The out-of-Africa thesis of our species’ ancestry is tested, found solid, and approved for consumption.
Oppenheimer (Eden in the East, 1999), a British physician and specialist in tropical diseases, brings only an amateur’s credentials to his study, which defends the single-exodus-from-Africa position on human origins against recent arguments for multi-regionalism. Scholars who advance the latter view have suggested that archaic populations such as Neanderthals in Europe and Homo erectus in Asia contributed genetically to modern human bloodlines, which accounts for typical differences among peoples today. But, counters Oppenheimer, mitochondrial DNA studies allow human ancestry to be traced to two distant parents whose Homo sapiens offspring left Africa “at the first available interglacial warm-up between ice ages” some 75,000 years ago. From the new knowledge afforded by DNA studies and cladistics, he writes, “a picture of the Adam and Eve gene lines spreading from Africa to every corner of the world has been developed over the last decade.” Oppenheimer allows that points of this single-origin program are controversial and that the dates now assigned to branches of the family tree are inexact at best. His account of the climatic forces that drove protohominids and modern human ancestors from the African cradle and thence all over the world is probably less controversial, though some critics may fault it as being overly deterministic. Specialists may grumble about Oppenheimer’s playing in their yard, but it’s clear throughout that he’s done his homework and acquired a good command of the scholarly literature in physical anthropology and population genetics, even if his presentation is sometimes a little too breezy (“Since many of the desert corridors in Africa and West Asia were green at that time, the would-be migrants to Australia could have walked briskly east straight from Israel to India”).
Of interest to students of prehistory, although scholars are likely to pick at some of the threads of Oppenheimer’s argument.