal |last= Bernal |first= John Desmond |authorlink= John Desmond Bernal |date= September 1949 |title= The Physical Basis of Life |journal= Proceedings of the Physical Society, Section A |volume= 62 |issue= 9 |pages= 537–558 |bibcode= 1949PPSA...62..537B |doi= 10.1088/0370-1298/62/9/301 }}</ref><ref>{{harvnb|Kauffman|1995}}</ref>

Bernal认为，进化始于第一和第二阶段之间。Bernal认为第三阶段是最困难的阶段，在这一阶段，生物反应被纳入细胞的边界之后。现代对细胞膜自组装方式的研究，以及对各种基质中微孔的研究，可能是理解独立自主生活细胞发展的关键一步。<ref>{{cite journal |last= Martin |first= William F. |date= January 2003 |title= On the origins of cells: a hypothesis for the evolutionary transitions from abiotic geochemistry to chemoautotrophic prokaryotes, and from prokaryotes to nucleated cells |journal=Phil. Trans. R. Soc. Lond. A |volume= 358 |issue= 1429 |pages= 59–83 |doi= 10.1098/rstb.2002.1183 |pmid=12594918 |pmc=1693102}}</ref><ref>{{cite journal |last= Bernal |first= John Desmond |date= September 1949 |title= The Physical Basis of Life |journal= Proceedings of the Physical Society, Section A |volume= 62 |issue= 9 |pages= 537–558 |bibcode= 1949PPSA...62..537B |doi= 10.1088/0370-1298/62/9/301 }}</ref><ref>{{harvnb|Kauffman|1995}}</ref>

“汤 ”理论最重要的实验支持之一是在1952年。Stanley Miller和Harold Urey做了一个实验，证明了在类似Oparin-Haldane假说所提出的条件下，有机分子是如何从无机前体自发形成的。现在著名的Miller-Urey实验使用高度还原性的混合气体--甲烷、氨、氢以及水蒸气—来形成简单的有机单体，如氨基酸。<ref>{{cite journal |last=Miller |first=Stanley L. |authorlink=Stanley Miller |date=15 May 1953 |title=A Production of Amino Acids Under Possible Primitive Earth Conditions |journal=[[Science (journal)|Science]] |volume=117 |issue=3046 |pages=528–529 |bibcode=1953Sci...117..528M |doi=10.1126/science.117.3046.528 |pmid=13056598}}</ref>混合气体通过一个装置循环，将电火花传递到混合物中。一周后，发现系统中约有10%至15%的碳以有机化合物的外消旋混合物的形式存在，其中包括氨基酸，而氨基酸是蛋白质的构件。这为 "汤 "理论的第二点提供了直接的实验支持，而现在很多争论的焦点正是围绕着该理论的其余两点。

“汤 ”理论最重要的实验支持之一是在1952年。Stanley Miller和Harold Urey做了一个实验，证明了在类似Oparin-Haldane假说所提出的条件下，有机分子是如何从无机前体自发形成的。现在著名的Miller-Urey实验使用高度还原性的混合气体--甲烷、氨、氢以及水蒸气—来形成简单的有机单体，如氨基酸。<ref>{{cite journal |last=Miller |first=Stanley L. |date=15 May 1953 |title=A Production of Amino Acids Under Possible Primitive Earth Conditions |journal=Science |volume=117 |issue=3046 |pages=528–529 |bibcode=1953Sci...117..528M |doi=10.1126/science.117.3046.528 |pmid=13056598}}</ref>混合气体通过一个装置循环，将电火花传递到混合物中。一周后，发现系统中约有10%至15%的碳以有机化合物的外消旋混合物的形式存在，其中包括氨基酸，而氨基酸是蛋白质的构件。这为 "汤 "理论的第二点提供了直接的实验支持，而现在很多争论的焦点正是围绕着该理论的其余两点。

== 生物分子的原始起源： 化学 ==

== 生物分子的原始起源： 化学 ==

生物前的早期地球的化学过程称为“化学进化”。除氢和氦外，其他元素最终都来自于恒星核合成。2016年，天文学家报告说，生命的非常基本的化学成分--碳氢分子（CH，或称次甲基自由基）、碳氢正离子（CH+）和碳离子（C+）--主要是来自恒星的紫外线的结果，而不是之前认为的来自超新星和年轻恒星的其他辐射形式。<ref name="NASA-20161012">{{cite web |last=Landau |first=Elizabeth |title=Building Blocks of Life's Building Blocks Come From Starlight |url=http://www.jpl.nasa.gov/news/news.php?feature=6645 |date=12 October 2016 |work=[[NASA]] |accessdate=13 October 2016 |url-status=live |archiveurl=https://web.archive.org/web/20161013135018/http://www.jpl.nasa.gov/news/news.php?feature=6645 |archivedate=13 October 2016}}</ref>复杂的分子，包括有机分子，在太空和行星上自然形成。<ref name="Ehrenfreund2010" /> 早期地球上的有机分子有两种可能的来源：

生物前的早期地球的化学过程称为“化学进化”。除氢和氦外，其他元素最终都来自于恒星核合成。2016年，天文学家报告说，生命的非常基本的化学成分--碳氢分子（CH，或称次甲基自由基）、碳氢正离子（CH+）和碳离子（C+）--主要是来自恒星的紫外线的结果，而不是之前认为的来自超新星和年轻恒星的其他辐射形式。<ref name="NASA-20161012">{{cite web |last=Landau |first=Elizabeth |title=Building Blocks of Life's Building Blocks Come From Starlight |url=http://www.jpl.nasa.gov/news/news.php?feature=6645 |date=12 October 2016 |work=NASA|accessdate=13 October 2016 |url-status=live |archiveurl=https://web.archive.org/web/20161013135018/http://www.jpl.nasa.gov/news/news.php?feature=6645 |archivedate=13 October 2016}}</ref>复杂的分子，包括有机分子，在太空和行星上自然形成。<ref name="Ehrenfreund2010" /> 早期地球上的有机分子有两种可能的来源：

# 地球起源 -- -- 撞击冲击或其他能量源(如紫外光、氧化还原耦合或放电；如，Miller的实验)驱动的有机分子合成。

# 地球起源 -- -- 撞击冲击或其他能量源(如紫外光、氧化还原耦合或放电；如，Miller的实验)驱动的有机分子合成。

# 地外起源--星际尘埃云中有机分子的形成，这些尘埃云降到行星上。<ref name="Gawlowicz 2011">{{cite news |last=Gawlowicz |first=Susan |date=6 November 2011 |title=Carbon-based organic 'carriers' in interstellar dust clouds? Newly discovered diffuse interstellar bands |url=https://www.sciencedaily.com/releases/2011/11/111102161149.htm |work=[[Science Daily]] |location=Rockville, MD |publisher=ScienceDaily, LLC |accessdate=2015-06-08 |url-status=live |archiveurl=https://web.archive.org/web/20150711114643/https://www.sciencedaily.com/releases/2011/11/111102161149.htm |archivedate=11 July 2015}}</ref>

# 地外起源--星际尘埃云中有机分子的形成，这些尘埃云降到行星上。<ref name="Gawlowicz 2011">{{cite news |last=Gawlowicz |first=Susan |date=6 November 2011 |title=Carbon-based organic 'carriers' in interstellar dust clouds? Newly discovered diffuse interstellar bands |url=https://www.sciencedaily.com/releases/2011/11/111102161149.htm |work=Science Daily|location=Rockville, MD |publisher=ScienceDaily, LLC |accessdate=2015-06-08 |url-status=live |archiveurl=https://web.archive.org/web/20150711114643/https://www.sciencedaily.com/releases/2011/11/111102161149.htm |archivedate=11 July 2015}}</ref>

=== 观察到的地外有机分子===

=== 观察到的地外有机分子===

有机化合物是指分子中含有碳的一大类气态、液态或固态化学物质的任何成员。<ref>{{cite encyclopedia |encyclopedia=Encyclopedia of Science |title=biological abundance of elements |url=http://www.daviddarling.info/encyclopedia/E/elbio.html |publisher=David Darling Enterprises |location=Dundee, Scotland |accessdate=2008-10-09 |url-status=live |archiveurl=https://web.archive.org/web/20120204033420/http://www.daviddarling.info/encyclopedia/E/elbio.html |archivedate=4 February 2012}}</ref>按质量计算，碳是宇宙中仅次于氢、氦和氧的第四大丰富元素。<ref name="NASA-20140221">{{cite web |url=http://www.nasa.gov/ames/need-to-track-organic-nano-particles-across-the-universe-nasas-got-an-app-for-that/ |title=Need to Track Organic Nano-Particles Across the Universe? NASA's Got an App for That |last=Hoover |first=Rachel |date=21 February 2014 |website=[[Ames Research Center]] |publisher=NASA |location=Mountain View, CA |accessdate=2015-06-22 |url-status=live |archiveurl=https://web.archive.org/web/20150906061428/http://www.nasa.gov/ames/need-to-track-organic-nano-particles-across-the-universe-nasas-got-an-app-for-that/ |archivedate=6 September 2015}}</ref>碳在太阳、恒星、彗星和大多数行星的大气层中含量丰富。有机化合物在太空中比较常见，是由分子云和环星包层中出现的 "复杂分子合成工厂"形成的，主要由电离辐射引发反应后发生化学演变。<ref name="Ehrenfreund2010">{{cite journal |last1=Ehrenfreund |first1=Pascale |last2=Cami |first2=Jan |date=December 2010 |title=Cosmic carbon chemistry: from the interstellar medium to the early Earth. |journal=Cold Spring Harbor Perspectives in Biology |volume=2 |issue=12 |page=a002097 |doi=10.1101/cshperspect.a002097 |pmc=2982172 |pmid=20554702}}</ref><ref name="FromADistantComet">{{cite news |last=Chang |first=Kenneth |date=18 August 2009 |title=From a Distant Comet, a Clue to Life |url=https://www.nytimes.com/2009/08/19/science/space/19comet.html |newspaper=The New York Times |location=New York |page=A18 |accessdate=2015-06-22 |url-status=live |archiveurl=https://web.archive.org/web/20150623005046/http://www.nytimes.com/2009/08/19/science/space/19comet.html |archivedate=23 June 2015}}</ref><ref>{{cite journal |last1=Goncharuk |first1=Vladislav V. |last2=Zui |first2=O. V. |date=February 2015 |title=Water and carbon dioxide as the main precursors of organic matter on Earth and in space |journal=Journal of Water Chemistry and Technology |volume=37 |issue=1 |pages=2–3 |doi=10.3103/S1063455X15010026 |s2cid=97965067 }}</ref><ref>{{cite journal |last1=Abou Mrad |first1=Ninette |last2=Vinogradoff |first2=Vassilissa |last3=Duvernay |first3=Fabrice |last4=Danger |first4=Grégoire |last5=Theulé |first5=Patrice |last6=Borget |first6=Fabien |last7=Chiavassa |first7=Thierry |display-authors=3 |year=2015 |title=Laboratory experimental simulations: Chemical evolution of the organic matter from interstellar and cometary ice analogs |url=http://popups.ulg.ac.be/0037-9565/index.php?id=4621&file=1|journal=Bulletin de la Société Royale des Sciences de Liège |volume=84 |pages=21–32 |bibcode=2015BSRSL..84...21A  |accessdate=2015-04-06 |url-status=live |archiveurl=https://web.archive.org/web/20150413050621/http://popups.ulg.ac.be/0037-9565/index.php?id=4621&file=1 |archivedate=13 April 2015}}</ref> 根据计算机模型研究，在地球形成之前，生命所需的复杂有机分子可能已经在太阳周围原行星盘的尘粒上形成。<ref name="Space-20120329" /> 根据计算机研究，这一过程也可能发生在其他获得行星的恒星周围。<ref name="Space-20120329" />

有机化合物是指分子中含有碳的一大类气态、液态或固态化学物质的任何成员。<ref>{{cite encyclopedia |encyclopedia=Encyclopedia of Science |title=biological abundance of elements |url=http://www.daviddarling.info/encyclopedia/E/elbio.html |publisher=David Darling Enterprises |location=Dundee, Scotland |accessdate=2008-10-09 |url-status=live |archiveurl=https://web.archive.org/web/20120204033420/http://www.daviddarling.info/encyclopedia/E/elbio.html |archivedate=4 February 2012}}</ref>按质量计算，碳是宇宙中仅次于氢、氦和氧的第四大丰富元素。<ref name="NASA-20140221">{{cite web |url=http://www.nasa.gov/ames/need-to-track-organic-nano-particles-across-the-universe-nasas-got-an-app-for-that/ |title=Need to Track Organic Nano-Particles Across the Universe? NASA's Got an App for That |last=Hoover |first=Rachel |date=21 February 2014 |website=Ames Research Center|publisher=NASA |location=Mountain View, CA |accessdate=2015-06-22 |url-status=live |archiveurl=https://web.archive.org/web/20150906061428/http://www.nasa.gov/ames/need-to-track-organic-nano-particles-across-the-universe-nasas-got-an-app-for-that/ |archivedate=6 September 2015}}</ref>碳在太阳、恒星、彗星和大多数行星的大气层中含量丰富。有机化合物在太空中比较常见，是由分子云和环星包层中出现的 "复杂分子合成工厂"形成的，主要由电离辐射引发反应后发生化学演变。<ref name="Ehrenfreund2010">{{cite journal |last1=Ehrenfreund |first1=Pascale |last2=Cami |first2=Jan |date=December 2010 |title=Cosmic carbon chemistry: from the interstellar medium to the early Earth. |journal=Cold Spring Harbor Perspectives in Biology |volume=2 |issue=12 |page=a002097 |doi=10.1101/cshperspect.a002097 |pmc=2982172 |pmid=20554702}}</ref><ref name="FromADistantComet">{{cite news |last=Chang |first=Kenneth |date=18 August 2009 |title=From a Distant Comet, a Clue to Life |url=https://www.nytimes.com/2009/08/19/science/space/19comet.html |newspaper=The New York Times |location=New York |page=A18 |accessdate=2015-06-22 |url-status=live |archiveurl=https://web.archive.org/web/20150623005046/http://www.nytimes.com/2009/08/19/science/space/19comet.html |archivedate=23 June 2015}}</ref><ref>{{cite journal |last1=Goncharuk |first1=Vladislav V. |last2=Zui |first2=O. V. |date=February 2015 |title=Water and carbon dioxide as the main precursors of organic matter on Earth and in space |journal=Journal of Water Chemistry and Technology |volume=37 |issue=1 |pages=2–3 |doi=10.3103/S1063455X15010026 }}</ref><ref>{{cite journal |last1=Abou Mrad |first1=Ninette |last2=Vinogradoff |first2=Vassilissa |last3=Duvernay |first3=Fabrice |last4=Danger |first4=Grégoire |last5=Theulé |first5=Patrice |last6=Borget |first6=Fabien |last7=Chiavassa |first7=Thierry |display-authors=3 |year=2015 |title=Laboratory experimental simulations: Chemical evolution of the organic matter from interstellar and cometary ice analogs |url=http://popups.ulg.ac.be/0037-9565/index.php?id=4621&file=1|journal=Bulletin de la Société Royale des Sciences de Liège |volume=84 |pages=21–32 |bibcode=2015BSRSL..84...21A  |accessdate=2015-04-06 |url-status=live |archiveurl=https://web.archive.org/web/20150413050621/http://popups.ulg.ac.be/0037-9565/index.php?id=4621&file=1 |archivedate=13 April 2015}}</ref> 根据计算机模型研究，在地球形成之前，生命所需的复杂有机分子可能已经在太阳周围原行星盘的尘粒上形成。<ref name="Space-20120329" /> 根据计算机研究，这一过程也可能发生在其他获得行星的恒星周围。<ref name="Space-20120329" />

====氨基酸====

====氨基酸====

在一颗彗星中发现甘氨酸，支持了生命的基本组成构件在太空中普遍存在的观点，并加强了宇宙中的生命可能是常见而非罕见的论点。<ref>{{cite news |author=<!--Staff writer(s); no by-line.--> |date=18 August 2009 |title='Life chemical' detected in comet |url=http://news.bbc.co.uk/2/hi/science/nature/8208307.stm |work=BBC News |location=London |accessdate=2015-06-23 |url-status=live |archiveurl=https://web.archive.org/web/20150525071228/http://news.bbc.co.uk/2/hi/science/nature/8208307.stm |archivedate=25 May 2015}}</ref>

在一颗彗星中发现甘氨酸，支持了生命的基本组成构件在太空中普遍存在的观点，并加强了宇宙中的生命可能是常见而非罕见的论点。<ref>{{cite news |author=<!--Staff writer(s); no by-line.--> |date=18 August 2009 |title='Life chemical' detected in comet |url=http://news.bbc.co.uk/2/hi/science/nature/8208307.stm |work=BBC News |location=London |accessdate=2015-06-23 |url-status=live |archiveurl=https://web.archive.org/web/20150525071228/http://news.bbc.co.uk/2/hi/science/nature/8208307.stm |archivedate=25 May 2015}}</ref>

</blockquote>

</blockquote>

彗星外层包裹着深色物质，被认为是一种焦油状物质，由简单的碳化合物经过主要由电离辐射引发的反应后形成的复杂有机物质组成。彗星的物质雨有可能将大量的这种复杂的有机分子带到地球上。<ref>{{cite journal |last1=Thompson |first1=William Reid |last2=Murray |first2=B. G. |last3=Khare |first3=Bishun Narain |authorlink3=Bishun Khare |last4=Sagan |first4=Carl |date=30 December 1987 |title=Coloration and darkening of methane clathrate and other ices by charged particle irradiation: Applications to the outer solar system |journal=[[Journal of Geophysical Research]] |volume=92 |issue=A13 |pages=14933–14947 |bibcode=1987JGR....9214933T |doi=10.1029/JA092iA13p14933 |pmid=11542127}}</ref><ref>{{cite web |url=https://www.llnl.gov/news/life-earth-shockingly-comes-out-world |title=Life on Earth shockingly comes from out of this world |last=Stark |first=Anne M. |date=5 June 2013 |publisher=[[Lawrence Livermore National Laboratory]] |location=Livermore, CA |accessdate=2015-06-23 |url-status=live |archiveurl=https://web.archive.org/web/20150916135630/https://www.llnl.gov/news/life-earth-shockingly-comes-out-world |archivedate=16 September 2015}}</ref><ref>{{cite journal |last1=Goldman |first1=Nir |last2=Tamblyn |first2=Isaac |date=20 June 2013 |title=Prebiotic Chemistry within a Simple Impacting Icy Mixture |journal=[[Journal of Physical Chemistry A]] |volume=117 |issue=24 |pages=5124–5131 |doi=10.1021/jp402976n |pmid=23639050|bibcode=2013JPCA..117.5124G |url=http://nparc.nrc-cnrc.gc.ca/eng/view/fulltext/?id=e89d2ac7-4cf8-40e0-bcc9-3c53f68ed70a }}</ref>在外星形成的氨基酸也可能通过彗星到达地球。<ref name="Follmann2009" /> 据估计，在晚期重型轰炸期间，陨石每年可能向地球输送多达500万吨的有机前生物元素。<ref name="Follmann2009" />

彗星外层包裹着深色物质，被认为是一种焦油状物质，由简单的碳化合物经过主要由电离辐射引发的反应后形成的复杂有机物质组成。彗星的物质雨有可能将大量的这种复杂的有机分子带到地球上。<ref>{{cite journal |last1=Thompson |first1=William Reid |last2=Murray |first2=B. G. |last3=Khare |first3=Bishun Narain |last4=Sagan |first4=Carl |date=30 December 1987 |title=Coloration and darkening of methane clathrate and other ices by charged particle irradiation: Applications to the outer solar system |journal=Journal of Geophysical Research|volume=92 |issue=A13 |pages=14933–14947 |bibcode=1987JGR....9214933T |doi=10.1029/JA092iA13p14933 |pmid=11542127}}</ref><ref>{{cite web |url=https://www.llnl.gov/news/life-earth-shockingly-comes-out-world |title=Life on Earth shockingly comes from out of this world |last=Stark |first=Anne M. |date=5 June 2013 |publisher=Lawrence Livermore National Laboratory|location=Livermore, CA |accessdate=2015-06-23 |url-status=live |archiveurl=https://web.archive.org/web/20150916135630/https://www.llnl.gov/news/life-earth-shockingly-comes-out-world |archivedate=16 September 2015}}</ref><ref>{{cite journal |last1=Goldman |first1=Nir |last2=Tamblyn |first2=Isaac |date=20 June 2013 |title=Prebiotic Chemistry within a Simple Impacting Icy Mixture |journal=Journal of Physical Chemistry A |volume=117 |issue=24 |pages=5124–5131 |doi=10.1021/jp402976n |pmid=23639050|bibcode=2013JPCA..117.5124G |url=http://nparc.nrc-cnrc.gc.ca/eng/view/fulltext/?id=e89d2ac7-4cf8-40e0-bcc9-3c53f68ed70a }}</ref>在外星形成的氨基酸也可能通过彗星到达地球。<ref name="Follmann2009" /> 据估计，在晚期重型轰炸期间，陨石每年可能向地球输送多达500万吨的有机前生物元素。<ref name="Follmann2009" />

==== 多环芳烃(PAH)世界假说 ====

==== 多环芳烃(PAH)世界假说 ====

众所周知，多环芳烃在宇宙中非常丰富，<ref name="SP-20051018">{{cite news |last= Carey |first= Bjorn |date= 18 October 2005 |title= Life's Building Blocks 'Abundant in Space' |url= http://www.space.com/1686-life-building-blocks-abundant-space.html |website= Space.com |location= Watsonville, CA |publisher= [[Imaginova]] |accessdate= 2015-06-23 |url-status= live |archiveurl= https://web.archive.org/web/20150626223942/http://www.space.com/1686-life-building-blocks-abundant-space.html |archivedate= 26 June 2015}}</ref><ref name="AJ-20051010">{{cite journal |last1=Hudgins |first1= Douglas M. |last2=Bauschlicher |first2=Charles W. Jr. |last3=Allamandola |first3=Louis J. |date=10 October 2005 |title=Variations in the Peak Position of the 6.2 μm Interstellar Emission Feature: A Tracer of N in the Interstellar Polycyclic Aromatic Hydrocarbon Population |journal=[[The Astrophysical Journal]] |volume=632 |pages=316–332 |issue=1 |bibcode=2005ApJ...632..316H |doi=10.1086/432495 |citeseerx=10.1.1.218.8786 }}</ref><ref name="NASA-20110413">{{cite web|url=http://amesteam.arc.nasa.gov/Research/cosmic.html |title=Cosmic Distribution of Chemical Complexity |last1=Des Marais |first1=David J. |last2=Allamandola |first2=Louis J. |last3=Sandford |first3=Scott |authorlink3=Scott Sandford |last4=Mattioda |first4=Andrew |last5=Gudipati |first5=Murthy |last6=Roser |first6=Joseph |last7=Bramall |first7=Nathan |last8=Nuevo |first8=Michel |last9=Boersma |first9=Christiaan |last10=Bernstein |first10=Max |last11=Peeters |first11=Els |last12=Cami |first12=Jan |last13=Cook |first13=Jamie Elsila |last14=Dworkin |first14=Jason |display-authors=3 |year=2009 |website=Ames Research Center |publisher=NASA |location=Mountain View, CA |accessdate=2015-06-24 |url-status=dead |archiveurl=https://web.archive.org/web/20140227184503/http://amesteam.arc.nasa.gov/Research/cosmic.html |archivedate=27 February 2014}} See the Ames Research Center 2009 annual team report to the [[NASA Astrobiology Institute]] here {{cite web|url=https://astrobiology.nasa.gov/nai/reports/annual-reports/2009/arc/ |title=Archived copy |accessdate=2015-06-24 |url-status=dead |archiveurl=https://web.archive.org/web/20130301064911/https://astrobiology.nasa.gov/nai/reports/annual-reports/2009/arc/ |archivedate=1 March 2013}}.</ref>包括在星际介质、彗星和陨石中，是迄今为止在空间发现的一些最复杂的分子。<ref name="NASA-20140221" />

众所周知，多环芳烃在宇宙中非常丰富，<ref name="SP-20051018">{{cite news |last= Carey |first= Bjorn |date= 18 October 2005 |title= Life's Building Blocks 'Abundant in Space' |url= http://www.space.com/1686-life-building-blocks-abundant-space.html |website= Space.com |location= Watsonville, CA |publisher= Imaginova |accessdate= 2015-06-23 |url-status= live |archiveurl= https://web.archive.org/web/20150626223942/http://www.space.com/1686-life-building-blocks-abundant-space.html |archivedate= 26 June 2015}}</ref><ref name="AJ-20051010">{{cite journal |last1=Hudgins |first1= Douglas M. |last2=Bauschlicher |first2=Charles W. Jr. |last3=Allamandola |first3=Louis J. |date=10 October 2005 |title=Variations in the Peak Position of the 6.2 μm Interstellar Emission Feature: A Tracer of N in the Interstellar Polycyclic Aromatic Hydrocarbon Population |journal=The Astrophysical Journal |volume=632 |pages=316–332 |issue=1 |bibcode=2005ApJ...632..316H |doi=10.1086/432495 |citeseerx=10.1.1.218.8786 }}</ref><ref name="NASA-20110413">{{cite web|url=http://amesteam.arc.nasa.gov/Research/cosmic.html |title=Cosmic Distribution of Chemical Complexity |last1=Des Marais |first1=David J. |last2=Allamandola |first2=Louis J. |last3=Sandford |first3=Scott |last4=Mattioda |first4=Andrew |last5=Gudipati |first5=Murthy |last6=Roser |first6=Joseph |last7=Bramall |first7=Nathan |last8=Nuevo |first8=Michel |last9=Boersma |first9=Christiaan |last10=Bernstein |first10=Max |last11=Peeters |first11=Els |last12=Cami |first12=Jan |last13=Cook |first13=Jamie Elsila |last14=Dworkin |first14=Jason |display-authors=3 |year=2009 |website=Ames Research Center |publisher=NASA |location=Mountain View, CA |accessdate=2015-06-24 |url-status=dead |archiveurl=https://web.archive.org/web/20140227184503/http://amesteam.arc.nasa.gov/Research/cosmic.html |archivedate=27 February 2014}} See the Ames Research Center 2009 annual team report to the NASA Astrobiology Institute]here {{cite web|url=https://astrobiology.nasa.gov/nai/reports/annual-reports/2009/arc/ |title=Archived copy |accessdate=2015-06-24 |url-status=dead |archiveurl=https://web.archive.org/web/20130301064911/https://astrobiology.nasa.gov/nai/reports/annual-reports/2009/arc/ |archivedate=1 March 2013}}.</ref>包括在星际介质、彗星和陨石中，是迄今为止在空间发现的一些最复杂的分子。<ref name="NASA-20140221" />

复杂分子的其他来源也被推测出来，包括地外恒星或星际起源。例如，根据光谱分析，已知有机分子存在于彗星和陨石中。2004年，一个团队在一个星云中检测到了多环芳烃的痕迹。<ref>{{cite conference |last1=Witt |first1=Adolf N. |last2=Vijh |first2=Uma P. |last3=Gordon |first3=Karl D. |date=January 2004 |title=Discovery of Blue Fluorescence by Polycyclic Aromatic Hydrocarbon Molecules in the Red Rectangle |url=https://aas.org/archives/BAAS/v35n5/aas203/189.htm |publisher=[[American Astronomical Society]] |bibcode=2003AAS...20311017W |archiveurl=https://web.archive.org/web/20031219175322/http://www.aas.org/publications/baas/v35n5/aas203/189.htm |archivedate=19 December 2003 |url-status=dead |conference=American Astronomical Society Meeting 203 |location=Atlanta, GA |access-date=16 January 2019 }}</ref>2010年，另一个团队也在星云中检测到了多环芳烃以及富勒烯。<ref name="AJL-20101120" />"多环芳烃世界"假说中还提出将多环芳烃作为RNA世界的前导。.<ref>{{Cite journal|last1=d'Ischia|first1=Marco|last2=Manini|first2=Paola|last3=Moracci|first3=Marco|last4=Saladino|first4=Raffaele|last5=Ball|first5=Vincent|last6=Thissen|first6=Helmut|last7=Evans|first7=Richard A.|last8=Puzzarini|first8=Cristina|last9=Barone|first9=Vincenzo|date=2019-08-21|title=Astrochemistry and Astrobiology: Materials Science in Wonderland?|journal=International Journal of Molecular Sciences|volume=20|issue=17|pages=4079|doi=10.3390/ijms20174079|issn=1422-0067|pmc=6747172|pmid=31438518}}</ref>斯皮策太空望远镜探测到一颗恒星HH 46-IR，它的形成过程与太阳的形成过程相似。在恒星周围的物质盘中，有非常多的分子，包括氰化合物、碳氢化合物和一氧化碳。2012年，美国宇航局的科学家报告说，多环芳烃在星际介质条件下，通过氢化、氧化和羟基化，转化为更复杂的有机物--"分别是向氨基酸和核苷酸（蛋白质和DNA的原料）道路上迈进的一步。 ""<ref name="Space-20120920">{{cite web |url= http://www.space.com/17681-life-building-blocks-nasa-organic-molecules.html |title= NASA Cooks Up Icy Organics to Mimic Life's Origins |date= 20 September 2012 |website= Space.com |location= Ogden, UT |publisher= Purch |accessdate= 2015-06-26 |url-status= live |archiveurl= https://web.archive.org/web/20150625035023/http://www.space.com/17681-life-building-blocks-nasa-organic-molecules.html |archivedate= 25 June 2015}}</ref><ref name="AJL-20120901">{{cite journal |last1=Gudipati |first1=Murthy S. |author2=Rui Yang |date=1 September 2012 |title=In-situ Probing of Radiation-induced Processing of Organics in Astrophysical Ice Analogs – Novel Laser Desorption Laser Ionization Time-of-flight Mass Spectroscopic Studies |journal=The Astrophysical Journal Letters |volume=756 |issue=1 |bibcode=2012ApJ...756L..24G |doi=10.1088/2041-8205/756/1/L24 |pages=L24}}</ref>此外，由于这些转化，多环芳烃失去了它们的光谱特征，这可能是 "星际冰粒，特别是寒冷的稠密云的外部区域或原行星盘的上层分子层中，缺乏检测到多环芳烃的原因之一。"<ref name="Space-20120920" /><ref name="AJL-20120901" />

复杂分子的其他来源也被推测出来，包括地外恒星或星际起源。例如，根据光谱分析，已知有机分子存在于彗星和陨石中。2004年，一个团队在一个星云中检测到了多环芳烃的痕迹。<ref>{{cite conference |last1=Witt |first1=Adolf N. |last2=Vijh |first2=Uma P. |last3=Gordon |first3=Karl D. |date=January 2004 |title=Discovery of Blue Fluorescence by Polycyclic Aromatic Hydrocarbon Molecules in the Red Rectangle |url=https://aas.org/archives/BAAS/v35n5/aas203/189.htm |publisher=American Astronomical Society |bibcode=2003AAS...20311017W |archiveurl=https://web.archive.org/web/20031219175322/http://www.aas.org/publications/baas/v35n5/aas203/189.htm |archivedate=19 December 2003 |url-status=dead |conference=American Astronomical Society Meeting 203 |location=Atlanta, GA |access-date=16 January 2019 }}</ref>2010年，另一个团队也在星云中检测到了多环芳烃以及富勒烯。<ref name="AJL-20101120" />"多环芳烃世界"假说中还提出将多环芳烃作为RNA世界的前导。.<ref>{{Cite journal|last1=d'Ischia|first1=Marco|last2=Manini|first2=Paola|last3=Moracci|first3=Marco|last4=Saladino|first4=Raffaele|last5=Ball|first5=Vincent|last6=Thissen|first6=Helmut|last7=Evans|first7=Richard A.|last8=Puzzarini|first8=Cristina|last9=Barone|first9=Vincenzo|date=2019-08-21|title=Astrochemistry and Astrobiology: Materials Science in Wonderland?|journal=International Journal of Molecular Sciences|volume=20|issue=17|pages=4079|doi=10.3390/ijms20174079|issn=1422-0067|pmc=6747172|pmid=31438518}}</ref>斯皮策太空望远镜探测到一颗恒星HH 46-IR，它的形成过程与太阳的形成过程相似。在恒星周围的物质盘中，有非常多的分子，包括氰化合物、碳氢化合物和一氧化碳。2012年，美国宇航局的科学家报告说，多环芳烃在星际介质条件下，通过氢化、氧化和羟基化，转化为更复杂的有机物--"分别是向氨基酸和核苷酸（蛋白质和DNA的原料）道路上迈进的一步。 ""<ref name="Space-20120920">{{cite web |url= http://www.space.com/17681-life-building-blocks-nasa-organic-molecules.html |title= NASA Cooks Up Icy Organics to Mimic Life's Origins |date= 20 September 2012 |website= Space.com |location= Ogden, UT |publisher= Purch |accessdate= 2015-06-26 |url-status= live |archiveurl= https://web.archive.org/web/20150625035023/http://www.space.com/17681-life-building-blocks-nasa-organic-molecules.html |archivedate= 25 June 2015}}</ref><ref name="AJL-20120901">{{cite journal |last1=Gudipati |first1=Murthy S. |author2=Rui Yang |date=1 September 2012 |title=In-situ Probing of Radiation-induced Processing of Organics in Astrophysical Ice Analogs – Novel Laser Desorption Laser Ionization Time-of-flight Mass Spectroscopic Studies |journal=The Astrophysical Journal Letters |volume=756 |issue=1 |bibcode=2012ApJ...756L..24G |doi=10.1088/2041-8205/756/1/L24 |pages=L24}}</ref>此外，由于这些转化，多环芳烃失去了它们的光谱特征，这可能是 "星际冰粒，特别是寒冷的稠密云的外部区域或原行星盘的上层分子层中，缺乏检测到多环芳烃的原因之一。"<ref name="Space-20120920" /><ref name="AJL-20120901" />

====核酸碱基====

====核酸碱基====

观测结果表明，星际尘埃颗粒引入地球的大多数有机化合物被认为是形成复杂分子的主要媒介，这是因为它们具有特殊的表面催化活性。<ref name="Lincei">{{cite journal |last=Gallori |first=Enzo |title=Astrochemistry and the origin of genetic material |journal=Rendiconti Lincei |date=June 2011 |volume=22 |issue=2 |pages=113–118 |doi=10.1007/s12210-011-0118-4 |s2cid=96659714 }} "Paper presented at the Symposium 'Astrochemistry: molecules in space and time' (Rome, 4–5 November 2010), sponsored by Fondazione 'Guido Donegani', Accademia Nazionale dei Lincei."</ref><ref>{{cite journal |last=Martins |first=Zita |authorlink=Zita Martins |date=February 2011 |title=Organic Chemistry of Carbonaceous Meteorites |journal=[[Elements (journal)|Elements]] |volume=7 |issue=1 |pages=35–40 |doi=10.2113/gselements.7.1.35 }}</ref>2008年报告的研究基于在默奇森陨石中发现的有机化合物的¹²C/¹³C同位素比率，表明RNA成分尿嘧啶和相关分子，包括黄嘌呤，是在外星形成的。<ref name="Murch_base">{{cite journal |last1=Martins |first1=Zita |last2=Botta |first2=Oliver |last3=Fogel |first3=Marilyn L. |last4=Sephton |first4=Mark A. |last5=Glavin |first5=Daniel P. |last6=Watson |first6=Jonathan S. |last7=Dworkin |first7=Jason P. |last8=Schwartz |first8=Alan W. |last9=Ehrenfreund |first9=Pascale |display-authors=3 |date=15 June 2008 |title=Extraterrestrial nucleobases in the Murchison meteorite |journal=Earth and Planetary Science Letters |volume=270 |issue=1–2 |pages=130–136 |bibcode=2008E&PSL.270..130M |arxiv=0806.2286 |doi=10.1016/j.epsl.2008.03.026 |s2cid=14309508 }}</ref><ref>{{cite news |author=<!--Staff writer(s); no by-line.--> |date=14 June 2008 |title=We may all be space aliens: study |url=http://www.abc.net.au/news/2008-06-14/we-may-all-be-space-aliens-study/2471434 |location=Sydney |publisher=[[Australian Broadcasting Corporation]] |agency=[[Agence France-Presse]] |accessdate=2015-06-22 |url-status=live |archiveurl=https://web.archive.org/web/20150623073332/http://www.abc.net.au/news/2008-06-14/we-may-all-be-space-aliens-study/2471434 |archivedate=23 June 2015}}</ref> 2011年，发表了一份基于美国宇航局对在地球上发现的陨石的研究的报告，表明DNA成分（腺嘌呤、鸟嘌呤和相关有机分子）是在外太空制造的。 <ref name="Lincei" /><ref name="Callahan">{{cite journal |last1=Callahan |first1=Michael P. |last2=Smith |first2=Karen E. |last3=Cleaves |first3=H. James, II |last4=Ruzica |first4=Josef |last5=Stern |first5=Jennifer C. |last6=Glavin |first6=Daniel P. |last7=House |first7=Christopher H. |last8=Dworkin |first8=Jason P. |display-authors=3 |date=23 August 2011 |title=Carbonaceous meteorites contain a wide range of extraterrestrial nucleobases |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=108 |issue=34 |pages=13995–13998 |bibcode=2011PNAS..10813995C |doi=10.1073/pnas.1106493108 |pmc=3161613 |pmid=21836052}}</ref><ref name="Steigerwald">{{cite web |url=http://www.nasa.gov/topics/solarsystem/features/dna-meteorites.html |title=NASA Researchers: DNA Building Blocks Can Be Made in Space |last=Steigerwald |first=John |date=8 August 2011 |work=[[Goddard Space Flight Center]] |publisher=NASA |location=Greenbelt, MD |accessdate=2015-06-23 |url-status=live |archiveurl=https://web.archive.org/web/20150623004556/http://www.nasa.gov/topics/solarsystem/features/dna-meteorites.html |archivedate=23 June 2015}}</ref>科学家们还发现，弥漫在宇宙中的宇宙尘埃中含有复杂的有机物（"具有芳香族-脂肪族混合结构的无定形有机固体"），这些有机物可能是由恒星自然地、迅速地创造出来的。<ref name="Space-20111026">{{cite news |last= Chow |first= Denise |date= 26 October 2011 |title= Discovery: Cosmic Dust Contains Organic Matter from Stars |url= http://www.space.com/13401-cosmic-star-dust-complex-organic-compounds.html |website= Space.com |location= Ogden, UT |publisher= Purch |accessdate= 2015-06-23 |url-status= live |archiveurl= https://web.archive.org/web/20150714084901/http://www.space.com/13401-cosmic-star-dust-complex-organic-compounds.html |archivedate= 14 July 2015}}</ref><ref name="ScienceDaily-20111026">{{cite news |author=The University of Hong Kong |date=27 October 2011 |title=Astronomers discover complex organic matter exists throughout the universe |url=https://www.sciencedaily.com/releases/2011/10/111026143721.htm |location=Rockville, MD |publisher= ScienceDaily, LLC |url-status=live |archiveurl=https://web.archive.org/web/20150703185252/https://www.sciencedaily.com/releases/2011/10/111026143721.htm |archivedate=3 July 2015|author-link=University of Hong Kong }}</ref><ref name="Nature-20111026">{{cite journal |author1=Sun Kwok |authorlink1=Sun Kwok |author2=Yong Zhang |date=3 November 2011 |title=Mixed aromatic–aliphatic organic nanoparticles as carriers of unidentified infrared emission features |journal=Nature |volume=479 |issue=7371 |pages=80–83 |bibcode=2011Natur.479...80K |doi=10.1038/nature10542 |pmid=22031328|s2cid=4419859 }}</ref>香港大学的郭新 Sun Kwok提出，这些化合物可能与地球上生命的发展有关，他说："如果是这样的话，地球上的生命可能更容易开始，因为这些有机物可以作为生命的基本原料。"<ref name="Space-20111026" />

观测结果表明，星际尘埃颗粒引入地球的大多数有机化合物被认为是形成复杂分子的主要媒介，这是因为它们具有特殊的表面催化活性。<ref name="Lincei">{{cite journal |last=Gallori |first=Enzo |title=Astrochemistry and the origin of genetic material |journal=Rendiconti Lincei |date=June 2011 |volume=22 |issue=2 |pages=113–118 |doi=10.1007/s12210-011-0118-4 }} "Paper presented at the Symposium 'Astrochemistry: molecules in space and time' (Rome, 4–5 November 2010), sponsored by Fondazione 'Guido Donegani', Accademia Nazionale dei Lincei."</ref><ref>{{cite journal |last=Martins |first=Zita |date=February 2011 |title=Organic Chemistry of Carbonaceous Meteorites |journal=Elements|volume=7 |issue=1 |pages=35–40 |doi=10.2113/gselements.7.1.35 }}</ref>2008年报告的研究基于在默奇森陨石中发现的有机化合物的¹²C/¹³C同位素比率，表明RNA成分尿嘧啶和相关分子，包括黄嘌呤，是在外星形成的。<ref name="Murch_base">{{cite journal |last1=Martins |first1=Zita |last2=Botta |first2=Oliver |last3=Fogel |first3=Marilyn L. |last4=Sephton |first4=Mark A. |last5=Glavin |first5=Daniel P. |last6=Watson |first6=Jonathan S. |last7=Dworkin |first7=Jason P. |last8=Schwartz |first8=Alan W. |last9=Ehrenfreund |first9=Pascale |display-authors=3 |date=15 June 2008 |title=Extraterrestrial nucleobases in the Murchison meteorite |journal=Earth and Planetary Science Letters |volume=270 |issue=1–2 |pages=130–136 |bibcode=2008E&PSL.270..130M |arxiv=0806.2286 |doi=10.1016/j.epsl.2008.03.026 }}</ref><ref>{{cite news |author=<!--Staff writer(s); no by-line.--> |date=14 June 2008 |title=We may all be space aliens: study |url=http://www.abc.net.au/news/2008-06-14/we-may-all-be-space-aliens-study/2471434 |location=Sydney |publisher=Australian Broadcasting Corporation|agency=Agence France-Presse |accessdate=2015-06-22 |url-status=live |archiveurl=https://web.archive.org/web/20150623073332/http://www.abc.net.au/news/2008-06-14/we-may-all-be-space-aliens-study/2471434 |archivedate=23 June 2015}}</ref> 2011年，发表了一份基于美国宇航局对在地球上发现的陨石的研究的报告，表明DNA成分（腺嘌呤、鸟嘌呤和相关有机分子）是在外太空制造的。 <ref name="Lincei" /><ref name="Callahan">{{cite journal |last1=Callahan |first1=Michael P. |last2=Smith |first2=Karen E. |last3=Cleaves |first3=H. James, II |last4=Ruzica |first4=Josef |last5=Stern |first5=Jennifer C. |last6=Glavin |first6=Daniel P. |last7=House |first7=Christopher H. |last8=Dworkin |first8=Jason P. |display-authors=3 |date=23 August 2011 |title=Carbonaceous meteorites contain a wide range of extraterrestrial nucleobases |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=108 |issue=34 |pages=13995–13998 |bibcode=2011PNAS..10813995C |doi=10.1073/pnas.1106493108 |pmc=3161613 |pmid=21836052}}</ref><ref name="Steigerwald">{{cite web |url=http://www.nasa.gov/topics/solarsystem/features/dna-meteorites.html |title=NASA Researchers: DNA Building Blocks Can Be Made in Space |last=Steigerwald |first=John |date=8 August 2011 |work=Goddard Space Flight Center|publisher=NASA |location=Greenbelt, MD |accessdate=2015-06-23 |url-status=live |archiveurl=https://web.archive.org/web/20150623004556/http://www.nasa.gov/topics/solarsystem/features/dna-meteorites.html |archivedate=23 June 2015}}</ref>科学家们还发现，弥漫在宇宙中的宇宙尘埃中含有复杂的有机物（"具有芳香族-脂肪族混合结构的无定形有机固体"），这些有机物可能是由恒星自然地、迅速地创造出来的。<ref name="Space-20111026">{{cite news |last= Chow |first= Denise |date= 26 October 2011 |title= Discovery: Cosmic Dust Contains Organic Matter from Stars |url= http://www.space.com/13401-cosmic-star-dust-complex-organic-compounds.html |website= Space.com |location= Ogden, UT |publisher= Purch |accessdate= 2015-06-23 |url-status= live |archiveurl= https://web.archive.org/web/20150714084901/http://www.space.com/13401-cosmic-star-dust-complex-organic-compounds.html |archivedate= 14 July 2015}}</ref><ref name="ScienceDaily-20111026">{{cite news |author=The University of Hong Kong |date=27 October 2011 |title=Astronomers discover complex organic matter exists throughout the universe |url=https://www.sciencedaily.com/releases/2011/10/111026143721.htm |location=Rockville, MD |publisher= ScienceDaily, LLC |url-status=live |archiveurl=https://web.archive.org/web/20150703185252/https://www.sciencedaily.com/releases/2011/10/111026143721.htm |archivedate=3 July 2015| }}</ref><ref name="Nature-20111026">{{cite journal |author1=Sun Kwok |author2=Yong Zhang |date=3 November 2011 |title=Mixed aromatic–aliphatic organic nanoparticles as carriers of unidentified infrared emission features |journal=Nature |volume=479 |issue=7371 |pages=80–83 |bibcode=2011Natur.479...80K |doi=10.1038/nature10542 |pmid=22031328}}</ref>香港大学的郭新 Sun Kwok提出，这些化合物可能与地球上生命的发展有关，他说："如果是这样的话，地球上的生命可能更容易开始，因为这些有机物可以作为生命的基本原料。"<ref name="Space-20111026" />

====糖-羟乙醛====

====糖-羟乙醛====

[[File:Formation of Glycolaldehyde in star dust.png|thumb|在星尘中羟乙醇醛的形成]]

[[File:Formation of Glycolaldehyde in star dust.png|thumb|在星尘中羟乙醇醛的形成]]

羟乙醛是星际糖分子的第一个例子，在银河系中心附近的恒星形成区被发现。它是由詹斯·约根森 Jes Jørgensen和简·霍利斯 Jan Hollis在2000年发现的。<ref name=Hollis>{{cite web |url=http://www.nasa.gov/vision/universe/starsgalaxies/interstellar_sugar.html |title=Space Sugar's a Sweet Find |first1=Lara |last1=Clemence |last2=Cohen |first2=Jarrett |date=7 February 2005 |work=Goddard Space Flight Center |publisher=NASA |location=Greenbelt, MD |accessdate=2015-06-23 |url-status=live |archiveurl=https://web.archive.org/web/20160305002758/http://www.nasa.gov/vision/universe/starsgalaxies/interstellar_sugar.html |archivedate=5 March 2016}}</ref>2012年，Jørgensen的团队报告了在一个遥远的恒星系统中发现羟乙醛。该分子是在距离地球400光年的原恒星双星IRAS 16293-2422周围发现的。<ref name="NG-20120829">{{cite news |last=Than |first=Ker |date=30 August 2012 |title=Sugar Found in Space: A Sign of Life? |url=http://news.nationalgeographic.com/news/2012/08/120829-sugar-space-planets-science-life/ |work=National Geographic News |location=Washington, D.C. |publisher=[[National Geographic Society]] |accessdate=2015-06-23 |url-status=live |archiveurl=https://web.archive.org/web/20150714073830/http://news.nationalgeographic.com/news/2012/08/120829-sugar-space-planets-science-life/ |archivedate=14 July 2015}}</ref><ref name="AP-20120829">{{cite news |author=<!--Staff writer(s); no by-line.--> |date=29 August 2012 |title=Sweet! Astronomers spot sugar molecule near star |url=http://apnews.excite.com/article/20120829/DA0V31D80.html |work=[[Excite]] |location=Yonkers, NY |publisher=[[Mindspark Interactive Network]] |agency=[[Associated Press]] |accessdate=2015-06-23 |url-status=live |archiveurl=https://web.archive.org/web/20150714101929/http://apnews.excite.com/article/20120829/DA0V31D80.html |archivedate=14 July 2015}}</ref><ref>{{cite web |url=http://www.news.leiden.edu/news-2012/building-blocks-for-life-found-on-young-star.html |title=Building blocks of life found around young star |author=<!--Staff writer(s); no by-line.--> |date=30 September 2012 |website=News & Events |publisher=[[Leiden University]] |location=Leiden, the Netherlands |accessdate=2013-12-11 |url-status=live |archiveurl=https://web.archive.org/web/20131213135815/http://www.news.leiden.edu/news-2012/building-blocks-for-life-found-on-young-star.html |archivedate=13 December 2013}}</ref>羟乙醛是形成RNA所需要的，RNA的功能与DNA相似。这些发现表明，复杂的有机分子可能在行星形成之前就在恒星系统中形成，最终在行星形成的早期到达年轻行星上。<ref>{{cite journal |last1=Jørgensen |first1=Jes K. |last2=Favre |first2=Cécile |last3=Bisschop |first3=Suzanne E. |last4=Bourke |first4=Tyler L. |last5=van Dishoeck |first5=Ewine F. |authorlink5=Ewine van Dishoeck |last6=Schmalzl |first6=Markus |display-authors=3 |date=2012 |title=Detection of the simplest sugar, glycolaldehyde, in a solar-type protostar with ALMA |url=http://www.eso.org/public/archives/releases/sciencepapers/eso1234/eso1234a.pdf |journal=The Astrophysical Journal Letters |volume=757 |issue=1 |arxiv=1208.5498 |bibcode=2012ApJ...757L...4J |doi=10.1088/2041-8205/757/1/L4 |accessdate=2015-06-23 |pages=L4 |s2cid=14205612 |url-status=live |archiveurl=https://web.archive.org/web/20150924021240/http://www.eso.org/public/archives/releases/sciencepapers/eso1234/eso1234a.pdf |archivedate=24 September 2015}}</ref><ref name="PNAS-20191113">{{Cite journal|last1=Furukawa|first1=Yoshihiro|last2=Chikaraishi|first2=Yoshito|last3=Ohkouchi|first3=Naohiko|last4=Ogawa|first4=Nanako O.|last5=Glavin|first5=Daniel P.|last6=Dworkin|first6=Jason P.|last7=Abe|first7=Chiaki|last8=Nakamura|first8=Tomoki|date=2019-11-13|title=Extraterrestrial ribose and other sugars in primitive meteorites|journal=Proceedings of the National Academy of Sciences|volume=116|issue=49|pages=24440–24445|language=en|doi=10.1073/pnas.1907169116|issn=0027-8424|pmid=31740594|pmc=6900709|bibcode=2019PNAS..11624440F}}</ref>由于糖类与新陈代谢和遗传密码这两个生命最基本的方面有关，因此认为发现地外糖类增加了银河系其他地方可能存在生命的可能性。<ref name="Hollis" />

羟乙醛是星际糖分子的第一个例子，在银河系中心附近的恒星形成区被发现。它是由詹斯·约根森 Jes Jørgensen和简·霍利斯 Jan Hollis在2000年发现的。<ref name=Hollis>{{cite web |url=http://www.nasa.gov/vision/universe/starsgalaxies/interstellar_sugar.html |title=Space Sugar's a Sweet Find |first1=Lara |last1=Clemence |last2=Cohen |first2=Jarrett |date=7 February 2005 |work=Goddard Space Flight Center |publisher=NASA |location=Greenbelt, MD |accessdate=2015-06-23 |url-status=live |archiveurl=https://web.archive.org/web/20160305002758/http://www.nasa.gov/vision/universe/starsgalaxies/interstellar_sugar.html |archivedate=5 March 2016}}</ref>2012年，Jørgensen的团队报告了在一个遥远的恒星系统中发现羟乙醛。该分子是在距离地球400光年的原恒星双星IRAS 16293-2422周围发现的。<ref name="NG-20120829">{{cite news |last=Than |first=Ker |date=30 August 2012 |title=Sugar Found in Space: A Sign of Life? |url=http://news.nationalgeographic.com/news/2012/08/120829-sugar-space-planets-science-life/ |work=National Geographic News |location=Washington, D.C. |publisher=National Geographic Society|accessdate=2015-06-23 |url-status=live |archiveurl=https://web.archive.org/web/20150714073830/http://news.nationalgeographic.com/news/2012/08/120829-sugar-space-planets-science-life/ |archivedate=14 July 2015}}</ref><ref name="AP-20120829">{{cite news |author=<!--Staff writer(s); no by-line.--> |date=29 August 2012 |title=Sweet! Astronomers spot sugar molecule near star |url=http://apnews.excite.com/article/20120829/DA0V31D80.html |work=Excite |location=Yonkers, NY |publisher=Mindspark Interactive Network |agency=Associated Press |accessdate=2015-06-23 |url-status=live |archiveurl=https://web.archive.org/web/20150714101929/http://apnews.excite.com/article/20120829/DA0V31D80.html |archivedate=14 July 2015}}</ref><ref>{{cite web |url=http://www.news.leiden.edu/news-2012/building-blocks-for-life-found-on-young-star.html |title=Building blocks of life found around young star |author=<!--Staff writer(s); no by-line.--> |date=30 September 2012 |website=News & Events |publisher=Leiden University|location=Leiden, the Netherlands |accessdate=2013-12-11 |url-status=live |archiveurl=https://web.archive.org/web/20131213135815/http://www.news.leiden.edu/news-2012/building-blocks-for-life-found-on-young-star.html |archivedate=13 December 2013}}</ref>羟乙醛是形成RNA所需要的，RNA的功能与DNA相似。这些发现表明，复杂的有机分子可能在行星形成之前就在恒星系统中形成，最终在行星形成的早期到达年轻行星上。<ref>{{cite journal |last1=Jørgensen |first1=Jes K. |last2=Favre |first2=Cécile |last3=Bisschop |first3=Suzanne E. |last4=Bourke |first4=Tyler L. |last5=van Dishoeck |first5=Ewine F. |last6=Schmalzl |first6=Markus |display-authors=3 |date=2012 |title=Detection of the simplest sugar, glycolaldehyde, in a solar-type protostar with ALMA |url=http://www.eso.org/public/archives/releases/sciencepapers/eso1234/eso1234a.pdf |journal=The Astrophysical Journal Letters |volume=757 |issue=1 |arxiv=1208.5498 |bibcode=2012ApJ...757L...4J |doi=10.1088/2041-8205/757/1/L4 |accessdate=2015-06-23 |pages=L4 |url-status=live |archiveurl=https://web.archive.org/web/20150924021240/http://www.eso.org/public/archives/releases/sciencepapers/eso1234/eso1234a.pdf |archivedate=24 September 2015}}</ref><ref name="PNAS-20191113">{{Cite journal|last1=Furukawa|first1=Yoshihiro|last2=Chikaraishi|first2=Yoshito|last3=Ohkouchi|first3=Naohiko|last4=Ogawa|first4=Nanako O.|last5=Glavin|first5=Daniel P.|last6=Dworkin|first6=Jason P.|last7=Abe|first7=Chiaki|last8=Nakamura|first8=Tomoki|date=2019-11-13|title=Extraterrestrial ribose and other sugars in primitive meteorites|journal=Proceedings of the National Academy of Sciences|volume=116|issue=49|pages=24440–24445|language=en|doi=10.1073/pnas.1907169116|issn=0027-8424|pmid=31740594|pmc=6900709|bibcode=2019PNAS..11624440F}}</ref>由于糖类与新陈代谢和遗传密码这两个生命最基本的方面有关，因此认为发现地外糖类增加了银河系其他地方可能存在生命的可能性。<ref name="Hollis" />

====多聚磷酸盐 ====

====多聚磷酸盐 ====

在大多数非生物发生的情况下，一个问题是氨基酸与肽的热力学平衡是向着分离氨基酸的方向发展的。一直以来，缺少的是某种推动聚合的力量。这个问题的解决很可能在于多聚磷酸盐的特性<ref>{{cite journal |last1=Brown |first1=Michael R. W. |last2=Kornberg |first2=Arthur |authorlink2=Arthur Kornberg |date=16 November 2004 |title=Inorganic polyphosphate in the origin and survival of species |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=101 |issue=46 |pages=16085–16087 |bibcode=2004PNAS..10116085B |doi=10.1073/pnas.0406909101|pmc=528972 |pmid=15520374}}</ref><ref>{{cite web |url=http://www.science.siu.edu/microbiology/micr425/425Notes/14-OriginLife.html |title=The Origin of Life |last=Clark |first=David P. |date=3 August 1999 |website=Microbiology 425: Biochemistry and Physiology of Microorganism |publisher=College of Science; [[Southern Illinois University Carbondale]] |location=Carbondale, IL |type=Lecture |archiveurl=https://web.archive.org/web/20001002142750/http://www.science.siu.edu/microbiology/micr425/425Notes/14-OriginLife.html |archivedate=2000-10-02 |url-status=dead |accessdate=2015-06-26}}</ref> 。聚磷酸盐是由普通的单磷酸离子PO₄^3-聚合而成。目前已经研究了几种有机分子合成的机制。多聚磷酸盐能使氨基酸聚合成肽。它们也是合成三磷酸腺苷(ATP)等关键生化化合物的逻辑前体。一个关键的问题似乎是，钙与可溶性磷酸盐反应形成不溶性的磷酸钙（磷灰石），所以必须找到一些似合理的机制来防止钙离子引起磷酸盐的沉淀。多年来，关于这个主题的工作很多，但一个有趣的新想法是，陨石可能在早期地球上引入了活性磷物种。<ref>{{cite journal |last=Pasek |first=Matthew A. |date=22 January 2008 |title=Rethinking early Earth phosphorus geochemistry |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=105 |issue=3 |pages=853–858 |bibcode=2008PNAS..105..853P |doi=10.1073/pnas.0708205105 |pmc=2242691 |pmid=18195373}}</ref>根据最近的计算机模型研究，在地球形成之前，生命所必需的复杂有机分子可能已经在太阳周围的尘粒的原行星盘中形成了。<ref name="Space-20120329">{{cite news |last=Moskowitz |first=Clara |date=29 March 2012 |title=Life's Building Blocks May Have Formed in Dust Around Young Sun |url=http://www.space.com/15089-life-building-blocks-young-sun-dust.html |website=[[Space.com]] |location=Salt Lake City, UT |publisher=[[Purch]] |accessdate=2012-03-30 |url-status=live |archiveurl=https://web.archive.org/web/20120814205056/http://www.space.com/15089-life-building-blocks-young-sun-dust.html |archivedate=14 August 2012}}</ref><ref>{{cite journal|last1=Ciesla|first1=F.J.|last2=Sandford|first2=S.A.|title=Organic Synthesis via Irradiation and Warming of Ice Grains in the Solar Nebula|journal=Science|date=29 March 2012|volume=336|issue=6080|pages=452–454|doi=10.1126/science.1217291|pmid=22461502|bibcode=2012Sci...336..452C|hdl=2060/20120011864|s2cid=25454671|hdl-access=free}}</ref> 根据计算机研究，这个相同的过程也可能发生在其他获得行星的恒星周围。

在大多数非生物发生的情况下，一个问题是氨基酸与肽的热力学平衡是向着分离氨基酸的方向发展的。一直以来，缺少的是某种推动聚合的力量。这个问题的解决很可能在于多聚磷酸盐的特性<ref>{{cite journal |last1=Brown |first1=Michael R. W. |last2=Kornberg |first2=Arthur |date=16 November 2004 |title=Inorganic polyphosphate in the origin and survival of species |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=101 |issue=46 |pages=16085–16087 |bibcode=2004PNAS..10116085B |doi=10.1073/pnas.0406909101|pmc=528972 |pmid=15520374}}</ref><ref>{{cite web |url=http://www.science.siu.edu/microbiology/micr425/425Notes/14-OriginLife.html |title=The Origin of Life |last=Clark |first=David P. |date=3 August 1999 |website=Microbiology 425: Biochemistry and Physiology of Microorganism |publisher=College of Science; Southern Illinois University Carbondale|location=Carbondale, IL |type=Lecture |archiveurl=https://web.archive.org/web/20001002142750/http://www.science.siu.edu/microbiology/micr425/425Notes/14-OriginLife.html |archivedate=2000-10-02 |url-status=dead |accessdate=2015-06-26}}</ref> 。聚磷酸盐是由普通的单磷酸离子PO₄^3-聚合而成。目前已经研究了几种有机分子合成的机制。多聚磷酸盐能使氨基酸聚合成肽。它们也是合成三磷酸腺苷(ATP)等关键生化化合物的逻辑前体。一个关键的问题似乎是，钙与可溶性磷酸盐反应形成不溶性的磷酸钙（磷灰石），所以必须找到一些似合理的机制来防止钙离子引起磷酸盐的沉淀。多年来，关于这个主题的工作很多，但一个有趣的新想法是，陨石可能在早期地球上引入了活性磷物种。<ref>{{cite journal |last=Pasek |first=Matthew A. |date=22 January 2008 |title=Rethinking early Earth phosphorus geochemistry |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=105 |issue=3 |pages=853–858 |bibcode=2008PNAS..105..853P |doi=10.1073/pnas.0708205105 |pmc=2242691 |pmid=18195373}}</ref>根据最近的计算机模型研究，在地球形成之前，生命所必需的复杂有机分子可能已经在太阳周围的尘粒的原行星盘中形成了。<ref name="Space-20120329">{{cite news |last=Moskowitz |first=Clara |date=29 March 2012 |title=Life's Building Blocks May Have Formed in Dust Around Young Sun |url=http://www.space.com/15089-life-building-blocks-young-sun-dust.html |website=Space.com |location=Salt Lake City, UT |publisher=Purch|accessdate=2012-03-30 |url-status=live |archiveurl=https://web.archive.org/web/20120814205056/http://www.space.com/15089-life-building-blocks-young-sun-dust.html |archivedate=14 August 2012}}</ref><ref>{{cite journal|last1=Ciesla|first1=F.J.|last2=Sandford|first2=S.A.|title=Organic Synthesis via Irradiation and Warming of Ice Grains in the Solar Nebula|journal=Science|date=29 March 2012|volume=336|issue=6080|pages=452–454|doi=10.1126/science.1217291|pmid=22461502|bibcode=2012Sci...336..452C|hdl=2060/20120011864|hdl-access=free}}</ref> 根据计算机研究，这个相同的过程也可能发生在其他获得行星的恒星周围。

2019年，科学家报告首次在陨石中检测到包括核糖在内的糖分子，表明小行星上的化学过程可以产生一些对生命很重要的基本生物原料，并支持地球上以DNA为基础的生命起源之前的RNA世界的概念，也可能支持泛种论的概念。<ref name="NASA-20191118">{{cite news |last1=Steigerwald |first1=Bill |last2=Jones |first2=Nancy |last3=Furukawa |first3=Yoshihiro |title=First Detection of Sugars in Meteorites Gives Clues to Origin of Life |url=https://www.nasa.gov/press-release/goddard/2019/sugars-in-meteorites |date=18 November 2019 |work=[[NASA]] |accessdate=18 November 2019 }}</ref><ref name="PNAS-20191113" />

2019年，科学家报告首次在陨石中检测到包括核糖在内的糖分子，表明小行星上的化学过程可以产生一些对生命很重要的基本生物原料，并支持地球上以DNA为基础的生命起源之前的RNA世界的概念，也可能支持泛种论的概念。<ref name="NASA-20191118">{{cite news |last1=Steigerwald |first1=Bill |last2=Jones |first2=Nancy |last3=Furukawa |first3=Yoshihiro |title=First Detection of Sugars in Meteorites Gives Clues to Origin of Life |url=https://www.nasa.gov/press-release/goddard/2019/sugars-in-meteorites |date=18 November 2019 |work=NASA |accessdate=18 November 2019 }}</ref><ref name="PNAS-20191113" />

***讨论：我觉得一方面我们要探寻生命起源前化学反应产生生命所需基本原料的可能，另一方面我们还需要知道这些反应发生的几率和量***

***讨论：我觉得一方面我们要探寻生命起源前化学反应产生生命所需基本原料的可能，另一方面我们还需要知道这些反应发生的几率和量***

甲酰胺在各种陆地矿物质存在下升温时，可产生所有四种核糖核苷酸和其他生物分子。甲酰胺在宇宙中无处不在，由水和氰化氢（HCN）反应生成。作为一种生物的前体，它有几个优点，包括通过水的蒸发而容易浓缩的能力。<ref name="Saladino2012">{{cite journal |last1=Saladino |first1=Raffaele |last2=Crestini |first2=Claudia |last3=Pino |first3=Samanta |last4=Costanzo |first4=Giovanna |last5=Di Mauro |first5=Ernesto |display-authors=3 |date=March 2012 |title=Formamide and the origin of life. |journal=[[Physics of Life Reviews]] |volume=9 |issue=1 |pages=84–104 |bibcode=2012PhLRv...9...84S |doi=10.1016/j.plrev.2011.12.002 |pmid=22196896|hdl=2108/85168 |url=https://art.torvergata.it/bitstream/2108/85168/1/PoLRev%202012.pdf }}</ref><ref name="Saladino2012b">{{cite journal |last1=Saladino |first1=Raffaele |last2=Botta |first2=Giorgia |last3=Pino |first3=Samanta |last4=Costanzo |first4=Giovanna |last5=Di Mauro |first5=Ernesto |display-authors=3 |date=July 2012 |title=From the one-carbon amide formamide to RNA all the steps are prebiotically possible |journal=[[Biochimie]] |volume=94 |issue=7 |pages=1451–1456 |doi=10.1016/j.biochi.2012.02.018 |pmid=22738728}}</ref>虽然HCN是有毒的，但它只影响需氧生物（真核生物和需氧细菌），它们当时还不存在。它也可以在其他化学过程中发挥作用，比如氨基酸甘氨酸的合成。<ref name="Follmann2009" />

甲酰胺在各种陆地矿物质存在下升温时，可产生所有四种核糖核苷酸和其他生物分子。甲酰胺在宇宙中无处不在，由水和氰化氢（HCN）反应生成。作为一种生物的前体，它有几个优点，包括通过水的蒸发而容易浓缩的能力。<ref name="Saladino2012">{{cite journal |last1=Saladino |first1=Raffaele |last2=Crestini |first2=Claudia |last3=Pino |first3=Samanta |last4=Costanzo |first4=Giovanna |last5=Di Mauro |first5=Ernesto |display-authors=3 |date=March 2012 |title=Formamide and the origin of life. |journal=Physics of Life Reviews|volume=9 |issue=1 |pages=84–104 |bibcode=2012PhLRv...9...84S |doi=10.1016/j.plrev.2011.12.002 |pmid=22196896|hdl=2108/85168 |url=https://art.torvergata.it/bitstream/2108/85168/1/PoLRev%202012.pdf }}</ref><ref name="Saladino2012b">{{cite journal |last1=Saladino |first1=Raffaele |last2=Botta |first2=Giorgia |last3=Pino |first3=Samanta |last4=Costanzo |first4=Giovanna |last5=Di Mauro |first5=Ernesto |display-authors=3 |date=July 2012 |title=From the one-carbon amide formamide to RNA all the steps are prebiotically possible |journal=Biochimie |volume=94 |issue=7 |pages=1451–1456 |doi=10.1016/j.biochi.2012.02.018 |pmid=22738728}}</ref>虽然HCN是有毒的，但它只影响需氧生物（真核生物和需氧细菌），它们当时还不存在。它也可以在其他化学过程中发挥作用，比如氨基酸甘氨酸的合成。<ref name="Follmann2009" />

====使用高温====

====使用高温====

1961年，研究表明核酸嘌呤碱基腺嘌呤可以通过加热氰化铵水溶液形成。<ref>{{cite journal |last=Oró |first=Joan |authorlink=Joan Oró |date=16 September 1961 |title=Mechanism of Synthesis of Adenine from Hydrogen Cyanide under Possible Primitive Earth Conditions |journal=Nature |volume=191 |issue=4794 |pages=1193–1194 |bibcode=1961Natur.191.1193O |doi=10.1038/1911193a0 |pmid=13731264|s2cid=4276712 }}</ref>

1961年，研究表明核酸嘌呤碱基腺嘌呤可以通过加热氰化铵水溶液形成。<ref>{{cite journal |last=Oró |first=Joan |date=16 September 1961 |title=Mechanism of Synthesis of Adenine from Hydrogen Cyanide under Possible Primitive Earth Conditions |journal=Nature |volume=191 |issue=4794 |pages=1193–1194 |bibcode=1961Natur.191.1193O |doi=10.1038/1911193a0 |pmid=13731264}}</ref>

====使用低（极冷的）温====

====使用低（极冷的）温====

还有人报道了从无机材料合成碱基的其他途径。<ref name="Basile1984">{{cite journal |last1=Basile |first1=Brenda |last2=Lazcano |first2=Antonio |authorlink2=Antonio Lazcano |last3=Oró |first3=Joan |year=1984 |title=Prebiotic syntheses of purines and pyrimidines |journal=[[Advances in Space Research]] |volume=4 |issue=12 |pages=125–131 |bibcode=1984AdSpR...4..125B |doi=10.1016/0273-1177(84)90554-4 |pmid=11537766}}</ref>Orgel及其同事的研究表明，由于氰化氢等关键前体的浓缩作用，冷冻温度对嘌呤的合成是有利的。<ref>{{cite journal |last=Orgel |first=Leslie E. |date=August 2004 |title=Prebiotic Adenine Revisited: Eutectics and Photochemistry |journal=Origins of Life and Evolution of Biospheres |volume=34 |issue=4 |pages=361–369 |bibcode=2004OLEB...34..361O |doi=10.1023/B:ORIG.0000029882.52156.c2 |pmid=15279171|s2cid=4998122 }}</ref>Miller及其同事的研究表明，腺嘌呤和鸟嘌呤的合成需要冷冻条件，而胞嘧啶和尿嘧啶可能需要沸腾的温度。<ref>{{cite journal |last1=Robertson |first1=Michael P. |last2=Miller |first2=Stanley L. |date=29 June 1995 |title=An efficient prebiotic synthesis of cytosine and uracil |journal=Nature |volume=375 |issue=6534 |pages=772–774 |bibcode=1995Natur.375..772R |doi=10.1038/375772a0 |pmid=7596408|s2cid=4351012 }}</ref>Miller课题组的研究指出，从1972年到1997年，当氨和氰化物被放置在冰柜中时，在冰中形成了7种不同的氨基酸和11种核酸碱基。<ref>{{cite journal |last=Fox |first=Douglas |date=February 2008 |url=http://discovermagazine.com/2008/feb/did-life-evolve-in-ice |title=Did Life Evolve in Ice? |journal=[[Discover (magazine)|Discover]] |accessdate=2008-07-03 |url-status=live |archiveurl=https://web.archive.org/web/20080630043228/http://discovermagazine.com/2008/feb/did-life-evolve-in-ice |archivedate=30 June 2008}}</ref><ref>{{cite journal |last1=Levy |first1=Matthew |last2=Miller |first2=Stanley L. |last3=Brinton |first3=Karen |last4=Bada |first4=Jeffrey L. |authorlink4=Jeffrey L. Bada |date=June 2000 |title=Prebiotic Synthesis of Adenine and Amino Acids Under Europa-like Conditions |journal=[[Icarus (journal)|Icarus]] |volume=145 |issue=2 |pages=609–613 |bibcode=2000Icar..145..609L |doi=10.1006/icar.2000.6365 |pmid=11543508}}</ref>其他研究证明了s-三嗪(替代核酸碱基)、嘧啶(包括胞嘧啶和尿嘧啶)和腺嘌呤从尿素溶液在还原性气氛下(以火花放电为能量来源)经过冻融循环形成。<ref>{{cite journal |last1=Menor-Salván |first1=César |last2=Ruiz-Bermejo |first2=Marta |last3=Guzmán |first3=Marcelo I. |last4=Osuna-Esteban |first4=Susana |last5=Veintemillas-Verdaguer |first5=Sabino |date=20 April 2009 |title=Synthesis of Pyrimidines and Triazines in Ice: Implications for the Prebiotic Chemistry of Nucleobases |journal=[[Chemistry: A European Journal]] |volume=15 |issue=17 |pages=4411–4418 |doi=10.1002/chem.200802656 |pmid=19288488}}</ref>对于这些反应在如此低的温度下的异常速度，给出的解释是共晶凝固。当冰晶形成时，它保持纯净：只有水分子加入生长的晶体，而盐或氰化物等杂质被排除在外。这些杂质在冰内变得拥挤在微观的液体口袋中，这种拥挤导致分子更频繁地碰撞。利用量子化学方法进行机理探索，可以更详细地了解化学演化中的一些化学过程，并对分子生物发生的基本问题做出部分回答。<ref>{{cite journal |last1=Roy |first1=Debjani |last2=Najafian |first2=Katayoun |last3=von Ragué Schleyer |first3=Paul |authorlink3=Paul von Ragué Schleyer |date=30 October 2007 |title=Chemical evolution: The mechanism of the formation of adenine under prebiotic conditions |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=104 |issue=44 |pages=17272–17277 |bibcode=2007PNAS..10417272R |doi=10.1073/pnas.0708434104|pmc=2077245 |pmid=17951429}}</ref>

还有人报道了从无机材料合成碱基的其他途径。<ref name="Basile1984">{{cite journal |last1=Basile |first1=Brenda |last2=Lazcano |first2=Antonio |last3=Oró |first3=Joan |year=1984 |title=Prebiotic syntheses of purines and pyrimidines |journal=Advances in Space Research|volume=4 |issue=12 |pages=125–131 |bibcode=1984AdSpR...4..125B |doi=10.1016/0273-1177(84)90554-4 |pmid=11537766}}</ref>Orgel及其同事的研究表明，由于氰化氢等关键前体的浓缩作用，冷冻温度对嘌呤的合成是有利的。<ref>{{cite journal |last=Orgel |first=Leslie E. |date=August 2004 |title=Prebiotic Adenine Revisited: Eutectics and Photochemistry |journal=Origins of Life and Evolution of Biospheres |volume=34 |issue=4 |pages=361–369 |bibcode=2004OLEB...34..361O |doi=10.1023/B:ORIG.0000029882.52156.c2 |pmid=15279171}}</ref>Miller及其同事的研究表明，腺嘌呤和鸟嘌呤的合成需要冷冻条件，而胞嘧啶和尿嘧啶可能需要沸腾的温度。<ref>{{cite journal |last1=Robertson |first1=Michael P. |last2=Miller |first2=Stanley L. |date=29 June 1995 |title=An efficient prebiotic synthesis of cytosine and uracil |journal=Nature |volume=375 |issue=6534 |pages=772–774 |bibcode=1995Natur.375..772R |doi=10.1038/375772a0 |pmid=7596408}}</ref>Miller课题组的研究指出，从1972年到1997年，当氨和氰化物被放置在冰柜中时，在冰中形成了7种不同的氨基酸和11种核酸碱基。<ref>{{cite journal |last=Fox |first=Douglas |date=February 2008 |url=http://discovermagazine.com/2008/feb/did-life-evolve-in-ice |title=Did Life Evolve in Ice? |journal=Discover|accessdate=2008-07-03 |url-status=live |archiveurl=https://web.archive.org/web/20080630043228/http://discovermagazine.com/2008/feb/did-life-evolve-in-ice |archivedate=30 June 2008}}</ref><ref>{{cite journal |last1=Levy |first1=Matthew |last2=Miller |first2=Stanley L. |last3=Brinton |first3=Karen |last4=Bada |first4=Jeffrey L. |date=June 2000 |title=Prebiotic Synthesis of Adenine and Amino Acids Under Europa-like Conditions |journal=Icarus |volume=145 |issue=2 |pages=609–613 |bibcode=2000Icar..145..609L |doi=10.1006/icar.2000.6365 |pmid=11543508}}</ref>其他研究证明了s-三嗪(替代核酸碱基)、嘧啶(包括胞嘧啶和尿嘧啶)和腺嘌呤从尿素溶液在还原性气氛下(以火花放电为能量来源)经过冻融循环形成。<ref>{{cite journal |last1=Menor-Salván |first1=César |last2=Ruiz-Bermejo |first2=Marta |last3=Guzmán |first3=Marcelo I. |last4=Osuna-Esteban |first4=Susana |last5=Veintemillas-Verdaguer |first5=Sabino |date=20 April 2009 |title=Synthesis of Pyrimidines and Triazines in Ice: Implications for the Prebiotic Chemistry of Nucleobases |journal=Chemistry: A European Journal|volume=15 |issue=17 |pages=4411–4418 |doi=10.1002/chem.200802656 |pmid=19288488}}</ref>对于这些反应在如此低的温度下的异常速度，给出的解释是共晶凝固。当冰晶形成时，它保持纯净：只有水分子加入生长的晶体，而盐或氰化物等杂质被排除在外。这些杂质在冰内变得拥挤在微观的液体口袋中，这种拥挤导致分子更频繁地碰撞。利用量子化学方法进行机理探索，可以更详细地了解化学演化中的一些化学过程，并对分子生物发生的基本问题做出部分回答。<ref>{{cite journal |last1=Roy |first1=Debjani |last2=Najafian |first2=Katayoun |last3=von Ragué Schleyer |first3=Paul |date=30 October 2007 |title=Chemical evolution: The mechanism of the formation of adenine under prebiotic conditions |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=104 |issue=44 |pages=17272–17277 |bibcode=2007PNAS..10417272R |doi=10.1073/pnas.0708434104|pmc=2077245 |pmid=17951429}}</ref>

====在Miller-Urey实验中使用还原性较低的气体t====

====在Miller-Urey实验中使用还原性较低的气体t====

 

在Miller-Urey实验时，科学界的共识是，早期地球有一个还原性大气层，其化合物中氢气相对丰富，而氧气相对贫乏（如CH₄和NH₃，而不是CO₂ 和二氧化氮（NO₂））。然而，目前的科学共识将原始大气层描述为弱还原性或中性<ref name="Cleaves 2008">{{cite journal |last1=Cleaves |first1=H. James |last2=Chalmers |first2=John H. |last3=Lazcano |first3=Antonio |last4=Miller |first4=Stanley L. |last5=Bada |first5=Jeffrey L. |display-authors=3 |date=April 2008 |title=A Reassessment of Prebiotic Organic Synthesis in Neutral Planetary Atmospheres |journal=Origins of Life and Evolution of Biospheres |volume=38 |issue=2 |pages=105–115 |bibcode=2008OLEB...38..105C |doi=10.1007/s11084-007-9120-3|pmid=18204914}}</ref><ref name="Chyba 2005">{{cite journal |last=Chyba |first=Christopher F. |date=13 May 2005 |title=Rethinking Earth's Early Atmosphere |journal=Science |volume=308 |issue=5724 |pages=962–963 |doi=10.1126/science.1113157 |pmid=15890865}}</ref> （另见氧气灾难）。这样的大气会减少可以产生的氨基酸的数量和种类，尽管在实验条件中加入铁和碳酸盐矿物（被认为存在于早期海洋中）的研究又产生了多种氨基酸。其他科学研究集中在另外两种潜在的还原性环境：外太空和深海热喷口。<ref name="Cleaves 2008" /> Other scientific research has focused on two other potential reducing environments: outer space and deep-sea thermal vents.<ref>{{harvnb|Barton|Briggs|Eisen|Goldstein|2007|pp=93–95}}</ref><ref>{{harvnb|Bada|Lazcano|2009|pp=56–57}}</ref><ref name="Bada 2003">{{cite journal |last1=Bada |first1=Jeffrey L. |last2=Lazcano |first2=Antonio |date=2 May 2003 |url=http://astrobiology.berkeley.edu/PDFs_articles/Bada_Science2003.pdf |title=Prebiotic Soup – Revisiting the Miller Experiment |journal=Science |volume=300 |issue=5620 |pages=745–746 |doi=10.1126/science.1085145  |pmid=12730584 |accessdate=2015-06-13 |url-status=live |archiveurl=https://web.archive.org/web/20160304222002/http://astrobiology.berkeley.edu/PDFs_articles/Bada_Science2003.pdf |archivedate=4 March 2016}}</ref>

 

 

在Miller-Urey实验时，科学界的共识是，早期地球有一个还原性大气层，其化合物中氢气相对丰富，而氧气相对贫乏（如CH₄和NH₃，而不是CO₂ 和二氧化氮（NO₂））。然而，目前的科学共识将原始大气层描述为弱还原性或中性<ref name="Cleaves 2008">{{cite journal |last1=Cleaves |first1=H. James |last2=Chalmers |first2=John H. |last3=Lazcano |first3=Antonio |last4=Miller |first4=Stanley L. |last5=Bada |first5=Jeffrey L. |display-authors=3 |date=April 2008 |title=A Reassessment of Prebiotic Organic Synthesis in Neutral Planetary Atmospheres |journal=Origins of Life and Evolution of Biospheres |volume=38 |issue=2 |pages=105–115 |bibcode=2008OLEB...38..105C |doi=10.1007/s11084-007-9120-3|pmid=18204914|s2cid=7731172 }}</ref><ref name="Chyba 2005">{{cite journal |last=Chyba |first=Christopher F. |s2cid=93303848 |date=13 May 2005 |title=Rethinking Earth's Early Atmosphere |journal=Science |volume=308 |issue=5724 |pages=962–963 |doi=10.1126/science.1113157 |pmid=15890865}}</ref> （另见氧气灾难）。这样的大气会减少可以产生的氨基酸的数量和种类，尽管在实验条件中加入铁和碳酸盐矿物（被认为存在于早期海洋中）的研究又产生了多种氨基酸。其他科学研究集中在另外两种潜在的还原性环境：外太空和深海热喷口。<ref name="Cleaves 2008" /> Other scientific research has focused on two other potential reducing environments: [[outer space]] and deep-sea thermal vents.<ref>{{harvnb|Barton|Briggs|Eisen|Goldstein|2007|pp=93–95}}</ref><ref>{{harvnb|Bada|Lazcano|2009|pp=56–57}}</ref><ref name="Bada 2003">{{cite journal |last1=Bada |first1=Jeffrey L. |last2=Lazcano |first2=Antonio |date=2 May 2003 |url=http://astrobiology.berkeley.edu/PDFs_articles/Bada_Science2003.pdf |title=Prebiotic Soup – Revisiting the Miller Experiment |journal=Science |volume=300 |issue=5620 |pages=745–746 |doi=10.1126/science.1085145  |pmid=12730584 |s2cid=93020326 |accessdate=2015-06-13 |url-status=live |archiveurl=https://web.archive.org/web/20160304222002/http://astrobiology.berkeley.edu/PDFs_articles/Bada_Science2003.pdf |archivedate=4 March 2016}}</ref>

====基于氰化氢的合成====

====基于氰化氢的合成====

约翰·萨瑟兰 John Sutherland 等人在2015年完成的一个研究项目发现，在紫外线照射的水流中，一个以氰化氢和硫化氢为起点的反应网络，可以产生蛋白质和脂类的化学成分，以及RNA的化学成分，<ref>{{cite news |last=Service |first=Robert F. |date=16 March 2015 |title=Researchers may have solved origin-of-life conundrum |url=http://news.sciencemag.org/biology/2015/03/researchers-may-have-solved-origin-life-conundrum |work=Science |type=News |location=Washington, D.C. |publisher=American Association for the Advancement of Science |accessdate=2015-07-26 |url-status=live |archiveurl=https://web.archive.org/web/20150812103559/http://news.sciencemag.org/biology/2015/03/researchers-may-have-solved-origin-life-conundrum |archivedate=12 August 2015}}</ref><ref name="patel">{{cite journal |last1=Patel |first1=Bhavesh H.|last2=Percivalle |first2=Claudia |last3=Ritson |first3=Dougal J. |last4=Duffy |first4=Colm D. |last5=Sutherland |first5=John D. |authorlink5=John Sutherland (chemist) |date=April 2015 |title=Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism |journal=[[Nature Chemistry]] |volume=7 |issue=4 |pages=301–307 |bibcode=2015NatCh...7..301P |doi=10.1038/nchem.2202 |pmid=25803468 |ref=harv |pmc=4568310}}</ref>同时不产生其他多种化合物。<ref>{{harvnb|Patel|Percivalle|Ritson|Duffy|2015|p=302}}</ref>研究人员用 "氰基硫化物 "一词来描述这个反应网络。<ref name="patel" />

约翰·萨瑟兰 John Sutherland 等人在2015年完成的一个研究项目发现，在紫外线照射的水流中，一个以氰化氢和硫化氢为起点的反应网络，可以产生蛋白质和脂类的化学成分，以及RNA的化学成分，<ref>{{cite news |last=Service |first=Robert F. |date=16 March 2015 |title=Researchers may have solved origin-of-life conundrum |url=http://news.sciencemag.org/biology/2015/03/researchers-may-have-solved-origin-life-conundrum |work=Science |type=News |location=Washington, D.C. |publisher=American Association for the Advancement of Science |accessdate=2015-07-26 |url-status=live |archiveurl=https://web.archive.org/web/20150812103559/http://news.sciencemag.org/biology/2015/03/researchers-may-have-solved-origin-life-conundrum |archivedate=12 August 2015}}</ref><ref name="patel">{{cite journal |last1=Patel |first1=Bhavesh H.|last2=Percivalle |first2=Claudia |last3=Ritson |first3=Dougal J. |last4=Duffy |first4=Colm D. |last5=Sutherland |first5=John D. |date=April 2015 |title=Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism |journal=Nature Chemistry |volume=7 |issue=4 |pages=301–307 |bibcode=2015NatCh...7..301P |doi=10.1038/nchem.2202 |pmid=25803468 |ref=harv |pmc=4568310}}</ref>同时不产生其他多种化合物。<ref>{{harvnb|Patel|Percivalle|Ritson|Duffy|2015|p=302}}</ref>研究人员用 "氰基硫化物 "一词来描述这个反应网络。<ref name="patel" />

====实验室合成过程中的问题====

====实验室合成过程中的问题====

在"汤"理论提出的条件下，由非生物生成的单体自发形成复杂的聚合物，根本不是一个简单的过程。<ref>{{cite journal |last1=Oró |first1=Joan |last2=Kimball |first2=Aubrey P. |date=February 1962 |title=Synthesis of purines under possible primitive earth conditions: II. Purine intermediates from hydrogen cyanide |journal=[[Archives of Biochemistry and Biophysics]] |volume=96 |issue=2 |pages=293–313 |doi=10.1016/0003-9861(62)90412-5 |pmid=14482339}}</ref>除了必要的基本有机单体外，在Miller-Urey和琼·奥罗 Joan Oró实验过程中，还形成了高浓度的禁止聚合物形成的化合物。例如，Miller-Urey实验会产生许多与氨基酸反应或终止其偶联成肽链的物质。<ref>{{cite book |editor-last=Ahuja |editor-first=Mukesh |year=2006 |chapter=Origin of Life |chapterurl=https://books.google.com/books?id=VJF12TlT58kC&pg=PA11 |title=Life Science |volume=1 |location=Delhi |publisher=Isha Books |page=11 |isbn=978-81-8205-386-1 |oclc=297208106 |ref=harv}}</ref>

在"汤"理论提出的条件下，由非生物生成的单体自发形成复杂的聚合物，根本不是一个简单的过程。<ref>{{cite journal |last1=Oró |first1=Joan |last2=Kimball |first2=Aubrey P. |date=February 1962 |title=Synthesis of purines under possible primitive earth conditions: II. Purine intermediates from hydrogen cyanide |journal=Archives of Biochemistry and Biophysics |volume=96 |issue=2 |pages=293–313 |doi=10.1016/0003-9861(62)90412-5 |pmid=14482339}}</ref>除了必要的基本有机单体外，在Miller-Urey和琼·奥罗 Joan Oró实验过程中，还形成了高浓度的禁止聚合物形成的化合物。例如，Miller-Urey实验会产生许多与氨基酸反应或终止其偶联成肽链的物质。<ref>{{cite book |editor-last=Ahuja |editor-first=Mukesh |year=2006 |chapter=Origin of Life |chapterurl=https://books.google.com/books?id=VJF12TlT58kC&pg=PA11 |title=Life Science |volume=1 |location=Delhi |publisher=Isha Books |page=11 |isbn=978-81-8205-386-1 |oclc=297208106 |ref=harv}}</ref>

有人提出，生命最初是以自催化的化学网络产生的。.<ref>{{harvnb|Kauffman|1993|loc=chpt. 7}}</ref> 英国伦理学家理查德·道金斯 Richard Dawkins在2004年出版的《祖先的故事 The Ancestor's Tale》一书中写道，自催化是生命起源的一种可能的解释。<ref>{{harvnb|Dawkins|2004}}</ref>在书中，Dawkins引用了朱利叶斯·雷贝克 Julius Rebek和他的同事所做的实验，他们将氨基腺苷和五氟苯基酯与自催化剂氨基腺苷三酸酯（AATE）相结合。其中一种产物是AATE的变体，它能催化自身的合成。这一实验表明，自催化剂有可能在具有遗传性的实体种群中表现出竞争，这可以被解释为自然选择的一种基本形式。<ref>{{cite journal |last1=Tjivikua |first1=T. |last2=Ballester |first2=Pablo |last3=Rebek |first3=Julius Jr. |authorlink3=Julius Rebek |date=January 1990 |title=Self-replicating system |journal=[[Journal of the American Chemical Society]] |volume=112 |issue=3 |pages=1249–1250 |doi=10.1021/ja00159a057 }}</ref><ref>{{cite news |last=Browne |first=Malcolm W. |authorlink=Malcolm Browne |date=30 October 1990 |title=Chemists Make Molecule With Hint of Life |url=https://www.nytimes.com/1990/10/30/science/chemists-make-molecule-with-hint-of-life.html |newspaper=The New York Times |location=New York |accessdate=2015-07-14 |url-status=live |archiveurl=https://web.archive.org/web/20150721135740/http://www.nytimes.com/1990/10/30/science/chemists-make-molecule-with-hint-of-life.html |archivedate=21 July 2015}}</ref>

有人提出，生命最初是以自催化的化学网络产生的。.<ref>{{harvnb|Kauffman|1993|loc=chpt. 7}}</ref> 英国伦理学家理查德·道金斯 Richard Dawkins在2004年出版的《祖先的故事 The Ancestor's Tale》一书中写道，自催化是生命起源的一种可能的解释。<ref>{{harvnb|Dawkins|2004}}</ref>在书中，Dawkins引用了朱利叶斯·雷贝克 Julius Rebek和他的同事所做的实验，他们将氨基腺苷和五氟苯基酯与自催化剂氨基腺苷三酸酯（AATE）相结合。其中一种产物是AATE的变体，它能催化自身的合成。这一实验表明，自催化剂有可能在具有遗传性的实体种群中表现出竞争，这可以被解释为自然选择的一种基本形式。<ref>{{cite journal |last1=Tjivikua |first1=T. |last2=Ballester |first2=Pablo |last3=Rebek |first3=Julius Jr. |date=January 1990 |title=Self-replicating system |journal=Journal of the American Chemical Society|volume=112 |issue=3 |pages=1249–1250 |doi=10.1021/ja00159a057 }}</ref><ref>{{cite news |last=Browne |first=Malcolm W. |date=30 October 1990 |title=Chemists Make Molecule With Hint of Life |url=https://www.nytimes.com/1990/10/30/science/chemists-make-molecule-with-hint-of-life.html |newspaper=The New York Times |location=New York |accessdate=2015-07-14 |url-status=live |archiveurl=https://web.archive.org/web/20150721135740/http://www.nytimes.com/1990/10/30/science/chemists-make-molecule-with-hint-of-life.html |archivedate=21 July 2015}}</ref>

== 胶囊化：形态学==

== 胶囊化：形态学==

===脂质世界===

===脂质世界===

脂质世界理论认为，第一个自我复制的物体是类脂质的。<ref>{{cite web |url=http://www.weizmann.ac.il/molgen/Lancet/research/prebiotic-evolution |title=Systems Prebiology-Studies of the origin of Life |last=Lancet |first=Doron |date=30 December 2014 |website=The Lancet Lab |publisher=Department of Molecular Genetics; [[Weizmann Institute of Science]] |location=Rehovot, Israel |accessdate=2015-06-26 |url-status=live |archiveurl=https://web.archive.org/web/20150626180507/http://www.weizmann.ac.il/molgen/Lancet/research/prebiotic-evolution |archivedate=26 June 2015}}</ref><ref>{{cite journal |last1=Segré |first1=Daniel |last2=Ben-Eli |first2=Dafna |last3=Deamer |first3=David W. |last4=Lancet |first4=Doron |date=February 2001 |title=The Lipid World |url=http://www.weizmann.ac.il/molgen/Lancet/sites/molgen.Lancet/files/uploads/segre_lipid_world.pdf |journal=Origins of Life and Evolution of the Biosphere |volume=31 |issue=1–2 |pages=119–145 |doi=10.1023/A:1006746807104 |pmid=11296516 |bibcode=2001OLEB...31..119S |s2cid=10959497 |accessdate=2008-09-11 |url-status=live |archiveurl=https://web.archive.org/web/20150626225745/http://www.weizmann.ac.il/molgen/Lancet/sites/molgen.Lancet/files/uploads/segre_lipid_world.pdf |archivedate=26 June 2015}}</ref>众所周知，磷脂在水中搅拌时形成脂质双层--与细胞膜的结构相同。这些分子在早期地球上并不存在，但其他两亲性质的长链分子也会形成膜。此外，这些脂质体可能会膨胀（通过插入额外的脂质），在过度膨胀下可能会发生自发的分裂，从而在两个后代中保留了相同的大小和脂质的组成。这一理论的主要观点是，脂质体的分子组成是信息储存的初步方式，进化导致了如RNA或DNA等聚合物实体的出现，它们可能有利地储存信息。迄今为止，对来自潜在的前生物两亲化合物的囊泡的研究还仅限于含有一两种两亲化合物的系统。这与模拟的前生物化学反应的产出形成鲜明对比，前生物化学反应通常会产生非常异质的化合物的混合物。<ref name="Chen 2010" />

脂质世界理论认为，第一个自我复制的物体是类脂质的。<ref>{{cite web |url=http://www.weizmann.ac.il/molgen/Lancet/research/prebiotic-evolution |title=Systems Prebiology-Studies of the origin of Life |last=Lancet |first=Doron |date=30 December 2014 |website=The Lancet Lab |publisher=Department of Molecular Genetics; Weizmann Institute of Science|location=Rehovot, Israel |accessdate=2015-06-26 |url-status=live |archiveurl=https://web.archive.org/web/20150626180507/http://www.weizmann.ac.il/molgen/Lancet/research/prebiotic-evolution |archivedate=26 June 2015}}</ref><ref>{{cite journal |last1=Segré |first1=Daniel |last2=Ben-Eli |first2=Dafna |last3=Deamer |first3=David W. |last4=Lancet |first4=Doron |date=February 2001 |title=The Lipid World |url=http://www.weizmann.ac.il/molgen/Lancet/sites/molgen.Lancet/files/uploads/segre_lipid_world.pdf |journal=Origins of Life and Evolution of the Biosphere |volume=31 |issue=1–2 |pages=119–145 |doi=10.1023/A:1006746807104 |pmid=11296516 |bibcode=2001OLEB...31..119S |accessdate=2008-09-11 |url-status=live |archiveurl=https://web.archive.org/web/20150626225745/http://www.weizmann.ac.il/molgen/Lancet/sites/molgen.Lancet/files/uploads/segre_lipid_world.pdf |archivedate=26 June 2015}}</ref>众所周知，磷脂在水中搅拌时形成脂质双层--与细胞膜的结构相同。这些分子在早期地球上并不存在，但其他两亲性质的长链分子也会形成膜。此外，这些脂质体可能会膨胀（通过插入额外的脂质），在过度膨胀下可能会发生自发的分裂，从而在两个后代中保留了相同的大小和脂质的组成。这一理论的主要观点是，脂质体的分子组成是信息储存的初步方式，进化导致了如RNA或DNA等聚合物实体的出现，它们可能有利地储存信息。迄今为止，对来自潜在的前生物两亲化合物的囊泡的研究还仅限于含有一两种两亲化合物的系统。这与模拟的前生物化学反应的产出形成鲜明对比，前生物化学反应通常会产生非常异质的化合物的混合物。<ref name="Chen 2010" />

在由各种不同的两亲化合物的混合物组成的脂质双层膜的假设中，这些两亲化合物在膜上的排列中有大量理论上可能的组合的机会。在所有这些潜在的组合中，膜的一个特定的局部排列将有利于超循环的构成，<ref>{{cite journal |last1=Eigen |first1=Manfred |authorlink1=Manfred Eigen |last2=Schuster |first2=Peter |authorlink2=Peter Schuster |date=November 1977 |title=The Hypercycle. A Principle of Natural Self-Organization. Part A: Emergence of the Hypercycle |url=http://jaguar.biologie.hu-berlin.de/~wolfram/pages/seminar_theoretische_biologie_2007/literatur/schaber/Eigen1977Naturwissenschaften64.pdf |journal=Naturwissenschaften |volume=64 |issue=11 |pages=541–65|bibcode=1977NW.....64..541E |doi=10.1007/bf00450633 |pmid=593400 |accessdate=2015-06-13 |url-status=dead |archiveurl=https://web.archive.org/web/20160303194728/http://jaguar.biologie.hu-berlin.de/~wolfram/pages/seminar_theoretische_biologie_2007/literatur/schaber/Eigen1977Naturwissenschaften64.pdf |archivedate=3 March 2016}}</ref><ref>{{cite journal |last1=Eigen |first1=Manfred |last2=Schuster |first2=Peter |date=July 1978 |title=The Hypercycle. A Principle of Natural Self-Organization. Part C: The Realistic Hypercycle |url=http://jaguar.biologie.hu-berlin.de/~wolfram/pages/seminar_theoretische_biologie_2007/literatur/schaber/Eigen1978Naturwissenschaften65b.pdf |journal=Naturwissenschaften |volume=65 |issue=7 |pages=341–369 |bibcode=1978NW.....65..341E |doi=10.1007/bf00439699 |s2cid=13825356 |accessdate=2015-06-13 |url-status=dead |archiveurl=https://web.archive.org/web/20160616180402/http://jaguar.biologie.hu-berlin.de/~wolfram/pages/seminar_theoretische_biologie_2007/literatur/schaber/Eigen1978Naturwissenschaften65b.pdf |archivedate=16 June 2016}}</ref><ref>{{cite journal |last1=Markovitch |first1=Omer |last2=Lancet |first2=Doron |date=Summer 2012 |title=Excess Mutual Catalysis Is Required for Effective Evolvability |journal=[[Artificial Life (journal)|Artificial Life]] |volume=18 |issue=3 |pages=243–266 |doi=10.1162/artl_a_00064|pmid=22662913 |s2cid=5236043 }}</ref> 实际上是由两个相互的催化剂组成的正反馈，由一个膜位点和一个被困在囊泡中的特定化合物代表。这样的位点/化合物对可以传递给子囊泡，从而导致不同的囊泡谱系的出现，这将允许达尔文的自然选择。<ref>{{cite journal |last=Tessera |first=Marc |year=2011 |title=Origin of Evolution ''versus'' Origin of Life: A Shift of Paradigm |journal=[[International Journal of Molecular Sciences]] |volume=12 |issue=6 |pages=3445–3458 |doi=10.3390/ijms12063445 |pmc=3131571 |pmid=21747687}} Special Issue: "Origin of Life 2011"</ref>

在由各种不同的两亲化合物的混合物组成的脂质双层膜的假设中，这些两亲化合物在膜上的排列中有大量理论上可能的组合的机会。在所有这些潜在的组合中，膜的一个特定的局部排列将有利于超循环的构成，<ref>{{cite journal |last1=Eigen |first1=Manfred last2=Schuster |first2=Peter |date=November 1977 |title=The Hypercycle. A Principle of Natural Self-Organization. Part A: Emergence of the Hypercycle |url=http://jaguar.biologie.hu-berlin.de/~wolfram/pages/seminar_theoretische_biologie_2007/literatur/schaber/Eigen1977Naturwissenschaften64.pdf |journal=Naturwissenschaften |volume=64 |issue=11 |pages=541–65|bibcode=1977NW.....64..541E |doi=10.1007/bf00450633 |pmid=593400 |accessdate=2015-06-13 |url-status=dead |archiveurl=https://web.archive.org/web/20160303194728/http://jaguar.biologie.hu-berlin.de/~wolfram/pages/seminar_theoretische_biologie_2007/literatur/schaber/Eigen1977Naturwissenschaften64.pdf |archivedate=3 March 2016}}</ref><ref>{{cite journal |last1=Eigen |first1=Manfred |last2=Schuster |first2=Peter |date=July 1978 |title=The Hypercycle. A Principle of Natural Self-Organization. Part C: The Realistic Hypercycle |url=http://jaguar.biologie.hu-berlin.de/~wolfram/pages/seminar_theoretische_biologie_2007/literatur/schaber/Eigen1978Naturwissenschaften65b.pdf |journal=Naturwissenschaften |volume=65 |issue=7 |pages=341–369 |bibcode=1978NW.....65..341E |doi=10.1007/bf00439699 |accessdate=2015-06-13 |url-status=dead |archiveurl=https://web.archive.org/web/20160616180402/http://jaguar.biologie.hu-berlin.de/~wolfram/pages/seminar_theoretische_biologie_2007/literatur/schaber/Eigen1978Naturwissenschaften65b.pdf |archivedate=16 June 2016}}</ref><ref>{{cite journal |last1=Markovitch |first1=Omer |last2=Lancet |first2=Doron |date=Summer 2012 |title=Excess Mutual Catalysis Is Required for Effective Evolvability |journal=Artificial Life |volume=18 |issue=3 |pages=243–266 |doi=10.1162/artl_a_00064|pmid=22662913}}</ref> 实际上是由两个相互的催化剂组成的正反馈，由一个膜位点和一个被困在囊泡中的特定化合物代表。这样的位点/化合物对可以传递给子囊泡，从而导致不同的囊泡谱系的出现，这将允许达尔文的自然选择。<ref>{{cite journal |last=Tessera |first=Marc |year=2011 |title=Origin of Evolution ''versus'' Origin of Life: A Shift of Paradigm |journal=International Journal of Molecular Sciences |volume=12 |issue=6 |pages=3445–3458 |doi=10.3390/ijms12063445 |pmc=3131571 |pmid=21747687}} Special Issue: "Origin of Life 2011"</ref>

***讨论：这样的膜位点和化合物对，如何保证遗传性？***

***讨论：这样的膜位点和化合物对，如何保证遗传性？***

[[File:Phospholipids aqueous solution structures.svg|thumb|upright|磷脂在溶液中自发形成的三个主要结构：脂质体（封闭的双层），胶束和双层。]]

[[File:Phospholipids aqueous solution structures.svg|thumb|upright|磷脂在溶液中自发形成的三个主要结构：脂质体（封闭的双层），胶束和双层。]]

原始细胞是一种自组织、自排序、球形的脂质集合，被提议作为生命起源的踏脚石。<ref name="Chen 2010">{{cite journal |first1=Irene A. |last1=Chen |first2=Peter |last2=Walde |title=From Self-Assembled Vesicles to Protocells |journal=Cold Spring Harbor Perspectives in Biology |date=July 2010 |volume=2 |issue=7 |page=a002170 |doi=10.1101/cshperspect.a002170 |pmc=2890201 |pmid=20519344}}</ref>进化论中的一个核心问题是简单的原始细胞是如何首先产生的，并对下一代的繁殖贡献不同，推动生命的进化。虽然在实验室环境中还没有实现功能性的原始细胞，但有科学家认为这个目标是可以实现的。<ref name="Exploring">{{cite web |url=http://exploringorigins.org/protocells.html |title=Exploring Life's Origins: Protocells |website=Exploring Life's Origins: A Virtual Exhibit |publisher=National Science Foundation |location=Arlington County, VA |accessdate=2014-03-18 |url-status=live |archiveurl=https://web.archive.org/web/20140228083459/http://exploringorigins.org/protocells.html |archivedate=28 February 2014}}</ref><ref name="Chen 2006">{{cite journal |last=Chen |first=Irene A. |date=8 December 2006 |title=The Emergence of Cells During the Origin of Life |journal=Science |volume=314 |issue=5805 |pages=1558–1559 |doi=10.1126/science.1137541 |pmid=17158315 |doi-access=free }}</ref><ref name="Discover 2004">{{cite journal |last=Zimmer |first=Carl |authorlink=Carl Zimmer |date=26 June 2004 |title=What Came Before DNA? |url=http://discovermagazine.com/2004/jun/cover |journal=Discover  |url-status=live |archiveurl=https://web.archive.org/web/20140319001351/http://discovermagazine.com/2004/jun/cover |archivedate=19 March 2014}}</ref>

原始细胞是一种自组织、自排序、球形的脂质集合，被提议作为生命起源的踏脚石。<ref name="Chen 2010">{{cite journal |first1=Irene A. |last1=Chen |first2=Peter |last2=Walde |title=From Self-Assembled Vesicles to Protocells |journal=Cold Spring Harbor Perspectives in Biology |date=July 2010 |volume=2 |issue=7 |page=a002170 |doi=10.1101/cshperspect.a002170 |pmc=2890201 |pmid=20519344}}</ref>进化论中的一个核心问题是简单的原始细胞是如何首先产生的，并对下一代的繁殖贡献不同，推动生命的进化。虽然在实验室环境中还没有实现功能性的原始细胞，但有科学家认为这个目标是可以实现的。<ref name="Exploring">{{cite web |url=http://exploringorigins.org/protocells.html |title=Exploring Life's Origins: Protocells |website=Exploring Life's Origins: A Virtual Exhibit |publisher=National Science Foundation |location=Arlington County, VA |accessdate=2014-03-18 |url-status=live |archiveurl=https://web.archive.org/web/20140228083459/http://exploringorigins.org/protocells.html |archivedate=28 February 2014}}</ref><ref name="Chen 2006">{{cite journal |last=Chen |first=Irene A. |date=8 December 2006 |title=The Emergence of Cells During the Origin of Life |journal=Science |volume=314 |issue=5805 |pages=1558–1559 |doi=10.1126/science.1137541 |pmid=17158315 |doi-access=free }}</ref><ref name="Discover 2004">{{cite journal |last=Zimmer |first=Carl |date=26 June 2004 |title=What Came Before DNA? |url=http://discovermagazine.com/2004/jun/cover |journal=Discover  |url-status=live |archiveurl=https://web.archive.org/web/20140319001351/http://discovermagazine.com/2004/jun/cover |archivedate=19 March 2014}}</ref>

自组装囊泡是原始细胞的必要组成部分。<ref name="Chen 2010" />热力学第二定律要求宇宙向熵增加的方向运动，然但生命以其组织程度高而著称。因此，需要一个边界来将生命过程与非生命物质分开。<ref name="SciAm 2007">{{cite journal |last=Shapiro |first=Robert |authorlink=Robert Shapiro (chemist) |date=June 2007 |title=A Simpler Origin for Life |url=http://www.scientificamerican.com/article/a-simpler-origin-for-life/ |journal=Scientific American |volume=296 |issue=6 |pages=46–53 |doi=10.1038/scientificamerican0607-46 |pmid=17663224 |accessdate=2015-06-15 |bibcode=2007SciAm.296f..46S |url-status=live |archiveurl=https://web.archive.org/web/20150614000643/http://www.scientificamerican.com/article/a-simpler-origin-for-life/ |archivedate=14 June 2015}}</ref>研究人员艾琳·陈 Irene Chen和绍斯塔克 Szostak等人认为，基本原细胞的简单物理化学特性可以引起基本的细胞行为，包括原始形式的差异繁殖竞争和能量储存。膜与包裹物之间的这种合作相互作用可以大大简化从简单复制分子到真正细胞的过渡。<ref name="Chen 2006" /> 此外，对膜分子的竞争将有利于稳定的膜，这表明交联脂肪酸甚至今天的磷脂的进化具有选择性优势。 <ref name="Chen 2006" /> 这种微胶囊将允许膜内的新陈代谢，小分子的交换，但防止大物质穿过膜。<ref>{{harvnb|Chang|2007}}</ref> 胶囊化的主要优势包括胶囊内所含货物的溶解度增加，以及以电化学梯度的形式储存能量。讨论***为什么胶囊内的货物的溶解度会增加呢？***

自组装囊泡是原始细胞的必要组成部分。<ref name="Chen 2010" />热力学第二定律要求宇宙向熵增加的方向运动，然但生命以其组织程度高而著称。因此，需要一个边界来将生命过程与非生命物质分开。<ref name="SciAm 2007">{{cite journal |last=Shapiro |first=Robert|date=June 2007 |title=A Simpler Origin for Life |url=http://www.scientificamerican.com/article/a-simpler-origin-for-life/ |journal=Scientific American |volume=296 |issue=6 |pages=46–53 |doi=10.1038/scientificamerican0607-46 |pmid=17663224 |accessdate=2015-06-15 |bibcode=2007SciAm.296f..46S |url-status=live |archiveurl=https://web.archive.org/web/20150614000643/http://www.scientificamerican.com/article/a-simpler-origin-for-life/ |archivedate=14 June 2015}}</ref>研究人员艾琳·陈 Irene Chen和绍斯塔克 Szostak等人认为，基本原细胞的简单物理化学特性可以引起基本的细胞行为，包括原始形式的差异繁殖竞争和能量储存。膜与包裹物之间的这种合作相互作用可以大大简化从简单复制分子到真正细胞的过渡。<ref name="Chen 2006" /> 此外，对膜分子的竞争将有利于稳定的膜，这表明交联脂肪酸甚至今天的磷脂的进化具有选择性优势。 <ref name="Chen 2006" /> 这种微胶囊将允许膜内的新陈代谢，小分子的交换，但防止大物质穿过膜。<ref>{{harvnb|Chang|2007}}</ref> 胶囊化的主要优势包括胶囊内所含货物的溶解度增加，以及以电化学梯度的形式储存能量。讨论***为什么胶囊内的货物的溶解度会增加呢？***

奥斯纳布吕克大学的穆尔基贾尼安 Mulkidjanian领导的一项2012年的研究表明，冷凝和冷却的地热蒸汽的内陆池具有生命起源的理想特征。.<ref name="Switek 2012">{{cite news |last=Switek |first=Brian |date=13 February 2012 |title=Debate bubbles over the origin of life |work=Nature |location=London |publisher=Nature Publishing Group |doi=10.1038/nature.2012.10024}}</ref>科学家在2002年证实，通过在脂肪酸胶束（脂质球）溶液中加入蒙脱石粘土，粘土将囊泡形成的速度加快了100倍。<ref name="Discover 2004" />此外，最近的研究还发现，脱水和补水的反复作用将RNA等生物分子困在了温泉内发现的脂质原始细胞内，为自然选择的进化提供了必要的前提条件。.<ref>{{Cite web|last=z3530495|date=2020-05-05|title='When chemistry became biology': looking for the origins of life in hot springs|url=https://newsroom.unsw.edu.au/news/science-tech/when-chemistry-became-biology-looking-origins-life-hot-springs|access-date=2020-10-12|website=UNSW Newsroom}}</ref>

奥斯纳布吕克大学的穆尔基贾尼安 Mulkidjanian领导的一项2012年的研究表明，冷凝和冷却的地热蒸汽的内陆池具有生命起源的理想特征。.<ref name="Switek 2012">{{cite news |last=Switek |first=Brian |date=13 February 2012 |title=Debate bubbles over the origin of life |work=Nature |location=London |publisher=Nature Publishing Group |doi=10.1038/nature.2012.10024}}</ref>科学家在2002年证实，通过在脂肪酸胶束（脂质球）溶液中加入蒙脱石粘土，粘土将囊泡形成的速度加快了100倍。<ref name="Discover 2004" />此外，最近的研究还发现，脱水和补水的反复作用将RNA等生物分子困在了温泉内发现的脂质原始细胞内，为自然选择的进化提供了必要的前提条件。.<ref>{{Cite web|last=z3530495|date=2020-05-05|title='When chemistry became biology': looking for the origins of life in hot springs|url=https://newsroom.unsw.edu.au/news/science-tech/when-chemistry-became-biology-looking-origins-life-hot-springs|access-date=2020-10-12|website=UNSW Newsroom}}</ref>

=== 由RNA类生化物质的混合物组成的囊泡===

=== 由RNA类生化物质的混合物组成的囊泡===

 

另一种原细胞模型是Jeewanu。1963年首次由简单的矿物质和基本有机物在阳光下合成，据报道，它仍具有一定的新陈代谢能力，存在半透膜、氨基酸、磷脂、碳水化合物和RNA类分子。<ref name="Grote 2011">{{cite journal |last=Grote |first=Mathias |date=September 2011 |title=''Jeewanu'', or the 'particles of life' |url=http://www.ias.ac.in/jbiosci/grote_3677.pdf |journal=Journal of Biosciences|volume=36 |issue=4 |pages=563–570 |doi=10.1007/s12038-011-9087-0 |pmid=21857103|accessdate=2015-06-15 |url-status=live |archiveurl=https://web.archive.org/web/20150924050938/http://www.ias.ac.in/jbiosci/grote_3677.pdf |archivedate=24 September 2015}}</ref><ref name="Gupta 2013">{{cite journal |last1=Gupta |first1=V.K. |last2=Rai |first2=R.K. |date=August 2013 |title=Histochemical localisation of RNA-like material in photochemically formed self-sustaining, abiogenic supramolecular assemblies 'Jeewanu' |url=https://www.academia.edu/9439398 |journal=International Research Journal of Science & Engineering |volume=1 |issue=1 |pages=1–4|accessdate=2015-06-15 |url-status=live |archiveurl=https://web.archive.org/web/20170628001930/http://www.academia.edu/9439398/Histochemical_Localisation_of_RNA_like_material_in_photochemically_formed_self-sustaining_abiogenic_supramolecular_assemblis_Jeewanu_ |archivedate=28 June 2017}}</ref>然而，Jeewanu 的性质和特性仍有待澄清。

 

另一种原细胞模型是Jeewanu。1963年首次由简单的矿物质和基本有机物在阳光下合成，据报道，它仍具有一定的新陈代谢能力，存在半透膜、氨基酸、磷脂、碳水化合物和RNA类分子。<ref name="Grote 2011">{{cite journal |last=Grote |first=Mathias |date=September 2011 |title=''Jeewanu'', or the 'particles of life' |url=http://www.ias.ac.in/jbiosci/grote_3677.pdf |journal=[[Journal of Biosciences]] |volume=36 |issue=4 |pages=563–570 |doi=10.1007/s12038-011-9087-0 |pmid=21857103 |s2cid=19551399 |accessdate=2015-06-15 |url-status=live |archiveurl=https://web.archive.org/web/20150924050938/http://www.ias.ac.in/jbiosci/grote_3677.pdf |archivedate=24 September 2015}}</ref><ref name="Gupta 2013">{{cite journal |last1=Gupta |first1=V.K. |last2=Rai |first2=R.K. |date=August 2013 |title=Histochemical localisation of RNA-like material in photochemically formed self-sustaining, abiogenic supramolecular assemblies 'Jeewanu' |url=https://www.academia.edu/9439398 |journal=International Research Journal of Science & Engineering |volume=1 |issue=1 |pages=1–4|accessdate=2015-06-15 |url-status=live |archiveurl=https://web.archive.org/web/20170628001930/http://www.academia.edu/9439398/Histochemical_Localisation_of_RNA_like_material_in_photochemically_formed_self-sustaining_abiogenic_supramolecular_assemblis_Jeewanu_ |archivedate=28 June 2017}}</ref>然而，Jeewanu 的性质和特性仍有待澄清。

由长度为7个氨基酸或更少的带正电荷的疏水性短肽引起的静电相互作用，可以将RNA附着在囊膜上，即基本细胞膜上。<ref>{{cite news |last=Welter |first=Kira |date=10 August 2015 |title=Peptide glue may have held first protocell components together |url=http://www.rsc.org/chemistryworld/2015/08/peptide-glue-rna-may-have-held-first-protocells-together |work=Chemistry World |type=News |location=London |publisher=Royal Society of Chemistry  |accessdate= 2015-08-29 |url-status=live |archiveurl=https://web.archive.org/web/20150905234238/http://www.rsc.org/chemistryworld/2015/08/peptide-glue-rna-may-have-held-first-protocells-together |archivedate=5 September 2015}}</ref><ref>{{cite journal |last1=Kamat |first1=Neha P. |last2=Tobé |first2=Sylvia |last3=Hill |first3=Ian T. |last4=Szostak |first4=Jack W. |authorlink4=Jack W. Szostak |title=Electrostatic Localization of RNA to Protocell Membranes by Cationic Hydrophobic Peptides |date=29 July 2015 |journal=Angewandte Chemie International Edition |doi=10.1002/anie.201505742 |pmid=26223820 |pmc=4600236 |volume=54 |issue=40 |pages=11735–11739}}</ref>

由长度为7个氨基酸或更少的带正电荷的疏水性短肽引起的静电相互作用，可以将RNA附着在囊膜上，即基本细胞膜上。<ref>{{cite news |last=Welter |first=Kira |date=10 August 2015 |title=Peptide glue may have held first protocell components together |url=http://www.rsc.org/chemistryworld/2015/08/peptide-glue-rna-may-have-held-first-protocells-together |work=Chemistry World |type=News |location=London |publisher=Royal Society of Chemistry  |accessdate= 2015-08-29 |url-status=live |archiveurl=https://web.archive.org/web/20150905234238/http://www.rsc.org/chemistryworld/2015/08/peptide-glue-rna-may-have-held-first-protocells-together |archivedate=5 September 2015}}</ref><ref>{{cite journal |last1=Kamat |first1=Neha P. |last2=Tobé |first2=Sylvia |last3=Hill |first3=Ian T. |last4=Szostak |first4=Jack W. |title=Electrostatic Localization of RNA to Protocell Membranes by Cationic Hydrophobic Peptides |date=29 July 2015 |journal=Angewandte Chemie International Edition |doi=10.1002/anie.201505742 |pmid=26223820 |pmc=4600236 |volume=54 |issue=40 |pages=11735–11739}}</ref>

=== 金属硫化物沉淀物===

=== 金属硫化物沉淀物===

威廉·马丁 William Martin和迈克尔·拉塞尔 Michael Russell说：

威廉·马丁 William Martin和迈克尔·拉塞尔 Michael Russell说：

. . . . that life evolved in structured iron monosulphide precipitates in a seepage site hydrothermal mound at a redox, pH, and temperature gradient between sulphide-rich hydrothermal fluid and iron(II)-containing waters of the Hadean ocean floor. The naturally arising, three-dimensional compartmentation observed within fossilized seepage-site metal sulphide precipitates indicates that these inorganic compartments were the precursors of cell walls and membranes found in free-living prokaryotes. The known capability of FeS and NiS to catalyze the synthesis of the acetyl-methylsulphide from carbon monoxide and methylsulphide, constituents of hydrothermal fluid, indicates that pre-biotic syntheses occurred at the inner surfaces of these metal-sulphide-walled compartments,..."

. . . . that life evolved in structured iron monosulphide precipitates in a seepage site hydrothermal mound at a redox, pH, and temperature gradient between sulphide-rich hydrothermal fluid and iron(II)-containing waters of the Hadean ocean floor. The naturally arising, three-dimensional compartmentation observed within fossilized seepage-site metal sulphide precipitates indicates that these inorganic compartments were the precursors of cell walls and membranes found in free-living prokaryotes. The known capability of FeS and NiS to catalyze the synthesis of the acetyl-methylsulphide from carbon monoxide and methylsulphide, constituents of hydrothermal fluid, indicates that pre-biotic syntheses occurred at the inner surfaces of these metal-sulphide-walled compartments,..."

     ......生命是在一个渗流点热液丘中的结构化一硫化铁沉淀物中演化出来的，其氧化还原、pH值和温度梯度介于富含硫化物的热液和冥古代洋底的含铁(II)水之间。在渗透点金属硫化物沉淀物化石中观察到的自然生成的三维分隔表明，这些无机分隔是在自由生活的原核生物中发现的细胞壁和细胞膜的前身。已知FeS和NiS能够催化一氧化碳和甲基硫化物（热液的成分）合成乙酰-甲基硫化物，这表明前生物合成发生在这些金属硫化物壁隔室的内表面，......"<ref name="Martin2003">{{cite journal |last1=Martin |first1=William |authorlink1=William F. Martin |last2=Russell |first2=Michael J. |date=29 January 2003 |title=On the origins of cells: a hypothesis for the evolutionary transitions from abiotic geochemistry to chemoautotrophic prokaryotes, and from prokaryotes to nucleated cells |journal=Philosophical Transactions of the Royal Society B |volume=358 |issue=1429 |pages=59–83; discussion 83–85 |doi=10.1098/rstb.2002.1183|pmid=12594918 |pmc=1693102}}</ref>

     ......生命是在一个渗流点热液丘中的结构化一硫化铁沉淀物中演化出来的，其氧化还原、pH值和温度梯度介于富含硫化物的热液和冥古代洋底的含铁(II)水之间。在渗透点金属硫化物沉淀物化石中观察到的自然生成的三维分隔表明，这些无机分隔是在自由生活的原核生物中发现的细胞壁和细胞膜的前身。已知FeS和NiS能够催化一氧化碳和甲基硫化物（热液的成分）合成乙酰-甲基硫化物，这表明前生物合成发生在这些金属硫化物壁隔室的内表面，......"<ref name="Martin2003">{{cite journal |last1=Martin |first1=William |last2=Russell |first2=Michael J. |date=29 January 2003 |title=On the origins of cells: a hypothesis for the evolutionary transitions from abiotic geochemistry to chemoautotrophic prokaryotes, and from prokaryotes to nucleated cells |journal=Philosophical Transactions of the Royal Society B |volume=358 |issue=1429 |pages=59–83; discussion 83–85 |doi=10.1098/rstb.2002.1183|pmid=12594918 |pmc=1693102}}</ref>

</blockquote>

</blockquote>

===Darwin的小池塘 ===

===Darwin的小池塘 ===

An early concept, that life originated from non-living matter in slow stages, appeared in [[Herbert Spencer]]'s 1864–1867 book ''''. In 1879 [[William Turner Thiselton-Dyer]] referred to this in a paper "On spontaneous generation and evolution". On 1 February 1871 [[Charles Darwin]] wrote about these publications to [[Joseph Dalton Hooker|Joseph Hooker]], and set out his own speculation,suggesting that the original spark of life may have begun in a < blockquote >< /blockquote > He went on to explain that < blockquote >at the present day such matter would be instantly devoured or absorbed, which would not have been the case before living creatures were formed.< /blockquote >

一个早期的概念，即生命在缓慢的阶段中起源于非生命物质，出现在赫伯特·斯宾塞 Herbert Spencer 1864-1867年的《生物学原理 Principles of Biology》一书中。1879年威廉·特纳·希塞尔顿-代尔 William Turner Thiselton-Dyer在论文"论自然发生和演化"中提到了这一点。1871年2月1日，Charles Darwin将这些出版物写信给约瑟夫·胡克 Joseph Hooker，并提出了自己的推测，<ref name="Darwin DCP-LETT-7471">{{cite web | title=Letter no. 7471, Charles Darwin to Joseph Dalton Hooker, 1 February (1871) | website=Darwin Correspondence Project | date= | url=https://www.darwinproject.ac.uk/letter/DCP-LETT-7471.xml | access-date=7 July 2020}}</ref><ref>{{cite web|url=https://www.nsf.gov/news/special_reports/darwin/textonly/polar_essay1.jsp|title=Origin and Evolution of Life on a Frozen Earth|last=Priscu|first=John C.|publisher=National Science Foundation|location=Arlington County, VA|archiveurl=https://web.archive.org/web/20131218070241/http://www.nsf.gov/news/special_reports/darwin/textonly/polar_essay1.jsp|archivedate=18 December 2013|url-status=live|accessdate=2014-03-01}}</ref>认为生命的最初火花可能是始于

<blockquote>

<blockquote>

     warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity, {{sic|hide=y|&c.}}, present, that a {{sic|hide=y|[[protein]]e}} compound was chemically formed ready to undergo still more complex changes.

     warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity, &c., present, that a proteine compound was chemically formed ready to undergo still more complex changes.

   温暖的小池塘，加上各种氨和磷盐，光、热、电等的存在，一种蛋白质化合物已经在化学上形成，准备进行更复杂的变化。

   温暖的小池塘，加上各种氨和磷盐，光、热、电等的存在，一种蛋白质化合物已经在化学上形成，准备进行更复杂的变化。

在今天，这种物质会被立即吞噬或吸收，而在生物形成之前是不会有这种情况的。

在今天，这种物质会被立即吞噬或吸收，而在生物形成之前是不会有这种情况的。

</blockquote>

</blockquote>

{{harvnb|Darwin|1887|p=[http://darwin-online.org.uk/content/frameset?viewtype=text&itemID=F1452.3&pageseq=30 18]}}:

{{harvnb|Darwin|1887|p=[http://darwin-online.org.uk/content/frameset?viewtype=text&itemID=F1452.3&pageseq=30 18]}}:

  <blockquote>

  <blockquote>

It is often said that all the conditions for the first production of a living organism are now present, which could ever have been present. But if (and oh! what a big if!) we could conceive in some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity, {{sic|&c.|hide=y}}, present, that a {{sic|[[protein]]e|hide=y}} compound was chemically formed ready to undergo still more complex changes, at the present day such matter would be instantly devoured or absorbed, which would not have been the case before living creatures were formed.

It is often said that all the conditions for the first production of a living organism are now present, which could ever have been present. But if (and oh! what a big if!) we could conceive in some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity, &c., present, that a proteine compound was chemically formed ready to undergo still more complex changes, at the present day such matter would be instantly devoured or absorbed, which would not have been the case before living creatures were formed.

人们常说，现在已经具备了生物体第一次生产的所有条件，而这些条件本来是可能存在的。但是，如果（哦！多么大的如果啊！）我们可以设想在某个温暖的小池塘里，在各种氨和磷盐、光、热、电等条件存在的情况下，一种蛋白质化合物被化学形成，准备进行更复杂的变化，在现在，这种物质会立即被吞噬或吸收，这在生物形成之前是不会出现的。

人们常说，现在已经具备了生物体第一次生产的所有条件，而这些条件本来是可能存在的。但是，如果（哦！多么大的如果啊！）我们可以设想在某个温暖的小池塘里，在各种氨和磷盐、光、热、电等条件存在的情况下，一种蛋白质化合物被化学形成，准备进行更复杂的变化，在现在，这种物质会立即被吞噬或吸收，这在生物形成之前是不会出现的。

2017年的最新研究支持这样的观点：生命可能在地球形成后就开始了，因为RNA分子从"温暖的小池塘"中出现。<ref name="IND-20171002">{{cite web |last=Johnston |first=Ian |title=Life first emerged in 'warm little ponds' almost as old as the Earth itself – Darwin's famous idea backed by new scientific study |url=https://www.independent.co.uk/news/science/origins-life-ponds-organisms-earth-age-study-a7978906.html |date=2 October 2017 |work=[[The Independent]] |accessdate=2 October 2017 |url-status=live |archiveurl=https://web.archive.org/web/20171003003027/http://www.independent.co.uk/news/science/origins-life-ponds-organisms-earth-age-study-a7978906.html |archivedate=3 October 2017}}</ref>

2017年的最新研究支持这样的观点：生命可能在地球形成后就开始了，因为RNA分子从"温暖的小池塘"中出现。<ref name="IND-20171002">{{cite web |last=Johnston |first=Ian |title=Life first emerged in 'warm little ponds' almost as old as the Earth itself – Darwin's famous idea backed by new scientific study |url=https://www.independent.co.uk/news/science/origins-life-ponds-organisms-earth-age-study-a7978906.html |date=2 October 2017 |work=The Independent |accessdate=2 October 2017 |url-status=live |archiveurl=https://web.archive.org/web/20171003003027/http://www.independent.co.uk/news/science/origins-life-ponds-organisms-earth-age-study-a7978906.html |archivedate=3 October 2017}}</ref>

===浅层或深层的火山温泉和热液喷口===

===浅层或深层的火山温泉和热液喷口===

Szostak提出，在有矿物质堆积的开放湖泊中，地热活动为生命的起源提供了更大的机会。2010年，伊格纳特·伊格纳托夫 Ignat Ignatov和奥列格·莫辛Oleg Mosin根据对海水和热矿泉水的光谱分析，证明生命可能主要起源于热矿泉水。含有碳酸氢盐和钙离子的热矿泉水具有最理想的范围。<ref>{{cite journal |last1=Ignatov |first1=Ignat |last2=Mosin |first2=Oleg V. |year=2013 |title=Possible Processes for Origin of Life and Living Matter with modeling of Physiological Processes of Bacterium ''Bacillus Subtilis'' in Heavy Water as Model System |journal=Journal of Natural Sciences Research |volume=3 |issue=9 |pages=65–76}}</ref>这种情况类似于热液喷口中的生命起源，但热水中含有碳酸氢盐和钙离子。这种水的pH值为9-11，有可能在海水中发生反应。根据梅尔文·卡尔文 Melvin Calvin的观点，在更后的进化阶段，在pH值为9-11的原生水球中，可能发生某些氨基酸和核苷酸在多肽和核酸各个区段中的脱水-缩合反应。<ref>{{harvnb|Calvin|1969}}</ref> 其中一些化合物如氢氰酸（HCN）已经在Miller的实验中得到证明。这就是产生叠层石的环境。蒙大拿州立大学的大卫·沃德 David Ward描述了黄石国家公园的热矿泉水中的叠层石的形成。叠层石存在于热矿泉水中和靠近火山活动的地区。<ref>{{cite journal |last=Schirber |first=Michael |date=1 March 2010 |title=First Fossil-Makers in Hot Water |url=http://www.astrobio.net/news-exclusive/first-fossil-makers-in-hot-water/ |journal=[[Astrobiology Magazine]] |accessdate=2015-06-19 |url-status=live |archiveurl=https://web.archive.org/web/20150714085640/http://www.astrobio.net/news-exclusive/first-fossil-makers-in-hot-water/ |archivedate=14 July 2015}}</ref>这些过程是在热矿泉水的间歇泉附近的海中演化的。2011年，东京大学的Tadashi Sugawara在热水中创造了一个原生细胞。

Szostak提出，在有矿物质堆积的开放湖泊中，地热活动为生命的起源提供了更大的机会。2010年，伊格纳特·伊格纳托夫 Ignat Ignatov和奥列格·莫辛Oleg Mosin根据对海水和热矿泉水的光谱分析，证明生命可能主要起源于热矿泉水。含有碳酸氢盐和钙离子的热矿泉水具有最理想的范围。<ref>{{cite journal |last1=Ignatov |first1=Ignat |last2=Mosin |first2=Oleg V. |year=2013 |title=Possible Processes for Origin of Life and Living Matter with modeling of Physiological Processes of Bacterium ''Bacillus Subtilis'' in Heavy Water as Model System |journal=Journal of Natural Sciences Research |volume=3 |issue=9 |pages=65–76}}</ref>这种情况类似于热液喷口中的生命起源，但热水中含有碳酸氢盐和钙离子。这种水的pH值为9-11，有可能在海水中发生反应。根据梅尔文·卡尔文 Melvin Calvin的观点，在更后的进化阶段，在pH值为9-11的原生水球中，可能发生某些氨基酸和核苷酸在多肽和核酸各个区段中的脱水-缩合反应。<ref>{{harvnb|Calvin|1969}}</ref> 其中一些化合物如氢氰酸（HCN）已经在Miller的实验中得到证明。这就是产生叠层石的环境。蒙大拿州立大学的大卫·沃德 David Ward描述了黄石国家公园的热矿泉水中的叠层石的形成。叠层石存在于热矿泉水中和靠近火山活动的地区。<ref>{{cite journal |last=Schirber |first=Michael |date=1 March 2010 |title=First Fossil-Makers in Hot Water |url=http://www.astrobio.net/news-exclusive/first-fossil-makers-in-hot-water/ |journal=Astrobiology Magazine |accessdate=2015-06-19 |url-status=live |archiveurl=https://web.archive.org/web/20150714085640/http://www.astrobio.net/news-exclusive/first-fossil-makers-in-hot-water/ |archivedate=14 July 2015}}</ref>这些过程是在热矿泉水的间歇泉附近的海中演化的。2011年，东京大学的Tadashi Sugawara在热水中创造了一个原生细胞。

实验研究和计算机建模表明，热液喷口内的矿物颗粒表面具有类似酶的催化特性，能够从水中溶解的二氧化碳中制造出简单的有机分子，如甲醇（CH₃OH）和甲酸、乙酸和丙酮酸。<ref name="organics">{{cite press release |last=Usher |first=Oli |date=27 April 2015 |title=Chemistry of seabed's hot vents could explain emergence of life |url=https://www.ucl.ac.uk/silva/mathematical-physical-sciences/maps-news-publication/maps1526 |publisher=[[University College London]] |accessdate=2015-06-19 |archive-url=https://web.archive.org/web/20150620012231/https://www.ucl.ac.uk/silva/mathematical-physical-sciences/maps-news-publication/maps1526 |archive-date=20 June 2015 |url-status=dead}}</ref><ref>{{cite journal |last1=Roldan |first1=Alberto |last2=Hollingsworth |first2=Nathan |last3=Roffey |first3=Anna |last4=Islam |first4=Husn-Ubayda |last5=Goodall |first5=Josephine B. M. |last6=Catlow |first6=C. Richard A. |authorlink6=Richard Catlow |last7=Darr |first7=Jawwad A. |last8=Bras |first8=Wim |last9=Sankar |first9=Gopinathan |last10=Holt |first10=Katherine B. |last11=Hogarth |first11=Graeme |last12=de Leeuw |first12=Nora Henriette |display-authors=4 |date=May 2015 |title=Bio-inspired CO2 conversion by iron sulfide catalysts under sustainable conditions |url=http://pubs.rsc.org/en/content/articlepdf/2015/cc/c5cc02078f|journal=Chemical Communications |volume=51 |issue=35 |pages=7501–7504 |doi=10.1039/C5CC02078F |pmid=25835242 |accessdate=2015-06-19 |url-status=live |archiveurl=https://web.archive.org/web/20150620003943/http://pubs.rsc.org/en/content/articlepdf/2015/cc/c5cc02078f |archivedate=20 June 2015|doi-access=free }}</ref>

实验研究和计算机建模表明，热液喷口内的矿物颗粒表面具有类似酶的催化特性，能够从水中溶解的二氧化碳中制造出简单的有机分子，如甲醇（CH₃OH）和甲酸、乙酸和丙酮酸。<ref name="organics">{{cite press release |last=Usher |first=Oli |date=27 April 2015 |title=Chemistry of seabed's hot vents could explain emergence of life |url=https://www.ucl.ac.uk/silva/mathematical-physical-sciences/maps-news-publication/maps1526 |publisher=University College London |accessdate=2015-06-19 |archive-url=https://web.archive.org/web/20150620012231/https://www.ucl.ac.uk/silva/mathematical-physical-sciences/maps-news-publication/maps1526 |archive-date=20 June 2015 |url-status=dead}}</ref><ref>{{cite journal |last1=Roldan |first1=Alberto |last2=Hollingsworth |first2=Nathan |last3=Roffey |first3=Anna |last4=Islam |first4=Husn-Ubayda |last5=Goodall |first5=Josephine B. M. |last6=Catlow |first6=C. Richard A. |last7=Darr |first7=Jawwad A. |last8=Bras |first8=Wim |last9=Sankar |first9=Gopinathan |last10=Holt |first10=Katherine B. |last11=Hogarth |first11=Graeme |last12=de Leeuw |first12=Nora Henriette |display-authors=4 |date=May 2015 |title=Bio-inspired CO2 conversion by iron sulfide catalysts under sustainable conditions |url=http://pubs.rsc.org/en/content/articlepdf/2015/cc/c5cc02078f|journal=Chemical Communications |volume=51 |issue=35 |pages=7501–7504 |doi=10.1039/C5CC02078F |pmid=25835242 |accessdate=2015-06-19 |url-status=live |archiveurl=https://web.archive.org/web/20150620003943/http://pubs.rsc.org/en/content/articlepdf/2015/cc/c5cc02078f |archivedate=20 June 2015|doi-access=free }}</ref>

Martin在2016年报告的上述研究支持这样的论点，<ref>{{cite journal | last1 = Baross | first1 = J.A. | last2 = Hoffman | first2 = S.E. | year = 1985 | title = Submarine hydrothermal vents and associated gradient environments as sites for the origin and evolution of life | journal = Origins LifeEvol. B | volume = 15 | issue = 4 | pages = 327–345 | doi=10.1007/bf01808177| bibcode = 1985OrLi...15..327B | s2cid = 4613918 }}</ref><ref>{{cite journal | last1 = Russell | first1 = M.J. | last2 = Hall | first2 = A.J. | year = 1997 | title = The emergence of life from iron monosulphide bubbles at a submarine hydrothermal redox and pH front | journal = Journal of the Geological Society| volume = 154 | issue = 3 | pages = 377–402 | doi=10.1144/gsjgs.154.3.0377| pmid = 11541234 | bibcode = 1997JGSoc.154..377R | s2cid = 24792282 }}</ref>即生命产生于热液喷口,地壳中由岩石-水相互作用驱动的非平衡热力学自发化学作用是生命起源的基础，<ref>{{cite journal | last1 = Amend | first1 = J.P. | last2 = LaRowe | first2 = D.E. | last3 = McCollom | first3 = T.M. | last4 = Shock | first4 = E.L. | year = 2013 | title = The energetics of organic synthesis inside and outside the cell | journal = Phil. Trans. R. Soc. Lond. B | volume = 368 | issue = 1622 | page = 20120255 | doi=10.1098/rstb.2012.0255| pmid = 23754809 | pmc = 3685458 }}</ref><ref>{{cite journal | last1 = Shock | first1 = E.L. | last2 = Boyd | first2 = E.S. | year = 2015 | title = Geomicrobiology and microbial geochemistry:principles of geobiochemistry | journal = Elements | volume = 11 | pages = 389–394 | doi = 10.2113/gselements.11.6.395 }}</ref>古细菌和细菌的创始系是依赖H2的自养生物，它们在能量代谢中使用CO2作为终端接受体。<ref>{{cite journal | last1 = Martin | first1 = W. | last2 = Russell | first2 = M.J. | year = 2007 | title = On the origin of biochemistry at an alkaline hydrothermal vent | journal = Phil. Trans. R. Soc. Lond. B | volume = 362 | issue = 1486 | pages = 1887–1925 | doi = 10.1098/rstb.2006.1881 | pmid = 17255002 | pmc = 2442388 }}</ref>Martin根据这些证据提出，LUCA "可能严重依赖喷口的地热能而生存"。<ref>Nature, Vol 535, 28 July 2016. p.468</ref>

Martin在2016年报告的上述研究支持这样的论点，<ref>{{cite journal | last1 = Baross | first1 = J.A. | last2 = Hoffman | first2 = S.E. | year = 1985 | title = Submarine hydrothermal vents and associated gradient environments as sites for the origin and evolution of life | journal = Origins LifeEvol. B | volume = 15 | issue = 4 | pages = 327–345 | doi=10.1007/bf01808177| bibcode = 1985OrLi...15..327B }}</ref><ref>{{cite journal | last1 = Russell | first1 = M.J. | last2 = Hall | first2 = A.J. | year = 1997 | title = The emergence of life from iron monosulphide bubbles at a submarine hydrothermal redox and pH front | journal = Journal of the Geological Society| volume = 154 | issue = 3 | pages = 377–402 | doi=10.1144/gsjgs.154.3.0377| pmid = 11541234 | bibcode = 1997JGSoc.154..377R}}</ref>即生命产生于热液喷口,地壳中由岩石-水相互作用驱动的非平衡热力学自发化学作用是生命起源的基础，<ref>{{cite journal | last1 = Amend | first1 = J.P. | last2 = LaRowe | first2 = D.E. | last3 = McCollom | first3 = T.M. | last4 = Shock | first4 = E.L. | year = 2013 | title = The energetics of organic synthesis inside and outside the cell | journal = Phil. Trans. R. Soc. Lond. B | volume = 368 | issue = 1622 | page = 20120255 | doi=10.1098/rstb.2012.0255| pmid = 23754809 | pmc = 3685458 }}</ref><ref>{{cite journal | last1 = Shock | first1 = E.L. | last2 = Boyd | first2 = E.S. | year = 2015 | title = Geomicrobiology and microbial geochemistry:principles of geobiochemistry | journal = Elements | volume = 11 | pages = 389–394 | doi = 10.2113/gselements.11.6.395 }}</ref>古细菌和细菌的创始系是依赖H2的自养生物，它们在能量代谢中使用CO2作为终端接受体。<ref>{{cite journal | last1 = Martin | first1 = W. | last2 = Russell | first2 = M.J. | year = 2007 | title = On the origin of biochemistry at an alkaline hydrothermal vent | journal = Phil. Trans. R. Soc. Lond. B | volume = 362 | issue = 1486 | pages = 1887–1925 | doi = 10.1098/rstb.2006.1881 | pmid = 17255002 | pmc = 2442388 }}</ref>Martin根据这些证据提出，LUCA "可能严重依赖喷口的地热能而生存"。<ref>Nature, Vol 535, 28 July 2016. p.468</ref>

=== 火山岛或原大陆上的波动性热液池 ===

=== 火山岛或原大陆上的波动性热液池 ===

约翰·帕内尔 John Parnell认为，在任何早期潮湿的岩石行星的早期阶段，这种过程都可能提供部分 "生命的坩埚"，只要该行星足够大，产生了板块构造系统，将放射性矿物带到地表。由于早期地球被认为有许多较小的板块，它可能为这种过程提供了合适的环境。<ref>{{cite journal |last=Parnell |first=John |date=December 2004 |title=Mineral Radioactivity in Sands as a Mechanism for Fixation of Organic Carbon on the Early Earth |journal=Origins of Life and Evolution of Biospheres |volume=34 |issue=6 |pages=533–547 |bibcode=2004OLEB...34..533P |doi=10.1023/B:ORIG.0000043132.23966.a1 |pmid=15570707|citeseerx=10.1.1.456.8955 |s2cid=6067448 }}</ref>

约翰·帕内尔 John Parnell认为，在任何早期潮湿的岩石行星的早期阶段，这种过程都可能提供部分 "生命的坩埚"，只要该行星足够大，产生了板块构造系统，将放射性矿物带到地表。由于早期地球被认为有许多较小的板块，它可能为这种过程提供了合适的环境。<ref>{{cite journal |last=Parnell |first=John |date=December 2004 |title=Mineral Radioactivity in Sands as a Mechanism for Fixation of Organic Carbon on the Early Earth |journal=Origins of Life and Evolution of Biospheres |volume=34 |issue=6 |pages=533–547 |bibcode=2004OLEB...34..533P |doi=10.1023/B:ORIG.0000043132.23966.a1 |pmid=15570707|citeseerx=10.1.1.456.8955 }}</ref>

== 代谢起源:生理学==

== 代谢起源:生理学==

在早期的地球历史中，具有不同起源过程的不同生命形式可能准同时出现。<ref>{{cite journal |last=Davies |first=Paul |authorlink=Paul Davies |date=December 2007 |title=Are Aliens Among Us? |url=http://www.zo.utexas.edu/courses/kalthoff/bio301c/readings/07Davies.pdf |journal=Scientific American |volume=297 |issue=6 |pages=62–69 |doi=10.1038/scientificamerican1207-62 |accessdate=2015-07-16 |quote=...if life does emerge readily under terrestrial conditions, then perhaps it formed many times on our home planet. To pursue this possibility, deserts, lakes and other extreme or isolated environments have been searched for evidence of "alien" life-forms—organisms that would differ fundamentally from known organisms because they arose independently. |bibcode=2007SciAm.297f..62D |url-status=live |archiveurl=https://web.archive.org/web/20160304185832/http://www.zo.utexas.edu/courses/kalthoff/bio301c/readings/07Davies.pdf |archivedate=4 March 2016}}</ref>其他形式可能已经灭绝(通过其不同的生物化学--如假设的生物化学类型--留下了独特的化石)。有人提出：

在早期的地球历史中，具有不同起源过程的不同生命形式可能准同时出现。<ref>{{cite journal |last=Davies |first=Paul |date=December 2007 |title=Are Aliens Among Us? |url=http://www.zo.utexas.edu/courses/kalthoff/bio301c/readings/07Davies.pdf |journal=Scientific American |volume=297 |issue=6 |pages=62–69 |doi=10.1038/scientificamerican1207-62 |accessdate=2015-07-16 |quote=...if life does emerge readily under terrestrial conditions, then perhaps it formed many times on our home planet. To pursue this possibility, deserts, lakes and other extreme or isolated environments have been searched for evidence of "alien" life-forms—organisms that would differ fundamentally from known organisms because they arose independently. |bibcode=2007SciAm.297f..62D |url-status=live |archiveurl=https://web.archive.org/web/20160304185832/http://www.zo.utexas.edu/courses/kalthoff/bio301c/readings/07Davies.pdf |archivedate=4 March 2016}}</ref>其他形式可能已经灭绝(通过其不同的生物化学--如假设的生物化学类型--留下了独特的化石)。有人提出：

<blockquote>

<blockquote>

The first organisms were self-replicating iron-rich clays which fixed carbon dioxide into oxalic and other [[dicarboxylic acid]]s. This system of replicating clays and their metabolic phenotype then evolved into the sulfide rich region of the hotspring acquiring the ability to fix nitrogen. Finally phosphate was incorporated into the evolving system which allowed the synthesis of nucleotides and phospholipids. If biosynthesis recapitulates biopoiesis, then the synthesis of amino acids preceded the synthesis of the purine and pyrimidine bases. Furthermore, the polymerization of the amino acid thioesters into polypeptides preceded the directed polymerization of amino acid esters by polynucleotides.

The first organisms were self-replicating iron-rich clays which fixed carbon dioxide into oxalic and other dicarboxylic acids. This system of replicating clays and their metabolic phenotype then evolved into the sulfide rich region of the hotspring acquiring the ability to fix nitrogen. Finally phosphate was incorporated into the evolving system which allowed the synthesis of nucleotides and phospholipids. If biosynthesis recapitulates biopoiesis, then the synthesis of amino acids preceded the synthesis of the purine and pyrimidine bases. Furthermore, the polymerization of the amino acid thioesters into polypeptides preceded the directed polymerization of amino acid esters by polynucleotides.

最早的生物是自我复制的富铁粘土，它将二氧化碳固定成草酸和其他二羧酸。这种复制粘土及其新陈代谢表型的系统随后进化到富含硫化物的热泉区获得了固氮的能力。最后磷酸盐被纳入进化的系统，使核苷酸和磷脂的合成成为可能。如果说生物合成概括了生物创建，那么氨基酸的合成就先于嘌呤和嘧啶碱基的合成。此外，氨基酸硫酯聚合成多肽，先于多核苷酸定向聚合氨基酸酯。<ref>{{cite journal |last=Hartman |first=Hyman |date=1998 |title=Photosynthesis and the Origin of Life |journal=Origins of Life and Evolution of Biospheres |volume=28 |issue=4–6 |pages=515–521 |bibcode=1998OLEB...28..515H |doi=10.1023/A:1006548904157 |pmid=11536891|s2cid=2464 }}</ref>

最早的生物是自我复制的富铁粘土，它将二氧化碳固定成草酸和其他二羧酸。这种复制粘土及其新陈代谢表型的系统随后进化到富含硫化物的热泉区获得了固氮的能力。最后磷酸盐被纳入进化的系统，使核苷酸和磷脂的合成成为可能。如果说生物合成概括了生物创建，那么氨基酸的合成就先于嘌呤和嘧啶碱基的合成。此外，氨基酸硫酯聚合成多肽，先于多核苷酸定向聚合氨基酸酯。<ref>{{cite journal |last=Hartman |first=Hyman |date=1998 |title=Photosynthesis and the Origin of Life |journal=Origins of Life and Evolution of Biospheres |volume=28 |issue=4–6 |pages=515–521 |bibcode=1998OLEB...28..515H |doi=10.1023/A:1006548904157 |pmid=11536891}}</ref>

</blockquote>

</blockquote>

=== 粘土假说 ===

=== 粘土假说 ===

蒙脱石是一种丰富的粘土，是RNA聚合和脂质形成膜的催化剂。<ref>{{cite press release |last=Perry |first=Caroline |date=7 February 2011 |title=Clay-armored bubbles may have formed first protocells |url=http://www.eurekalert.org/pub_releases/2011-02/hu-cbm020411.php |location=Cambridge, MA |publisher=[[Harvard University]] |agency=EurekAlert! |accessdate=2015-06-20 |url-status=live |archiveurl=https://web.archive.org/web/20150714101638/http://www.eurekalert.org/pub_releases/2011-02/hu-cbm020411.php |archivedate=14 July 2015}}</ref>1985年，亚历山大·凯恩斯-史密斯 Alexander Cairns-Smith提出了一个利用粘土进行生命起源的模型，并被一些科学家作为一种似可信的机制进行了探索。<ref>{{harvnb|Dawkins|1996|pp=148–161}}</ref> 粘土假说假定复杂的有机分子是在溶液中的硅酸盐晶体预先存在的非有机重复表面上逐渐产生的。

蒙脱石是一种丰富的粘土，是RNA聚合和脂质形成膜的催化剂。<ref>{{cite press release |last=Perry |first=Caroline |date=7 February 2011 |title=Clay-armored bubbles may have formed first protocells |url=http://www.eurekalert.org/pub_releases/2011-02/hu-cbm020411.php |location=Cambridge, MA |publisher=Harvard University|agency=EurekAlert! |accessdate=2015-06-20 |url-status=live |archiveurl=https://web.archive.org/web/20150714101638/http://www.eurekalert.org/pub_releases/2011-02/hu-cbm020411.php |archivedate=14 July 2015}}</ref>1985年，亚历山大·凯恩斯-史密斯 Alexander Cairns-Smith提出了一个利用粘土进行生命起源的模型，并被一些科学家作为一种似可信的机制进行了探索。<ref>{{harvnb|Dawkins|1996|pp=148–161}}</ref> 粘土假说假定复杂的有机分子是在溶液中的硅酸盐晶体预先存在的非有机重复表面上逐渐产生的。

2007年，来自华盛顿大学的巴特·卡尔Bart Kahr 及其同事报告了他们的实验，利用邻苯二甲酸氢钾的晶体，检验了晶体可以作为可转移信息的来源的想法。有缺陷的"母"晶体被切割用作种子以从溶液中生长出"子"晶体。然后，他们检查了新晶体中缺陷的分布，发现母晶体中的缺陷在子晶体中重现，但子晶体也有许多额外的缺陷。要想观察到类似基因的行为，这些缺陷的遗传的量应该超过连续几代中的突变的量，但事实并非如此。因此Kahr 得出结论，这些晶体 "不够忠实，无法存储信息并将信息从一代传给下一代”。<ref>{{cite journal |last=Moore |first=Caroline |date=16 July 2007 |title=Crystals as genes? |url=http://www.rsc.org/Publishing/ChemScience/Volume/2007/08/Crystals_as_genes.asp |journal=Highlights in Chemical Science |accessdate=2015-06-21 |url-status=live |archiveurl=https://web.archive.org/web/20150714094855/http://www.rsc.org/Publishing/ChemScience/Volume/2007/08/Crystals_as_genes.asp |archivedate=14 July 2015}}

2007年，来自华盛顿大学的巴特·卡尔Bart Kahr 及其同事报告了他们的实验，利用邻苯二甲酸氢钾的晶体，检验了晶体可以作为可转移信息的来源的想法。有缺陷的"母"晶体被切割用作种子以从溶液中生长出"子"晶体。然后，他们检查了新晶体中缺陷的分布，发现母晶体中的缺陷在子晶体中重现，但子晶体也有许多额外的缺陷。要想观察到类似基因的行为，这些缺陷的遗传的量应该超过连续几代中的突变的量，但事实并非如此。因此Kahr 得出结论，这些晶体 "不够忠实，无法存储信息并将信息从一代传给下一代”。<ref>{{cite journal |last=Moore |first=Caroline |date=16 July 2007 |title=Crystals as genes? |url=http://www.rsc.org/Publishing/ChemScience/Volume/2007/08/Crystals_as_genes.asp |journal=Highlights in Chemical Science |accessdate=2015-06-21 |url-status=live |archiveurl=https://web.archive.org/web/20150714094855/http://www.rsc.org/Publishing/ChemScience/Volume/2007/08/Crystals_as_genes.asp |archivedate=14 July 2015}}

* {{cite journal |last1=Bullard |first1=Theresa |last2=Freudenthal |first2=John |last3=Avagyan |first3=Serine |last4=Kahr |first4=Bart |display-authors=3 |year=2007 |title=Test of Cairns-Smith's 'crystals-as-genes' hypothesis |journal=[[Faraday Discussions]] |volume=136 |pages=231–245 |bibcode=2007FaDi..136..231B |doi=10.1039/b616612c |pmid=17955812 }}</ref>

* {{cite journal |last1=Bullard |first1=Theresa |last2=Freudenthal |first2=John |last3=Avagyan |first3=Serine |last4=Kahr |first4=Bart |display-authors=3 |year=2007 |title=Test of Cairns-Smith's 'crystals-as-genes' hypothesis |journal=Faraday Discussions |volume=136 |pages=231–245 |bibcode=2007FaDi..136..231B |doi=10.1039/b616612c |pmid=17955812 }}</ref>

=== 铁-硫世界===

=== 铁-硫世界===

20世纪80年代，Günter Wächtershäuser在卡尔·波普尔 Karl Popper<ref>{{cite journal |last=Yue-Ching Ho |first=Eugene |date=July–September 1990 |title=Evolutionary Epistemology and Sir Karl Popper's Latest Intellectual Interest: A First-Hand Report |url=http://www.tkpw.net/hk-ies/n15/ |journal=Intellectus |volume=15 |pages=1–3 |oclc=26878740 |accessdate=2012-08-13 |url-status=live |archiveurl=https://web.archive.org/web/20120311074143/http://www.tkpw.net/hk-ies/n15/ |archivedate=11 March 2012}}</ref><ref>{{cite news |last=Wade |first=Nicholas |date=22 April 1997 |title=Amateur Shakes Up Ideas on Recipe for Life |url=https://www.nytimes.com/1997/04/22/science/amateur-shakes-up-ideas-on-recipe-for-life.html?src=pm&pagewanted=2&pagewanted=all |newspaper=The New York Times |location=New York  |accessdate=2015-06-16 |url-status=live |archiveurl=https://web.archive.org/web/20150617122450/http://www.nytimes.com/1997/04/22/science/amateur-shakes-up-ideas-on-recipe-for-life.html?src=pm&pagewanted=2&pagewanted=all |archivedate=17 June 2015}}</ref><ref>{{cite journal |last=Popper |first=Karl R. |authorlink=Karl Popper |date=29 March 1990 |title=Pyrite and the origin of life |journal=Nature |volume=344 |issue=6265 |page=387 |bibcode=1990Natur.344..387P |doi=10.1038/344387a0 |s2cid=4322774 }}</ref> 的鼓励和支持下，提出了他的铁-硫世界，这是一个关于前生物化学途径进化的理论，是生命进化的起点。它系统地将今天的生物化学追溯到原始反应，原始反应提供了从简单的气体化合物合成有机构件的替代途径。

20世纪80年代，Günter Wächtershäuser在卡尔·波普尔 Karl Popper<ref>{{cite journal |last=Yue-Ching Ho |first=Eugene |date=July–September 1990 |title=Evolutionary Epistemology and Sir Karl Popper's Latest Intellectual Interest: A First-Hand Report |url=http://www.tkpw.net/hk-ies/n15/ |journal=Intellectus |volume=15 |pages=1–3 |oclc=26878740 |accessdate=2012-08-13 |url-status=live |archiveurl=https://web.archive.org/web/20120311074143/http://www.tkpw.net/hk-ies/n15/ |archivedate=11 March 2012}}</ref><ref>{{cite news |last=Wade |first=Nicholas |date=22 April 1997 |title=Amateur Shakes Up Ideas on Recipe for Life |url=https://www.nytimes.com/1997/04/22/science/amateur-shakes-up-ideas-on-recipe-for-life.html?src=pm&pagewanted=2&pagewanted=all |newspaper=The New York Times |location=New York  |accessdate=2015-06-16 |url-status=live |archiveurl=https://web.archive.org/web/20150617122450/http://www.nytimes.com/1997/04/22/science/amateur-shakes-up-ideas-on-recipe-for-life.html?src=pm&pagewanted=2&pagewanted=all |archivedate=17 June 2015}}</ref><ref>{{cite journal |last=Popper |first=Karl R. |date=29 March 1990 |title=Pyrite and the origin of life |journal=Nature |volume=344 |issue=6265 |page=387 |bibcode=1990Natur.344..387P |doi=10.1038/344387a0 }}</ref> 的鼓励和支持下，提出了他的铁-硫世界，这是一个关于前生物化学途径进化的理论，是生命进化的起点。它系统地将今天的生物化学追溯到原始反应，原始反应提供了从简单的气体化合物合成有机构件的替代途径。

与经典的Miller实验依赖外部能量来源（模拟闪电、紫外线照射）不同，" Wächtershäuser系统 "自带内置能量来源：铁的硫化物（黄铁矿）和其他矿物。这些金属硫化物的氧化还原反应所释放的能量可用于有机分子的合成，这种系统可能已经演化成自催化组，构成自我复制、代谢活跃的实体，早于今天已知的生命形式。<ref name="Ralser 2014" /><ref name="Metabolism 2014" />在100℃的水环境中用这种硫化物进行实验，产生了产量相对较小的二肽 (0.4%～12.4%)和更小产量的三肽 (0.10%)，尽管在相同的条件下，二肽很快被分解。<ref>{{cite journal |last1=Huber |first1=Claudia |last2=Wächtershäuser |first2=Günter |authorlink2=Günter Wächtershäuser |date=31 July 1998 |title=Peptides by Activation of Amino Acids with CO on (Ni,Fe)S Surfaces: Implications for the Origin of Life |journal=Science |volume=281 |issue=5377 |pages=670–672 |bibcode=1998Sci...281..670H |doi=10.1126/science.281.5377.670 |pmid=9685253}}</ref>

与经典的Miller实验依赖外部能量来源（模拟闪电、紫外线照射）不同，" Wächtershäuser系统 "自带内置能量来源：铁的硫化物（黄铁矿）和其他矿物。这些金属硫化物的氧化还原反应所释放的能量可用于有机分子的合成，这种系统可能已经演化成自催化组，构成自我复制、代谢活跃的实体，早于今天已知的生命形式。<ref name="Ralser 2014" /><ref name="Metabolism 2014" />在100℃的水环境中用这种硫化物进行实验，产生了产量相对较小的二肽 (0.4%～12.4%)和更小产量的三肽 (0.10%)，尽管在相同的条件下，二肽很快被分解。<ref>{{cite journal |last1=Huber |first1=Claudia |last2=Wächtershäuser |first2=Günter |date=31 July 1998 |title=Peptides by Activation of Amino Acids with CO on (Ni,Fe)S Surfaces: Implications for the Origin of Life |journal=Science |volume=281 |issue=5377 |pages=670–672 |bibcode=1998Sci...281..670H |doi=10.1126/science.281.5377.670 |pmid=9685253}}</ref>

Several models reject the self-replication of a "naked-gene", postulating instead the emergence of a primitive metabolism providing a safe environment for the later emergence of RNA replication. The centrality of the [[Citric acid cycle|Krebs cycle]] (citric acid cycle) to energy production in aerobic organisms, and in drawing in carbon dioxide and hydrogen ions in biosynthesis of complex organic chemicals, suggests that it was one of the first parts of the metabolism to evolve. Concordantly, [[Geochemistry|geochemist]] Russell has proposed that "the purpose of life is to hydrogenate carbon dioxide" (as part of a "metabolism-first," rather than a "genetics-first," scenario). [[Physicist]] [[Jeremy England]] has proposed that life was inevitable from general thermodynamic considerations:< /blockquote >

有几个模型否定了"裸基因"的自我复制，而是假设出现了一种原始的新陈代谢，为后来出现的RNA复制提供了安全的环境。克雷布斯循环 Krebs cycle(柠檬酸循环)在需氧生物体内产生能量，以及在复杂有机化学物的生物合成中吸取二氧化碳和氢离子的中心地位，表明它是新陈代谢中最早进化的部分之一。<ref name="Lane 2009">{{harvnb|Lane|2009}}</ref>与此相一致的是，地球化学家Russell提出“生命的目的是使二氧化碳氢化”(这是“新陈代谢优先”而不是“基因优先”情形的一部分)。<ref name="Musser">{{cite web |url=http://blogs.scientificamerican.com/observations/how-life-arose-on-earth-and-how-a-singularity-might-bring-it-down/ |title=How Life Arose on Earth, and How a Singularity Might Bring It Down |last=Musser |first=George |date=23 September 2011 |work=Observations |type=Blog  |accessdate=2015-06-17 |url-status=live |archiveurl=https://web.archive.org/web/20150617211804/http://blogs.scientificamerican.com/observations/how-life-arose-on-earth-and-how-a-singularity-might-bring-it-down/ |archivedate=17 June 2015}}</ref><ref name="Carroll">{{cite web |url=http://blogs.discovermagazine.com/cosmicvariance/2010/03/10/free-energy-and-the-meaning-of-life/ |title=Free Energy and the Meaning of Life |last=Carroll |first=Sean |date=10 March 2010 |work=Cosmic Variance |type=Blog |publisher=Discover|accessdate=2015-06-17 |url-status=live |archiveurl=https://web.archive.org/web/20150714074327/http://blogs.discovermagazine.com/cosmicvariance/2010/03/10/free-energy-and-the-meaning-of-life/ |archivedate=14 July 2015}}</ref>物理学家杰里米·英格兰Jeremy England提出，从一般的热力学考虑，生命是不可避免的：

<blockquote>

 

... when a group of atoms is driven by an external source of energy (like the sun or chemical fuel) and surrounded by a heat bath (like the ocean or atmosphere), it will often gradually restructure itself in order to dissipate increasingly more energy. This could mean that under certain conditions, matter inexorably acquires the key physical attribute associated with life.<ref>{{cite journal |last=Wolchover |first=Natalie |date=22 January 2014 |title=A New Physics Theory of Life |url=https://www.quantamagazine.org/20140122-a-new-physics-theory-of-life/ |journal=Quanta Magazine |accessdate=2015-06-17 |url-status=live |archiveurl=https://web.archive.org/web/20150613052830/https://www.quantamagazine.org/20140122-a-new-physics-theory-of-life/ |archivedate=13 June 2015}}</ref><ref>{{cite journal |last=England |first=Jeremy L. |date=28 September 2013 |title=Statistical physics of self-replication |url=http://www.englandlab.com/uploads/7/8/0/3/7803054/2013jcpsrep.pdf |journal=Journal of Chemical Physics|volume=139 |issue=12 |page=121923 |arxiv=1209.1179 |bibcode=2013JChPh.139l1923E |doi=10.1063/1.4818538 |pmid=24089735  |accessdate=2015-06-18 |url-status=live |archiveurl=https://web.archive.org/web/20150604131515/http://www.englandlab.com/uploads/7/8/0/3/7803054/2013jcpsrep.pdf |archivedate=4 June 2015|hdl=1721.1/90392}}</ref>

<blockquote>

... when a group of atoms is driven by an external source of energy (like the sun or chemical fuel) and surrounded by a heat bath (like the ocean or atmosphere), it will often gradually restructure itself in order to dissipate increasingly more energy. This could mean that under certain conditions, matter inexorably acquires the key physical attribute associated with life.<ref>{{cite journal |last=Wolchover |first=Natalie |date=22 January 2014 |title=A New Physics Theory of Life |url=https://www.quantamagazine.org/20140122-a-new-physics-theory-of-life/ |journal=Quanta Magazine |accessdate=2015-06-17 |url-status=live |archiveurl=https://web.archive.org/web/20150613052830/https://www.quantamagazine.org/20140122-a-new-physics-theory-of-life/ |archivedate=13 June 2015}}</ref><ref>{{cite journal |last=England |first=Jeremy L. |authorlink=Jeremy England |date=28 September 2013 |title=Statistical physics of self-replication |url=http://www.englandlab.com/uploads/7/8/0/3/7803054/2013jcpsrep.pdf |journal=[[Journal of Chemical Physics]] |volume=139 |issue=12 |page=121923 |arxiv=1209.1179 |bibcode=2013JChPh.139l1923E |doi=10.1063/1.4818538 |pmid=24089735  |accessdate=2015-06-18 |url-status=live |archiveurl=https://web.archive.org/web/20150604131515/http://www.englandlab.com/uploads/7/8/0/3/7803054/2013jcpsrep.pdf |archivedate=4 June 2015|hdl=1721.1/90392 |s2cid=478964 }}</ref>

   ...当一组原子受到外部能量源(如太阳或化学燃料)的驱动，并被热浴(如海洋或大气层)所包围时，它往往会逐渐重组自己，以耗散越来越多的能量。这可能意味着，在某些条件下，物质不可避免地获得了与生命相关的关键物理属性。

   ...当一组原子受到外部能量源(如太阳或化学燃料)的驱动，并被热浴(如海洋或大气层)所包围时，它往往会逐渐重组自己，以耗散越来越多的能量。这可能意味着，在某些条件下，物质不可避免地获得了与生命相关的关键物理属性。

</blockquote>

</blockquote>

***讨论：给我们一堆原子，我们会创造出什么呢？可是生命不是为了简单地耗散更多能量，相反，生物具有经济性***

***讨论：给我们一堆原子，我们会创造出什么呢？可是生命不是为了简单地耗散更多能量，相反，生物具有经济性***

这一思想最早的化身之一是在1924年提出的Oparin的原始自复制囊泡的概念，这比DNA结构的发现还要早。20世纪80年代和90年代的变体包括Wächtershäuser的铁-硫世界理论和克里斯蒂安·德·杜夫 Christian de Duve提出的基于硫酯的化学的模型。对于在没有基因存在的情况下新陈代谢出现的合理性，更加抽象和理论化的论证，包括弗里曼·戴森Freeman Dyson在20世纪80年代初提出的数学模型和斯图亚特·考夫曼Stuart Kauffman的集体自催化集的概念，该观点在该十年晚些时候进行了讨论。

这一思想最早的化身之一是在1924年提出的Oparin的原始自复制囊泡的概念，这比DNA结构的发现还要早。20世纪80年代和90年代的变体包括Wächtershäuser的铁-硫世界理论和克里斯蒂安·德·杜夫 Christian de Duve提出的基于硫酯的化学的模型。对于在没有基因存在的情况下新陈代谢出现的合理性，更加抽象和理论化的论证，包括弗里曼·戴森Freeman Dyson在20世纪80年代初提出的数学模型和斯图亚特·考夫曼Stuart Kauffman的集体自催化集的概念，该观点在该十年晚些时候进行了讨论。

锌世界理论已经被在古细菌、细菌和原真核生物演化之前的第一批原细胞内部的离子构成的实验和理论上的证据进一步充实了。阿奇博尔德·麦卡勒姆 Archibald Macallum注意到血液和淋巴等体液与海水的相似性；<ref>{{cite journal |last=Macallum |first=A. B. |authorlink=Archibald Macallum |date=1 April 1926 |title=The Paleochemistry of the body fluids and tissues |journal=[[Physiological Reviews]] |volume=6 |issue=2 |pages=316–357|doi=10.1152/physrev.1926.6.2.316 }}</ref>然而，所有细胞的无机成分与现代海水的无机成分不同，这使得Mulkidjanian及其同事结合地球化学分析和系统发育组学审查现代细胞普遍成分的无机离子需求，重建了第一批细胞的"孵化器"。作者得出的结论是，普遍存在的，并根据推断，原始的蛋白质和功能系统显示出对K⁺, Zn²⁺, Mn²⁺和[PO4]3−的亲和性和功能需求。

锌世界理论已经被在古细菌、细菌和原真核生物演化之前的第一批原细胞内部的离子构成的实验和理论上的证据进一步充实了。阿奇博尔德·麦卡勒姆 Archibald Macallum注意到血液和淋巴等体液与海水的相似性；<ref>{{cite journal |last=Macallum |first=A. B. |date=1 April 1926 |title=The Paleochemistry of the body fluids and tissues |journal=Physiological Reviews |volume=6 |issue=2 |pages=316–357|doi=10.1152/physrev.1926.6.2.316 }}</ref>然而，所有细胞的无机成分与现代海水的无机成分不同，这使得Mulkidjanian及其同事结合地球化学分析和系统发育组学审查现代细胞普遍成分的无机离子需求，重建了第一批细胞的"孵化器"。作者得出的结论是，普遍存在的，并根据推断，原始的蛋白质和功能系统显示出对K⁺, Zn²⁺, Mn²⁺和[PO4]3−的亲和性和功能需求。

地球化学重建表明，有利于细胞起源的离子成分不可能存在于我们今天所说的海洋环境中，而是与我们今天所说的内陆地热系统的蒸汽主导区的排放相符合。在缺氧的、以二氧化碳为主的原始大气下，地热场附近的水凝结物和蒸发物的化学性质会类似于现代细胞的内环境。因此，细胞前的进化阶段可能发生在浅层的"达尔文池塘"中，池塘内衬与金属硫化物混合的多孔硅酸盐矿物，富含K⁺, Zn²⁺和磷化合物。<ref>{{cite journal |last1=Mulkidjanian |first1=Armen Y. |last2=Bychkov |first2=Andrew Yu. |last3=Dibrova |first3=Daria V. |last4=Galperin |first4=Michael Y. |last5=Koonin |first5=Eugene V. |display-authors=3 |date=3 April 2012 |title=Origin of first cells at terrestrial, anoxic geothermal fields |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=109 |issue=14 |pages=E821–E830 |bibcode=2012PNAS..109E.821M |doi=10.1073/pnas.1117774109  |pmc=3325685 |pmid=22331915}}</ref><ref>For a deeper integrative version of this hypothesis, see in particular {{harvnb|Lankenau|2011|pp=225–286}}, interconnecting the "Two RNA worlds" concept and other detailed aspects; and {{cite journal |last1=Davidovich |first1=Chen |last2=Belousoff |first2=Matthew |last3=Bashan |first3=Anat |last4=Yonath |first4=Ada |authorlink4=Ada Yonath |date=September 2009 |title=The evolving ribosome: from non-coded peptide bond formation to sophisticated translation machinery |journal=Research in Microbiology |volume=160 |issue=7 |pages=487–492 |doi=10.1016/j.resmic.2009.07.004 |pmid=19619641}}</ref>

地球化学重建表明，有利于细胞起源的离子成分不可能存在于我们今天所说的海洋环境中，而是与我们今天所说的内陆地热系统的蒸汽主导区的排放相符合。在缺氧的、以二氧化碳为主的原始大气下，地热场附近的水凝结物和蒸发物的化学性质会类似于现代细胞的内环境。因此，细胞前的进化阶段可能发生在浅层的"达尔文池塘"中，池塘内衬与金属硫化物混合的多孔硅酸盐矿物，富含K⁺, Zn²⁺和磷化合物。<ref>{{cite journal |last1=Mulkidjanian |first1=Armen Y. |last2=Bychkov |first2=Andrew Yu. |last3=Dibrova |first3=Daria V. |last4=Galperin |first4=Michael Y. |last5=Koonin |first5=Eugene V. |display-authors=3 |date=3 April 2012 |title=Origin of first cells at terrestrial, anoxic geothermal fields |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=109 |issue=14 |pages=E821–E830 |bibcode=2012PNAS..109E.821M |doi=10.1073/pnas.1117774109  |pmc=3325685 |pmid=22331915}}</ref><ref>For a deeper integrative version of this hypothesis, see in particular {{harvnb|Lankenau|2011|pp=225–286}}, interconnecting the "Two RNA worlds" concept and other detailed aspects; and {{cite journal |last1=Davidovich |first1=Chen |last2=Belousoff |first2=Matthew |last3=Bashan |first3=Anat |last4=Yonath |first4=Ada |date=September 2009 |title=The evolving ribosome: from non-coded peptide bond formation to sophisticated translation machinery |journal=Research in Microbiology |volume=160 |issue=7 |pages=487–492 |doi=10.1016/j.resmic.2009.07.004 |pmid=19619641}}</ref>

===计算机描述的化学通路===

===计算机描述的化学通路===

2020年9月，化学家们首次基于一个名为“ALLCHEMY”的新计算机程序，描述了从无生命生命起源以前的化学物质到复杂的生物化学物质可能产生生命体的化学通路。<ref name="SA-20200103">{{cite news |last=Starr |first=Michelle |title=A New Chemical 'Tree of The Origins of Life' Reveals Our Possible Molecular Evolution |url=https://www.sciencealert.com/a-new-chemical-tree-of-the-origins-of-life-reveals-our-possible-chemical-evolution |date=3 October 2020 |work=[[ScienceAlert]] |accessdate=3 October 2020 }}</ref><ref name="SCI-20200925">{{cite journal |author=Wolos, Agnieszka |display-authors=et al. |title=Synthetic connectivity, emergence, and self-regeneration in the network of prebiotic chemistry |url=https://science.sciencemag.org/content/369/6511/eaaw1955 |date=25 September 2020 |journal=[[Science (journal)|Science]] |volume=369 |issue=6511 |doi=10.1126/science.aaw1955 |doi-broken-date=10 October 2020 |pmid=32973002 |accessdate=3 October 2020 }}</ref>

2020年9月，化学家们首次基于一个名为“ALLCHEMY”的新计算机程序，描述了从无生命生命起源以前的化学物质到复杂的生物化学物质可能产生生命体的化学通路。<ref name="SA-20200103">{{cite news |last=Starr |first=Michelle |title=A New Chemical 'Tree of The Origins of Life' Reveals Our Possible Molecular Evolution |url=https://www.sciencealert.com/a-new-chemical-tree-of-the-origins-of-life-reveals-our-possible-chemical-evolution |date=3 October 2020 |work=ScienceAlert |accessdate=3 October 2020 }}</ref><ref name="SCI-20200925">{{cite journal |author=Wolos, Agnieszka |display-authors=et al. |title=Synthetic connectivity, emergence, and self-regeneration in the network of prebiotic chemistry |url=https://science.sciencemag.org/content/369/6511/eaaw1955 |date=25 September 2020 |journal=Science |volume=369 |issue=6511 |doi=10.1126/science.aaw1955 |doi-broken-date=10 October 2020 |pmid=32973002 |accessdate=3 October 2020 }}</ref>

===耗散结构中的有机颜料===

===耗散结构中的有机颜料===

在他的 "生命起源和进化的热力学耗散理论 Thermodynamic Dissipation Theory of the Origin and Evolution of Life "中，<ref>{{cite journal |bibcode=2011ESD.....2...37M |title= Thermodynamic Origin of Life |journal=Earth System Dynamics |volume=0907 |issue=2011 |pages=37–51 |last1=Michaelian |first1=K |year=2009 |arxiv=0907.0042 |doi=10.5194/esd-2-37-2011 |s2cid= 14574109 }}</ref><ref name="Michaelian, K. 2011">{{cite journal |doi=10.5194/esd-2-37-2011 |title= Thermodynamic dissipation theory for the origin of life |journal=Earth System Dynamics |volume=2 |issue=1 |pages=37–51 |year=2011 |last1= Michaelian |first1=K |bibcode=2011ESD.....2...37M |arxiv=0907.0042 |s2cid= 14574109 }}</ref><ref name="Michaelian, K. 2017">{{cite journal |doi= 10.1016/j.heliyon.2017.e00424 |pmid=29062973 |pmc=5647473 |title=Microscopic dissipative structuring and proliferation at the origin of life |journal=Heliyon |volume=3 |issue=10 |pages=e00424 |year=2017 |last1=Michaelian |first1=Karo }}</ref>卡洛·米迦勒安 Karo Michaelian将Boltzmann的洞见和Prigogine的工作用于关于生命起源的最终结果。该理论假设生命起源和进化的标志是有机颜料的微观耗散结构及其在整个地球表面的扩散。现今的生命通过将紫外线和可见光子通过水中的有机颜料耗散成热能，增强了地球在太阳环境中的熵产生。这种热量就会催化大量的二次耗散过程，如水循环、洋流和风流、飓风等。<ref name="Michaelian, K. 2011"/><ref name="HESS Opinions 'Biological catalysis"/> Michaelian认为，如果说今天生命的热力学功能是通过有机颜料中光子耗散产生熵，那么这可能是它在一开始就具有的功能。事实证明，RNA和DNA在水溶液中时，都是230-290nm波长（UV-C）区域内紫外线的极强吸收者和极快耗散者，这是太阳光谱中可能穿透生命起源以前大气层的一部分。<ref>Sagan, C. (1973) Ultraviolet Selection Pressure on the Earliest Organisms, J. Theor. Biol., 39, 195–200.</ref> 事实上，不仅是RNA和DNA，许多生命的基本分子（生命所有三个域共同的分子）也是在UV-C中吸收的色素，其中许多也与RNA和DNA有化学亲和力。<ref>{{cite journal |doi=10.5194/bg-12-4913-2015 |title=Fundamental molecules of life are pigments which arose and co-evolved as a response to the thermodynamic imperative of dissipating the prevailing solar spectrum |journal=Biogeosciences |volume=12 |issue=16 |pages=4913–4937 |year=2015 |last1=Michaelian |first1=K |last2=Simeonov |first2=A |bibcode=2015BGeo...12.4913M |arxiv=1405.4059v2 }}</ref> 因此，核酸可能通过提供一个超快的耗散通道，充当了UV-C光子激发的天线色素供体分子的受体分子。Michaelian用非线性不可逆热力学的形式体系表明，在太古宙，如果这些色素作为催化剂来增强太阳光子的耗散，那么这些色素的生命起源前UV-C光化学合成和扩散在整个地球表面就会存在一种热力学上的必然性。<ref>{{cite journal |doi=10.1088/1742-6596/475/1/012010 |title=A non-linear irreversible thermodynamic perspective on organic pigment proliferation and biological evolution |journal= Journal of Physics: Conference Series |volume=475 |issue=1 |pages=012010 |year=2013 |last1=Michaelian |first1=K |bibcode= 2013JPhCS.475a2010M |arxiv=1307.5924 |s2cid=118564759 }}</ref> 到了太古宙末期，随着生命诱导的臭氧使地球上层大气中的UV-C光耗散，要想出现一种不依赖已有的复杂代谢通路的全新生命将变得越来越不可能，因为现在到达地球表面的光子中的自由能已经不足以直接破坏和重造共价键。然而，有人认为，由于影响大气层的地球物理事件造成的紫外线辐射的地表通量的这种变化，可能是在现有代谢通路的基础上促进生命复杂性发展的原因，例如在寒武纪生命大爆发期间。<ref>{{cite journal | last1 = Doglioni | first1 = C. | last2 = Pignatti | first2 = J. | last3 = Coleman | first3 = M. | year = 2016 | title = Why did life develop on the surface of the Earth in the Cambrian? | journal = Geoscience Frontiers | volume = 7 | issue = 6| pages = 865–873 | doi=10.1016/j.gsf.2016.02.001| url = https://iris.uniroma1.it/bitstream/11573/925124/1/Doglioni_Why_2016.pdf }}</ref>

在他的 "生命起源和进化的热力学耗散理论 Thermodynamic Dissipation Theory of the Origin and Evolution of Life "中，<ref>{{cite journal |bibcode=2011ESD.....2...37M |title= Thermodynamic Origin of Life |journal=Earth System Dynamics |volume=0907 |issue=2011 |pages=37–51 |last1=Michaelian |first1=K |year=2009 |arxiv=0907.0042 |doi=10.5194/esd-2-37-2011 }}</ref><ref name="Michaelian, K. 2011">{{cite journal |doi=10.5194/esd-2-37-2011 |title= Thermodynamic dissipation theory for the origin of life |journal=Earth System Dynamics |volume=2 |issue=1 |pages=37–51 |year=2011 |last1= Michaelian |first1=K |bibcode=2011ESD.....2...37M |arxiv=0907.0042}}</ref><ref name="Michaelian, K. 2017">{{cite journal |doi= 10.1016/j.heliyon.2017.e00424 |pmid=29062973 |pmc=5647473 |title=Microscopic dissipative structuring and proliferation at the origin of life |journal=Heliyon |volume=3 |issue=10 |pages=e00424 |year=2017 |last1=Michaelian |first1=Karo }}</ref>卡洛·米迦勒安 Karo Michaelian将Boltzmann的洞见和Prigogine的工作用于关于生命起源的最终结果。该理论假设生命起源和进化的标志是有机颜料的微观耗散结构及其在整个地球表面的扩散。现今的生命通过将紫外线和可见光子通过水中的有机颜料耗散成热能，增强了地球在太阳环境中的熵产生。这种热量就会催化大量的二次耗散过程，如水循环、洋流和风流、飓风等。<ref name="Michaelian, K. 2011"/><ref name="HESS Opinions 'Biological catalysis"/> Michaelian认为，如果说今天生命的热力学功能是通过有机颜料中光子耗散产生熵，那么这可能是它在一开始就具有的功能。事实证明，RNA和DNA在水溶液中时，都是230-290nm波长（UV-C）区域内紫外线的极强吸收者和极快耗散者，这是太阳光谱中可能穿透生命起源以前大气层的一部分。<ref>Sagan, C. (1973) Ultraviolet Selection Pressure on the Earliest Organisms, J. Theor. Biol., 39, 195–200.</ref> 事实上，不仅是RNA和DNA，许多生命的基本分子（生命所有三个域共同的分子）也是在UV-C中吸收的色素，其中许多也与RNA和DNA有化学亲和力。<ref>{{cite journal |doi=10.5194/bg-12-4913-2015 |title=Fundamental molecules of life are pigments which arose and co-evolved as a response to the thermodynamic imperative of dissipating the prevailing solar spectrum |journal=Biogeosciences |volume=12 |issue=16 |pages=4913–4937 |year=2015 |last1=Michaelian |first1=K |last2=Simeonov |first2=A |bibcode=2015BGeo...12.4913M |arxiv=1405.4059v2 }}</ref> 因此，核酸可能通过提供一个超快的耗散通道，充当了UV-C光子激发的天线色素供体分子的受体分子。Michaelian用非线性不可逆热力学的形式体系表明，在太古宙，如果这些色素作为催化剂来增强太阳光子的耗散，那么这些色素的生命起源前UV-C光化学合成和扩散在整个地球表面就会存在一种热力学上的必然性。<ref>{{cite journal |doi=10.1088/1742-6596/475/1/012010 |title=A non-linear irreversible thermodynamic perspective on organic pigment proliferation and biological evolution |journal= Journal of Physics: Conference Series |volume=475 |issue=1 |pages=012010 |year=2013 |last1=Michaelian |first1=K |bibcode= 2013JPhCS.475a2010M |arxiv=1307.5924 }}</ref> 到了太古宙末期，随着生命诱导的臭氧使地球上层大气中的UV-C光耗散，要想出现一种不依赖已有的复杂代谢通路的全新生命将变得越来越不可能，因为现在到达地球表面的光子中的自由能已经不足以直接破坏和重造共价键。然而，有人认为，由于影响大气层的地球物理事件造成的紫外线辐射的地表通量的这种变化，可能是在现有代谢通路的基础上促进生命复杂性发展的原因，例如在寒武纪生命大爆发期间。<ref>{{cite journal | last1 = Doglioni | first1 = C. | last2 = Pignatti | first2 = J. | last3 = Coleman | first3 = M. | year = 2016 | title = Why did life develop on the surface of the Earth in the Cambrian? | journal = Geoscience Frontiers | volume = 7 | issue = 6| pages = 865–873 | doi=10.1016/j.gsf.2016.02.001| url = https://iris.uniroma1.it/bitstream/11573/925124/1/Doglioni_Why_2016.pdf }}</ref>

***讨论：应该做一张图，标注这些理论试图解释的生命起源的时间段，以及瞄准的方面，看看理论之间是否自洽，如何互相联系，以及各自缺乏哪些方面的思考***

***讨论：应该做一张图，标注这些理论试图解释的生命起源的时间段，以及瞄准的方面，看看理论之间是否自洽，如何互相联系，以及各自缺乏哪些方面的思考***

===淀粉样蛋白===

===淀粉样蛋白===

2009年莫里 Maury提出了一种基于自复制β-片层结构的新的生命起源理论。<ref>{{cite journal | last1 = Maury | first1 = CP | year = 2009 | title = Self-proagating beta-sheet polypeptide structures as prebiotic informational entities:The amyloid world | journal = Origins of Life and Evolution of Biospheres | volume = 39 | issue = 2| pages = 141–150 | doi = 10.1007/s11084-009-9165-6 | pmid = 19301141 | s2cid = 20073536 }}</ref><ref>{{cite journal | last1 = Maury | first1 = CP | year = 2015 | title = Origin of Life.Primordial genetics: Information transfer in a pre-RNA world based on self-replicating beta-sheet amyloid conformers | journal = Journal of Theoretical Biology | volume = 382 | pages = 292–297 | doi = 10.1016/j.jtbi.2015.07.008 | pmid = 26196585 | doi-access = free }}</ref>该理论认为，自复制和自组装催化的淀粉样蛋白是原始的前RNA世界中的第一个信息聚合物。“淀粉样蛋白假说”的主要论据是基于β-片层为基础的信息系统的结构稳定性、自催化和催化性以及可进化性。这种系统还具有纠错性<ref>{{cite journal | last1 = Nanda | first1 = J | last2 = Rubinov | first2 = B | last3 = Ivnitski | first3 = D | last4 = Mukherjee | first4 = R | last5 = Shtelman | first5 = E | last6 = Motro | first6 = Y | last7 = Miller | first7 = Y | last8 = Wagner | first8 = N | last9 = Cohen-Luria | first9 = R | last10 = Ashkenasy | first10 = G | year = 2017 | title = Emergence of native peptide seuqences in prebiotic replication networks | journal = Nature Communications | volume = 8 | issue = 1| page = 343 | doi = 10.1038/s41467-017-00463-1 | pmid = 28874657 | pmc = 5585222 | bibcode = 2017NatCo...8..434N }}</ref> 和手性选择性。<ref>{{cite journal | last1 = Rout | first1 = SK | last2 = Friedmann | first2 = MP | last3 = Riek | first3 = R | last4 = Greenwald | first4 = J | year = 2018 | title = A prebiotic templated-directed synthesis based on amyloids | journal = Nature Communications | volume = 9 | issue = 1| pages = 234–242 | doi = 10.1038/s41467-017-02742-3 | pmid = 29339755 | pmc = 5770463 }}</ref>

2009年莫里 Maury提出了一种基于自复制β-片层结构的新的生命起源理论。<ref>{{cite journal | last1 = Maury | first1 = CP | year = 2009 | title = Self-proagating beta-sheet polypeptide structures as prebiotic informational entities:The amyloid world | journal = Origins of Life and Evolution of Biospheres | volume = 39 | issue = 2| pages = 141–150 | doi = 10.1007/s11084-009-9165-6 | pmid = 19301141 }}</ref><ref>{{cite journal | last1 = Maury | first1 = CP | year = 2015 | title = Origin of Life.Primordial genetics: Information transfer in a pre-RNA world based on self-replicating beta-sheet amyloid conformers | journal = Journal of Theoretical Biology | volume = 382 | pages = 292–297 | doi = 10.1016/j.jtbi.2015.07.008 | pmid = 26196585 | doi-access = free }}</ref>该理论认为，自复制和自组装催化的淀粉样蛋白是原始的前RNA世界中的第一个信息聚合物。“淀粉样蛋白假说”的主要论据是基于β-片层为基础的信息系统的结构稳定性、自催化和催化性以及可进化性。这种系统还具有纠错性<ref>{{cite journal | last1 = Nanda | first1 = J | last2 = Rubinov | first2 = B | last3 = Ivnitski | first3 = D | last4 = Mukherjee | first4 = R | last5 = Shtelman | first5 = E | last6 = Motro | first6 = Y | last7 = Miller | first7 = Y | last8 = Wagner | first8 = N | last9 = Cohen-Luria | first9 = R | last10 = Ashkenasy | first10 = G | year = 2017 | title = Emergence of native peptide seuqences in prebiotic replication networks | journal = Nature Communications | volume = 8 | issue = 1| page = 343 | doi = 10.1038/s41467-017-00463-1 | pmid = 28874657 | pmc = 5585222 | bibcode = 2017NatCo...8..434N }}</ref> 和手性选择性。<ref>{{cite journal | last1 = Rout | first1 = SK | last2 = Friedmann | first2 = MP | last3 = Riek | first3 = R | last4 = Greenwald | first4 = J | year = 2018 | title = A prebiotic templated-directed synthesis based on amyloids | journal = Nature Communications | volume = 9 | issue = 1| pages = 234–242 | doi = 10.1038/s41467-017-02742-3 | pmid = 29339755 | pmc = 5770463 }}</ref>

今天发酵的生物能过程是由上述柠檬酸循环或乙酰-辅酶A通路进行的，这两种通路都与原始的铁-硫世界有关。

今天发酵的生物能过程是由上述柠檬酸循环或乙酰-辅酶A通路进行的，这两种通路都与原始的铁-硫世界有关。

热合成假说则用不同的方法，认为在细胞呼吸和光合作用中起着必要作用的化学渗透的生物能量过程比发酵更基础：提出维持化学渗透的ATP合成酶是目前现存的与第一个代谢过程关系最密切的酶。<ref>{{cite journal |last=Muller |first=Anthonie W. J. |date=7 August 1985 |pages=429–453 |title=Thermosynthesis by biomembranes: Energy gain from cyclic temperature changes |journal=[[Journal of Theoretical Biology]] |volume=115 |issue=3 |doi=10.1016/S0022-5193(85)80202-2 |pmid=3162066}}</ref><ref>{{cite journal |last=Muller |first=Anthonie W. J. |year=1995 |title=Were the first organisms heat engines? A new model for biogenesis and the early evolution of biological energy conversion |journal=Progress in Biophysics and Molecular Biology |volume=63 |issue=2 |pages=193–231 |doi=10.1016/0079-6107(95)00004-7 |pmid=7542789}}</ref>

热合成假说则用不同的方法，认为在细胞呼吸和光合作用中起着必要作用的化学渗透的生物能量过程比发酵更基础：提出维持化学渗透的ATP合成酶是目前现存的与第一个代谢过程关系最密切的酶。<ref>{{cite journal |last=Muller |first=Anthonie W. J. |date=7 August 1985 |pages=429–453 |title=Thermosynthesis by biomembranes: Energy gain from cyclic temperature changes |journal=Journal of Theoretical Biology|volume=115 |issue=3 |doi=10.1016/S0022-5193(85)80202-2 |pmid=3162066}}</ref><ref>{{cite journal |last=Muller |first=Anthonie W. J. |year=1995 |title=Were the first organisms heat engines? A new model for biogenesis and the early evolution of biological energy conversion |journal=Progress in Biophysics and Molecular Biology |volume=63 |issue=2 |pages=193–231 |doi=10.1016/0079-6107(95)00004-7 |pmid=7542789}}</ref>

然而铁-硫世界确定的循环通路是最简单的，热合成假说甚至没有调用通路。ATP合成酶的结合变化机制类似于产生自由能的物理吸附过程，,<ref>{{cite journal |last1=Muller |first1=Anthonie W. J. |last2=Schulze-Makuch |first2=Dirk |authorlink2=Dirk Schulze-Makuch |date=1 April 2006 |title=Sorption heat engines: Simple inanimate negative entropy generators |journal=[[Physica (journal)#Physica A: Statistical Mechanics and its Applications|Physica A: Statistical Mechanics and its Applications]] |volume=362 |issue=2 |pages=369–381 |arxiv=physics/0507173 |bibcode=2006PhyA..362..369M |doi=10.1016/j.physa.2005.12.003 |s2cid=96186464 }}</ref> 而不是减少自由能的普通的酶的机制，。

然而铁-硫世界确定的循环通路是最简单的，热合成假说甚至没有调用通路。ATP合成酶的结合变化机制类似于产生自由能的物理吸附过程，,<ref>{{cite journal |last1=Muller |first1=Anthonie W. J. |last2=Schulze-Makuch |first2=Dirk |date=1 April 2006 |title=Sorption heat engines: Simple inanimate negative entropy generators |journal=Physica (journal)#Physica A: Statistical Mechanics and its Applications|Physica A: Statistical Mechanics and its Applications|volume=362 |issue=2 |pages=369–381 |arxiv=physics/0507173 |bibcode=2006PhyA..362..369M |doi=10.1016/j.physa.2005.12.003}}</ref> 而不是减少自由能的普通的酶的机制，。

在只需要一条保守的氨基酸残基的短序列的意义上，所述的第一种蛋白质可能是简单的，这条序列足以满足适当的催化裂隙。相反，有人声称，由于许多所需序列的长度，出现诸如发酵所需的蛋白质催化剂的循环系统是不可信的。<ref>{{harvnb|Orgel|1987|pp=9–16}}</ref>

在只需要一条保守的氨基酸残基的短序列的意义上，所述的第一种蛋白质可能是简单的，这条序列足以满足适当的催化裂隙。相反，有人声称，由于许多所需序列的长度，出现诸如发酵所需的蛋白质催化剂的循环系统是不可信的。<ref>{{harvnb|Orgel|1987|pp=9–16}}</ref>

讨论***可见，其实不同假说只是从不同角度考虑“生命的本质是xxx”这一问题***

讨论***可见，其实不同假说只是从不同角度考虑“生命的本质是xxx”这一问题***

=== 前RNA世界:核糖问题和及其旁路 ===

=== 前RNA世界:核糖问题和及其旁路 ===

有可能一种不同类型的核酸，如肽核酸、苏糖核酸或乙二醇核酸，最先以自再生分子的形式出现，只是后来被RNA所取代。<ref>{{cite journal |last=Orgel |first=Leslie E. |date=17 November 2000 |title=A Simpler Nucleic Acid |journal=Science |volume=290 |issue=5495 |pages=1306–1307 |doi=10.1126/science.290.5495.1306  |pmid=11185405|s2cid=83662769 }}</ref><ref>{{cite journal |last1=Nelson |first1=Kevin E. |last2=Levy |first2=Matthew |last3=Miller |first3=Stanley L. |date=11 April 2000 |title=Peptide nucleic acids rather than RNA may have been the first genetic molecule |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=97 |issue=8 |pages=3868–3871 |bibcode=2000PNAS...97.3868N |doi=10.1073/pnas.97.8.3868|pmc=18108 |pmid=10760258}}</ref>拉腊尔德 Larralde等人说，

有可能一种不同类型的核酸，如肽核酸、苏糖核酸或乙二醇核酸，最先以自再生分子的形式出现，只是后来被RNA所取代。<ref>{{cite journal |last=Orgel |first=Leslie E. |date=17 November 2000 |title=A Simpler Nucleic Acid |journal=Science |volume=290 |issue=5495 |pages=1306–1307 |doi=10.1126/science.290.5495.1306  |pmid=11185405}}</ref><ref>{{cite journal |last1=Nelson |first1=Kevin E. |last2=Levy |first2=Matthew |last3=Miller |first3=Stanley L. |date=11 April 2000 |title=Peptide nucleic acids rather than RNA may have been the first genetic molecule |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=97 |issue=8 |pages=3868–3871 |bibcode=2000PNAS...97.3868N |doi=10.1073/pnas.97.8.3868|pmc=18108 |pmid=10760258}}</ref>拉腊尔德 Larralde等人说，

<blockquote>

<blockquote>

</blockquote>

</blockquote>

已知RNA中核糖和磷酸的酯连接容易发生水解。<ref>{{cite journal |last=Lindahl |first=Tomas |author-link=Tomas Lindahl |date=22 April 1993 |title=Instability and decay of the primary structure of DNA |journal=Nature |volume=362 |issue=6422 |pages=709–715 |bibcode=1993Natur.362..709L |doi=10.1038/362709a0|pmid=8469282|s2cid=4283694 }}</ref>

已知RNA中核糖和磷酸的酯连接容易发生水解。<ref>{{cite journal |last=Lindahl |first=Tomas |date=22 April 1993 |title=Instability and decay of the primary structure of DNA |journal=Nature |volume=362 |issue=6422 |pages=709–715 |bibcode=1993Natur.362..709L |doi=10.1038/362709a0|pmid=8469282}}</ref>

嘧啶核糖核苷及其各自的核苷酸已经通过一连串的反应，绕过游离的糖类，利用含氮或含氧的化学反应，一步步地组装起来，进行了生物起源以前的合成。Sutherland已经证明了由小的2和3个碳片段如羟乙醛、甘油醛或甘油醛-3-磷酸、氰胺和氰基乙炔构建胞嘧啶和尿嘧啶核糖核苷酸的高产路线。该序列中的一个步骤允许分离出对映纯的核糖氨基噁唑啉，如果甘油醛的对映体过量为大于或等于60％。<ref>{{cite journal |last1=Anastasi |first1=Carole |last2=Crowe |first2=Michael A. |last3=Powner |first3=Matthew W. |last4=Sutherland |first4=John D. |date=18 September 2006 |title=Direct Assembly of Nucleoside Precursors from Two- and Three-Carbon Units |journal=Angewandte Chemie International Edition |volume=45 |issue=37 |pages=6176–6179 |doi=10.1002/anie.200601267|pmid=16917794}}</ref> 这可以看作是一个生物起源以前的纯化步骤，所述化合物自发地从其他戊糖氨基恶唑啉的混合物中结晶出来。然后，核糖氨基恶唑啉可以以温和和高效的方式与氰基乙炔反应，给出α胞嘧啶核糖核苷酸。用紫外光进行光异构化，可以实现关于1'异构中心的倒置，从而给出正确的β立体化学。<ref>{{cite journal |last1=Powner |first1=Matthew W. |last2=Sutherland |first2=John D. |date=13 October 2008 |title=Potentially Prebiotic Synthesis of Pyrimidine β-D-Ribonucleotides by Photoanomerization/Hydrolysis of α-D-Cytidine-2'-Phosphate |journal=[[ChemBioChem]] |volume=9 |issue=15 |pages=2386–2387 |doi=10.1002/cbic.200800391 |pmid=18798212|s2cid=5704391 }}</ref>2009年，他们表明，同样的简单构件允许通过磷酸盐控制的核碱基加工，直接获得2',3'-环状嘧啶核苷酸，已知这些核苷酸能够聚合成RNA。这篇文章还强调了嘧啶-2',3'-环状磷酸盐的光致消毒的可能性。<ref name="pmid19444213">{{cite journal |last1=Powner |first1=Matthew W. |last2=Gerland |first2=Béatrice |last3=Sutherland |first3=John D. |date=14 May 2009 |title=Synthesis of activated pyrimidine ribonucleotides in prebiotically plausible conditions |journal=Nature |volume=459 |issue=7244 |pages=239–242 |bibcode=2009Natur.459..239P |doi=10.1038/nature08013  |pmid=19444213|s2cid=4412117 }}</ref>

嘧啶核糖核苷及其各自的核苷酸已经通过一连串的反应，绕过游离的糖类，利用含氮或含氧的化学反应，一步步地组装起来，进行了生物起源以前的合成。Sutherland已经证明了由小的2和3个碳片段如羟乙醛、甘油醛或甘油醛-3-磷酸、氰胺和氰基乙炔构建胞嘧啶和尿嘧啶核糖核苷酸的高产路线。该序列中的一个步骤允许分离出对映纯的核糖氨基噁唑啉，如果甘油醛的对映体过量为大于或等于60％。<ref>{{cite journal |last1=Anastasi |first1=Carole |last2=Crowe |first2=Michael A. |last3=Powner |first3=Matthew W. |last4=Sutherland |first4=John D. |date=18 September 2006 |title=Direct Assembly of Nucleoside Precursors from Two- and Three-Carbon Units |journal=Angewandte Chemie International Edition |volume=45 |issue=37 |pages=6176–6179 |doi=10.1002/anie.200601267|pmid=16917794}}</ref> 这可以看作是一个生物起源以前的纯化步骤，所述化合物自发地从其他戊糖氨基恶唑啉的混合物中结晶出来。然后，核糖氨基恶唑啉可以以温和和高效的方式与氰基乙炔反应，给出α胞嘧啶核糖核苷酸。用紫外光进行光异构化，可以实现关于1'异构中心的倒置，从而给出正确的β立体化学。<ref>{{cite journal |last1=Powner |first1=Matthew W. |last2=Sutherland |first2=John D. |date=13 October 2008 |title=Potentially Prebiotic Synthesis of Pyrimidine β-D-Ribonucleotides by Photoanomerization/Hydrolysis of α-D-Cytidine-2'-Phosphate |journal=ChemBioChem |volume=9 |issue=15 |pages=2386–2387 |doi=10.1002/cbic.200800391 |pmid=18798212 }}</ref>2009年，他们表明，同样的简单构件允许通过磷酸盐控制的核碱基加工，直接获得2',3'-环状嘧啶核苷酸，已知这些核苷酸能够聚合成RNA。这篇文章还强调了嘧啶-2',3'-环状磷酸盐的光致消毒的可能性。<ref name="pmid19444213">{{cite journal |last1=Powner |first1=Matthew W. |last2=Gerland |first2=Béatrice |last3=Sutherland |first3=John D. |date=14 May 2009 |title=Synthesis of activated pyrimidine ribonucleotides in prebiotically plausible conditions |journal=Nature |volume=459 |issue=7244 |pages=239–242 |bibcode=2009Natur.459..239P |doi=10.1038/nature08013  |pmid=19444213 }}</ref>

***评论：不依赖模板链的RNA合成***

***评论：不依赖模板链的RNA合成***

===RNA结构===

===RNA结构===

虽然自组织和自复制的特征经常被认为是生命系统的标志，但有许多无生命分子在适当条件下表现出这种特征的实例。斯坦·帕拉塞克 Stan Palasek根据理论模型提出，核糖核酸分子（RNA）的自组装可以由于热液喷口的物理因素而自发地发生。<ref>{{cite arXiv |last=Palasek |first=Stan |eprint=1305.5581v1 |title=Primordial RNA Replication and Applications in PCR Technology |class=q-bio.BM |date=23 May 2013}}</ref>病毒在宿主细胞内的自组装对生命起源的研究有启示，<ref name="pmid16984643">{{cite journal |last1=Koonin |first1=Eugene V. |author-link=Eugene Koonin |last2=Senkevich |first2=Tatiana G. |last3=Dolja |first3=Valerian V. |date=19 September 2006 |title=The ancient Virus World and evolution of cells |journal=[[Biology Direct]] |volume=1 |page=29 |doi=10.1186/1745-6150-1-29 |pmc=1594570 |pmid=16984643}}</ref>因为它进一步证实了生命可能是从自组装有机分子开始的假说。<ref name="pmid16044244">{{cite journal |last1=Vlassov |first1=Alexander V. |last2=Kazakov |first2=Sergei A. |last3=Johnston |first3=Brian H. |last4=Landweber |first4=Laura F. |display-authors=3 |date=August 2005 |title=The RNA World on Ice: A New Scenario for the Emergence of RNA Information |journal=[[Journal of Molecular Evolution]] |volume=61 |issue=2 |pages=264–273 |doi=10.1007/s00239-004-0362-7 |pmid=16044244|bibcode=2005JMolE..61..264V |s2cid=21096886 }}</ref><ref>{{cite journal |last1=Nussinov |first1=Mark D. |last2=Otroshchenko |first2=Vladimir A. |last3=Santoli |first3=Salvatore |year=1997 |title=The emergence of the non-cellular phase of life on the fine-grained clayish particles of the early Earth's regolith |journal=[[BioSystems]] |volume=42 |issue=2–3 |pages=111–118 |doi=10.1016/S0303-2647(96)01699-1 |pmid=9184757}}</ref>

虽然自组织和自复制的特征经常被认为是生命系统的标志，但有许多无生命分子在适当条件下表现出这种特征的实例。斯坦·帕拉塞克 Stan Palasek根据理论模型提出，核糖核酸分子（RNA）的自组装可以由于热液喷口的物理因素而自发地发生。<ref>{{cite arXiv |last=Palasek |first=Stan |eprint=1305.5581v1 |title=Primordial RNA Replication and Applications in PCR Technology |class=q-bio.BM |date=23 May 2013}}</ref>病毒在宿主细胞内的自组装对生命起源的研究有启示，<ref name="pmid16984643">{{cite journal |last1=Koonin |first1=Eugene V. |last2=Senkevich |first2=Tatiana G. |last3=Dolja |first3=Valerian V. |date=19 September 2006 |title=The ancient Virus World and evolution of cells |journal=Biology Direct |volume=1 |page=29 |doi=10.1186/1745-6150-1-29 |pmc=1594570 |pmid=16984643}}</ref>因为它进一步证实了生命可能是从自组装有机分子开始的假说。<ref name="pmid16044244">{{cite journal |last1=Vlassov |first1=Alexander V. |last2=Kazakov |first2=Sergei A. |last3=Johnston |first3=Brian H. |last4=Landweber |first4=Laura F. |display-authors=3 |date=August 2005 |title=The RNA World on Ice: A New Scenario for the Emergence of RNA Information |journal=Journal of Molecular Evolution|volume=61 |issue=2 |pages=264–273 |doi=10.1007/s00239-004-0362-7 |pmid=16044244|bibcode=2005JMolE..61..264V }}</ref><ref>{{cite journal |last1=Nussinov |first1=Mark D. |last2=Otroshchenko |first2=Vladimir A. |last3=Santoli |first3=Salvatore |year=1997 |title=The emergence of the non-cellular phase of life on the fine-grained clayish particles of the early Earth's regolith |journal=BioSystems |volume=42 |issue=2–3 |pages=111–118 |doi=10.1016/S0303-2647(96)01699-1 |pmid=9184757}}</ref>

===病毒的起源===

===病毒的起源===

最近有人提出了"病毒优先”假说的证据，这可能支持RNA世界的理论。<ref name="Urbana–Champaign_pr">{{cite press release |last=Yates |first=Diana |date=25 September 2015 |title=Study adds to evidence that viruses are alive |url=https://news.illinois.edu/blog/view/6367/250879 |location=Champaign, IL |publisher=[[University of Illinois at Urbana–Champaign]] |access-date=2015-10-20 |url-status=live |archive-url=https://web.archive.org/web/20151119153226/https://news.illinois.edu/blog/view/6367/250879 |archive-date=19 November 2015}}</ref><ref name="ReferenceA">{{cite journal |doi=10.1089/ast.2018.1851 |title=The Need for Including Virus Detection Methods in Future Mars Missions |journal=Astrobiology |volume=18 |issue=12 |pages=1611–1614 |year=2018 |last1=Janjic |first1=Aleksandar |bibcode=2018AsBio..18.1611J }}</ref>研究病毒起源的困难之一是它们的高突变率;尤其是像HIV这样的RNA逆转录病毒。<ref>{{cite journal |doi=10.1098/rstb.2012.0493 |pmid=23938747 |pmc=3758182 |title=Paleovirology: Inferring viral evolution from host genome sequence data |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |volume=368 |issue=1626 |page=20120493 |year=2013 |last1=Katzourakis |first1=A }}</ref>2015年的一项研究比较了生命树不同分支的蛋白质折叠结构，研究人员可以重建折叠和基因组编码这些折叠的生物体的进化史。他们认为，蛋白质折叠是古代事件的更好标志，因为即使编码那些折叠的序列开始变化，它们的三维结构也能保持不变。<ref name="Urbana–Champaign_pr" />因此，病毒蛋白库保留了古代进化史的痕迹，可以使用先进的生物信息学方法来恢复。那些研究人员认为，"基因组和颗粒大小减少的长期压力最终将病毒细胞缩减成现代病毒（通过细胞组成的完全丧失来识别），同时其他共存的细胞系也多样化成了现代细胞。"<ref>{{cite journal |last1=Arshan |first1=Nasir |last2=Caetano-Anollés |first2=Gustavo |date=25 September 2015 |title=A phylogenomic data-driven exploration of viral origins and evolution |journal=[[Science Advances]] |volume=1 |number=8 |page=e1500527 |doi=10.1126/sciadv.1500527 |pmid=26601271 |pmc=4643759 |bibcode=2015SciA....1E0527N }}</ref> 数据表明，病毒起源于与现代细胞的祖先共存的古细胞。这些古细胞很可能包含分段的RNA基因组。<ref name="Urbana–Champaign_pr" /><ref>{{cite journal |last1=Nasir |first1=Arshan |last2=Naeem |first2=Aisha |last3=Jawad Khan |first3=Muhammad |last4=Lopez-Nicora |first4=Horacio D. |last5=Caetano-Anollés |first5=Gustavo |display-authors=3 |date=December 2011 |title=Annotation of Protein Domains Reveals Remarkable Conservation in the Functional Make up of Proteomes Across Superkingdoms |journal=[[Genes (journal)|Genes]] |volume=2 |issue=4 |pages=869–911 |doi=10.3390/genes2040869 |pmc=3927607 |pmid=24710297}}</ref>

最近有人提出了"病毒优先”假说的证据，这可能支持RNA世界的理论。<ref name="Urbana–Champaign_pr">{{cite press release |last=Yates |first=Diana |date=25 September 2015 |title=Study adds to evidence that viruses are alive |url=https://news.illinois.edu/blog/view/6367/250879 |location=Champaign, IL |publisher=University of Illinois at Urbana–Champaign |access-date=2015-10-20 |url-status=live |archive-url=https://web.archive.org/web/20151119153226/https://news.illinois.edu/blog/view/6367/250879 |archive-date=19 November 2015}}</ref><ref name="ReferenceA">{{cite journal |doi=10.1089/ast.2018.1851 |title=The Need for Including Virus Detection Methods in Future Mars Missions |journal=Astrobiology |volume=18 |issue=12 |pages=1611–1614 |year=2018 |last1=Janjic |first1=Aleksandar |bibcode=2018AsBio..18.1611J }}</ref>研究病毒起源的困难之一是它们的高突变率;尤其是像HIV这样的RNA逆转录病毒。<ref>{{cite journal |doi=10.1098/rstb.2012.0493 |pmid=23938747 |pmc=3758182 |title=Paleovirology: Inferring viral evolution from host genome sequence data |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |volume=368 |issue=1626 |page=20120493 |year=2013 |last1=Katzourakis |first1=A }}</ref>2015年的一项研究比较了生命树不同分支的蛋白质折叠结构，研究人员可以重建折叠和基因组编码这些折叠的生物体的进化史。他们认为，蛋白质折叠是古代事件的更好标志，因为即使编码那些折叠的序列开始变化，它们的三维结构也能保持不变。<ref name="Urbana–Champaign_pr" />因此，病毒蛋白库保留了古代进化史的痕迹，可以使用先进的生物信息学方法来恢复。那些研究人员认为，"基因组和颗粒大小减少的长期压力最终将病毒细胞缩减成现代病毒（通过细胞组成的完全丧失来识别），同时其他共存的细胞系也多样化成了现代细胞。"<ref>{{cite journal |last1=Arshan |first1=Nasir |last2=Caetano-Anollés |first2=Gustavo |date=25 September 2015 |title=A phylogenomic data-driven exploration of viral origins and evolution |journal=Science Advances|volume=1 |number=8 |page=e1500527 |doi=10.1126/sciadv.1500527 |pmid=26601271 |pmc=4643759 |bibcode=2015SciA....1E0527N }}</ref> 数据表明，病毒起源于与现代细胞的祖先共存的古细胞。这些古细胞很可能包含分段的RNA基因组。<ref name="Urbana–Champaign_pr" /><ref>{{cite journal |last1=Nasir |first1=Arshan |last2=Naeem |first2=Aisha |last3=Jawad Khan |first3=Muhammad |last4=Lopez-Nicora |first4=Horacio D. |last5=Caetano-Anollés |first5=Gustavo |display-authors=3 |date=December 2011 |title=Annotation of Protein Domains Reveals Remarkable Conservation in the Functional Make up of Proteomes Across Superkingdoms |journal=Genes |volume=2 |issue=4 |pages=869–911 |doi=10.3390/genes2040869 |pmc=3927607 |pmid=24710297}}</ref>

***讨论：那么和病毒最近源的细胞谱系是哪一支呢***

***讨论：那么和病毒最近源的细胞谱系是哪一支呢***

一个计算模型（2015）表明，病毒的衣壳可能起源于RNA世界，它们作为复制因子群体之间水平转移的工具，因为如果基因寄生虫的数量增加，这些群体就无法生存，某些基因负责这些结构的形成，而那些基因有利于自复制群体的生存。<ref>{{cite journal | vauthors = Jalasvuori M, Mattila S, Hoikkala V | title = Chasing the Origin of Viruses: Capsid-Forming Genes as a Life-Saving Preadaptation within a Community of Early Replicators | journal = PLOS ONE | volume = 10 | issue = 5 | page = e0126094 | date = 2015 | pmid = 25955384 | pmc = 4425637 | doi = 10.1371/journal.pone.0126094 | bibcode = 2015PLoSO..1026094J }}</ref> 这些祖先基因在细胞生物之间的位移可能有利于进化中新病毒的出现。<ref name=Krupovic2019 >{{cite journal | vauthors = Krupovic M, Dolja VV, Koonin EV | s2cid = 169035711 | title = Origin of viruses: primordial replicators recruiting capsids from hosts | journal = Nature Reviews. Microbiology | volume = 17 | issue = 7 | pages = 449–458 | date = July 2019 | pmid = 31142823 | doi = 10.1038/s41579-019-0205-6 | url = https://hal-pasteur.archives-ouvertes.fr/pasteur-02557191/file/Krupovic_NRMICRO-19-022_MS_v3_clean.pdf }}</ref>病毒保留了从前生物阶段继承的复制模块，因为它在细胞中是不存在的。<ref name=Krupovic2019/>所以这是病毒可能起源于RNA世界的证据，也可能在进化中通过细胞中的遗传逃逸而多次出现。<ref name=Krupovic2019/>

一个计算模型（2015）表明，病毒的衣壳可能起源于RNA世界，它们作为复制因子群体之间水平转移的工具，因为如果基因寄生虫的数量增加，这些群体就无法生存，某些基因负责这些结构的形成，而那些基因有利于自复制群体的生存。<ref>{{cite journal | vauthors = Jalasvuori M, Mattila S, Hoikkala V | title = Chasing the Origin of Viruses: Capsid-Forming Genes as a Life-Saving Preadaptation within a Community of Early Replicators | journal = PLOS ONE | volume = 10 | issue = 5 | page = e0126094 | date = 2015 | pmid = 25955384 | pmc = 4425637 | doi = 10.1371/journal.pone.0126094 | bibcode = 2015PLoSO..1026094J }}</ref> 这些祖先基因在细胞生物之间的位移可能有利于进化中新病毒的出现。<ref name=Krupovic2019 >{{cite journal | vauthors = Krupovic M, Dolja VV, Koonin EV| title = Origin of viruses: primordial replicators recruiting capsids from hosts | journal = Nature Reviews. Microbiology | volume = 17 | issue = 7 | pages = 449–458 | date = July 2019 | pmid = 31142823 | doi = 10.1038/s41579-019-0205-6 | url = https://hal-pasteur.archives-ouvertes.fr/pasteur-02557191/file/Krupovic_NRMICRO-19-022_MS_v3_clean.pdf }}</ref>病毒保留了从前生物阶段继承的复制模块，因为它在细胞中是不存在的。<ref name=Krupovic2019/>所以这是病毒可能起源于RNA世界的证据，也可能在进化中通过细胞中的遗传逃逸而多次出现。<ref name=Krupovic2019/>

***讨论：阮病毒的出现和某种“位移”或“逃逸”有关吗？这里所谓“从前生物阶段继承的复制模块”是什么呢？***

***讨论：阮病毒的出现和某种“位移”或“逃逸”有关吗？这里所谓“从前生物阶段继承的复制模块”是什么呢？***

已经合成了相对较短的RNA分子，能够进行复制。<ref>{{cite journal |last1=Johnston |first1=Wendy K. |last2=Unrau |first2=Peter J. |last3=Lawrence |first3=Michael S. |last4=Glasner |first4=Margaret E. |last5=Bartel |first5=David P. |authorlink5=David Bartel |display-authors=3 |date=18 May 2001 |title=RNA-Catalyzed RNA Polymerization: Accurate and General RNA-Templated Primer Extension |journal=Science |volume=292 |issue=5520 |pages=1319–1325 |bibcode=2001Sci...292.1319J |doi=10.1126/science.1060786 |pmid=11358999|citeseerx=10.1.1.70.5439 |s2cid=14174984 }}</ref>这种复制酶RNA，既起密码，又起催化剂的作用，提供了自己的模板，可以在其上进行复制。Szostak已经证明，某些起催化作用的RNA可以将较小的RNA序列连接在一起，从而产生自复制的潜力。如果具备这些条件，Darwin的自然选择就会有利于这种自催化集的增殖，可以在其上添加进一步的功能。<ref>{{cite web |url=http://www.hhmi.org/research/origins-cellular-life |title=The Origins of Function in Biological Nucleic Acids, Proteins, and Membranes |last=Szostak |first=Jack W. |authorlink=Jack W. Szostak |date=5 February 2015 |publisher=[[Howard Hughes Medical Institute]] |location=Chevy Chase (CDP), MD |accessdate=2015-06-16 |url-status=live |archiveurl=https://web.archive.org/web/20150714092225/http://www.hhmi.org/research/origins-cellular-life |archivedate=14 July 2015}}</ref> 这种能够自我维持复制的RNA自催化系统已经被发现。<ref>{{cite journal |last1=Lincoln |first1=Tracey A. |last2=Joyce |first2=Gerald F. |date=27 February 2009 |title=Self-Sustained Replication of an RNA Enzyme |journal=Science |volume=323 |issue=5918 |pages=1229–1232 |bibcode=2009Sci...323.1229L |doi=10.1126/science.1167856 |pmc=2652413 |pmid=19131595}}</ref>RNA复制系统包括两个催化彼此的合成的核酶，产物的翻倍时间约为1小时，并且在实验中存在的条件下，受到自然选择的影响。<ref name="Joyce2009" />在进化竞争实验中，这导致了新系统的出现，它们的复制效率更高。<ref name="Robertson2012" /> 这是在分子遗传系统中发生进化适应的第一次证明。<ref name="Joyce2009">{{cite journal |last=Joyce |first=Gerald F. |year=2009 |title=Evolution in an RNA world |journal=Cold Spring Harbor Perspectives in Biology |volume=74 |issue=Evolution: The Molecular Landscape |pages=17–23 |doi=10.1101/sqb.2009.74.004 |pmc=2891321 |pmid=19667013 }}</ref>

已经合成了相对较短的RNA分子，能够进行复制。<ref>{{cite journal |last1=Johnston |first1=Wendy K. |last2=Unrau |first2=Peter J. |last3=Lawrence |first3=Michael S. |last4=Glasner |first4=Margaret E. |last5=Bartel |first5=David P. |display-authors=3 |date=18 May 2001 |title=RNA-Catalyzed RNA Polymerization: Accurate and General RNA-Templated Primer Extension |journal=Science |volume=292 |issue=5520 |pages=1319–1325 |bibcode=2001Sci...292.1319J |doi=10.1126/science.1060786 |pmid=11358999|citeseerx=10.1.1.70.5439}}</ref>这种复制酶RNA，既起密码，又起催化剂的作用，提供了自己的模板，可以在其上进行复制。Szostak已经证明，某些起催化作用的RNA可以将较小的RNA序列连接在一起，从而产生自复制的潜力。如果具备这些条件，Darwin的自然选择就会有利于这种自催化集的增殖，可以在其上添加进一步的功能。<ref>{{cite web |url=http://www.hhmi.org/research/origins-cellular-life |title=The Origins of Function in Biological Nucleic Acids, Proteins, and Membranes |last=Szostak |first=Jack W. |date=5 February 2015 |publisher=Howard Hughes Medical Institute|location=Chevy Chase (CDP), MD |accessdate=2015-06-16 |url-status=live |archiveurl=https://web.archive.org/web/20150714092225/http://www.hhmi.org/research/origins-cellular-life |archivedate=14 July 2015}}</ref> 这种能够自我维持复制的RNA自催化系统已经被发现。<ref>{{cite journal |last1=Lincoln |first1=Tracey A. |last2=Joyce |first2=Gerald F. |date=27 February 2009 |title=Self-Sustained Replication of an RNA Enzyme |journal=Science |volume=323 |issue=5918 |pages=1229–1232 |bibcode=2009Sci...323.1229L |doi=10.1126/science.1167856 |pmc=2652413 |pmid=19131595}}</ref>RNA复制系统包括两个催化彼此的合成的核酶，产物的翻倍时间约为1小时，并且在实验中存在的条件下，受到自然选择的影响。<ref name="Joyce2009" />在进化竞争实验中，这导致了新系统的出现，它们的复制效率更高。<ref name="Robertson2012" /> 这是在分子遗传系统中发生进化适应的第一次证明。<ref name="Joyce2009">{{cite journal |last=Joyce |first=Gerald F. |year=2009 |title=Evolution in an RNA world |journal=Cold Spring Harbor Perspectives in Biology |volume=74 |issue=Evolution: The Molecular Landscape |pages=17–23 |doi=10.1101/sqb.2009.74.004 |pmc=2891321 |pmid=19667013 }}</ref>

***讨论：就算我们最后提出了一种成功的生命起源机制，我们也很难证实地球生命真的是那样起源的***

***讨论：就算我们最后提出了一种成功的生命起源机制，我们也很难证实地球生命真的是那样起源的***

根据定义，当RNA链开始自复制时，生命就开始了，启动了达尔文选择的三种机制：遗传性、类型的变异和生殖输出差异。一个RNA复制因子的适应性（其人均增长率）很可能是其内在适应能力的函数，由其核苷酸序列以及资源的可用性决定。<ref name="Bernstein">{{cite journal |last1=Bernstein |first1=Harris |last2=Byerly |first2=Henry C. |last3=Hopf |first3=Frederick A. |last4=Michod |first4=Richard A. |last5=Vemulapalli |first5=G. Krishna |display-authors=3 |date=June 1983 |title=The Darwinian Dynamic |journal=[[The Quarterly Review of Biology]] |volume=58 |issue=2 |pages=185–207 |doi=10.1086/413216 |jstor=2828805}}</ref><ref name="Michod 1999">{{harvnb|Michod|1999}}</ref>三种主要的适应能力可能是：

根据定义，当RNA链开始自复制时，生命就开始了，启动了达尔文选择的三种机制：遗传性、类型的变异和生殖输出差异。一个RNA复制因子的适应性（其人均增长率）很可能是其内在适应能力的函数，由其核苷酸序列以及资源的可用性决定。<ref name="Bernstein">{{cite journal |last1=Bernstein |first1=Harris |last2=Byerly |first2=Henry C. |last3=Hopf |first3=Frederick A. |last4=Michod |first4=Richard A. |last5=Vemulapalli |first5=G. Krishna |display-authors=3 |date=June 1983 |title=The Darwinian Dynamic |journal=The Quarterly Review of Biology|volume=58 |issue=2 |pages=185–207 |doi=10.1086/413216 |jstor=2828805}}</ref><ref name="Michod 1999">{{harvnb|Michod|1999}}</ref>三种主要的适应能力可能是：

# 中等保真度的复制，在允许类型变异的同时增加遗传性；

# 中等保真度的复制，在允许类型变异的同时增加遗传性；

# 抗衰减能力；

# 抗衰减能力；

[[File:J. Craig Venter crop 2011 CHAO2011-49.jpg|thumb|upright|克雷格·文特 J. Craig Venter]]

[[File:J. Craig Venter crop 2011 CHAO2011-49.jpg|thumb|upright|克雷格·文特 J. Craig Venter]]

Eigen和索尔·斯皮格尔曼 Sol Spiegelman都证明了进化，包括复制、变异和自然选择，可以发生在分子群体中，也可以发生在生物群体中。<ref name="Follmann2009">{{cite journal |last1= Follmann |first1= Hartmut |last2= Brownson |first2= Carol |date= November 2009 |title= Darwin's warm little pond revisited: from molecules to the origin of life |journal= [[Naturwissenschaften]] |volume= 96 |issue= 11 |pages= 1265–1292 |bibcode= 2009NW.....96.1265F |pmid= 19760276 |doi= 10.1007/s00114-009-0602-1|s2cid= 23259886 }}</ref>继化学进化之后，是生物进化的开始，导致了第一个细胞的出现。<ref name="Follmann2009" />目前还没有人用简单的成分合成一个具有必要生命特征的"原细胞"（所谓"自下而上的方法"）。在没有这样的原理证明的情况下，解释往往集中在化学合成上。<ref>{{cite press release |last1= McCollom |first1= Thomas |last2= Mayhew |first2= Lisa |last3= Scott |first3= Jim |date= 7 October 2014 |title= NASA awards CU-Boulder-led team $7 million to study origins, evolution of life in universe |url= http://www.colorado.edu/news/releases/2014/10/07/nasa-awards-cu-boulder-led-team-7-million-study-origins-evolution-life |location= Boulder, CO |publisher= [[University of Colorado Boulder]] |accessdate= 2015-06-08 |url-status= dead |archiveurl= https://web.archive.org/web/20150731015530/http://www.colorado.edu/news/releases/2014/10/07/nasa-awards-cu-boulder-led-team-7-million-study-origins-evolution-life |archivedate= 31 July 2015}}</ref> 然而，一些研究者从事这一领域的研究，著名的有斯蒂恩·拉斯穆森 Steen Rasmussen和Szostak。

Eigen和索尔·斯皮格尔曼 Sol Spiegelman都证明了进化，包括复制、变异和自然选择，可以发生在分子群体中，也可以发生在生物群体中。<ref name="Follmann2009">{{cite journal |last1= Follmann |first1= Hartmut |last2= Brownson |first2= Carol |date= November 2009 |title= Darwin's warm little pond revisited: from molecules to the origin of life |journal= Naturwissenschaften |volume= 96 |issue= 11 |pages= 1265–1292 |bibcode= 2009NW.....96.1265F |pmid= 19760276 |doi= 10.1007/s00114-009-0602-1}}</ref>继化学进化之后，是生物进化的开始，导致了第一个细胞的出现。<ref name="Follmann2009" />目前还没有人用简单的成分合成一个具有必要生命特征的"原细胞"（所谓"自下而上的方法"）。在没有这样的原理证明的情况下，解释往往集中在化学合成上。<ref>{{cite press release |last1= McCollom |first1= Thomas |last2= Mayhew |first2= Lisa |last3= Scott |first3= Jim |date= 7 October 2014 |title= NASA awards CU-Boulder-led team $7 million to study origins, evolution of life in universe |url= http://www.colorado.edu/news/releases/2014/10/07/nasa-awards-cu-boulder-led-team-7-million-study-origins-evolution-life |location= Boulder, CO |publisher= University of Colorado Boulder |accessdate= 2015-06-08 |url-status= dead |archiveurl= https://web.archive.org/web/20150731015530/http://www.colorado.edu/news/releases/2014/10/07/nasa-awards-cu-boulder-led-team-7-million-study-origins-evolution-life |archivedate= 31 July 2015}}</ref> 然而，一些研究者从事这一领域的研究，著名的有斯蒂恩·拉斯穆森 Steen Rasmussen和Szostak。

另一些人则认为"自上而下的方法"更可行，从当前生命的简单形式开始。Spiegelman利用自然选择的优势合成了Spiegelman怪兽，它的基因组只有218个核苷酸碱基，是由4500个碱基的细菌RNA解构进化而来的。Eigen在Spiegelman的研究基础上，制造了一个类似的系统，该系统进一步退化为仅有48或54个核苷酸——这是复制酶结合所需的最低限度。<ref name="EIG">{{cite journal|last1=Oehlenschläger|first1=Frank|last2=Eigen|first2=Manfred|authorlink2=Manfred Eigen|date=December 1997|title=30 Years Later – a New Approach to Sol Spiegelman's and Leslie Orgel's in vitro Evolutionary Studies Dedicated to Leslie Orgel on the occasion of his 70th birthday|journal=[[Origins of Life and Evolution of Biospheres]]|volume=27|issue=5–6|pages=437–457|doi=10.1023/A:1006501326129|pmid=9394469|bibcode=1997OLEB...27..437O|s2cid=26717033}}</ref>美国克雷格·文特尔研究所 J.Craig Venter研究所的克雷格·文特尔 Craig Venter等人对现有的原核细胞进行了基因逐渐减少的工程，试图分辨出在哪一点上达到了生命的最基本要求。<ref>{{cite journal |last1= Gibson |first1= Daniel G.|last2= Glass |first2= John I. |last3= Lartigue |first3= Carole | last4 = Noskov | first4 = V.| last5 = Chuang | first5 = R.| last6 = Algire | first6 = M.| last7 = Benders | first7 = G.| last8 = Montague | first8 = M.| last9 = Ma | first9 = L.| last10 = Moodie | first10 = M.M.| last11 = Merryman | first11 = C.| last12 = Vashee | first12 = S.| last13 = Krishnakumar | first13 = R.| last14 = Assad-Garcia | first14 = N.| last15 = Andrews-Pfannkoch | first15 = C.| last16 = Denisova | first16 = E.A.| last17 = Young | first17 = L.| last18 = Qi | first18 = Z.-Q.| last19 = Segall-Shapiro | first19 = T.H.| last20 = Calvey | first20 = C.H.| last21 = Parmar | first21 = P.P.| last22 = Hutchison Ca | first22 = C.A.| last23 = Smith | first23 = H.O.| last24 = Venter | first24 = J.C. |display-authors= 3 |date= 2 July 2010 |title= Creation of a Bacterial Cell Controlled by a Chemically Synthesized Genome |journal= Science |volume= 329 |issue= 5987 |pages= 52–56 |bibcode= 2010Sci...329...52G |doi= 10.1126/science.1190719 |pmid= 20488990| citeseerx = 10.1.1.167.1455 |s2cid= 7320517}}</ref><ref>{{cite news |last= Swaby |first= Rachel |date= 20 May 2010 |title= Scientists Create First Self-Replicating Synthetic Life |url= https://www.wired.com/2010/05/scientists-create-first-self-replicating-synthetic-life-2/ |work= [[Wired (website)|Wired]] |location= New York |accessdate= 2015-06-08 |url-status= live |archiveurl= https://web.archive.org/web/20150617125555/http://www.wired.com/2010/05/scientists-create-first-self-replicating-synthetic-life-2/ |archivedate= 17 June 2015}}</ref><ref>Coughlan, Andy (2016) "Smallest ever genome comes to life: Humans built it but we don't know what a third of its genes actually do" (New Scientist 2 April 2016 No 3067)p.6</ref>

另一些人则认为"自上而下的方法"更可行，从当前生命的简单形式开始。Spiegelman利用自然选择的优势合成了Spiegelman怪兽，它的基因组只有218个核苷酸碱基，是由4500个碱基的细菌RNA解构进化而来的。Eigen在Spiegelman的研究基础上，制造了一个类似的系统，该系统进一步退化为仅有48或54个核苷酸——这是复制酶结合所需的最低限度。<ref name="EIG">{{cite journal|last1=Oehlenschläger|first1=Frank|last2=Eigen|first2=Manfred|date=December 1997|title=30 Years Later – a New Approach to Sol Spiegelman's and Leslie Orgel's in vitro Evolutionary Studies Dedicated to Leslie Orgel on the occasion of his 70th birthday|journal=Origins of Life and Evolution of Biospheres|volume=27|issue=5–6|pages=437–457|doi=10.1023/A:1006501326129|pmid=9394469|bibcode=1997OLEB...27..437O}}</ref>美国克雷格·文特尔研究所 J.Craig Venter研究所的克雷格·文特尔 Craig Venter等人对现有的原核细胞进行了基因逐渐减少的工程，试图分辨出在哪一点上达到了生命的最基本要求。<ref>{{cite journal |last1= Gibson |first1= Daniel G.|last2= Glass |first2= John I. |last3= Lartigue |first3= Carole | last4 = Noskov | first4 = V.| last5 = Chuang | first5 = R.| last6 = Algire | first6 = M.| last7 = Benders | first7 = G.| last8 = Montague | first8 = M.| last9 = Ma | first9 = L.| last10 = Moodie | first10 = M.M.| last11 = Merryman | first11 = C.| last12 = Vashee | first12 = S.| last13 = Krishnakumar | first13 = R.| last14 = Assad-Garcia | first14 = N.| last15 = Andrews-Pfannkoch | first15 = C.| last16 = Denisova | first16 = E.A.| last17 = Young | first17 = L.| last18 = Qi | first18 = Z.-Q.| last19 = Segall-Shapiro | first19 = T.H.| last20 = Calvey | first20 = C.H.| last21 = Parmar | first21 = P.P.| last22 = Hutchison Ca | first22 = C.A.| last23 = Smith | first23 = H.O.| last24 = Venter | first24 = J.C. |display-authors= 3 |date= 2 July 2010 |title= Creation of a Bacterial Cell Controlled by a Chemically Synthesized Genome |journal= Science |volume= 329 |issue= 5987 |pages= 52–56 |bibcode= 2010Sci...329...52G |doi= 10.1126/science.1190719 |pmid= 20488990| citeseerx = 10.1.1.167.1455 }}</ref><ref>{{cite news |last= Swaby |first= Rachel |date= 20 May 2010 |title= Scientists Create First Self-Replicating Synthetic Life |url= https://www.wired.com/2010/05/scientists-create-first-self-replicating-synthetic-life-2/ |work= Wired |location= New York |accessdate= 2015-06-08 |url-status= live |archiveurl= https://web.archive.org/web/20150617125555/http://www.wired.com/2010/05/scientists-create-first-self-replicating-synthetic-life-2/ |archivedate= 17 June 2015}}</ref><ref>Coughlan, Andy (2016) "Smallest ever genome comes to life: Humans built it but we don't know what a third of its genes actually do" (New Scientist 2 April 2016 No 3067)p.6</ref>

2018年10月，麦克马斯特大学的研究人员宣布开发出一种名为"行星模拟器"的新技术，以帮助研究地球及其他星球上生命的起源。<ref name="BW-20181004">{{cite news |last=Balch |first=Erica |title=Ground-breaking lab poised to unlock the mystery of the origins of life on Earth and beyond |url=https://brighterworld.mcmaster.ca/articles/ground-breaking-lab-poised-to-unlock-the-mystery-of-the-origins-of-life-on-earth-and-beyond/ |date=4 October 2018 |work=[[McMaster University]] |accessdate=4 October 2018 }}</ref><ref name="EA-20181004">{{cite news |author=Staff |title=Ground-breaking lab poised to unlock the mystery of the origins of life |url=https://www.eurekalert.org/pub_releases/2018-10/mu-glp100418.php |date=4 October 2018 |work=[[EurekAlert!]] |accessdate=14 October 2018 }}</ref><ref name="IVG-2018">{{cite web |author=Staff |title=Planet Simulator |url=https://www.intravisiongroup.com/planet-simulator |date=2018 |work=IntraVisionGroup.com |accessdate=14 October 2018 }}</ref><ref name="ES-209181014">{{cite web |last=Anderson |first=Paul Scott |title=New technology may help solve mystery of life's origins – How did life on Earth begin? A new technology, called Planet Simulator, might finally help solve the mystery. |url=http://earthsky.org/space/new-technology-solve-mystery-of-lifes-origins |date=14 October 2018 |work=[[EarthSky]] |accessdate=14 October 2018 }}</ref>它由一个复杂的气候室组成，以研究生命的构件是如何组装的，以及这些前生物分子如何过渡到自我复制的RNA分子。<ref name="BW-20181004"/>

2018年10月，麦克马斯特大学的研究人员宣布开发出一种名为"行星模拟器"的新技术，以帮助研究地球及其他星球上生命的起源。<ref name="BW-20181004">{{cite news |last=Balch |first=Erica |title=Ground-breaking lab poised to unlock the mystery of the origins of life on Earth and beyond |url=https://brighterworld.mcmaster.ca/articles/ground-breaking-lab-poised-to-unlock-the-mystery-of-the-origins-of-life-on-earth-and-beyond/ |date=4 October 2018 |work=McMaster University|accessdate=4 October 2018 }}</ref><ref name="EA-20181004">{{cite news |author=Staff |title=Ground-breaking lab poised to unlock the mystery of the origins of life |url=https://www.eurekalert.org/pub_releases/2018-10/mu-glp100418.php |date=4 October 2018 |work=EurekAlert |accessdate=14 October 2018 }}</ref><ref name="IVG-2018">{{cite web |author=Staff |title=Planet Simulator |url=https://www.intravisiongroup.com/planet-simulator |date=2018 |work=IntraVisionGroup.com |accessdate=14 October 2018 }}</ref><ref name="ES-209181014">{{cite web |last=Anderson |first=Paul Scott |title=New technology may help solve mystery of life's origins – How did life on Earth begin? A new technology, called Planet Simulator, might finally help solve the mystery. |url=http://earthsky.org/space/new-technology-solve-mystery-of-lifes-origins |date=14 October 2018 |work=EarthSky |accessdate=14 October 2018 }}</ref>它由一个复杂的气候室组成，以研究生命的构件是如何组装的，以及这些前生物分子如何过渡到自我复制的RNA分子。<ref name="BW-20181004"/>

== See also ==

== See also ==

* {{annotated link|Tholin}} Tholin – Class of molecules formed by ultraviolet irradiation of organic compounds 托林--有机化合物经紫外线照射形成的一类分子。

* {{annotated link|Tholin}} Tholin – Class of molecules formed by ultraviolet irradiation of organic compounds 托林--有机化合物经紫外线照射形成的一类分子。

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