Darwin, South Africa and the emergence of the genus Homo

Abstract

The genus Homo has been identified in early Pleistocene deposits at Sterkfontein, Swartkrans and Kromdraai in South Africa. However, the boundary between Homo and australopithecines is not clearly distinct. Examples are given whereby certain specimens attributed to Homo have been assigned instead to an australopithecine, or vice versa. Remarkably, the earliest purported Homo from Africa 2.4 Ma), specimen KNM-BC 1 from Chemeron (Baringo area) in Kenya, is morphologically very similar to the type specimen of Paranthropus robustus from Kromdraai, at least 1.95 Ma. It is suggested that the emergence of Homo was more of a gradual phenomenon, associated with genetic drift and a spectrum of morphological variability in space and time, rather than a punctuated ‘Homo event’. This view is assessed in relation to a statement by Charles Darwin in The Descent of Man, published in 1871, and in relation to African hominins dated between 1.5 and 2.5 Ma.