Why did Neanderthals disappear? New data challenges old theories
An international team of scientists decoded the DNA of 27 Neanderthals who lived in Belgium and France shortly before the extinction of their species. The results showed that many popular ideas about the last Neanderthals may be wrong: they were more genetically diverse than previously thought and showed no signs of rapid decline.
Neanderthals inhabited Europe and much of Asia for hundreds of thousands of years until their extinction around 40,000 years ago. However, not all Neanderthal populations were alike.
In a new study published in the journal Nature, scientists focused on northwestern Europe. They analyzed the remains of 27 Neanderthals from France and Belgium, many of whom lived just a few thousand years before the final extinction of their species. Thanks to modern DNA sequencing methods, the researchers have obtained one of the most detailed pictures yet of the lives of late Neanderthals.
Didn’t Neanderthals become extinct due to inbreeding?
P. Semal (Royal Belgian Institute of Natural Sciences) via Max Planck Institute for Evolutionary Anthropology
For a long time, one of the main reasons for the extinction of Neanderthals was considered to be their small numbers and constant interbreeding between relatives. This idea was suggested by individual discoveries, including the famous Neanderthal woman from the Altai Mountains, whose genome revealed evidence of severe inbreeding.
However, new data paint a different picture. It turns out that Neanderthals in northwestern Europe maintained connections between groups and possessed a relatively diverse gene pool. Researchers found no evidence of a progressive accumulation of harmful mutations or a sharp decline in genetic diversity.
This means that, at least in this region, Neanderthals did not appear to be a doomed population on the brink of genetic collapse.
The Riddle of Living Next to People
A fragment of a Neanderthal femur from which a DNA sample was taken.
© E. Dewamme, Royal Belgian Institute of Natural Sciences
Another unexpected result concerns Homo sapiens. Modern humans and Neanderthals are known to have interbred repeatedly. This is why many people today carry a small amount of Neanderthal DNA.
Researchers suggest that the last Neanderthals in Europe may have coexisted with modern humans for hundreds of generations. However, almost no traces of human DNA were found in their own genomes.
This creates a strange asymmetry: humans inherited Neanderthal genes, but scientists have yet to find any counterexamples. Why this happened remains one of the most intriguing mysteries of ancient history.
Extinction Was More Complex Than It Seemed
These results force us to reconsider the idea of Neanderthals as a single population that gradually degenerated before disappearing.
Judging by the new data, different groups lived differently. Some may have faced population decline and isolation, while others remained connected and maintained genetic diversity. The causes of their extinction may have varied across regions and included a combination of climate change, competition with humans, and other factors.
Source: https://www.techinsider.ru