Were Neanderthals our enemies or lovers?

Long ago, the world was ruled by a different kind of a human, a squat and rugged sort who was adapted to the chill of an ice age. From 300,000 years ago, the land of the Neanderthals stretched from Asia to Western Europe, where they hunted with heavy spears in forests and grassland.

The beginning of the end came some 45,000 to 50,000 years ago, when they came across a band of modern humans. No one knows for sure what happened when our ancestors met their robust cousins except that, a few millennia later, the Neanderthal empire was no more.

Even today, the demise of the Neanderthals has the power to chill. The reason for this is that they were so human. What happened to them remains a mystery and will be one of the themes debated this week, as scientists meet at the International Union for Quaternary Research in Cairns, Australia.

The first Neanderthal specimen was recognised in the Neander Valley, outside Düsseldorf, Germany, hence the name. We have known for a long time that Neanderthals reached Britain but new evidence about their reign here is emerging all the time.

A jawbone, thought to be at least 31,000 years old and excavated from Kent's Cavern in Torquay in 1926, is being reassessed by an international team who believe that advances in analytical methods may help establish if it is more ancient than was first thought and is perhaps Neanderthal.

"If it does turn out to be Neanderthal, this would be the first proper mainland late Neanderthal from Britain," says Prof Chris Stringer, of the Natural History Museum, one of the research team and author of Homo Britannicus: The Incredible Story of Human Life in Britain.

Our ancient cousin, Homo neanderthalensis, was formidable. Using methods of manufacture dating back more than a million years, he fashioned weapons and probably hunted in packs.

His peace was disturbed when modern humans made an initial foray into Neanderthal territory some 135,000 to 115,000 years ago but that encroachment ended in the Levant a few tens of millennia later. However, at around the same time, according to one theory of human migration, another group of modern humans set out much further south, at the mouth of the Red Sea, and headed east.

By around 50,000 years ago, the group had pushed into the Levant. They moved on Europe, where they lived side by side with Neanderthals between 43,000 to 38,000 years ago. It was soon after the Neanderthals encountered this second invasion of modern humans that they disappeared from the fossil record.

What happened? To quote Prof Stringer: "When these populations met, did they regard each other as simply people, enemies, alien or even prey?"

One difficulty in working out how these ancient humans rubbed along is that there is a lack of clear evidence of close encounters. That changed two years ago when a paper was published by Prof Paul Mellars, of Cambridge University, and his student Brad Gravina, suggesting the two kinds of human lived together at Grotte des Fées at Châtelperron in France.

The study was criticised but the Cambridge team published a detailed rebuttal. "The importance of the new paper is that it confirms at least 2,000 years of coexistence/overlap between Neanderthals and modern humans in this one small region," said Prof Mellars. "This is the only direct, unambiguous evidence of this so far."

But if they coexisted there for many generations -- and this is still subject to dispute -- how can it be argued that modern humans wiped out Neanderthals? And if they did not make war, surely they made love?

One important clue comes from shreds of DNA from Neanderthal bone being studied by teams in America and the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. Although it will take a couple of years to reconstruct the entire genetic makeup -- genome -- of Neanderthals, interbreeding appears unlikely to have been significant, according to the latest findings from Svante Pääbo, head of the Max Planck team.

A paper published in last week's issue of the journal Nature reached a similar conclusion. The study of human genetic diversity by Dr Andrea Manica of Cambridge University was combined with measurements of more than 6,000 skulls. "There was no significant flow of genes from Neanderthal (or other ancient human species) to anatomically modern humans," he said.

Not everyone is convinced. Some, like Sarah Tishkoff, of the University of Maryland, point out that the pattern of inheritance of some human genes could be consistent with interbreeding. And there is tantalising evidence of apparent hybrids. Prof João Zilhão, of the University of Bristol, and Prof Erik Trinkaus, of Washington University, described one mosaic of modern and ancient features in a 40,000-year-old modern human cranium found in the Pestera cu Oase (the Cave with Bones) in southwestern Romania.

The reconstructed cranium -- named Oase 2 -- was flattened at the front and featured exceptionally large upper molars with a size progression found principally among Neanderthals. ...

•	Were Neanderthals our enemies or lovers? Telegraph.co.uk (UK), Tuesday, July 31, 2007 Byline: Roger Highfield