Beginning my ethnographic work with hunter-gatherers I assumed that most distinctive human features evolved as a consequence of ancestral females pairing with hunting males to form nuclear families with men provisioning their wives and dependent offspring. Challenges to that “hunting hypothesis” have mounted in paleoanthropology and archaeology, but it was behavioral findings that forced my own paradigm shift. I’ll review some of those findings, including evidence of the important role of grandmothers, and some life history comparisons between humans and chimpanzees."
Kristen Hawkes is Distinguished Professor of Anthropology at the University of Utah. Her ethnographic projects with hunter-gatherers investigate sex and age differences in foraging strategies to improve hypotheses about human evolution. The importance of grandmothers' help for youngsters when their mothers have newborns focused her attention on the evolution of human longevity, and prompted continuing comparisons of human and chimpanzee life history. She is a member of the National Academy of Sciences, The American Academy of Arts and Sciences, and the Scientific Executive Committee of the Leakey Foundation.
Evolution of modern human beings from extinct nonhuman and humanlike forms. Genetic evidence points to an evolutionary divergence between the lineages of humans and the great apes on the African continent 85 million years ago (mya). The earliest fossils considered to be remains of hominins (members of the human lineage) date to at least 4 mya in Africa; they include the genus Australopithecus and other forms. The next major evolutionary stage, Homo habilis, inhabited sub-Saharan Africa about 21.5 mya. Homo habilis appears to have been supplanted by a taller and more humanlike species, Homo erectus, which lived from c. 1,700,000 to 200,000 years ago, gradually migrating into Asia and parts of Europe. Between c. 600,000 and 200,000 years ago, Homo heidelbergensis, sometimes called archaic Homo sapiens, lived in Africa, Europe, and perhaps parts of Asia. Having features resembling those of both H. erectus and modern humans, H. heidelbergensis may have been an ancestor of modern humans and also of the Neanderthals (H. neanderthalensis), who inhabited Europe and western Asia from c. 200,000 to 28,000 years ago. Fully modern humans (H. sapiens) seem to have emerged in Africa only c. 150,000 years ago, perhaps having descended directly from H. erectus or from an intermediate species such as H. heidelbergensis.