A new study of ancient DNA from a megalithic tomb near Paris has uncovered a dramatic population collapse and replacement in Neolithic France around 5,000 years ago. The genetic analysis of 132 individuals buried at the site of Bury, about 50 kilometers north of Paris, shows that the original population was entirely replaced by a new group with distinct genetic ties, offering a striking glimpse into the turbulent events of the Neolithic decline.
The research, published in Nature Ecology & Evolution, centers on a large megalithic tomb used during two distinct periods, separated by a population decline around 3000 BC. By analyzing the genetic material preserved in the bones, scientists discovered that the two groups buried before and after this decline were not genetically related, pointing to a complete population turnover in the region.
"We see a clear genetic break between the two periods," said Frederik Valeur Seersholm, assistant professor at the Globe Institute at the University of Copenhagen and one of the lead authors of the study. "The earlier group resembles Stone Age farming populations from northern France and Germany, while the later group shows strong genetic links to southern France and the Iberian Peninsula."
The findings suggest a sharp reduction in the local population followed by the arrival of entirely new groups from the south. The burial site itself spans the period from approximately 3200 to 2450 BC, making it a rare window into a pivotal and poorly understood transition in European prehistory.
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Location of Bury and similar sites with genetic data available, with the geographical extent of the Paris Basin highlighted. b, Diagram of the Bury grave showing the two distinct burial phases separated by the population collapse around 3000 BC. (Seersholm et al./Nature)
The Plague and High Mortality Rates
The earlier burial phase at the Bury tomb shows unusually high mortality rates, particularly among children and young people. According to Laure Salanova, research director at France's National Centre for Scientific Research (CNRS), "The demographic pattern is a strong indicator of crisis." To understand what might have caused this catastrophe, researchers utilized a DNA method that analyzes all genetic material preserved in bone, allowing them to detect traces of ancient pathogens.
They found evidence of the plague bacterium Yersinia pestis, as well as louse-borne relapsing fever caused by Borrelia recurrentis. While the presence of these diseases is significant, it is unlikely to be the whole story. "We can confirm that plague was present, but the evidence does not support it as the sole cause of the population collapse," explained Martin Sikora, associate professor at the University of Copenhagen and senior author of the study. "The decline was likely driven by a combination of disease, environmental stress and other disruptive events." The discovery of Yersinia pestis at this site is consistent with growing evidence that early plague was circulating across Neolithic Europe long before the better-known medieval Black Death.
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A Shift in Social Organization
The genetic data from the Bury tomb also reveals a marked change in social structure between the two periods. During the earlier phase, before the population collapse, multiple generations from the same extended families were buried together, suggesting tightly knit communities with strong familial bonds. In the later phase, following the arrival of the new population, burials became more selective and were dominated by a single male lineage.
"This indicates that the population change was accompanied by a shift in how society was structured," Seersholm noted. This shift from communal, family-based burials to a more patriarchal and selective system highlights the profound cultural changes that occurred alongside the genetic replacement. The new inhabitants not only brought different ancient DNA but also entirely new ways of organizing their society and honoring their dead, pointing to a wholesale transformation of the cultural landscape.
The End of the Megalith Builders
The findings from the Paris Basin add to the growing body of evidence that the so-called Neolithic decline was a widespread phenomenon that affected much of northern and western Europe. Previously, this population crash had been well-documented in Scandinavia and northern Germany, but the new study confirms that it extended much further south and west, reaching deep into the heart of France. The study also connects the Paris Basin collapse to broader patterns of Yamnaya and Iberian population movements that reshaped the continent during the late Neolithic and early Bronze Age.
The research also offers a compelling explanation for a longstanding archaeological mystery: why the construction of megalithic tombs and other large stone monuments abruptly ended across Europe around the same time.
"We now see that the end of these monumental constructions coincides with the disappearance of the population that built them," Seersholm concluded.
The original builders of these impressive structures were wiped out by a combination of disease and environmental stress, and the strangers who replaced them simply did not continue the tradition. In this sense, the stones themselves stand as silent monuments not only to the dead they contain, but to an entire civilization that was lost.
Top image: Example of Neolithic burial structure in France. The Dolmen de Bagneux, the largest megalithic tomb in France, near Saumur in the Loire Valley. Source: Manfred Heyde / CC BY-SA 3.0
By Gary Manners
References
Salanova, L., Seersholm, F. V., Sikora, M., et al. 2026. Population discontinuity in the Paris Basin linked to evidence of the Neolithic decline. Nature Ecology & Evolution. Available at: https://www.nature.com/articles/s41559-026-03027-z
Seersholm, F. V. 2026. Stone age population collapse revealed by DNA study in France. EurekAlert! / University of Copenhagen. Available at: https://www.eurekalert.org/news-releases/1124798
