Neanderthals disappeared earlier – study

BRUSSELS: Neanderthal fossils from a cave in Belgium believed to belong to the last survivors of their species ever discovered in Europe are thousands of years older than once thought, a new study said Monday (Tuesday in Manila).

Previous radiocarbon dating of the remains from the Spy Cave yielded ages as recent as approximately 24,000 years ago, but the new testing pushes the clock back to between 44,200 to 40,600 years ago.

The research appeared in the Proceedings of the National Academy of Sciences and was carried out by a team from Belgium, Britain and Germany.

Co-lead author Thibaut Deviese from the University of Oxford and Aix-Marseille University told the Agence France-Presse that he and colleagues had developed a more robust method to prepare samples, which was better able to exclude contaminants.

Having a firm idea of when our closest human relatives disappeared is considered a key first step toward understanding more about their nature and capabilities, as well as why they eventually went extinct while our own ancestors prospered.

The new method still relies on radiocarbon dating, long considered the gold standard of archeological dating, but refines the way specimens are collected.

All living things absorb carbon from the atmosphere and their food, including the radioactive form carbon-14, which decays over time.

Since plants and animals stop absorbing carbon-14 when they die, the amount that remains when they are dated tells us how long ago they lived. When it comes to bones, scientists extract the part made up of collagen because it is organic.

“What we have done is to go one step further,” said Deviese, since contamination from the burial environment or through glues used for museum work can spoil the sample.

Instead, the team looked for the building blocks of collagen, molecules called amino acids, and in particular selected specific single amino acids they could be sure were part of the collagen.

The authors also dated Neanderthal specimens from two additional Belgian sites, Fonds-de-Foret and Engis, finding comparable ages.

“Dating all these Belgian specimens was very exciting as they played a major role in the understanding and the definition of Neanderthals,” said co-lead author Gregory Abrams, of the Scladina Cave Archaeological Center in Belgium.

“Almost two centuries after the discovery of the Neanderthal child of Engis, we were able to provide a reliable age.”