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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|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>

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="Oparin1953"/><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>Yarus, Michael (2010). Life from an RNA World: The Ancestor Within. Cambridge, MA: Harvard University Press. ISBN 978-0-674-05075-4. LCCN 2009044011.</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>

对自然发生的研究旨在确定生命前的化学反应是如何在与今天地球上截然不同的条件下产生生命的。<ref>{{harvnb|Voet|Voet|2004|p=29}}</ref>它主要使用生物学、化学和地球物理学<ref name="Dyson 1999">{{harvnb|Dyson|1999}}</ref>的工具，最近的研究方法试图将这三者综合起来：<ref>{{cite book |author= Davies, Paul |date= 1998 |title= The Fifth Miracle, Search for the origin and meaning of life |publisher= Penguin}}{{page needed|date=February 2017}}</ref>更具体地说，就是天体生物学、生物化学、生物物理学、地球化学、分子生物学、海洋学和古生物学。生命的功能是通过碳和水的特定化学作用来实现的，并主要建立在四个关键的化学物质家族之上：脂类（细胞膜）、碳水化合物（糖类、纤维素）、氨基酸（蛋白质代谢）和核酸（DNA和RNA）。任何成功的自然发生理论都必须解释这些类别分子的起源和相互作用。<ref>{{cite book |author1= Ward, Peter|author2= Kirschvink, Joe |date= 2015 |title= A New History of Life: the radical discoveries about the origins and evolution of life on earth |publisher= Bloomsbury Press |pages= 39–40 |isbn= 978-1608199105}}</ref>许多自然发生的方法都在研究自我复制的分子或它们的组成部分是如何产生的。研究者普遍认为，目前的生命是从RNA世界中诞生的，<ref name="RNA" />尽管在RNA之前可能还有其他自我复制分子。<ref name="Robertson2012" /><ref name="Cech2012" />

对自然发生的研究旨在确定生命前的化学反应是如何在与今天地球上截然不同的条件下产生生命的。<ref>Voet, Donald; Voet, Judith G. (2004). Biochemistry. 1 (3rd ed.). New York: John Wiley & Sons. ISBN 978-0-471-19350-0. LCCN 2003269978.</ref>它主要使用生物学、化学和地球物理学<ref name="Dyson 1999">Dyson, Freeman (1999). Origins of Life (Revised ed.). Cambridge, UK; New York: Cambridge University Press. ISBN 978-0-521-62668-2. LCCN 99021079.</ref>的工具，最近的研究方法试图将这三者综合起来：<ref>{{cite book |author= Davies, Paul |date= 1998 |title= The Fifth Miracle, Search for the origin and meaning of life |publisher= Penguin}}{{page needed|date=February 2017}}</ref>更具体地说，就是天体生物学、生物化学、生物物理学、地球化学、分子生物学、海洋学和古生物学。生命的功能是通过碳和水的特定化学作用来实现的，并主要建立在四个关键的化学物质家族之上：脂类（细胞膜）、碳水化合物（糖类、纤维素）、氨基酸（蛋白质代谢）和核酸（DNA和RNA）。任何成功的自然发生理论都必须解释这些类别分子的起源和相互作用。<ref>{{cite book |author1= Ward, Peter|author2= Kirschvink, Joe |date= 2015 |title= A New History of Life: the radical discoveries about the origins and evolution of life on earth |publisher= Bloomsbury Press |pages= 39–40 |isbn= 978-1608199105}}</ref>许多自然发生的方法都在研究自我复制的分子或它们的组成部分是如何产生的。研究者普遍认为，目前的生命是从RNA世界中诞生的，<ref name="RNA" />尽管在RNA之前可能还有其他自我复制分子。<ref name="Robertson2012" /><ref name="Cech2012" />

[[File:Miller-Urey experiment JP.png|thumb|'''Miller–Urey实验''' 在简单气体混合物中合成有机小分子，通过同时加热（左）和冷却（右）将混合物置于热梯度中，这种混合物也会受到放电的作用]]

[[File:Miller-Urey_experiment-en.svg.png|thumb|'''Miller–Urey实验''' 在简单气体混合物中合成有机小分子，通过同时加热（左）和冷却（右）将混合物置于热梯度中，这种混合物也会受到放电的作用]]

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>

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>Altermann, Wladyslaw (2009). "Introduction: A Roadmap to Fata Morgana?". In Seckbach, Joseph; Walsh, Maud (eds.). From Fossils to Astrobiology: Records of Life on Earth and the Search for Extraterrestrial Biosignatures. Cellular Origin, Life in Extreme Habitats and Astrobiology. 12. Dordrecht, the Netherlands; London: Springer Science+Business Media. ISBN 978-1-4020-8836-0. LCCN 2008933212</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>Dalrymple, G. Brent (2001). "The age of the Earth in the twentieth century: a problem (mostly) solved". In Lewis, C.L.E.; Knell, S.J. (eds.). The Age of the Earth: from 4004 BC to AD 2002. Geological Society of London, Special Publications. Geological Society Special Publication. 190. London: Geological Society of London. pp. 205–221. Bibcode:2001GSLSP.190..205D,pp205–221}}</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">Raven, Peter H.; Johnson, George B. (2002). Biology (6th ed.). Boston: McGraw-Hill. ISBN 978-0-07-112261-0,p68</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>

==== 获得自由能 ====

==== 获得自由能 ====

伯纳尔Bernal在 Miller-Urey 的实验中说，

Bernal在 Miller-Urey 的实验中说，

< blockquote >it is not enough to explain the formation of such molecules, what is necessary, is a physical-chemical explanation of the origins of these molecules that suggests the presence of suitable sources and sinks for free energy.

<blockquote>it is not enough to explain the formation of such molecules, what is necessary, is a physical-chemical explanation of the origins of these molecules that suggests the presence of suitable sources and sinks for free energy.

仅仅解释这些分子的形成是不够的，需要的是对这些分子的起源作出物理-化学解释，表明存在合适的自由能源和自由能汇。<ref>{{harvnb|Bernal|1967|p=143}}</ref>

仅仅解释这些分子的形成是不够的，需要的是对这些分子的起源作出物理-化学解释，表明存在合适的自由能源和自由能汇。<ref name="Bernal 1967"/>

</blockquote>

</blockquote>

在关于生命起源的书籍中也可以找到这种差异。约翰·卡斯蒂John Casti给出了一句话：

在关于生命起源的书籍中也可以找到这种差异。约翰·卡斯蒂 John Casti给出了一句话：

<blockquote>

<blockquote>

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>

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}}</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===

====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 |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>

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>Chaichian, Masud; Rojas, Hugo Perez; Tureanu, Anca (2014). "Physics and Life". Basic Concepts in Physics: From the Cosmos to Quarks. Undergraduate Lecture Notes in Physics. Berlin; Heidelberg: Springer Berlin Heidelberg. doi:10.1007/978-3-642-19598-3_12. ISBN 978-3-642-19597-6. LCCN 2013950482. OCLC 900189038.pp353–364}}</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>

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>Hazen, Robert M. (2005). Genesis: The Scientific Quest for Life's Origin. Washington, DC: Joseph Henry Press. ISBN 978-0-309-09432-0. LCCN 2005012839. OCLC 60321860.</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===

===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. |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" />

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 |bibcode=1993Sci...259..920K |accessdate=2015-07-28 |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>Fesenkov, V.G. (1959). "Some Considerations about the Primaeval State of the Earth". In Oparin, A.I.; et al. (eds.). The Origin of Life on the Earth. I.U.B. Symposium Series. 1. Edited for the International Union of Biochemistry by Frank Clark and R.L.M. Synge (English-French-German ed.). London; New York: Pergamon Press. ISBN 978-1-4832-2240-0. LCCN 59012060,p9</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" />

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。

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>Davies, Paul (December 2007). "Are Aliens Among Us?" . Scientific American. 297 (6): 62–69. Bibcode:2007SciAm.297f..62D. doi:10.1038/scientificamerican1207-62.,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。

据估计，晚期重型轰炸还可能对数十米深的地球表面进行了有效的灭菌。如果生命进化到比这更深的地方，它也会被屏蔽在太阳进化的T金牛座阶段的早期高水平紫外线辐射之外。对地热加热的海洋地壳进行模拟，得到的有机物远比Miller–Urey实验中发现的多。在深层热液喷口中，埃弗雷特·休克 Everett Shock发现 "存在着形成有机化合物的巨大热力学驱动力，因为海水和热液远未达到平衡，混合并向更稳定的状态发展。"<ref>{{harvnb|Davies|1999|p=155}}</ref>Shock发现，可用的能量在100-150 C左右达到最大，而这正是发现嗜热细菌和嗜热古细菌的温度，处于最接近最后普遍共同祖先（LUCA）的生命系统发育树的底部。<ref>{{harvnb|Bock|Goode|1996}}</ref>

据估计，晚期重型轰炸还可能对数十米深的地球表面进行了有效的灭菌。如果生命进化到比这更深的地方，它也会被屏蔽在太阳进化的T金牛座阶段的早期高水平紫外线辐射之外。对地热加热的海洋地壳进行模拟，得到的有机物远比Miller–Urey实验中发现的多。在深层热液喷口中，埃弗雷特·休克 Everett Shock发现 "存在着形成有机化合物的巨大热力学驱动力，因为海水和热液远未达到平衡，混合并向更稳定的状态发展。"<ref>Davies, Paul (1999). The Fifth Miracle: The Search for the Origin of Life. London: Penguin Books. ISBN 978-0-14-028226-9.,p155</ref>Shock发现，可用的能量在100-150 C左右达到最大，而这正是发现嗜热细菌和嗜热古细菌的温度，处于最接近最后普遍共同祖先（LUCA）的生命系统发育树的底部。<ref>Bock, Gregory R.; Goode, Jamie A., eds. (1996). Evolution of Hydrothermal Ecosystems on Earth (and Mars?). Ciba Foundation Symposium. 202. Chichester, UK; New York: John Wiley & Sons. ISBN 978-0-471-96509-1. LCCN 96031351.</ref>

== 生命的最早证据：古生物学==

== 生命的最早证据：古生物学==

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>

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>Davies, Paul (1999). The Fifth Miracle: The Search for the Origin of Life. London: Penguin Books. ISBN 978-0-14-028226-9.</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==

== 20世纪60年代以前的概念演变史：生物学==

====19世纪之前，人们普遍接受自然发生论====

====19世纪之前，人们普遍接受自然发生论====

传统宗教把生命的起源归结为超自然的神灵，他们创造了自然界。“自然发生”，是第一个从非生命中产生生命的自然主义理论，它可以追溯到Aristotle和古希腊哲学，并在西方学术界一直得到支持，直到19世纪。<ref>{{harvnb|Sheldon|2005}}</ref>"自然发生”的古典观念认为，某些 "低等 "或 "害虫 "动物是由腐烂的有机物质产生的。根据Aristotle的观点，很容易观察到蚜虫从植物上的露水中产生，苍蝇从腐烂的物质中产生，老鼠从肮脏的干草中产生，鳄鱼从腐烂的沉木中产生，等等。<ref>{{harvnb|Lennox|2001|pp=229–258}}</ref> A related theory was ''heterogenesis'': that some forms of life could arise from different forms (e.g. bees from flowers).<ref>{{harvnb|Vartanian|1973|pp=307–312}}</ref>一个相关的理论是异生论：某些生命形式可以从不同的形式中产生（如蜜蜂从花中产生）。现代科学家约翰·德斯蒙德·贝纳尔John Desmond Bernal说，这种理论的基本思想是生命是作为偶然事件的结果而不断产生的。<ref name="Bernal 1967">{{harvnb|Bernal|1967}}</ref>

传统宗教把生命的起源归结为超自然的神灵，他们创造了自然界。“自然发生”，是第一个从非生命中产生生命的自然主义理论，它可以追溯到Aristotle和古希腊哲学，并在西方学术界一直得到支持，直到19世纪。<ref>Sheldon, Robert B. (22 September 2005). Hoover, Richard B.; Levin, Gilbert V.; Rozanov, Alexei Y.; Gladstone, G. Randall (eds.). Historical Development of the Distinction between Bio- and Abiogenesis. Astrobiology and Planetary Missions. 5906. Bellingham, WA: SPIE. doi:10.1117/12.663480. ISBN 978-0-8194-5911-4. LCCN 2005284378</ref>"自然发生”的古典观念认为，某些 "低等 "或 "害虫 "动物是由腐烂的有机物质产生的。根据Aristotle的观点，很容易观察到蚜虫从植物上的露水中产生，苍蝇从腐烂的物质中产生，老鼠从肮脏的干草中产生，鳄鱼从腐烂的沉木中产生，等等。<ref>Lennox, James G. (2001). Aristotle's Philosophy of Biology: Studies in the Origins of Life Science. Cambridge Studies in Philosophy and Biology. Cambridge, UK; New York: Cambridge University Press. ISBN 978-0-521-65976-5. LCCN 00026070.,pp229–258</ref> A related theory was ''heterogenesis'': that some forms of life could arise from different forms (e.g. bees from flowers).<ref>Vartanian, Aram (1973). "Spontaneous Generation". In Wiener, Philip P. (ed.). Dictionary of the History of Ideas. IV. New York: Charles Scribner's Sons. ISBN 978-0-684-13293-8. LCCN 72007943.,pp307–312</ref>一个相关的理论是异生论：某些生命形式可以从不同的形式中产生（如蜜蜂从花中产生）。现代科学家约翰·德斯蒙德·贝纳尔John Desmond Bernal说，这种理论的基本思想是生命是作为偶然事件的结果而不断产生的。<ref name="Bernal 1967">Bernal, J.D. (1967) [Reprinted work by A.I. Oparin originally published 1924; Moscow: The Moscow Worker]. The Origin of Life. The Weidenfeld and Nicolson Natural History. Translation of Oparin by Ann Synge. London: Weidenfeld & Nicolson. LCCN 67098482.</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.

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>

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>Ross, Alexander (1652). Arcana Microcosmi. Book II. London. Retrieved 7 July 2015.</ref>

</blockquote>  

</blockquote>  

[[File:Anton van Leeuwenhoek.png|thumb|upright|安东尼·范·列文虎克 Antonie van Leeuwenhoek]]

[[File:Anton van Leeuwenhoek.png|thumb|upright|安东尼·范·列文虎克 Antonie van Leeuwenhoek]]

1665年，罗伯特·胡克Robert Hooke发表了第一本微生物的图画。1676年，安东尼·范·列文虎克(Antonie van Leeuwenhoek)紧随其后，他绘制并描述了现在被认为是原生动物和细菌的微生物。<ref>{{harvnb|Dobell|1960}}</ref> 许多人认为微生物的存在是支持自然发生的证据，因为微生物对于有性生殖来说似乎过于简单，而通过细胞分裂的无性生殖尚未被观察到。Van Leeuwenhoek对当时常见的跳蚤和虱子可能由腐烂作用自发产生，以及青蛙同样可能由粘液产生的观点提出了异议。他利用广泛的实验，从密封和开放的肉孵化以及对昆虫繁殖的仔细研究，到1680年代，他确信自然发生是不正确的。<ref>{{harvnb|Bondeson|1999}}</ref>

1665年，罗伯特·胡克Robert Hooke发表了第一本微生物的图画。1676年，安东尼·范·列文虎克(Antonie van Leeuwenhoek)紧随其后，他绘制并描述了现在被认为是原生动物和细菌的微生物。<ref>Dobell, Clifford (1960) [Originally published 1932; New York: Harcourt, Brace & Company]. Antony van Leeuwenhoek and His 'Little Animals'. New York: Dover Publications. LCCN 60002548.</ref> 许多人认为微生物的存在是支持自然发生的证据，因为微生物对于有性生殖来说似乎过于简单，而通过细胞分裂的无性生殖尚未被观察到。Van Leeuwenhoek对当时常见的跳蚤和虱子可能由腐烂作用自发产生，以及青蛙同样可能由粘液产生的观点提出了异议。他利用广泛的实验，从密封和开放的肉孵化以及对昆虫繁殖的仔细研究，到1680年代，他确信自然发生是不正确的。<ref>Bondeson, Jan (1999). The Feejee Mermaid and Other Essays in Natural and Unnatural History. Ithaca, NY: Cornell University Press. ISBN 978-0-8014-3609-3. LCCN 98038295.</ref>

到19世纪中叶，生源论已经积累了大量的证据，以至于自然发生的替代理论已经被有效地否定。Pasteur评论道，他在1864年的一项发现被他认为是决定性的：

到19世纪中叶，生源论已经积累了大量的证据，以至于自然发生的替代理论已经被有效地否定。Pasteur评论道，他在1864年的一项发现被他认为是决定性的：

< blockquote >

<blockquote>

Never will the doctrine of spontaneous generation recover from the mortal blow struck by this simple experiment.

Never will the doctrine of spontaneous generation recover from the mortal blow struck by this simple experiment.

自然发生的学说永远不会从这个简单的实验所带来的致命打击中恢复过来。<ref>{{harvnb|Oparin|1953|p=196}}</ref><ref name="Tyndall Fragments2">{{harvnb|Tyndall|1905|loc=IV, XII (1876), XIII (1878)}}</ref>  

自然发生的学说永远不会从这个简单的实验所带来的致命打击中恢复过来。<ref name="Oparin1953">Oparin, A.I. (1953) [Originally published 1938; New York: The Macmillan Company]. The Origin of Life. Translation and new introduction by Sergius Morgulis (2nd ed.). Mineola, NY: Dover Publications. ISBN 978-0-486-49522-4. LCCN 53010161.,p196</ref><ref name="Tyndall Fragments2">Tyndall, John (1905) [Originally published 1871; London; New York: Longmans, Green & Co.; D. Appleton and Company]. Fragments of Science. 2 (6th ed.). New York: P.F. Collier & Sons. OCLC 726998155. Retrieved 6 June 2015.</ref>  

< blockquote >

<blockquote>

实验给出了一个机制，通过这个机制，生命从几个简单的生物体多样化到各种复杂的形式。今天，科学家们一致认为，目前所有的生命都是早期生命的后裔，而早期生命通过Charles Darwin的自然选择进化机制，逐渐变得更加复杂和多样化。Darwin在1863年给Hooker写信指出：

实验给出了一个机制，通过这个机制，生命从几个简单的生物体多样化到各种复杂的形式。今天，科学家们一致认为，目前所有的生命都是早期生命的后裔，而早期生命通过Charles Darwin的自然选择进化机制，逐渐变得更加复杂和多样化。Darwin在1863年给Hooker写信指出：

====生源论（生物起源）和非生源论（非生物起源）的词源学====

====生源论（生物起源）和非生源论（非生物起源）的词源学====

生物起源一词通常归功于亨利·巴斯蒂安 Henry Bastian或托马斯·赫胥黎 Thomas Huxley。<ref name="eohtBiogenesis">{{cite encyclopedia |encyclopedia=Hmolpedia |title=Biogenesis |url=http://www.eoht.info/page/Biogenesis |accessdate=2014-05-19 |publisher=WikiFoundry, Inc. |location=Ancaster, Ontario, Canada |url-status=live |archiveurl=https://web.archive.org/web/20140520001148/http://www.eoht.info/page/Biogenesis |archivedate=20 May 2014}}</ref>Bastian大约在1869年与约翰·廷德尔John Tyndall的一次未发表的交流中使用了这个词，意思是“生命-起源或开始”。1870年，Huxley作为英国科学促进会的新任主席，发表了题为《生物起源和非生物起源 Biogenesis and Abiogenesis》的演讲。<ref name="Huxley 1968">{{harvnb|Huxley|1968}}</ref> 在演讲中，他介绍了“生物起源”（与Bastian的意思相反）以及“非生物起源”这个术语。

生物起源一词通常归功于亨利·巴斯蒂安 Henry Bastian或托马斯·赫胥黎 Thomas Huxley。<ref name="eohtBiogenesis">{{cite encyclopedia |encyclopedia=Hmolpedia |title=Biogenesis |url=http://www.eoht.info/page/Biogenesis |accessdate=2014-05-19 |publisher=WikiFoundry, Inc. |location=Ancaster, Ontario, Canada |url-status=live |archiveurl=https://web.archive.org/web/20140520001148/http://www.eoht.info/page/Biogenesis |archivedate=20 May 2014}}</ref>Bastian大约在1869年与约翰·廷德尔John Tyndall的一次未发表的交流中使用了这个词，意思是“生命-起源或开始”。1870年，Huxley作为英国科学促进会的新任主席，发表了题为《生物起源和非生物起源 Biogenesis and Abiogenesis》的演讲。<ref name="Huxley 1968">Huxley, Thomas Henry (1968) [Originally published 1897]. "VIII Biogenesis and Abiogenesis [1870]". Discourses, Biological and Geological. Collected Essays. VIII (Reprint ed.). New York: Greenwood Press. LCCN 70029958.</ref> 在演讲中，他介绍了“生物起源”（与Bastian的意思相反）以及“非生物起源”这个术语。

随后，在Bastian1871年出版的《最低级生物的起源模式 The Modes of Origin of Lowest Organisms》<ref>{{harvnb|Bastian|1871}}</ref>一书的序言中，Bastian提到了可能与Huxley的用法相混淆，并明确放弃了自己的意思。

随后，在Bastian1871年出版的《最低级生物的起源模式 The Modes of Origin of Lowest Organisms》<ref name="Bastian1871">Bastian, H. Charlton (1871). The Modes of Origin of Lowest Organisms. London; New York: Macmillan and Company. LCCN 11004276. OCLC 42959303. Retrieved 6 June 2015.</ref>一书的序言中，Bastian提到了可能与Huxley的用法相混淆，并明确放弃了自己的意思。

关于新术语 "生物自生 "的引入，似乎有必要作一解释。我最初在未发表的著作中，采用了 "生物起源 "一词来表达同样的意思，即生命的起源或开始。但与此同时，“生物起源”这个词已经被一位杰出的生物学家Huxley独立地使用了，他希望使它具有完全不同的意义。他还介绍了“非生物起源”这个词。然而，我从最权威的人士那里得知，这些词无论它们来自什么语言，都不应具有最近公开赋予它们的含义。为了避免一切不必要的混淆，我因此放弃了使用 "生物起源 "这个词，而且由于刚才所讲的原因，我无法采用另一个词，我不得不引入一个新词，以便指定生命物质被认为是独立于先前存在的生命物质而产生的过程。<ref>{{harvnb|Bastian|1871|p=[https://ia902701.us.archive.org/BookReader/BookReaderImages.php?zip=/23/items/modesoforiginofl00bast/modesoforiginofl00bast_jp2.zip&file=modesoforiginofl00bast_jp2/modesoforiginofl00bast_0015.jp2&scale=4&rotate=0 xi–xii]}}</ref>

关于新术语 "生物自生 "的引入，似乎有必要作一解释。我最初在未发表的著作中，采用了 "生物起源 "一词来表达同样的意思，即生命的起源或开始。但与此同时，“生物起源”这个词已经被一位杰出的生物学家Huxley独立地使用了，他希望使它具有完全不同的意义。他还介绍了“非生物起源”这个词。然而，我从最权威的人士那里得知，这些词无论它们来自什么语言，都不应具有最近公开赋予它们的含义。为了避免一切不必要的混淆，我因此放弃了使用 "生物起源 "这个词，而且由于刚才所讲的原因，我无法采用另一个词，我不得不引入一个新词，以便指定生命物质被认为是独立于先前存在的生命物质而产生的过程。<ref name="Bastian1871"/>

Oparin和Haldane提出，早期地球的大气可能具有化学还原性，主要由甲烷(CH₄)、氨(NH₃)、水(H₂O)、硫化氢(H₂S、二氧化碳(CO₂)或一氧化碳(CO)和磷酸盐(PO₄³⁻)组成，分子氧(O₂)和臭氧(O₃)很少或没有。根据后来的模型，冥古代晚期的大气主要由氮气(N₂)和二氧化碳组成，还有少量的一氧化碳、氢气(H₂)和硫磺化合物;<ref>{{harvnb|Kasting|1993|p=922}}</ref>虽然它确实缺乏分子氧和臭氧，<ref>{{harvnb|Kasting|1993|p=920}}</ref>但它并不像Oparin和Haldane所认为的那样具有化学还原性。

Oparin和Haldane提出，早期地球的大气可能具有化学还原性，主要由甲烷(CH₄)、氨(NH₃)、水(H₂O)、硫化氢(H₂S、二氧化碳(CO₂)或一氧化碳(CO)和磷酸盐(PO₄³⁻)组成，分子氧(O₂)和臭氧(O₃)很少或没有。根据后来的模型，冥古代晚期的大气主要由氮气(N₂)和二氧化碳组成，还有少量的一氧化碳、氢气(H₂)和硫磺化合物；虽然它确实缺乏分子氧和臭氧，<ref> Kasting, James F. (12 February 1993). "Earth's Early Atmosphere" (PDF). Science. 259 (5097): 920–926. Bibcode:1993Sci...259..920K. doi:10.1126/science.11536547. PMID 11536547. S2CID 21134564,p920-922</ref>但它并不像Oparin和Haldane所认为的那样具有化学还原性。

直到1924年，才出现了关于这个问题的新的著名研究或假说，Oparin推理出大气中的氧气阻碍了某些有机化合物的合成，而这些有机化合物是生命的必要构件。在他的《生命的起源 The Origin of Life》一书中，<ref>{{harvnb|Bernal|1967|loc=[http://www.valencia.edu/~orilife/textos/The%20Origin%20of%20Life.pdf ''The Origin of Life'' (A.I. Oparin, 1924), pp. 199–234]}}</ref><ref>{{harvnb|Oparin|1953}}</ref> 他提出(与Darwin相呼应)，被Pasteur抨击的 "生命的自然发生"事实上确实曾经发生过，但现在是不可能的，因为早期地球上发现的条件已经发生了变化，先前存在的生物体会立即消耗任何自发产生的生物体。Oparin认为，在无氧的大气中，通过太阳光的作用，可以产生有机分子的 "原始汤"。这些分子会以越来越复杂的方式结合在一起，直到形成凝聚的液滴。这些液滴会通过与其他液滴的融合而"生长"，并通过裂变"繁殖"成子液滴，因此具有原始的新陈代谢，在这种新陈代谢中，能促进 "细胞完整性"的因子得以生存，而不能促进的因子则会灭绝。现代许多关于生命起源的理论仍然以Oparin的思想为出发点。

直到1924年，才出现了关于这个问题的新的著名研究或假说，Oparin推理出大气中的氧气阻碍了某些有机化合物的合成，而这些有机化合物是生命的必要构件。在他的《生命的起源 The Origin of Life》一书中，<ref name="Bernal 1967"/><ref name="Oparin1953"/> 他提出(与Darwin相呼应)，被Pasteur抨击的 "生命的自然发生"事实上确实曾经发生过，但现在是不可能的，因为早期地球上发现的条件已经发生了变化，先前存在的生物体会立即消耗任何自发产生的生物体。Oparin认为，在无氧的大气中，通过太阳光的作用，可以产生有机分子的 "原始汤"。这些分子会以越来越复杂的方式结合在一起，直到形成凝聚的液滴。这些液滴会通过与其他液滴的融合而"生长"，并通过裂变"繁殖"成子液滴，因此具有原始的新陈代谢，在这种新陈代谢中，能促进 "细胞完整性"的因子得以生存，而不能促进的因子则会灭绝。现代许多关于生命起源的理论仍然以Oparin的思想为出发点。

大约在这个时候，Haldane提出，地球上的前生物海洋（与现代的同类海洋截然不同）会形成一种 "热稀汤"，有机化合物可能在其中形成。Bernal将这一观点称为“生物创建”或“生物创造”，即有生命的物质从自我复制但无生命的分子中演化出来的过程，<ref name="Bernal 1967" /><ref>{{harvnb|Bryson|2004|pp=300–302}}</ref>并提出生物创建经过许多中间阶段。

大约在这个时候，Haldane提出，地球上的前生物海洋（与现代的同类海洋截然不同）会形成一种 "热稀汤"，有机化合物可能在其中形成。Bernal将这一观点称为“生物创建”或“生物创造”，即有生命的物质从自我复制但无生命的分子中演化出来的过程，<ref name="Bernal 1967" /><ref>Bryson, Bill (2004). A Short History of Nearly Everything. London: Black Swan. ISBN 978-0-552-99704-1. OCLC 55589795.,p300-302</ref>并提出生物创建经过许多中间阶段。

罗伯特·夏皮罗 Robert Shapiro将Oparin和Haldane的 "原始汤"理论的 "成熟形态 "总结如下：<ref>{{harvnb|Shapiro|1987|p=110}}</ref>

罗伯特·夏皮罗 Robert Shapiro将Oparin和Haldane的 "原始汤"理论的 "成熟形态 "总结如下：<ref>Shapiro, Robert (1987). Origins: A Skeptic's Guide to the Creation of Life on Earth. Toronto; New York: Bantam Books. ISBN 978-0-553-34355-7.</ref>

# 早期的地球有一个化学还原的大气层。

# 早期的地球有一个化学还原的大气层。

# 这种大气层暴露在各种形式的能量之下，产生了简单的有机化合物（"单质"）。

# 这种大气层暴露在各种形式的能量之下，产生了简单的有机化合物（"单质"）。

# 这些化合物积聚在 "汤 "中，可能集中在不同的地点（海岸线、海洋喷口等）。

# 这些化合物积聚在 "汤 "中，可能集中在不同的地点（海岸线、海洋喷口等）。

# 通过进一步的转化，更复杂的有机聚合物--最终在汤中发展出生命。

# 通过进一步的转化，更复杂的有机聚合物--最终在汤中发展出生命。

Bernal在1949年创造了“生物创建”这一术语，用来指代生命的起源。<ref>{{harvnb|Bernal|1951}}</ref>1967年，他提出生命起源的三个 "阶段 "：

Bernal在1949年创造了“生物创建”这一术语，用来指代生命的起源。<ref>Bernal, J.D. (1951). The Physical Basis of Life. London: Routledge & Kegan Paul. LCCN 51005794.</ref>1967年，他提出生命起源的三个 "阶段 "：

# 生物单体的起源

# 生物单体的起源

# 生物聚合物的起源

# 生物聚合物的起源

# 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. |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>

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>Kauffman, Stuart (1995). At Home in the Universe: The Search for Laws of Self-Organization and Complexity. New York: Oxford University Press. ISBN 978-0-19-509599-9. LCCN 94025268.</ref>

# 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。

=== 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 }}</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====

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" />

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 Polycyclic aromatic hydrocarbon（PAH）是可观测宇宙中已知的多原子分子中最常见、最丰富的一种，被认为是原始海的一种可能成分。<ref name="SP-20051018" /><ref name="AJ-20051010" /><ref name="NASA-20110413" /> 2010 年，在星云中检测到多环芳烃。<ref name="AJL-20101120">{{cite journal |last1=García-Hernández |first1=Domingo. A. |last2=Manchado |first2=Arturo |last3=García-Lario |first3=Pedro |last4=Stanghellini |first4=Letizia |last5=Villaver |first5=Eva |last6=Shaw |first6=Richard A. |last7=Szczerba |first7=Ryszard |last8=Perea-Calderón |first8=Jose Vicente |display-authors=3 |date=20 November 2010 |title=Formation of Fullerenes in H-Containing Planetary Nebulae |journal=The Astrophysical Journal Letters |volume=724 |issue=1 |pages=L39–L43 |arxiv=1009.4357 |bibcode=2010ApJ...724L..39G |doi=10.1088/2041-8205/724/1/L39}}</ref>

多环芳烃 Polycyclic aromatic hydrocarbon（PAH）是可观测宇宙中已知的多原子分子中最常见、最丰富的一种，被认为是原始海的一种可能成分。<ref name="SP-20051018" /><ref name="AJ-20051010" /><ref name="NASA-20110413" /> 2010 年，在星云中检测到多环芳烃。<ref name="AJL-20101120">{{cite journal |last1=García-Hernández |first1=Domingo. A. |last2=Manchado |first2=Arturo |last3=García-Lario |first3=Pedro |last4=Stanghellini |first4=Letizia |last5=Villaver |first5=Eva |last6=Shaw |first6=Richard A. |last7=Szczerba |first7=Ryszard |last8=Perea-Calderón |first8=Jose Vicente |display-authors=3 |date=20 November 2010 |title=Formation of Fullerenes in H-Containing Planetary Nebulae |journal=The Astrophysical Journal Letters |volume=724 |issue=1 |pages=L39–L43 |arxiv=1009.4357 |bibcode=2010ApJ...724L..39G |doi=10.1088/2041-8205/724/1/L39}}</ref>

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" />

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====

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>

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====

====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}}</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>Barton, Nicholas H.; Briggs, Derek E.G.; Eisen, Jonathan A.; et al. (2007). Evolution. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory Press. ISBN 978-0-87969-684-9. LCCN 2007010767. OCLC 86090399.</ref><ref>Bada, Jeffrey L.; Lazcano, Antonio (2009). "The Origin of Life". In Ruse, Michael; Travis, Joseph (eds.). Evolution: The First Four Billion Years. Foreword by Edward O. Wilson. Cambridge: Belknap Press of Harvard University Press. ISBN 978-0-674-03175-3. LCCN 2008030270. OCLC 225874308.</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>

====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. |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 }}</ref>同时不产生其他多种化合物。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}}</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>

有人提出，生命最初是以自催化的化学网络产生的。.<ref>Kauffman, Stuart (1993). The Origins of Order: Self-Organization and Selection in Evolution. New York: Oxford University Press. ISBN 978-0-19-507951-7. LCCN 91011148. OCLC 23253930.</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>Dawkins, Richard (2004). The Ancestor's Tale: A Pilgrimage to the Dawn of Evolution. Boston: Houghton Mifflin. ISBN 978-0-618-00583-3. LCCN 2004059864. OCLC 56617123.</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==

氨基酸组合形成类蛋白，而类蛋白组合成小球，福克斯称之为 "微球体"。他的类蛋白不是细胞，虽然它们形成的团块和链子让人联想到蓝藻，但它们不含任何功能性核酸或任何编码信息。基于这样的实验，科林·布里斯顿 Colin Pittendrigh在1967年说："实验室将在十年内创造出一个活细胞。"这句话反映了当代人对细胞结构复杂性的典型天真。.<ref>{{harvnb|Woodward|1969|p=287}}</ref>

氨基酸组合形成类蛋白，而类蛋白组合成小球，福克斯称之为 "微球体"。他的类蛋白不是细胞，虽然它们形成的团块和链子让人联想到蓝藻，但它们不含任何功能性核酸或任何编码信息。基于这样的实验，科林·布里斯顿 Colin Pittendrigh在1967年说："实验室将在十年内创造出一个活细胞。"这句话反映了当代人对细胞结构复杂性的典型天真。.<ref>Woodward, Robert J., ed. (1969). Our Amazing World of Nature: Its Marvels & Mysteries. Pleasantville, NY: Reader's Digest Association. ISBN 978-0-340-13000-1. LCCN 69010418.</ref>

=== 原始细胞 ===

=== 原始细胞 ===

[[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。]]

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？***

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>Chang, Thomas Ming Swi (2007). Artificial Cells: Biotechnology, Nanomedicine, Regenerative Medicine, Blood Substitutes, Bioencapsulation, and Cell/Stem Cell Therapy. Regenerative Medicine, Artificial Cells and Nanomedicine. 1. Hackensack, NJ: World Scientific. ISBN 978-981-270-576-1. LCCN 2007013738. OCLC 173522612.</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？***

at the present day such matter would be instantly devoured or absorbed, which would not have been the case before living creatures were formed.

at the present day such matter would be instantly devoured or absorbed, which would not have been the case before living creatures were formed.

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。<ref>Darwin, Charles (1887). Darwin, Francis (ed.). The Life and Letters of Charles Darwin, Including an Autobiographical Chapter. 3 (3rd ed.). London: John Murray. OCLC 834491774.</ref>

</blockquote>

</blockquote>

  <blockquote>

  <blockquote>

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===

# 由浓度梯度引起的扩散力--包括离子在内的所有粒子都倾向于从高浓度向低浓度扩散。

# 由浓度梯度引起的扩散力--包括离子在内的所有粒子都倾向于从高浓度向低浓度扩散。

# 电位梯度引起的静电力--质子H⁺等阳离子倾向于顺着电位扩散，阴离子则相反。

# 电位梯度引起的静电力--质子H⁺等阳离子倾向于顺着电位扩散，阴离子则相反。

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>Calvin, Melvin (1969). Chemical Evolution: Molecular Evolution Towards the Origin of Living Systems on the Earth and Elsewhere. Oxford, UK: Clarendon Press. ISBN 978-0-19-855342-7. LCCN 70415289. OCLC 25220.</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。

=== 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>Dawkins, Richard (1996). The Blind Watchmaker (Reissue with a new introduction ed.). New York: W.W. Norton & Company. </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。

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：

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">Lane, Nick (2009). Life Ascending: The 10 Great Inventions of Evolution (1st American ed.). New York: W.W. Norton & Company. ISBN 978-0-393-06596-1. LCCN 2009005046. OCLC 286488326.</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>

<blockquote>

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。

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 |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>Lankenau, Dirk-Henner (2011). "Two RNA Worlds: Toward the Origin of Replication, Genes, Recombination and Repair". In Egel, Richard; Lankenau, Dirk-Henner; Mulkidjanian, Armen Y. (eds.). Origins of Life: The Primal Self-Organization. Heidelberg: Springer. doi:10.1007/978-3-642-21625-1. ISBN 978-3-642-21624-4. LCCN 2011935879. OCLC 733245537.</ref><ref>{{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>

20世纪70年代初，曼弗雷德·艾根 Manfred Eigen和彼得·舒斯特 Peter Schuster研究了分子混沌和前生物汤中的自复制超循环之间的瞬时阶段。<ref>{{harvnb|Eigen|Schuster|1979}}</ref>在超循环中，信息存储系统（可能是RNA）产生一种酶，这种酶依次催化另一个信息系统的形成，直到最后一个信息系统的产物帮助第一个信息系统的形成。经过数学处理，超循环可以创造准物种，通过自然选择进入一种达尔文的进化论的形式。对超循环理论的推动是发现了能够催化他们自身的化学反应的核酶。超循环理论要求存在如核苷酸等复杂的生化物质，而在Miller–Urey实验提出的条件下，核苷酸是不会形成的。

20世纪70年代初，曼弗雷德·艾根 Manfred Eigen和彼得·舒斯特 Peter Schuster研究了分子混沌和前生物汤中的自复制超循环之间的瞬时阶段。<ref>Eigen, M.; Schuster, P. (1979). The Hypercycle: A Principle of Natural Self-Organization. Berlin; New York: Springer-Verlag. ISBN 978-0-387-09293-5. LCCN 79001315. OCLC 4665354.</ref>在超循环中，信息存储系统（可能是RNA）产生一种酶，这种酶依次催化另一个信息系统的形成，直到最后一个信息系统的产物帮助第一个信息系统的形成。经过数学处理，超循环可以创造准物种，通过自然选择进入一种达尔文的进化论的形式。对超循环理论的推动是发现了能够催化他们自身的化学反应的核酶。超循环理论要求存在如核苷酸等复杂的生化物质，而在Miller–Urey实验提出的条件下，核苷酸是不会形成的。

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>Orgel, Leslie E. (1987). "Evolution of the Genetic Apparatus: A Review". Evolution of Catalytic Function. Cold Spring Harbor Symposia on Quantitative Biology. 52. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory Press. pp. 9–16. doi:10.1101/SQB.1987.052.01.004. ISBN 978-0-87969-054-0. OCLC 19850881. PMID 2456886. "Proceedings of a symposium held at Cold Spring Harbor Laboratory in 1987"</ref>

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">Michod, Richard E. (1999). Darwinian Dynamics: Evolutionary Transitions in Fitness and Individuality. Princeton, NJ: Princeton University Press. ISBN 978-0-691-02699-2. LCCN 98004166. OCLC 38948118.</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；