Functional aspects of pelvic morphology in simian Primates

In functional analyses of the Primate pelvis only selective forces resulting from locomotory functions have traditionally been taken into account, therefore neglecting possible selective forces resulting from obstetrical functions. This paper analyzes the nature, degree, and action of the selective forces acting on the pelvis of simian Primates which result from maternal-fetal size relationships and their interaction with selective forces resulting from locomotory functions. Based on the analysis of these factors in living Primates, an estimate of their degree and interaction in Australopithecus africanus is given to further elucidate the problem of the evolution of hominid bipedalism.