French site sparks Neandertal debate.

Around 36,000 years ago, Neandertals and people lived side by side in southwestern France for at least a millennium, according to a newly assembled chronology of ancient occupations there. Paul Mellars of Cambridge University in England and his coworkers say that their work supports the controversial view that shortly before dying out about 28,000 years ago, Neandertals borrowed toolmaking techniques from neighboring Homo sapiens.

Mellars' team took radiocarbon measurements to date animal bones previously excavated at a French cave. Neandertal stone tools recovered there, dubbed Chatelperronian artifacts, display a toolmaking style that blends techniques typical of Neandertals and of Late Stone Age people.

From the ages of bones found with various tools, the scientists conclude that two periods of Chatelperronian toolmaking occurred in the cave, one 40,000 to 39,000 years ago and the second between 36,000 and 34,500 years ago. Implements with sharpened edges characteristic of human toolmaking were also unearthed in the cave and date to between 39,000 and 36,000 years ago, the scientists report in an upcoming Nature.

The Neandertal occupations of the cave coincided with relatively warm eras that sandwiched a colder period during which modern humans moved in, Mellars says. The artifact record shows an overlap of the two species in the cave around 36,000 years ago, though the two groups might not actually have used the cave simultaneously.

It was during such brief periods of coexistence between the two species in southwestern Europe that Neandertals adopted some modern toolmaking techniques, Mellars argues.

It's more likely that Neandertals developed Chatelperronian tools on their own and never abandoned the French site, counters Joao Zilhao of Cidade University in Lisbon, Portugal. The cave studied by Mellars contained only a few humanmade tools that are probably about 36,000 years old, reflecting no more than a brief incursion, Zilhao says.--B.B.