Planetary Science Section 3225, MS:183-301, Jet Propulsion Laboratory, California Institute of Technology, , 4800 Oak Grove Drive, Pasadena, CA 91109-8099, USA.
Philos Trans R Soc Lond B Biol Sci. 2013 Jun 10;368(1622):20120254. doi: 10.1098/rstb.2012.0254. Print 2013 Jul 19.
Life is evolutionarily the most complex of the emergent symmetry-breaking, macroscopically organized dynamic structures in the Universe. Members of this cascading series of disequilibria-converting systems, or engines in Cottrell's terminology, become ever more complicated-more chemical and less physical-as each engine extracts, exploits and generates ever lower grades of energy and resources in the service of entropy generation. Each one of these engines emerges spontaneously from order created by a particular mother engine or engines, as the disequilibrated potential daughter is driven beyond a critical point. Exothermic serpentinization of ocean crust is life's mother engine. It drives alkaline hydrothermal convection and thereby the spontaneous production of precipitated submarine hydrothermal mounds. Here, the two chemical disequilibria directly causative in the emergence of life spontaneously arose across the mineral precipitate membranes separating the acidulous, nitrate-bearing CO2-rich, Hadean sea from the alkaline and CH4/H2-rich serpentinization-generated effluents. Essential redox gradients-involving hydrothermal CH4 and H2 as electron donors, CO2 and nitrate, nitrite, and ferric iron from the ambient ocean as acceptors-were imposed which functioned as the original 'carbon-fixing engine'. At the same time, a post-critical-point (milli)voltage pH potential (proton concentration gradient) drove the condensation of orthophosphate to produce a high energy currency: 'the pyrophosphatase engine'.
生命是宇宙中从对称性破缺中涌现出的最复杂的宏观组织动态结构,在进化上也是如此。在这个级联的非平衡转换系统系列中,或者用科特雷尔的术语来说,是引擎,成员变得越来越复杂——在每一个引擎中,随着能量和资源的等级不断降低,它们从物理状态更多地转化为化学状态,以服务于熵的产生。这些引擎中的每一个都是由特定的母引擎或多个母引擎创造的秩序中自发涌现出来的,因为失衡的潜在子系统被驱动到超过临界点。海洋地壳的放热蛇纹石化作用是生命的母引擎。它驱动碱性热液对流,从而自发产生沉淀的海底热液丘。在这里,两个直接导致生命出现的化学非平衡状态,跨越了分离酸性、富含硝酸盐、富含 Hadean 海的碳酸二乙酯的矿物沉淀膜,以及碱性和蛇纹石化生成的流出物。必需的氧化还原梯度——涉及热液 CH4 和 H2 作为电子供体,以及来自周围海洋的 CO2 和硝酸盐、亚硝酸盐和三价铁作为受体——被强加,它们充当了原始的“碳固定引擎”。同时,一个超过临界点的(毫)电压 pH 势能(质子浓度梯度)驱动正磷酸盐的缩合,产生高能量货币:“焦磷酸酶引擎”。