Researchers led by the University of Copenhagen have published a major genomic study in Nature Ecology and Evolution revealing a dramatic population shift in Neolithic France roughly 5,000 years ago. By analyzing 132 ancient genomes from a megalithic burial site in Bury, north of Paris, the team identified two distinct genetic phases separated by a sudden influx of migrants from the Iberian Peninsula. This new group almost entirely replaced the existing local Neolithic communities within a few centuries.
The study found a stark social divide between the two phases, characterized by a significant male bias in burials (71-73%), suggesting a social structure based on female exogamy, where women were moved to other communities for marriage. Most strikingly, researchers identified the presence of the plague bacterium (Yersinia pestis) in multiple individuals, suggesting that early outbreaks of the plague may have played a critical role in destabilizing the original population before the Iberian migration.
This genomic mapping provides a rare window into one of European prehistory's least understood turning points. It confirms that the transition to the Bronze Age was not just a cultural evolution but a period of intense human migration and biological upheaval. The findings also highlight the sophisticated kinship networks of these early Europeans, showing how shared burial practices and genetic lineages were used to maintain social cohesion during times of rapid environmental and demographic change.