Miocene Hominids and the Origins of the African Apes and Humans

Abstract

In the past 20 years, new discoveries of fossil apes from the Miocene have transformed our ideas about the timing, geography, and causes of the evolution of the African apes and humans. Darwin predicted that the common ancestor of African apes and humans would be found in Africa. Yet the majority of fossil great apes are from Europe and Asia. I briefly review the fossil record of great apes and then examine the main competing hypotheses of our origins, African or European, inspired by these recent discoveries, concluding that elements of both ideas are likely to be correct. Given current interpretations of the paleobiology of fossil apes and relationships among living hominids, I suggest that the last common ancestor of chimpanzees and humans was morphologically unique, but more chimpanzee-like than hominin-like: a knuckle-walker with a chimpanzee-sized brain, canine sexual dimorphism, and many probable behavioral similarities to living chimpanzees.