Speculations about the selective basis for modern human craniofacial form

The last few decades have seen an explosion of knowledge about the time and place of origin of our species, Homo sapiens. New fossils, more sites, better dates, modern and fossil DNA, and scores of analyses have mostly disproved the multiregional model of human evolution. By and large, the evidence generally sup-ports some version of the out-of-Africa model, according to which humans first evolved in Africa at least 200,000 years ago and then migrated to other parts of the world. Remaining debates about human origins primarily address if and how much hybridization occurred between modern humans and taxa of archaic Homo such as H. neanderthalensis. Ironically, despite a growing con-sensus about when and where H. sapiens first evolved, we know little more today than we did 20 years ago about why we evolved. A key unre-solved question is: What were th