The international research team, led by Professor Cosimo Posth at the Senckenberg Centre for Human Evolution and Palaeoenvironment at the University of Tübingen, traced the dramatic genetic history of European Neanderthals. The new study, published in the journal PNAS, indicates that one localized group survived the severe climate by retreating to a glacial refugium in what is now southwestern France approximately 75,000 years ago. The descendants of these resilient survivors then spread across Europe after 65,000 years ago.
Genetically speaking, almost all late Neanderthals descended from this one lineage.
"Our data enabled us to reconstruct geographically that Neanderthals retreated to what is now southwestern France," explained Professor Posth. "There, around 65,000 years ago, a new population emerged and later spread across the whole of Europe. This explains why almost all Late Neanderthals sequenced so far - from the Iberian Peninsula to the Caucasus - belong to the same line of inherited mitochondrial DNA."
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Artist’s impression of the glacial landscape encountered by Neanderthals during the Ice Age. (Direction de l’archéologie du Pas-de-Calais/Benoît Clarys/University of Tuebingen)
The Severe Neanderthal Population Bottleneck
To uncover this history, the researchers focused on mitochondrial DNA, which is inherited independently of the main DNA in the cell nucleus. The team sequenced the mitochondrial DNA of ten new Neanderthal individuals from six archaeological sites in Belgium, France, Germany, and Serbia. These were analyzed alongside 49 previously published samples of Neanderthal mitochondrial DNA.
"Mitochondrial DNA does not contain nearly as much genetic information as the entire genome of a human being, but it usually survives longer and is easier to obtain," said Charoula Fotiadou, first author of the study. The results were combined with data on the presence of Neanderthals in Europe drawn from the large-scale archaeological database ROAD.
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Excavations at the Tourtoirac rock shelter in France, where three Neanderthal remains analyzed in this study were found. (Luc Doyon/University of Tuebingen)
The harsh climatic conditions of the Ice Age around 75,000 years ago severely depleted the genetically diverse European Neanderthal populations. During this period, archaeological sites declined in number and became increasingly concentrated in southwestern Europe. This severe genetic bottleneck meant that when the climate warmed and the population rebounded, the Neanderthals were very genetically similar.
Entrance to the Pešturina Cave in Serbia, where a genetically analyzed Neanderthal tooth was discovered. (Dusan Mihailovic/University of Tuebingen)
A Rapid Decline Before Final Extinction
The researchers also utilized a statistical program to calculate whether the genetic changes in mitochondrial DNA diversity over time were consistent with a population of constant size. The results showed that this was not the case. According to the calculations, the number of Neanderthals declined rapidly and sharply between 45,000 and 42,000 years ago.
This rapid fall in numbers reached a minimum around 42,000 years ago, shortly before the Neanderthals became extinct altogether and were replaced by modern humans, Homo sapiens. The lack of genetic diversity may have played a crucial role in their demise.
"Genetically speaking, the Late Neanderthals were a very homogeneous group," noted Professor Posth. "So it may be that the low genetic diversity- and possibly also the subsequent isolation of small groups - contributed to the disappearance of the Neanderthals."
Rare Exceptions to the Rule
While the vast majority of late Neanderthals belonged to this single lineage, recent discoveries have shown rare exceptions. An individual nicknamed Thorin, found in Grotte Mandrin in France and dated to about 50,000 years ago, belonged to an older lineage that had been isolated for millennia. However, Thorin remains the exception rather than the rule for late European Neanderthals.
The findings from this comprehensive DNA analysis provide a much clearer picture of the evolutionary developments that preceded the extinction of the Neanderthals. By combining genetic evidence with archaeological data, scientists are finally unraveling the complex and dramatic demographic history of our closest ancient relatives.
Top image: Entrance to the Pešturina Cave in Serbia, where a genetically analyzed Neanderthal tooth was discovered. Source: Dusan Mihailovic/University of Tuebingen
By Gary Manners
References
Fotiadou, C. M. et al. 2026. Archaeogenetic insights into the demographic history of Late Neanderthals. Proceedings of the National Academy of Sciences. Available at: https://doi.org/10.1073/pnas.2520565123
Marshall, M. 2026. Genetic clues tell the story of Neanderthals' decline. New Scientist. Available at: https://www.newscientist.com/article/2520319-genetic-clues-tell-the-story-of-neanderthals-decline/
Posth, C. et al. 2026. Späte Neandertaler in Europa gehen auf eine einzelne Gruppe zurück. University of Tübingen. Available at: https://uni-tuebingen.de/universitaet/aktuelles-und-publikationen/pressemitteilungen/newsfullview-pressemitteilungen/article/spaete-neandertaler-in-europa-gehen-auf-eine-einzelne-gruppe-zurueck/
Yirka, B. 2026. Europe's Late Neanderthals descended from a single population, DNA analysis suggests. Phys.org. Available at: https://phys.org/news/2026-03-europe-late-neanderthals-descended-population.html
