Many Possibilities for Life's Emergence
B.L. Tang (2005), JBIS, 58, 218-222Refcode
: Europa, Extremophiles, FeS, habitable zone, Mars, TitanAbstract:
It was recently cautioned that the discoveries of extremophiles, multiple locations within the solar system where these might flourish and the growing number of extrasolar planets might be irrelevant to the origin of life (Cleaves II and Chalmers, 2004, Astrobiology, 4:1-9). Central to this argument is the notion that emergence of life may require specific environmental and geological conditions that are much less common than the mere existence of liquid water. Although logical, the notion ignores the following relevant possibilities: 1) Life on Earth may have emerged very quickly and efficiently, 2) There may be several routes to life's emergence on a number of terrestrial geological niches, 3) Some extraterrestrial environments bear good resemblances to terrestrial geological niches capable of hosting the emergence of life and 4) There are exotic, but not inconceivable, extraterrestrial geological niches and geochemical processes that could drive the emergence of life with terrestrial-like biochemistry. Thus, the robustness of life manifested by the widespread existence of extremophiles is not merely a testimony of how well life adapts to different environments, but may also reflect the myriad of possibilities whereby it may emerged from abiotic geochemistry.
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