Thursday, September 14, 2006

Neanderthal's last stand

Source: Nature

Cave in Gibraltar may be most recent home of extinct species.

David Brill

Gibraltar may have been the last refuge of the Neanderthals, according to the results of a six-year archaeological dig.

The findings, which show that Neanderthals lived alongside modern humans for thousands of years, bring fresh evidence to the debate on what happened to our evolutionary cousins, and whether modern humans drove them to extinction.

Clive Finlayson from the Gibraltar Museum and his colleagues found Neanderthal artefacts in a site called Gorham's Cave. The dig there has so far unearthed 103 items, including spear-points, knives and scraping devices, bearing the marks of Neanderthal craftsmanship. Radiocarbon dating suggests that most of the objects are about 28,000 years old, with the youngest being 24,000 years old.

Data from nearby sites show that modern humans were present 32,000 years ago, so the two seem to have overlapped for millennia.

But dating such material is tricky, notes Paul Mellars, an archaeologist at the University of Cambridge, UK. "Radiocarbon dates can easily be too young because of contamination," he says. "Just a tiny amount can take several thousand years off the age."

He adds that a large number of the artefacts in Gorham's Cave date from 30,000-31,000 years ago, which he thinks may be more representative of the samples. That wouldn't make it the youngest Neanderthal site.

Pockets of survival

Finlayson suggests that the area's mountains could have sheltered the Neanderthals. "It lends itself to little valley populations, rather than the sweeping approach of one population and the disappearance of another," he says.

Signs of Neanderthal technology were first discovered close to the outside of Gorham's Cave in the 1950s, but that deeper excavations only began in 1997. These latest findings, published online in Nature1 this week, are the results of work done between 1999 and 2005.

This site appears to have been ideal for Neanderthals. "They had a whole range of resources," says Finlayson. "In spite of cooling in other parts of Europe there were typical Mediterranean plants there — wild olives and so on. They were also clearly eating a lot of marine material such as mussels. And we have some pretty good indications that they were de-fleshing marine mammals such as seals," he says.

Neanderthals' stronghold was Europe, although they also lived in parts of Asia. Previous work has suggested that when Homo sapiens swept up from Africa some 40,000 years ago, the newcomers displaced Neanderthals from Central and Western Europe within 5,000 years2.

Gorham's Cave should provide an opportunity to understand how the transition from Neanderthals to modern humans took place. "This does suggest that in some parts of Europe they were well enough adapted to hang on, even if modern humans were in the vicinity," says palaeontologist Chris Stringer of the Natural History Museum in London, another author on the report. "How much they contacted each other remains unclear," he adds.


1. Finlayson C., et al. Nature, advanced online publication doi : 10.1038/nature05195 (2006).
2. Mellers P., et al. Nature, 439. 931 - 935 (2006).

No comments: