In a development which could reveal the links between modern humans and their prehistoric cousins, scientists said yesterday they have mapped a first draft of the Neanderthal genome.
Researchers used DNA fragments extracted from three Croatian fossils to map out more than 60 percent of the entire Neanderthal genome by sequencing 3 billion bases of DNA.
“The Neanderthal genome sequence will clarify the evolutionary relationship between humans and Neanderthals, as well as help identify those genetic changes that enabled modern humans to leave Africa and rapidly spread around the world,” Germany’s Max Planck Institute for Evolutionary Anthropology said in a press release. “These DNA sequences can now be compared to the previously sequenced human and chimpanzee genomes in order to arrive at some initial insights into how the genome of this extinct form differed from that of modern humans.”
Research suggests that the last common ancestor of Neanderthals and humans lived about 660,000 years ago.
Neanderthals are widely believed to be the hominid form most closely related to present-day humans, although the precise relationship remains unclear.
The squat, low-browed Neanderthals lived in parts of Europe, Central Asia and the Middle East for around 170,000 years, but traces of them disappear some 28,000 years ago, their last known refuge being Gibraltar.
Why they died out is a matter of furious debate, because they co-existed alongside modern man.
Some argue Neanderthals were slowly wiped out by the smarter Homo sapiens in the competition for resources.
Other contend that interbreeding took place, which explains why the Neanderthal line died out, but implies that we could have Neanderthal heritage in our genome today.
Lead researcher Svante Paabo has organized a consortium of researchers from around the world to help analyze the Neanderthal genome. They will examine a number of genes that have been identified as playing a role in recent human evolution, including those implicated in brain aging and development which have been suggested to have come from Neanderthals.
“The preliminary results suggest that Neanderthals have contributed, at most, a very small fraction of the variation found in contemporary human populations,” the institute said.