Much has been unearthed about Neanderthal Man since a skull and bones were famously dug out of the Neander Valley near Düsseldorf in 1856. But not since that date has there been such excitement about this archaic form of humanity. He was a thick-set, muscular sort with a tough jaw, but diminutive chin. Not very tall, but with more intelligence than originally given credit, the Neanderthal occupied much of Europe for about 200,000 years prior to the arrival of anatomically modern humans – our own species, Homo sapiens.
Yet there is one enduring puzzle about this early cousin of ours that is now engaging scientists in frenzied debate. If the Neanderthal managed to survive for so long and lived through an ice age, what caused them to disappear? Was it, as some have suggested, a period of intense climate change that even they could not adapt to?
Or did it have something to do with the arrival of a taller, less bulky but more intelligent rival?
This debate over the demise of the Neanderthal has sparked unprecedented levels of interest in them – and us. It raises issues about human nature and what sort of ancestors we came from. Could the disappearance of a closely related human being perhaps tell us something about the brutish nature of our own species?
And, perhaps the most difficult question of all, did the loss of the Neanderthal from Europe represent something more violent? Could it have been an early form of ethnic cleansing perpetrated by our direct ancestors?
The latest evidence appears to point in the direction of the Neanderthal being pushed out of their European heartland rather than being struck down by a change in weather patterns. A team of scientists led by Katerina Harvati of the Max Planck Institute for Evolutionary Anthropology in Leipzig has all but ruled out climate change as the sole cause of their demise.
"Our findings suggest that there was no single, abrupt climatic event that caused the extinction of the Neanderthal," Dr Harvati said yesterday.
"Only a controversial date for very late Neanderthal survival places their disappearance just before a major environmental shift. But even in this case the role of climate would have been indirect, perhaps by promoting migration and competition with other human groups.
"This leaves a whole range of other possibilities which could have included other forms of competition with modern humans. We can only speculate on how that competition took place."
The research, published today in the journal Nature, compared radiocarbon dating of Neanderthal bones and archaeological artefacts with data of climate fluctuations that have occurred in the North Atlantic region – which has dominated the climatic history of western Europe. "Until now, there have been three limitations to understanding the role of climate in the Neanderthal extinction," said Professor Chronis Tzedakis, of the University of Leeds, a member of the research team. "These are: uncertainty over the exact timing of their disappearance, uncertainties in converting radiocarbon dates to actual calendar years, and the chronological imprecision of the ancient climate record. We have circumvented the last two problems."
Some scientists believe it is no coincidence that the demise of the Neanderthal coincided with the arrival of modern humans in Europe about 50,000 years ago. Once the Neanderthal's range stretched from the Middle East and the north Caucasus to the Balkans and Portugal. But their habitat gradually shrank with the arrival of modern humans. Their last enclave seems to be a cave system in Gibraltar at the southern tip of Spain where Neanderthal bones have been dated to about 24,000 years ago.
Professor Chris Stringer, head of human origins at the Natural History Museum in London, said that as Homo sapiens moved across Europe from the Middle East there is likely to have been competition between the two species for the same resources.
"My view is that these groups had been biologically separate for much longer than any modern human groups have been separated," he said. "There could have been profound differences in appearance, body language, language and general behaviour, which would have impinged on how they saw each other.
"The question then is whether, when the populations met, they regarded each other as simple people, enemies, alien or even prey. We simply don't know the answer, and the answer may have varied from one time and place to another, especially given the vagaries of human behaviour."
Physically, Neanderthals were clearly human but there were distinct anatomical differences with modern humans. They had no waist as their ribcage flared out. Such a wide chest would have retained body heat, a clear advantage in a cold climate.
Recent studies of Neanderthal skeletons also suggest they had powerful muscles and a strong grip. This supports the idea that they were good hunters – stone spear points have been found alongside Neanderthal bones.
Their jaws were thick set, and their skulls had a double arch over the eyebrow – giving Neanderthals their distinctive, heavy beetle brow. However, their braincase was just as large, indeed probably slightly larger, than that of Homo sapiens.
Brain size in itself is not a definitive indication of intelligence. Nevertheless, it has become increasingly clear in recent years that the Neanderthal engaged in behaviour that puts them on the same sort of footing as modern humans. They controlled fire, used relatively sophisticated tools, wore animal skins for warmth and buried their dead.A diseased jaw of one Neanderthal, who had clearly lived for many years without being able to chew his food properly, also showed the Neanderthal cared for their sick. And research published this week has revealed that grooves in a Neanderthal tooth formed by rubbing a stick between the teeth indicate that they were aware of dental hygiene.
Like modern humans, they also had a hyoid bone in the throat – essential for talking. Neanderthals may well have used some form of language to communicate, although whatever speech they had, it was almost certainly more rudimentary than the language developed by their leaner cousins.
Indeed, some scientists believe it was the evolution of sophisticated language abilities in modern humans between 50,000 and 100,000 years ago that led to the rapid increase in brain complexity. A disadvantage of language is that the speaker can lie. But the advantage is that this puts more pressure on the brain to evolve the sort of Machiavellian intelligence that would have made modern humans better at outcompeting a less devious rival.
Nevertheless, some anthropologists now believe the similarities between the Neanderthal and modern man are so close that it begs the question of whether they would have interbred with one another. As one proponent of the idea once put it: it's a question of whether they made war, or made whoopee.
Milford Wolpoff, a veteran anthropologist at Michigan University, is one of the more vocal supporters of the idea that Neanderthals and modern humans did engage in sex with one another. "I have heard it said that Neanderthals were so ugly that 'modern' humans did not want to have sex with them. That is a crazy argument."
A decade ago, scientists found the skeleton of a young boy who died in Spain about 25,000 years ago. They suggested that its thick-set features suggested he was a hybrid between Neanderthal and Cro-Magnon man, the anatomically modern humans who lived in the area at the time. Other scientists, however, are sceptical of the find, suggesting that the boy was merely an unusually stocky lad. Since then, a number of studies, where Neanderthal DNA has been compared with modern human DNA, has failed to support the idea that there was any inter-breeding between the two human species.
Professor Stringer said all the evidence indicated a scenario of competition rather than cooperation and intermarriage. "The blame for the extinction of the Neanderthal about 30,000 years ago has often been placed at the door of the modern-looking Cro-Magnon, who entered Europe at least 40,000 years ago, having originated in Africa. There could have been conflict between the groups; the Cro-Magnon might have had better technology; the Neanderthal might have been pushed into marginal and less productive environments; or they might have been outbred if the Cro-Magnon had better infant survival.
"Equally, of course, it's possible that given the range across which the Neanderthal lived – from Portugal to Uzbekistan or beyond – there was no single cause of their demise. Perhaps the reasons for their extinction in Israel were different from those in the Caucasus, or Italy, or Gibraltar, or Britain."
So whatever it was that resulted in the extinction of the last human species to live alongside our ancestors, it was likely to involve a range of different pressures – including violent conflict. Like much of human history, the story of the Neanderthal's final end may have been a brutal and bloody affair.
Who were the Neanderthals?
When did they live?
For a 200,000-year period that ended about 30,000 years ago.
When were they discovered?
The first Neanderthal skull was found in Belgium in 1829, and another in Gibraltar in 1848. But the official "original" discovery, from which they were named, was in the Neander Valley in Germany in 1856.
Where did they live?
Across a vast area of northern and southern Europe, from the Mediterranean to the Russian steppes.
How similar were they to modern humans?
Their skulls were different. But recent findings suggest a match of 99.5 to 99.9 per cent between our DNA and theirs.
What did they look like?
They walked on two feet, had barrel chests and big bones, and lots of hair, possibly red.
What tools did they use?
Stone flakes, hand axes and spears and possibly wooden objects as well.
Could they talk?
The discovery in 1983 of a Neanderthal hyoid bone, which braces the tongue and larynx together, suggested that they had the anatomy for more complex speech.
Were they stupid?
They had a larger average brain capacity than modern man but it is thought that it was structured differently.
Are we descended from them?
Probably not. We may have had a common ancestor 500,000 years ago. But modern scientists now believe that Neanderthals were probably an evolutionary dead end that became completely extinct about 30,000 years ago.
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