Artist's impression of a Neanderthal hunter. New evidence suggests these hominids survived thousands of years longer than previously thought.
Credit: American Museum of Natural History
PARIS, 14 September 2006: A century and a half after the first Neanderthal bones were coaxed from a German lime quarry, new evidence suggests that these puzzling hominids survived thousands of years longer than anyone thought.
With Europe in the grip of an Ice Age and with their smarter cousins, Homo sapiens, spreading across the continent, the last Neanderthals holed up in a refuge on the balmy southern tip of Europe until their lineage withered away, according to a new study led by Clive Finlayson of the Gibraltar Museum.
The study, published today in the British journal Nature, suggests that Homo neanderthalis may have drawn his final breath as recently as 24,000 years ago, challenging previous estimates that put their extinction around 30,000 to 33,000 years ago. While this date has been fiercely debated, an even greater mystery remains: who, or what, killed them?
The new piece in the puzzle comes from artefacts found at a site on Gibraltar called Gorham's Cave, where Neanderthal stone tools were discovered more than 50 years ago. Further excavations of the cave floor between 1999 and 2005 have exposed the remains of hearths where Neanderthals, known to be skilled with flints, would keep a fire.
The researchers used a technique called accelerator mass spectrometry to date pieces of charcoal found in the hearths, and conclude Neanderthals definitely lived there until 28,000 years years ago, and possibly as recently as 24,000 years ago.
Wrongly lampooned in popular humour as moronic grunters, the Neanderthals had the smarts to choose an excellent site for their redoubt, according to the researchers. Natural light penetrated deep within the cave's walls and a high ceiling allowed smoke to ventilate. The cave was "a favoured location that was visited repeatedly over many thousands of years," say the authors.
The location, too, was a winner. While northerly latitudes of Europe remained locked in a deep and hostile chill, the warmer Mediterranean rim offered a good chance of survival for hunter-gatherers like the Neanderthals.
"The last Neanderthals that occupied Gorham's Cave had access to a diverse community of plants and vertebrates on the sandy plains, open woodland and shrubland, wetlands, cliff and coastal environments surrounding the site," the study says. "Such ecological diversity might have facilitated their long survival."
Seven other sites occupied by Neanderthals have been found in the rock of Gibraltar, which is only six kilometres long.
As to the great whodunnit of palaeontology, the paper discounts the theory that these Neanderthals were annihilated by Homo sapiens in the competition for food and territory.
Evidence of stone-age technology at Malaga, about 100 km east of Gibraltar, shows that anatomically modern man had ventured into the neighbourhood at the time when the Neanderthals lived in Gorham Cave. This suggests that for several thousand years the region was a 'mosaic' of remnant Neanderthals and pioneering Homo sapiens living in thinly-scattered communities.
Another theory to explain the disappearance of the Neanderthals is that they did not disappear - not genetically, at any rate. Under this hypothesis, Neanderthals and Homo sapiens co-mingled. Far from being a dead branch of the human tree, the Neanderthals may even have bequeathed some of the traits in the Homo sapiens genome that we see today.
The new paper does not address this controversial theory, but notes there is no evidence of 'transitional' tools or activities at the cave. This adds weight to the argument that the last Neanderthals had only limited contact with Homo sapiens, so inter-breeding was unlikely.
The first evidence for the Neanderthals emerged in 1856, when workers at a lime quarry in the Neander Valley, western Germany, came across bones initially thought to be that of a bear. Since then, the remains of about 400 Neanderthals have been found, at sites ranging from southern England to continental Europe and the Middle East.
