Thursday, February 5, 2015

Fossil Provides Evidence Of Early Human Migration To Europe

Some 55,000 years ago, a person — whether female or male, we don't know — lived in Manot Cave in the western Galilee area of what is now Israel. Judging from the partial skull recovered from the cave, and described in Nature last week by Israel Hershkovitz of Tel Aviv University and his co-authors, the person was anatomically modern and closely related to the first modern humans who went on to colonize Europe.

Greedy for any solid evidence that sheds light on the migration of anatomically modern humans (AMH) out of Africa and into Europe, paleoanthropologists welcome detailed analysis like this one about the Manot Cave person (known as "Manot 1").

AMH — people like us — evolved in Africa right around 200,000 years ago from earlier human-like ancestors. For many millennia, Africa remained the center of our evolution — and not just anatomically: The fascinating paint factory found at Blombos Cave in South Africa, dated to 100,000 years ago is just one illustration of the behavioral and cognitive sophistication that developed in Africa.

By about 45,000 years ago, AMH had reached Europe in a migration out of Africa. Europe had, of course, been inhabited before that time by other human-like species including Homo heidelbergensis, but we ourselves only arrived at this relatively late period. Within about 15,000 years, at places like Chauvet Cave in France, our AMH ancestors were painting cave walls with gloriously colorful, highly accurate representations of animals.

But how can we understand something about that initial migration and the people who made it? Here's where Manot 1 comes in. Israel was part of a key evolutionary landscape for our species, in part because of the travel corridor in the Levant region through which migrants passed out of Africa. Lead author Hershkovitz told The New York Times last week that the Manot cranium "is the missing connection between African and European populations."

In other words, as the Times also emphasized, in this new discovery we have the very first fossil evidence of the "out of Africa" migration at this critical time period. That's big news.

Certain details of the skull anatomy, as reported in Nature, are particularly significant. The skull has what's called an occipital bun, a particular shape at the skull base that is, Hershkovitz and his co-authors write, "a feature very frequently found both in European Neanderthals and in the majority of Upper Paleolithic modern humans." This feature sets the skull apart from those of other AMH living in the Levant at the same time, and links the Manot person to Europe.

But it also links Manot 1, at least potentially, to Neanderthals, who also lived in the same region. And here, the Nature team's conclusion is circumspect: "The Manot 1 specimen could potentially represent a hybrid between AMH's and Neanderthals." npr

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