Ultima Thule

In ancient times the northernmost region of the habitable world - hence, any distant, unknown or mysterious land.

Thursday, September 14, 2006

Neanderthals and humans lived side by side

By Aussiegirl

Intersting article about Neanderthals and modern humans living side by side -- yet there's no evidence of any interbreeding. There's also some disagreement as to why the Neanderthal died out, and one theory, that I posted just below this one, has it that it was Homo sapiens's expert use of free trade that gave them the edge.

Neanderthals and humans lived side by side - being-human - 13 September 2006 - New Scientist

Neanderthals and humans lived side by side
Rowan Hooper

Neanderthals were thought to have died out as modern humans arrived in Europe. Now, artifacts found in a cave in Gibraltar reveal that the two groups coexisted for millennia before Neanderthals finally dwindled out of existence.

Homo sapiens moved into Europe about 32,000 years ago. But the newly unearthered artefacts shows that a remnant population of Homo neanderthalensis clung on until at least 28,000 years ago, a significant overlap.

Clive Finlayson at the Gibraltar Museum, and colleagues, recovered 240 stone tools and artefacts from sediments dated to the Upper Palaeolithic period – between 10,000 and 30,000 years ago. Mass spectrometry dating puts them between 28,000 and 24,000 years old.

The exciting point is that the tools are all of a type known to palaeontologists as Mousterian: they are flints, cherts and quartzites exclusively associated with Neanderthal manufacture.

“Mousterian technology is firmly associated with Neanderthals across Europe,” says Finlayson, who adds that in the sediment layers where the tools where found there is no hint of intrusion from more recent layers, and no sign of tools made by modern humans.

Genetically distinct

Since modern humans and Neanderthals seem to have overlapped for thousands of years in Europe, the big question is: did they interbreed?

“The consensus now sees Neanderthals as having been largely replaced rather than assimilated into the modern human gene pool,” says Katerina Harvati, at the department of human evolution at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. “Genetic evidence from several Neanderthals shows that they were very distant genetically in their mitochondrial DNA from modern humans.”

So, if they did interbred, the Neanderthal genes did not survive. “The more realistic demographic models suggest that admixture (gene mixing) was unlikely, and probably minimal or zero,” says Harvati.

The finding has implications for the status of a skeleton known as the Lagar Velho child. This individual, purported to be a hybrid of a Neanderthal and a modern human, was found in Portugal and has been dated to 24,500 years ago.

Hanging in there

Lagar Velho's juvenile nature has made it difficult to determine if it is indeed a hybrid, and one of the other objections has been the fact that it lived thousands of years after the Neanderthals were thought to have died out. “Clearly, our results show Neanderthals may have been around at the time,” says Finlayson.

The site of the discovery in Gibraltar is Gorham’s Cave, where Neanderthal artefacts were first discovered more than 50 years ago. Animal bones found with the tools indicate that the occupants butchered their hunted prey in the cave. The environment is rich and diverse, which perhaps enabled the last of the Neanderthal stragglers to survive a little longer than most. Finlayson estimates that only a small group lived in the cave itself.

Although modern humans were breeding all around them, we are not thought to have actively exterminated the Neanderthals.

“Fragmented populations survived in southern localities and their final extinction may have been due to their small numbers,” says Finlayson. “Modern humans played a minor or no role in this.”


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