About 5,000 years ago, parts of Europe faced a major crisis. Communities shrank, farms were abandoned, and burial sites fell silent. After a long gap, new people moved into these areas.
A study of ancient DNA from a site near Paris takes a closer look at this moment. It shows a sharp break, not a slow shift. One group disappeared, and another replaced it.
This event is linked to the Neolithic decline, when populations across northwestern Europe dropped quickly. The impact was widespread and changed entire communities.
A burial site tells two different stories
The site, known as Bury, sits about 30 miles north of Paris. It was used as a burial ground during two separate periods, divided by several centuries. The people buried before and after that gap were not the same.
Scientists studied DNA from 132 individuals buried there. The results showed a clear divide between the two groups.
“We can see a clear genetic break between the two burial phases. The people who used the tomb before and after the collapse appear to be two completely different populations,” said Frederik Seersholm, researcher at the University of Copenhagen.
The gap in time is just as telling. After the earlier group used the site, it was abandoned. When people returned generations later, they brought a different genetic background with them.
“This tells us that something significant happened, like a major disruption that led to the decline of one population and the arrival of another,” said Seersholm.
The earlier group, buried around 3200 to 3100 BC, shows troubling patterns. Many of the dead were young, pointing to unusually high mortality.
Laure Salanova is a research director at the French National Centre for Scientific Research (CNRS) who led the Bury project.
“This kind of mortality pattern is not what we expect in a normal, healthy population,” said Salanova. “It suggests that some catastrophic event may have occurred, such as disease, famine or conflict.”
This kind of crisis leaves marks beyond bones. When populations fall quickly, farming slows down. Forests begin to grow back over abandoned land.
Other studies from the same time show exactly that. Nature started reclaiming areas once used for crops.
Disease in ancient remains
The DNA analysis also uncovered signs of disease, including genetic traces of Yersinia pestis, the bacterium behind plague, and Borrelia recurrentis, which causes louse-borne relapsing fever.
Martin Sikora is an associate professor of evolutionary genomics at the University of Copenhagen.
“The presence of pathogenic DNA shows that infectious diseases were affecting human populations at this time,” said Sikora.
“While there is no strong case to say that plague alone caused the population collapse, the total disease load could have been one of several contributing factors.”
Plague appeared in both burial phases, but it showed up more often in the earlier group. That detail suggests disease may have played a role during the worst of the decline, even if it was not the only cause.
A new population moves in
When people returned to the site centuries later, they were not descendants of those who came before. Their DNA points to a different origin.
“This second group had strong genetic ties to Southern France and Iberia, suggesting that it represents people who migrated northwards into the Paris Basin after the population collapse,” said Salanova.
The timing matters. A weakened or nearly empty region would have made it easier for new groups to settle there.
“These results suggest that the decline created space for new groups to expand into the region,” she adds.
Changing family ties
The study also looked at how people in these communities were related. The earlier group included large families, with multiple generations buried together.
“This suggests a tightly knit community where biological family ties were central,” said Sikora.
The later group looked different. There were fewer close family connections, and many individuals traced back to a single paternal line.
“This tells us that not only the population changed, but also how society itself was structured, at least in the funerary sphere.”
A wider pattern across Europe
The findings fit with a broader picture seen across Europe. During the Neolithic decline, many regions show signs of population loss, abandoned settlements, and environmental recovery.
“In demographic terms, the later phase is characterized by burials spread out over time, which may correspond to a highly reduced population or to a selected part of the population,” said Philippe Chambon, an archaeologist at CNRS who analyzed the skeletal remains.
The study adds weight to the idea that this was not an isolated event. It was a widespread shift that changed who lived where and how communities were organized.
Piecing together a distant past
Researchers used several methods, including genetics, archaeology, radiocarbon dating, and pollen analysis. Together, they help uncover a story that might have stayed hidden.
“By joining forces of experts from a wide variety of disciplines, we can now begin to understand what happened during one of the most dramatic transitions in European prehistory,” said Kristian Kristiansen, professor of archaeology at the University of Gothenburg.
What happened 5,000 years ago still shapes Europe today. The gap between these two groups at a quiet burial site near Paris shows how fast human history can change.
The full study was published in the journal Nature Ecology & Evolution.
—–
Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.
Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.
—–