FEMUR ONTOGENY IN HUMANS AND GREAT-APES - HETEROCHRONIC IMPLICATIONS FOR HOMINID EVOLUTION

Did the first hominids have a short developmental period similar to th at of the great apes, or a longer period closer to that of modern huma ns? Some morphological modifications undergone by the human femur duri ng growth are shown to be excellent markers of different developmental stages. The femur of the first hominids (Australopithecus afarensis) shows only features of infantile growth, whereas characters of both in fantile and adolescent growth are typical of later hominids (Homo). In the first australopithecines the period of peripubertal growth would have still been short. The prolongation of the adolescent period appea rs to be a characteristic of Homo.