Neanderthals

The scenario of replacement of Neanderthals by early modern humans is complicated, however, by evidence that the Neanderthals themselves were gradually evolving a modern physique. This raises some intriguing questions: If early modern humans had never existed, would Neanderthals eventually have evolved into a modern form? Is it possible that some Neanderthals actually did evolve into modern humans?Although early modern humans expanded throughout Eurasia some time between 30,000 and 40,000 years ago, not enough evidence yet exists to prove where they originated or how extensive their expansion may have been. Perhaps Neanderthals in some areas were replaced by modern humans, while those in other regions evolved into modern humans on their own. And if Neanderthals in certain regions were replaced, perhaps some, or maybe even all, of the modern human groups that replaced them had evolved not in Africa, but somewhere in Eurasia, from a Neanderthal stock.These different possibilities concerning the transition from Neanderthals to modern humans in Eurasia tie into a wider debate on the origin of modern humans in general. Researchers have been puzzling over modern human origins for decades. Numerous explanations have been put forward, but these have tended to lean toward one or the other of two competing theories:One theory posits that modern humans arose as early as 200,000 years ago in Africa, then spread to the Near East, and then colonized the rest of the Old World. This "Out-of Africa" theory claims that these early modern Africans replaced all indigenous populations of archaic humans, including the Neanderthals, by about 30,000 years ago and that all people living today are descended from these Africans. Support for this theory comes from the fact that fossils of modern humans from Africa and the Near East are much older than those found elsewhere. These fossils are 100,000 to 120,000 years old, and some may be even older. This is long before the period 30,000 to 40,000 years ago when modern humans began appearing in other regions. These early modern Africans and Near Easterners could therefore have served as source populations for subsequent migrations of modern humans.