Patterns of evolution in the Archean and Proterozoic Eons

Abstract

Problems of taphonomy and sampling adequacy hinder direct evolutionary interpretations of pattern in the Precambrian paleontological record; however, molecular studies of microbial phylogeny and comparative physiological and ecological investigations of living microorganisms can be combined with geological research to establish patterns of early evolution. The Late Proterozoic record of planktonic algae resembles those of Phanerozoic plants, animals, and microplankton in its patterns of diversification and turnover, as well as in the importance of major extinction events in shaping the course of evolution. Late Proterozoic eukaryotes thus appear to be discussable in terms of the macroevolutionary issues that have become central to Phanerozoic paleobiology. In contrast, evolutionary patterns in Precambrian prokaryotes appear to be different from those of plants and animals, a possible consequence of their differing systems of genetic organization and recombination.