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Paper: A Hot Climate on Early Earth: Implications to Biospheric Evolution
Volume: 420, Bioastronomy 2007: Molecules, Microbes and Extraterrestrial Life
Page: 221
Authors: Schwartzman, D. W.; Knauth, L. P.
Abstract: There is now robust evidence for a much warmer climate on the early Earth than now. Both oxygen and silicon isotopes in sedimentary chert and the compelling case for a near constant isotopic oxygen composition of seawater over geologic time support thermophilic surface temperatures until about 1.5–2 billion years ago, aside from a glacial episode in the early Proterozoic. This temperature scenario has important implications to biospheric evolution, including a temperature constraint that held back the emergence of major organismal groups, starting with phototrophs. A geophysiology of biospheric evolution raises the potential of similar coevolutionary relationships of life and its environment on Earth-like planets around Sun-like stars.
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