Washington: Neanderthals might have died off
thousands of years earlier than previously thought, suggesting
that they weren't around to mingle with modern humans, a new
study has claimed.
It's believed that Neanderthals might have interbred with
our ancestors before they all died off and thus many of we
possess their genes. But it remains uncertain how long modern
humans interacted with them as when and how they went extinct
is still debated.
The latest study by an international team of scientists
focused on Mezmaiskaya Cave -- a key site in the northern
Caucasus Mountains within European Russia.
This region "is seen by many as a crossroads for the
movement of modern humans into the wider Russian plains," said
researcher Tom Higham at the University of Oxford in England.
"The extinction of Neanderthals here is, therefore, an
indicator we think, of when that first probably happened,"
Higham was quoted as saying by LiveScience.
The researchers, who analysed a fossil of a late
Neanderthal infant there, found that it was 39,700 years old.
"For some years now we thought that the Mezmaiskaya
Neanderthals survived until 30,000 years ago, but now we know
that they actually became extinct by around 40,000 years ago,
so there was no chance of modern humans who first arrived to
the region 4,000 to 5,000 years later to meet them," said Ron
Pinhasi of University College Cork in Ireland.
"This fits well with results of other teams from the
southern Caucasus," he said, adding that past research on
Neanderthals may have underestimated their age due to
contamination with later materials, giving the erroneous
impression they survived much longer than they actually did.
Based on this new data, "we are suggesting that
Neanderthals may have went extinct in Europe by this date
(40,000 years ago)," Pinhasi said.
However, Clive Finlayson, an evolutionary biologist at
the Gibraltar Museum in Spain, said: "All this paper shows is
that Neanderthals lived somewhere in the Caucasus about 40,000
years ago."
"It doesn't mean they went extinct then," said Finlayson,
whose team has recently found clusters of Neanderthals that
might have lasted until as late as 24,000 years ago.
"We have to be careful with some radiocarbon dates that,
on revision, appear older, which we knew already. But this
doesn't mean all dates are bad," he said.
In response, Pinhasi did note there may have been sites
"in which Neanderthals survived perhaps even as late as 24,000
years ago".
"More systematic dating and careful selection of
materials to date is necessary in order to obtain true ages of
key events such as Neanderthal extinction," he added.
The scientists detailed their findings online in the
Proceedings of the National Academy of Sciences.
PTI
First Published: Sunday, May 15, 2011, 09:28