A chronological framework for human origins

Current views on the timing of some of the more important events in human evolution are outlined, beginning with the divergence of hominids from the great apes during the late Miocene. The contribution of molecular genetics and its integration with the palaeontological evidence is discussed in relation to problems of phylogenetic reconstruction. The "molecular clock' for primate evolution predicts an ape-hominid divergence at about 8 Ma, but the hominid fossil record is exceedingly sparse from 8 to 4 Ma. Faunal turnover in the hominid clade peaks at about 2.5 Ma, coinciding with the appearance of the first stone tools and the emergence of both Homo and the "robust' australopithecines. Finally, the evidence for the evolution of anatomically modern Homo sapiens is summarized. -Authors