Neanderthals Were Dying Out Before Humans Arrived

Neanderthals in Western Europe started disappearing long before Homo sapiens showed up, suggesting that cold weather, and not cold-hearted humans, might have been responsible for the species' ultimate demise.

The findings, published in the journal Molecular Biology and Evolution, suggest that at least one population of Neanderthals was vulnerable to climate change.

Love Dalén, lead author of the paper, told Discovery News that "even if the Neanderthals were capable of surviving periods of extreme cold, the game species they relied on likely could not, so their resource base would have been severely depleted."

Neanderthals appear to have favored hunting wooly mammoths and other big game. Neanderthals were also big-brained, with the ability to make stone tools, construct garments, control fire and find shelter.

For the study, Dalén of the Swedish Museum of Natural History and his colleagues analyzed mitochondrial DNA sequences from 13 Neanderthal individuals, including a new sequence from the site of Valdegoba cave in northern Spain.

The researchers found that Neanderthals from Western Europe, Asia and the Middle East that were older than 50,000 years showed a high degree of genetic variation, on par with what might be expected from a species that had been abundant in those areas for a long period of time.

But Neanderthals from Western Europe younger than 50,000 years ago showed an extremely reduced amount of genetic variation. The scientists believe this means the earlier population of Neanderthals there was dwindling.

"We argue that Neanderthals disappeared in Western Europe for a period of time," co-author Rolf Quam, a Binghamton University anthropologist, told Discovery News.

"Subsequently, the region was re-occupied by individuals from a surrounding region," Quam added. "It is not possible, based on the current genetic data, to determine the geographic region of this new source population."

The scientists suspect that climatic conditions were not as extreme in the surrounding areas at the time, so that Neanderthals were able to move back into Western Europe. At present, there is no clear evidence of Homo sapiens being in Europe earlier than about 35,000 to 40,000 years ago, according to Quam -- so it seems humans did not play a role in the early Neanderthal population's demise.

Read more at Discovery News