A new genetic study has changed how researchers view the last Neanderthals in Western Europe. Evidence from 27 individuals found in present-day Belgium and France suggests these groups were more connected and more diverse than many scientists thought. The findings challenge the idea that growing genetic problems played a major role in Neanderthal extinction.
Neanderthal family, photo taken at the Anthropos Pavilion in Brno, Czech Republic. Credit: Jaroslav A. Polák
The study, published in Nature, focused on Neanderthals who lived less than 52,500 years ago. Researchers recovered DNA from remains found at ten archaeological sites. Among them was a high-quality genome from a Neanderthal known as GN1, who lived around 45,000 years ago at Goyet in Belgium.
Scientists have long known that Neanderthals often lived in small groups. A key question remained unanswered. Were those groups isolated from one another, or did they stay connected across larger regions?
The new data point toward strong links between communities. Most of the Neanderthals studied were more closely related to each other than to other late Neanderthals living elsewhere in Europe. Genetic differences between individuals from sites across Belgium and France were surprisingly small. Such patterns suggest regular contact between groups over long distances.
Researchers also found traces of an older Neanderthal lineage in some individuals. This lineage existed before the rise of later Neanderthal populations. Its presence shows that different ancestral groups continued to mix and leave genetic traces until late in Neanderthal history.
A key role in the study came from a Neanderthal specimen from Les Cottés in France. Earlier work had shown that this individual carried a genetic profile linked to populations far outside Western Europe. In the new research, the Les Cottés genome helped scientists interpret newly recovered DNA and piece together the history of Europe’s final Neanderthal populations.
Neanderthal hunters depicted in the Gallo-Romeins Museum, Tongeren (Belgium). Credit: Benoit Brummer / CC BY 4.0
The results suggest that late Neanderthals in Western Europe did not belong to a single uniform group. They formed a network of communities connected through movement and social ties. At the same time, some groups retained signs of older ancestry.
The study also challenges another common assumption about Neanderthals. Earlier genetic work from Siberia’s Altai Mountains found evidence of mating between close relatives. Those findings led some researchers to view Neanderthals as isolated populations with low genetic diversity.
The new genomes tell a different story. The Neanderthals from Belgium and France showed no signs of the close-relative mating seen in some eastern populations. Their genetic diversity was higher, suggesting larger populations or stronger links between neighboring groups.
Researchers examined whether harmful genetic mutations built up over time and weakened Neanderthal populations. The evidence did not support that idea. Genetic burden did not increase in these late Western European groups.
The team also looked for signs of recent contact with modern humans. Neanderthals and early Homo sapiens lived in northwestern Europe at the same time beginning around 47,000 years ago. Yet none of the genomes studied showed evidence of recent interbreeding with modern humans.
According to the researchers, most gene flow between Neanderthals and modern humans likely took place outside northwestern Europe.
Taken together, the findings paint a picture of Neanderthals who remained connected across large parts of Western Europe until near the end of their existence. Rather than isolated groups in decline, these communities maintained social links and healthy levels of genetic diversity during their final millennia.