The picture of early-human origins in Africa grows more complex
For decades, scientists who studied early modern humans believed that our ancestors initially inhabited only small areas of Africa, the savannas of the eastern and southern part of the continent, and then moved north into Asia, Europe and beyond. In this view, early humans bypassed West and Central Africa, especially tropical forests. These areas, the argument went, were populated much later.
But now, a growing group of researchers has cast doubt on this narrative. Working in Senegal, Cameroon, Malawi and elsewhere, they are uncovering evidence that early humans spread across much more of Africa before venturing elsewhere. This work has moved the field beyond the old out-of-Africa narrative and is transforming our understanding of how multiple groups of early modern humans intermingled and spread across the continent, providing a more nuanced picture of our species’ complex origins.
“It’s becoming more and more clear that humans didn’t originate in a single population in one region of Africa,” says Eleanor Scerri, an archaeologist at the Max Planck Institute of Geoanthropology in Jena, Germany. “If we really want to understand human evolution, we need to look at all of the African continent.”
Most researchers agree that early modern humans emerged in Africa between 200,000 and 300,000 years ago. About 60,000 years ago, they spread to other parts of the world. Until recently, though, most experts thought these humans populated West and Central Africa, especially the tropical forests there, only within the past 20,000 or so years.
For some researchers, this narrative made little sense. “Humans like to move around a lot,” says University of Pennsylvania geneticist Sarah Tishkoff, who has been working to unravel Africa’s deep genetic lineage for more than two decades. “They had this beautiful continent, they could move all over, go to different niches, with different resources.”
The reason no one found evidence of early human settlement in West and Central Africa, Scerri and others say, is that few people had looked there. [Continue reading…]