Neanderthals 'not close family'

[Guest guest]

Neanderthals 'not close family'

 

By Paul Rincon

BBC News Online science staff

 

 

 

Researchers compared 3D coordinates on more than 1,000 skulls

 

 

Enlarge Image

 

The Neanderthals were not close relatives of modern humans and represent a single species quite distinct from our own, scientists say.

3D comparisons of Neanderthal, modern human and other primate skulls confirm theories that the ancient people were a breed apart, the researchers report.

 

Others claim Neanderthals contributed significantly to the modern gene pool.

 

Details of the research are published in the US journal Proceedings of the National Academy of Sciences.

 

"If we accept that Neanderthals were not the same species, what we're really saying is they did not contribute at all to modern human populations and in particular modern Europeans," co-author Dr Katerina Harvati of New York University, US, told BBC News Online.

 

Ancestral contribution

 

Researchers collected data on 15 standard "landmarks", or features, on over 1,000 primate skulls. Computer software transformed this data into 3D coordinates for each skull and superimposed them on each other.

 

Using statistical analysis, they compared differences between modern human and Neanderthal skulls with those found between and within 12 primate species.

 

The results support the view that Neanderthals were indeed a distinct species.

 

 

Neanderthals seem to have been a species distinct from our own

 

 

Enlarge Image

 

However, other researchers view Neanderthals as a sub-species or population of Homo sapiens that passed on genes to modern humans either by evolving into them or by interbreeding with them.

 

Evolving hypothesis

 

The new research shows that differences between Neanderthals and the modern human populations studied are smallest in early Europeans.

 

Dr Harvati believes this has little significance because the distance is only slightly smaller than that between Neanderthals and living humans.

 

But John Hawks, assistant professor of anthropology at the University of Wisconsin, US, disagrees: "It does perhaps suggest that they have some characteristics in common," he said.

 

THE NEANDERTHALS

 

The name means 'Man from the Neander Valley'

These human 'cousins' lived 190,000-28,000 years ago

They lived in Europe, Central Asia, and the Middle East

Skulls had large noses and prominent brow ridges

Body shape was stocky and muscular

If interbreeding with Homo sapiens occurred it was limited

"My own view is that the rate of evolutionary change was great enough that when we compare samples we are going to find that they were different because of the time.

 

"[Neanderthals] existed at an earlier time and hadn't yet acquired all the characteristics that we have today."

 

'Lost genes'

 

This view is at odds with the single origin, or Out of Africa 2, theory, which postulates that all living humans expanded from a single, small population that evolved in Africa more than 150,000 years ago.

 

As modern humans left their African homeland, they replaced "archaic" humans living in other parts of the world.

 

Neanderthals appeared in Europe around 190,000 years ago, characterised by a stocky physique ideal for conserving heat in an Ice Age climate.

 

Shortly after modern humans arrived in Europe 35,000 years ago, Neanderthals disappear from the fossil record.

 

Studies of mitochondrial DNA from Neanderthal bones also suggest they had little affinity to modern populations.

 

But some researchers believe this does not exclude the possibility that interbreeding occurred.

 

Dr Magnus Nordborg, of Lund University in Sweden, has calculated that even if Neanderthals had comprised 25% of the population after merging with modern humans, their DNA might be impossible to detect today.