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William Martin和Michael Russell说

William Martin和Michael Russell说

    ......生命是在一个渗漏点热液丘中的结构化单硫化铁沉淀物中演化出来的，其氧化还原、pH值和温度梯度介于富含硫化物的热液和冥古代洋底的含铁(II)水之间。在化石渗出地金属硫化物沉淀物中观察到的自然生成的三维分层表明，这些无机分层是在自由生活的原核生物中发现的细胞壁和细胞膜的前身。已知FeS和NiS能够催化一氧化碳和甲基硫化物（热液的成分）合成乙酰-甲基硫化物，这表明生物前的合成发生在这些金属硫化物壁室的内表面，......"

 

......生命是在一个渗漏点热液丘中的结构化单硫化铁沉淀物中演化出来的，其氧化还原、pH值和温度梯度介于富含硫化物的热液和冥古代洋底的含铁(II)水之间。在化石渗出地金属硫化物沉淀物中观察到的自然生成的三维分层表明，这些无机分层是在自由生活的原核生物中发现的细胞壁和细胞膜的前身。已知FeS和NiS能够催化一氧化碳和甲基硫化物（热液的成分）合成乙酰-甲基硫化物，这表明生物前的合成发生在这些金属硫化物壁室的内表面，......"

 

 

== Pertinent geological environments ==

== Pertinent geological environments ==

一个早期的概念，即生命起源于非生命物质的缓慢阶段，出现在Herbert Spencer 1864-1867年的《生物学原理》一书中。1879年William Turner Thiselton-Dyer在 "论自然发生和进化 "一文中提到了这一点。1871年2月1日，Charles Darwin将这些出版物写信给Joseph Hooker，并提出了自己的推测，认为生命的最初火花可能是始于

一个早期的概念，即生命起源于非生命物质的缓慢阶段，出现在Herbert Spencer 1864-1867年的《生物学原理》一书中。1879年William Turner Thiselton-Dyer在 "论自然发生和进化 "一文中提到了这一点。1871年2月1日，Charles Darwin将这些出版物写信给Joseph Hooker，并提出了自己的推测，认为生命的最初火花可能是始于

 

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

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

 

他继续解释说，

他继续解释说，

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。Krebs循环(柠檬酸循环)在好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。 与此相一致的是，地球化学家Russell 罗素提出“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”方案的一部分)。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。Krebs循环(柠檬酸循环)在好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。 与此相一致的是，地球化学家Russell 罗素提出“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”方案的一部分)。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：

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

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

One of the earliest incarnations of this idea was put forward in 1924 with Oparin's notion of primitive self-replicating vesicles which predated the discovery of the structure of DNA. Variants in the 1980s and 1990s include Wächtershäuser's iron–sulfur world theory and models introduced by [[Christian de Duve]] based on the chemistry of [[thioester]]s. More abstract and theoretical arguments for the plausibility of the emergence of metabolism without the presence of genes include a mathematical model introduced by [[Freeman Dyson]] in the early 1980s and [[Stuart Kauffman]]'s notion of collectively autocatalytic sets, discussed later that decade.

One of the earliest incarnations of this idea was put forward in 1924 with Oparin's notion of primitive self-replicating vesicles which predated the discovery of the structure of DNA. Variants in the 1980s and 1990s include Wächtershäuser's iron–sulfur world theory and models introduced by [[Christian de Duve]] based on the chemistry of [[thioester]]s. More abstract and theoretical arguments for the plausibility of the emergence of metabolism without the presence of genes include a mathematical model introduced by [[Freeman Dyson]] in the early 1980s and [[Stuart Kauffman]]'s notion of collectively autocatalytic sets, discussed later that decade.

Orgel总结他的分析说，

Orgel总结他的分析说，

<blockquote> 目前没有理由期望多步循环，如还原性柠檬酸循环会在FeS/FeS2或其他一些矿物的表面自组织。"

  目前没有理由期望多步循环，如还原性柠檬酸循环会在FeS/FeS2或其他一些矿物的表面自组织。"

有可能在生命诞生之初就使用了另一种代谢途径。例如，"开放的 "乙酰-CoA途径（当今自然界公认的五种二氧化碳固定方式中的另一种）代替了还原性柠檬酸循环，就符合金属硫化物表面自组织的想法。该途径的关键酶--一氧化碳脱氢酶/乙酰-CoA合成酶，在其反应中心藏有镍-铁-硫混合簇，并在一个步骤中催化形成乙酰-CoA（类似乙酰-硫醇）。然而，越来越多的人担心，在热力学和动力学上，生命起源以前的硫醇化和硫酯化合物不利于在假定的生命起源以前的条件(即热液喷口)中积累。然而也有人提出，半胱氨酸和同型半胱氨酸可能已经与Stecker反应产生的亚硝酸盐反应，容易形成催化硫醇达到的弹力肽。

有可能在生命诞生之初就使用了另一种代谢途径。例如，"开放的 "乙酰-CoA途径（当今自然界公认的五种二氧化碳固定方式中的另一种）代替了还原性柠檬酸循环，就符合金属硫化物表面自组织的想法。该途径的关键酶--一氧化碳脱氢酶/乙酰-CoA合成酶，在其反应中心藏有镍-铁-硫混合簇，并在一个步骤中催化形成乙酰-CoA（类似乙酰-硫醇）。然而，越来越多的人担心，在热力学和动力学上，生命起源以前的硫醇化和硫酯化合物不利于在假定的生命起源以前的条件(即热液喷口)中积累。然而也有人提出，半胱氨酸和同型半胱氨酸可能已经与Stecker反应产生的亚硝酸盐反应，容易形成催化硫醇达到的弹力肽。

非生物起源理论很少涉及哈罗德-布卢姆Harold Blum提出的警告：如果生命的关键信息元素--原核酸链--自发形成双联结构，那么就没有办法将它们解离。

非生物起源理论很少涉及哈罗德-布卢姆Harold Blum提出的警告：如果生命的关键信息元素--原核酸链--自发形成双联结构，那么就没有办法将它们解离。

在这个循环的某个地方，必须做功，这意味着自由能必须被消耗。如果零件自发地在模板上组装起来，就必须做功才能把复制品取下来;或者，如果复制品自动从模板上脱落，必须先把零件装上。

  在这个循环的某个地方，必须做功，这意味着自由能必须被消耗。如果零件自发地在模板上组装起来，就必须做功才能把复制品取下来;或者，如果复制品自动从模板上脱落，必须先把零件装上。

The Oparin–Haldane conjecture addresses the formation, but not the dissociation, of nucleic acid polymers and duplexes. However, nucleic acids are unusual because, in the absence of counterions (low salt) to neutralize the high charges on opposing phosphate groups, the nucleic acid duplex dissociates into single chains.<ref name="ReferenceB">{{Cite journal |doi = 10.1016/j.icarus.2003.10.018|title = Fast tidal cycling and the origin of life|year = 2004|last1 = Lathe|first1 = Richard|journal = Icarus|volume = 168|issue = 1|pages = 18–22|bibcode = 2004Icar..168...18L}}</ref> Early tides, driven by a close moon, could have generated rapid cycles of dilution (high tide, low salt) and concentration (dry-down at low tide, high salt) that exclusively promoted the replication of nucleic acids<ref name="ReferenceB"/> through a process dubbed tidal chain reaction (TCR).<ref>{{Cite journal |doi = 10.1017/S1473550405002314|title = Tidal chain reaction and the origin of replicating biopolymers|year = 2005|last1 = Lathe|first1 = Richard|journal = International Journal of Astrobiology|volume = 4|issue = 1|pages = 19–31|bibcode = 2005IJAsB...4...19L}}</ref> This theory has been criticized on the grounds that early tides may not have been so rapid,<ref>{{Cite journal |doi = 10.1016/j.icarus.2005.04.022|title = Comment on the paper "Fast tidal cycling and the origin of life" by Richard Lathe|year = 2006|last1 = Varga|first1 = P.|last2 = Rybicki|first2 = K.|last3 = Denis|first3 = C.|journal = Icarus|volume = 180|issue = 1|pages = 274–276|bibcode = 2006Icar..180..274V}}</ref> although regression from current values requires an Earth–Moon juxtaposition at around two Ga, for which there is no evidence, and early tides may have been approximately every seven hours.<ref>{{Cite journal |doi = 10.1016/j.icarus.2005.08.019|title = Early tides: Response to Varga et al|year = 2006|last1 = Lathe|first1 = R.|journal = Icarus|volume = 180|issue = 1|pages = 277–280|bibcode = 2006Icar..180..277L}}</ref> Another critique is that only 2–3% of the Earth's crust may have been exposed above the sea until late in terrestrial evolution.<ref>{{Cite journal | doi=10.1016/j.epsl.2008.08.029| title=A case for late-Archaean continental emergence from thermal evolution models and hypsometry| year=2008| last1=Flament| first1=Nicolas| last2=Coltice| first2=Nicolas| last3=Rey| first3=Patrice F.| journal=Earth and Planetary Science Letters| volume=275| issue=3–4| pages=326–336| bibcode=2008E&PSL.275..326F}}</ref>

The Oparin–Haldane conjecture addresses the formation, but not the dissociation, of nucleic acid polymers and duplexes. However, nucleic acids are unusual because, in the absence of counterions (low salt) to neutralize the high charges on opposing phosphate groups, the nucleic acid duplex dissociates into single chains.<ref name="ReferenceB">{{Cite journal |doi = 10.1016/j.icarus.2003.10.018|title = Fast tidal cycling and the origin of life|year = 2004|last1 = Lathe|first1 = Richard|journal = Icarus|volume = 168|issue = 1|pages = 18–22|bibcode = 2004Icar..168...18L}}</ref> Early tides, driven by a close moon, could have generated rapid cycles of dilution (high tide, low salt) and concentration (dry-down at low tide, high salt) that exclusively promoted the replication of nucleic acids<ref name="ReferenceB"/> through a process dubbed tidal chain reaction (TCR).<ref>{{Cite journal |doi = 10.1017/S1473550405002314|title = Tidal chain reaction and the origin of replicating biopolymers|year = 2005|last1 = Lathe|first1 = Richard|journal = International Journal of Astrobiology|volume = 4|issue = 1|pages = 19–31|bibcode = 2005IJAsB...4...19L}}</ref> This theory has been criticized on the grounds that early tides may not have been so rapid,<ref>{{Cite journal |doi = 10.1016/j.icarus.2005.04.022|title = Comment on the paper "Fast tidal cycling and the origin of life" by Richard Lathe|year = 2006|last1 = Varga|first1 = P.|last2 = Rybicki|first2 = K.|last3 = Denis|first3 = C.|journal = Icarus|volume = 180|issue = 1|pages = 274–276|bibcode = 2006Icar..180..274V}}</ref> although regression from current values requires an Earth–Moon juxtaposition at around two Ga, for which there is no evidence, and early tides may have been approximately every seven hours.<ref>{{Cite journal |doi = 10.1016/j.icarus.2005.08.019|title = Early tides: Response to Varga et al|year = 2006|last1 = Lathe|first1 = R.|journal = Icarus|volume = 180|issue = 1|pages = 277–280|bibcode = 2006Icar..180..277L}}</ref> Another critique is that only 2–3% of the Earth's crust may have been exposed above the sea until late in terrestrial evolution.<ref>{{Cite journal | doi=10.1016/j.epsl.2008.08.029| title=A case for late-Archaean continental emergence from thermal evolution models and hypsometry| year=2008| last1=Flament| first1=Nicolas| last2=Coltice| first2=Nicolas| last3=Rey| first3=Patrice F.| journal=Earth and Planetary Science Letters| volume=275| issue=3–4| pages=326–336| bibcode=2008E&PSL.275..326F}}</ref>