Evidence for life on Earth before 3,800 million years ago

  title={Evidence for life on Earth before 3,800 million years ago},
  author={Stephen J. Mojzsis and Gustaf Arrhenius and Kevin D. McKeegan and T. Mark Harrison and Allen P. Nutman and Clark R.L. Friend},
IT is unknown when life first appeared on Earth. The earliest known microfossils (˜3,500 Myr before present) are structurally complex, and if it is assumed that the associated organisms required a long time to develop this degree of complexity, then the existence of life much earlier than this can be argued1,2. But the known examples of crustal rocks older than ˜3,500 Myr have experienced intense metamorphism, which would have obliterated any fragile microfossils contained therein. It is… Expand

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