New excavations on the Mediterranean coast suggest that Neanderthals - a long extinct prehistoric human - survived in Europe several thousand years longer than thought. The new findings indicate that they continued to live long after the arrival of modern humans more than 30,000 years ago and may not have died off immediately as a result of the encroachment.
Research published in the journal Nature shows that Neanderthals may have survived at the very southern tip of the Europe long after modern humans arrived in western Europe about 30,000 to 32,000 years ago.
The findings are of stone tools usually associated with Neanderthals and other artifacts. They suggest that the short-armed, thick-torsoed species shared the landscape with their slenderer modern cousins for several thousand years.
The tools were unearthed in a seaside cave overlooking the Mediterranean in Gibraltar, a rocky outcrop off the Spanish coast that may have been the Neanderthals' last refuge.
A scientist at the Gibraltar Museum, Clive Finlayson, and colleagues dated the artifacts, including a series of hearths all created at the same location within the cave. He says the objects show just how long-lasting the Neanderthal settlement was.
"There are places where they were making their tools, left their tools, hearths, the food that they were eating, and we've been able to date this very accurately with radio carbon dating to at least 28,000 years ago, but very likely much more recently than that, perhaps as recently as 24,000 years ago," said Clive Finlayson.
That would be about 2,000 to 8,000 years later than the arrival of modern humans.
Yet other scientists express caution. In a Nature magazine commentary, Eric Delson of the American Museum of Natural History in New York and Katerina Harvati of the Max-Planck Institute for Evolutionary Anthropology in Leipzig, Germany say the dates might not be reliable. They cite the researchers' own data showing several cases where samples lower down in the dig were younger than those above them. They call for more extensive excavation.
If Neanderthals did persist as recently the new data suggest, Finlayson says the rich environment outside the Gibraltar cave probably helped. Fossils and pollen his team extracted from the site show that the Neanderthals had access to diverse plants and animals, sandy plains, woodlands, and wetlands.
"What seems to becoming through is that this was one of those perhaps localized, privileged spots because of the benign climate that perhaps contributed significantly to this late survival," he said. "So I think it goes beyond just the issue of late survival and possible overlap with modern humans. It also suggests reasons why it was that they survived."
Why did Neanderthals become extinct? If it wasn't competition with modern humans after all, Finlayson says it might have been a deteriorating climate. He says cores of dirt dredged up from the Mediterranean floor suggest that the climate got colder and dryer 24,000 to 28,000 years ago.
"So it could be these last surviving Neanderthals lived in very small populations and any slight environmental change, perhaps a famine over a period of years caused by drought, may well have tilted them over the edge, never to recover again," noted Clive Finlayson.