14 DAY TRIAL // Neanderthals were a human species that emerged roughly 350,000 years ago in Europe and spread from Britain to Iberia and Israel to the south and Uzbekistan in the east.
40,000 years ago, the modern humans entered Europe from Africa through the Middle East and in about 10,000 years ago they displaced the Neanderthals.
Their last hold on Europe by about 30,000 years ago was on the warmer Southern Iberia, but 24,000 years ago, their last population went out for good.
Even if Neanderthals survived several glaciations, resisting in local pockets from where bounced back in warmer interglacials, it seems that finally, the cold led to their extinction, as experts from the Gibraltar Museum and Spain point out.
A severe and sudden episode of cold might have caused an intense drought, leaving the last surviving Neanderthals in a shortage of fresh water and game animals they ate.
Sediment analysis in probes off the Balearic Islands revealed a sea-surface temperature drop to 8C (46F) from 14-20 C (57-68 F).
The higher sand content deposited in the seabed indicated a drier climate on land.
"This event was the most severe the region had seen for 250,000 years. It looks pretty severe and also quite short", said Professor Clive Finlayson, from the Gibraltar Museum.
"Things like oak trees that are still with us today managed to ride it out. But a very fragmented, stressed population of Neanderthals - and perhaps other elements of the fauna - did not."
It seems that the cold episode was triggered by a rare combination of cold polar air blowing down the Rhone valley and Saharan air blowing north.
But a new research signals another site of late Neanderthal survival in southern Iberia, in the Carihuela cave (southeast Spain).
Professor Jose Carrion and Santiago Fernandez Jimenez, from the University of Murcia analyzed fossil pollen from soil layers of the cave to find how vegetation had changed in the area on the last 15,000 years, employing radiocarbon dating and uranium-thorium dating.
They were surprised to date Neanderthal tools from 45,000 years ago until 21,000 years ago.
These radiocarbon dates are "raw" and cannot be compared directly with those from Gibraltar, which have been precisely calibrated.
The researchers also found Neanderthal bones and even a male skull fragment.
The Carihuela cave has been extensively investigated between 1979 and 1992, but is currently closed due to a dispute between national and regional governments over rights to dig at the cave.
"The human bones have been recovered in different excavation campaigns over 50 years. The relationship between them and the dates I provide must be treated with caution," said Carrion.
Many sediments seem to have been mixed up, thus Carrion points that new excavations on Carihuela could solve some controversies.
Finlayson believe that Carihuela probes could correlate with those from Gibraltar once their age will be precisely detected.