Darwin (1871) recognised that Africa was the continent from which humans originated. This suggestion was based not on fossils but on comparative anatomy of modern primates. Of all the living primates, it is the African chimpanzee (Pan) and Gorilla that are most similar to Homo in terms of gross anatomy. The discovery of Australopithecus africanus at Taung in southern Africa in 1924, described by Raymond Dart (1925), supported Darwin's statement regarding an African origin for humanity. Robert Broom described Paranthropus robustus as another hominin from the South African site of Kromdraai (Broom 1938; Broom & Schepers 1946), and additional specimens of A. africanus were discovered by Broom (1947) at Sterkfontein. Broom & Robinson (1949, 1950) reported the presence of Telanthropus, later recognised as early Homo, at Swartkrans in Early Pleistocene contexts. Initially it was possible to 'pigeon-hole' new hominin discoveries into discrete genera and distinct species, but with the discovery of additional specimens from South Africa as well as Ethiopia, Kenya, Tanzania, Malawi and Chad, boundaries between species and even between genera have become questionable. There is clearly a need for an approach whereby the degree of similarity between specimens can be re-assessed in the context of a species definition which is applicable to hominin fossils.