Feb 20, 2007
The ancient humans are thought to have died out in most parts of Europe by about 35,000 years ago.
And now new data from their last known refuge in southern Iberia indicates the final population was probably beaten by a cold spell some 24,000 years ago.
The research is reported by experts from the Gibraltar Museum and Spain.
They say a climate downturn may have caused a drought, placing pressure on the last surviving Neanderthals by reducing their supplies of fresh water and killing off the animals they hunted.
Sediment cores drilled from the sea bed near the Balearic Islands show the average sea-surface temperature plunged to 8C (46F). Modern-day sea surface temperatures in the same region vary from 14C (57F) to 20C (68F).
In addition, increased amounts of sand were deposited in the sea and the amount of river water running into the sea also plummeted.
Neanderthals appear in the fossil record about 350,000 years ago and, at their peak, these squat, physically powerful hunters dominated a wide range, spanning Britain and Iberia in the west to Israel in the south and Uzbekistan in the east.
Our own species, Homo sapiens, evolved in Africa, and displaced the Neanderthals after entering Europe about 40,000 years ago.
During the last Ice Age, the Iberian Peninsula was a refuge where Neanderthals lived on for several thousand years after they had died out elsewhere in Europe.
These creatures (Homo neanderthalensis) had survived in local pockets during previous Ice Ages, bouncing back when conditions improved. But the last one appears to have been characterised by several rapid and severe changes in climate which hit a peak 30,000 years ago.
Southern Iberia appears to have been sheltered from the worst of these. But about 24,000 years ago, conditions did deteriorate there.
This event was the most severe the region had seen for 250,000 years, report Clive Finlayson, from the Gibraltar Museum; Francisco Jimenez-Espejo, from the University of Granada, Spain; and colleagues.
Their findings are published in the journal Quaternary Science Reviews.