HENRY HARPENDING holds the Thomas Chair as Distinguished Professor in the Department of Anthropolgy at the University of Utah, the strongest biological anthropology department in the United States. He is a member of the National Academy of Sciences. He is a unique blend of field anthropologist (having spent years with the Bushmen and other peoples of the northern Kalahari) and population geneticist -one of international reputation, particularly active in the analysis of modern human origins. He played an important role in the development of the Out-of-Africa theory of human origins. He is coauthor, with Gregory Cochran, of The 10,000 Year Explosion.