Scientists map genome of modern humans' Neanderthal cousins

Researchers have mapped the genome of a Neanderthal, a scientific breakthrough yielding fascinating insights into how humans have evolved differently from our closest prehistoric cousins, a study released recently.

Among the research revelations, they said, is that modern humans and Neanderthals most likely interbred, although probably only to a very limited extent.

"We can now say that, in all probability, there was gene flow from Neanderthals to modern humans," said Richard Green of the University of California, Santa Cruz, one of the leaders of the research.

The study published in the May 7 issue of the journal Science said the Neanderthal DNA was collected from 40,000-year-old bones retrieved from a cave in Croatia.

Neanderthals, our closest evolutionary relatives, appeared some 400,000 years ago and ranged across Europe and Western Asia. They became extinct approximately 30,000 years ago.

Researchers said completion of the Neanderthal genome - hugely important for what it reveals about our ancestral relative - is perhaps even more significant because of the treasure trove of information that can be gleaned about modern humans.

"For the first time we can now identify genetic features that sets us apart from all other organisms, including our closest evolutionary relatives," said the lead researcher on the international study, Svante Paabo of the Max-Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

The researchers produced a catalog of genetic features that exist in all modern humans but are not found in Neandertals or apes.

The squat, low-browed Neanderthals lived in parts of Europe, Central Asia and the Middle East for around 170,000 years but all evidence of them disappears 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.

Neanderthals and modern humans shared a common ancestor from which they diverged about 300,000 years ago, and the study revealed that we share a gene which plays a key function in speech and language.

But an analysis of the genomes also shows a variety of genes unique to modern humans.

"With this paper, we are just scratching the surface," said Green.

"The Neanderthal genome is a goldmine of information about recent human evolution, and it will be put to use for years to come."

Scientists said they compared genes involved in cognitive development, skull structure, energy metabolism, and skin morphology and physiology, among others, to determine changes brought about by recent human evolution.

AFP