Abstract
The debate over human origins has focused on two competing theories. The single African origin model holds that anatomically modern Homo sapiens evolved in Africa 100,000-200,000 years ago. Members of this population migrated out of Africa, replacing archaic human groups through Asia and Europe, with racial differentiation occurring within the past 100,000 years. The alternative regional continuity model proposes continuous evolution over the past million years, with racial variation developing early, and similar modern human traits developing in all regions as the result of worldwide gene flow. The persistence of specific morphological features within regions over the past million years supports regional continuity, whereas the identification of anatomically modern fossil specimens from Africa and the Levant 50-60,000 years before they are found elsewhere, provides support for a single origin. I give here the first quantitative test of the fossil evidence for each of these models. Results support a single African and/or Levantine origin for modern humans.