Neanderthal DNA shows no close link to humans
PARIS (AFP-Jiji) DNA tests on the fossilized rib of a Neanderthal infant who died about 28,000 years ago have confirmed that the mysterious hominids were not ancestors of humans, British researchers said Tuesday.
The results back a landmark 1997 study, which DNA-tested the first Neanderthal remains, unearthed in Germany's Neander Valley in 1856.
A team led by William Goodwin of the University of Glasgow said another fossil, found at Mezmaiskaya in the Caucasus Mountains of southern Russia, yielded a sequence that was closely related to the German find, with just 3.48 percent difference.
But even more significant, the researchers said, was that neither sequence showed any close relationship to modern European populations.
This argues against the idea that modern Europeans are partly of Neanderthal descent, they said.
The work was to appear in Thursday's issue of the British scientific weekly Nature. The article was made public Tuesday.
Matthias Hoess, a member of the Swiss Institute for Experimental Cancer Research, said the Russian fossil was of huge importance.
As the second find was located 2,200 km from the first, "it provides invaluable corroboration" of the Neanderthals' genetic past, he said.
Squat, thick-skulled and broad-jawed, the Neanderthals were initially presented as one of the evolutionary links between apes and Homo sapiens, an idea that many Victorians found repulsive.
But that theory eventually lost ground and was dealt a potentially fatal blow in 1997, when the University of Munich team found in its famous sample no DNA strands that related to modern human tissues.
The Neanderthals became relegated to the status of a separate and unsuccessful species whose habitat was overtaken by a smarter hominid known as the Cro-Magnon, the first man of modern shape.
Still unresolved is what caused the Neanderthals to die out, and how long they may have existed alongside Cro-Magnon beings.
In October, U.S. researchers reported that carbon-dating of two pieces of a skull from a cave in Croatia showed that Neanderthals may have roamed Central Europe as recently as 28,000 years ago.
That date would deal a blow to theories that the Neanderthals died out in Spain about 6,000 years earlier.
In turn, it would also suggest that Neanderthals and Cro-Magnons lived together for a long period, possibly having contacts and even cross-absorption.
The Glasgow University team said the next goal should be to gain a "more complete picture" of the relationship between Neanderthals and modern humans, especially from the regions where they may have coexisted.
Even so, all evidence backed the hypothesis that there could only have been a "very low gene flow" between Neanderthals and modern humans, the team members said.