When did Neanderthals disappear? The question has stirred scientists for a long time. The human remains of a cave in Belgium are contributing to the debate today by revealing themselves to be much older than what had previously been envisaged.
According to previous radiocarbon dating, specimens from Spy cave, where many human remains have been found since the 19th century.e century, dated back only 24,000 years. But, according to a study published Monday, March 8 in the scientific journal PNAS, they are, in fact, 44,200 or 40,600 years old.
A multidisciplinary team from Belgium, Great Britain and Germany has developed a method to prepare the samples, making it possible to avoid any external contamination, explained to Agence France-Presse (AFP) one of the co-authors of the study, Thibaut Deviese, from the University of Oxford and Aix-Marseille. The study thus concludes that Neanderthals “Disappeared from northern Europe (…) much earlier than previously suggested ”.
Getting a better idea of when Neanderthals went extinct is seen as an important first step in better understanding his nature, as well as why he eventually gave way to modern humans.
The method still relies on radiocarbon (radioactive variants of carbon, like carbon-14), which is considered the best dating method, but improves the way samples are processed. All living things absorb carbon from the atmosphere or from food, including carbon-14, which decays over time. Since plants and animals stop taking in when they die, what is left in matter helps determine when that being lived.
For bones, scientists extract the part made of collagen for analysis, because it is organic. “What we have done goes further”, explains Thibaut Deviese. This is because the environment where the remains were found can contaminate the samples. So the researchers focused on molecules called “amino acids,” which they were absolutely certain were part of collagen.
The authors also dated the remains of two other sites in Belgium, Fonds-de-Foret and Engis, with comparable results. There is evidence that it may have survived longer in other regions than in Belgium, the study notes, however.
“Dating is crucial in archeology, because without a reliable framework of chronology one cannot be sure of understanding the relationship between the Neanderthal and homo sapiens », emphasizes Thibaut Deviese. Some stone tools have been attributed to Neanderthals, which has been interpreted as a sign of their cognitive development, he explains. However, if it turns out that they did not exist as long as expected, then these objects must be re-examined to determine if they were really their work.
The disappearance of Neanderthals could be linked to climatic causes, too much inbreeding or competition between species, recalls the study – but this is another burning question that it does not answer. not.