In this view, early humans bypassed West and Central Africa, especially tropical forests. Working in Senegal, Cameroon, Malawi and elsewhere, they are uncovering evidence that early humans spread across much more of Africa before venturing elsewhere. This has contributed to the idea that early modern humans primarily inhabited these regions. She has shown that Middle Stone Age culture persisted in West Africa until quite recently, less than about 11,000 years ago. Richard Klein, a paleoanthropologist at Stanford University who has spent decades studying early modern human origins and migration in Africa, says, “I don’t understand the evolutionary mechanism behind” the pan-African origins theory.
