A new piece of evidence—one sure to prove controversial—has been flung into the human origins debate. A study published March 7 in Nature presents genetic evidence that humans left Africa in at least three waves of migration. It suggests that modern humans (Homo sapiens) interbred with archaic humans (Homo erectus and Neandertals) who had migrated earlier from Africa, rather than displacing them. Ancient Origins In the human origins debate, which has been highly charged for at least 15 years, there is a consensus among scientists that Homo erectus, the precursor to modern humans, originated in Africa and expanded to Eurasia ...
