Evidence of Archaean life - A brief appraisal

Attention is called to the question of whether the meagerness of the Archaean fossil record is a function of a sparsity of preserved, cratonal, fossiliferous facies, or whether the abrupt break in the known fossil record near the Archaean-Proterozoic boundary reflects a major event in biological evolution. The paper then reviews the currently available geochemical and paleobiological data on Archaean biota. The occurrence of stromatolites in the Archaean, and the carbon isotopic composition of Archaean organic matter, both suggest strongly the existence of an Archaean biota. The presence of relatively abundant and morphologically complex microorganisms in deposits of early Proterozoic age seems to be certain evidence for a prior episode of Archaean evolution.