| Abstract: | Two competing hypotheses have long dominated specialist thinking on modern human origins. The first posits that modern people emerged in a limited area and spread from there to replace archaic people elsewhere. Proponents of this view currently favor Africa as the modern human birthplace.1–5 The second suggests that the evolution of modern humans was not geographically restricted, but invlved substantial continuity between archaic and modern populations in all major regions of the occupied world.6–7 Based solely on the fossil record, both hypotheses are equally defensible, but the spread-and-replationships scenario is far more strongly supported by burgeoning data on the genetic relationships and diversity of living humans.8–16 These data impy that there was a common ancestor for all living humans in Africa between 280,000 and 140,000 year ago, and that Neanderthals and other archaic humans who inhabited Eurasia during the same interval contributed few, if any, genes to living peiple. I argue here that the spread-and-replacement hypothesis is also more compatible with a third line of evidence: the spread-and-replacement hypothesis is also more compatible with a third line of evidence: the archeological record for human behavioral evolution. |
