Department of Earth and Space Sciences, University of Washington, Seattle, WA, USA.
Geobiology. 2013 Mar;11(2):101-26. doi: 10.1111/gbi.12025. Epub 2013 Jan 18.
Many decades of experimental and theoretical research on the origin of life have yielded important discoveries regarding the chemical and physical conditions under which organic compounds can be synthesized and polymerized. However, such conditions often seem mutually exclusive, because they are rarely encountered in a single environmental setting. As such, no convincing models explain how living cells formed from abiotic constituents. Here, we propose a new approach that considers the origin of life within the global context of the Hadean Earth. We review previous ideas and synthesize them in four central hypotheses: (i) Multiple microenvironments contributed to the building blocks of life, and these niches were not necessarily inhabitable by the first organisms; (ii) Mineral catalysts were the backbone of prebiotic reaction networks that led to modern metabolism; (iii) Multiple local and global transport processes were essential for linking reactions occurring in separate locations; (iv) Global diversity and local selection of reactants and products provided mechanisms for the generation of most of the diverse building blocks necessary for life. We conclude that no single environmental setting can offer enough chemical and physical diversity for life to originate. Instead, any plausible model for the origin of life must acknowledge the geological complexity and diversity of the Hadean Earth. Future research may therefore benefit from identifying further linkages between organic precursors, minerals, and fluids in various environmental contexts.
几十年来,对生命起源的实验和理论研究取得了重要发现,这些发现涉及到有机化合物可以被合成和聚合的化学和物理条件。然而,这些条件往往相互排斥,因为它们很少在单一的环境中同时出现。因此,没有令人信服的模型可以解释无生命的成分是如何形成活细胞的。在这里,我们提出了一种新的方法,即在 Hadean 地球的全球背景下考虑生命的起源。我们回顾了以前的想法,并将它们综合在四个核心假设中:(i) 多个微环境有助于生命的构建块的形成,而这些小生境不一定适合第一批生物体居住;(ii) 矿物催化剂是导致现代代谢的前生物反应网络的骨干;(iii) 多种局部和全球运输过程对于连接发生在不同位置的反应至关重要;(iv) 反应物和产物的全球多样性和局部选择为生成生命所需的大部分不同构建块提供了机制。我们得出结论,没有单一的环境可以提供足够的化学和物理多样性来产生生命。相反,任何合理的生命起源模型都必须承认 Hadean 地球的地质复杂性和多样性。因此,未来的研究可能会受益于在各种环境背景下进一步确定有机前体、矿物和流体之间的联系。