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Neanderthal fossils from a cave in Belgium believed to belong to the last survivors of their species ever found in Europe are thousands of years older than previously thought, according to a new study on Monday.
Earlier radiocarbon dating of the Spy Cave remains has yielded ages as recent as around 24,000 years ago, but new tests push the clock back to 44,200 to 40,600 years.
The research appeared in the Proceedings of the National Academy of Sciences and was produced by a team from Belgium, Great Britain and Germany.
Co-lead author Thibaut Deviese of the University of Oxford and the University of Aix-Marseille told AFP that he and his colleagues had developed a more robust method for preparing samples, which was better at even to exclude contaminants.
Getting a clear idea of when our closest human relatives passed away is seen as a key first step in better understanding their nature and abilities, as well as why they ultimately passed away while our own ancestors thrived.
The new method still relies on radiocarbon dating, long considered the gold standard of archaeological dating, but refines the way specimens are collected.
All living things take up carbon from the atmosphere and from their food, including the radioactive form of 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 they have lived.
When it comes to bones, scientists extract the part that is collagen because it is organic.
“What we’ve done is take it one step further,” Deviese said, as contamination from the burial environment or from the glues used for museum work can spoil the sample.
Instead, the team researched the building blocks of collagen, molecules called amino acids, and in particular selected specific unique amino acids that they could be sure were part of collagen.
‘Reliable framework’
The authors also dated Neanderthal specimens from two additional Belgian sites, Fonds-de-Foret and Engis, finding comparable ages.
“Meeting all of these Belgian specimens was very exciting as they played a major role in understanding and defining Neanderthals,” said lead co-author Gregory Abrams, from the Scladina Cave Archaeological Center in Belgium.
“Almost two centuries after the discovery of Engis’ Neanderthal child, we were able to provide a reliable age.”
Genetic sequencing has shown that a Neanderthal shoulder bone dated previously 28,000 years old was heavily contaminated with bovine DNA, suggesting that the bone had been preserved with a glue made from cattle bones.
“Dating is crucial in archeology. Without a reliable timeline, we can’t really be sure that we understand the relationships between Neanderthals and homo sapiensAdded co-author Tom Higham of the University of Oxford.
Some uses of stone tools have been attributed to Neanderthals and have been interpreted as a sign of their cognitive evolution, Deviese said.
But if the timeline for Neanderthals’ existence is pushed back, Deviese added, then Paleolithic industries should be re-examined to determine if they were really the work of the extinct hominid species.
© Agence France-Presse
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