Dry period in Spain explains Neanderthals' last stand

• 18 May 2007
• NewScientist.com news service

While modern humans were taking over the rest of Europe, Neanderthals were somehow able to cling on in southern Iberia. Now a climate model has helped to explain why. It suggests the region became desert-like around 39,000 years ago, making it undesirable for modern humans.

Pierre Sepulchre from the University of California, Santa Cruz, and colleagues modelled climate and vegetation patterns over the Iberian peninsula around 40,000 years ago. In particular they were interested in the impact of "Heinrich event 4" - an episode of sluggish circulation and falling temperatures in the Atlantic Ocean lasting around 2000 years.

The results show severe drying over southern Iberia, starting around 39,000 years ago and persisting for at least 1000 years (Earth and Planetary Science Letters, DOI: 10.1016/j.epsl.2007.03.041). "Climate change reduced the resources, so that modern humans had no interest in continuing their expansion to the south," says Sepulchre. They did so only after conditions became favourable again.

The finding quashes the theory that rapid climate swings made Europe uninhabitable, but that southern Iberia remained a "Garden of Eden" in which the Neanderthals could still survive.

From issue 2604 of New Scientist magazine, 18 May 2007, page 21