The plague may have wiped out most northern Europe 5000 years ago
Around 5400 years ago, Europe’s Neolithic culture, known for creating structures like Stonehenge, experienced a dramatic decline. Recent discoveries now offer strong evidence that a major cause of this decline could have been plague outbreaks. Researchers, including Frederik Seersholm from the University of Copenhagen, have sequenced ancient DNA from 108 individuals who lived in northern…
Around 5400 years ago, Europe’s Neolithic culture, known for creating structures like Stonehenge, experienced a dramatic decline. Recent discoveries now offer strong evidence that a major cause of this decline could have been plague outbreaks. Researchers, including Frederik Seersholm from the University of Copenhagen, have sequenced ancient DNA from 108 individuals who lived in northern Europe during this period.
The findings revealed that the plague bacterium Yersinia pestis was present in 18 of these individuals at the time of their death. Seersholm and his team believe that these individuals likely succumbed to the plague. “We think that the plague did kill them,” he said.
During this time, the population of northern Europe decreased sharply, and the reason behind this decline has remained a mystery until now.In recent years, studies of ancient human DNA have shown that local populations in Europe did not fully recover from this Neolithic decline. Instead, they were largely replaced by new groups migrating from the Eurasian steppes.
For instance, in Britain, by around 4000 years ago, less than 10 percent of the population had ancestry from the people who constructed Stonehenge.The discovery of Y. pestis in these ancient human remains offers a compelling explanation: the plague may have caused widespread mortality, enabling the migration of people from the steppes into Europe with minimal resistance.However, this theory has faced skepticism.
In 2021, Ben Krause-Kyora from Kiel University argued that early forms of Y. pestis were unlikely to have caused a pandemic, as their DNA indicated they couldn’t survive in fleas—the main way people contract bubonic plague. Krause-Kyora suggested that sporadic plague cases were more likely, not a continent-wide pandemic.
To investigate further, Seersholm’s team focused on individuals buried in nine tombs in Sweden and Denmark, who lived between 5200 and 4900 years ago. Their analysis identified three separate plague outbreaks over these generations, with the last outbreak being caused by a strain with reshuffled genes, potentially making it more virulent.
Seersholm noted that the plague DNA was primarily found in the teeth of the deceased, indicating that the bacterium entered their bloodstream, causing severe illness and likely death. The evidence also pointed to person-to-person transmission, possibly through droplets, which would suggest pneumonic plague. Additionally, recent studies indicate that human lice, not just fleas, can spread bubonic plague.
One notable observation is that these individuals received proper burials, indicating that society had not completely collapsed during this time. “If there was in fact an epidemic, we only see the very beginning of it,” Seersholm remarked. After 4900 years ago, megalithic tombs appear to have been abandoned for several centuries.
However, 10 individuals buried in these tombs between 4100 and 3000 years ago were unrelated to the original inhabitants, instead being of steppes origin. “It is 100 percent complete replacement,” said Seersholm. “Five thousand years ago, these Neolithic people disappear. And now we show that plague was widespread and abundant at exactly the same time.”
While these findings strengthen the argument that plague played a significant role in the Neolithic decline, Seersholm acknowledges that they are not definitive proof. “I would say that we’ve definitely shown that it had the potential to spread within humans, and that it had the potential to kill an entire family, for example.” Krause-Kyora concedes that the findings suggest Y. pestis was more prevalent than previously thought but remains cautious, pointing out that the evidence for widespread plague in other regions is lacking. He also notes that the proper burials suggest there was no widespread deadly epidemic. “The results could even suggest that the Yersinia infection was more of a chronic disease over a long period of time,” he said.
Seersholm and his colleagues plan to continue their search for more evidence across Europe. However, determining the true lethality of the reshuffled strain would require resurrecting it, a task too dangerous to undertake.Nicolás Rascovan, from the Pasteur Institute in Paris, whose team first proposed the plague theory in 2018, believes the new findings will sway many skeptics. “I think that this paper will convince many colleagues who were skeptical about our previous work,” he said.
SciTech Magazine Contributor
Rebecca Grace is an archaeologist who focuses on ancient human skeletons and science communication. Her research has been published in many scientific journals, and her articles have appeared in Forbes, Mental Floss, and Smithsonian. She has a Ph.D. in anthropology from the University of North Carolina at Chapel Hill and holds bachelor's degree in classical archaeology.