The chemistry that preceded life's origin: When is an evolutionary story an emergent story?

摘要

It seems that the question may be answered, at best, only abstractedly. Because there is exceedingly little knowledge about the actual origin(s) of life, we have reasonably extended to its beginnings the same fundamental evolutionary nature that has been recorded throughout life’s cellular history. Albeit a posteriori, this reasoning warrants the general assumption that life was preceded by a prebiotic molecular evolution, where “non living parts”, such as the simple molecules that multiple sources made available on the early Earth, reacted into more complex chemical structures and, of these, some attained selected associations, desirable interactions, self-copying preservation and eventually “emerged” in the self reproductive and evolving systems we call life. In these terms, the basic question in the study of the origins of life is not whether life emerged but when and how. A host of more questions easily follow about which particular molecules could have learned first such useful assembling, interacting and so on. Eventually, therefore, the proofs that “interactions and self-organization of non living parts” could be systemic and prebiotically relevant must be analytical. Analytical approaches may never get to learn the very paths that terrestrial life followed for its emergence (Eschenmoser 2007) but they alone may yet recognize the likely physico-chemical processes where “novel properties…. arise when parts or components assemble together into a higher hierarchic order”.