The Prehistoric Plague That Ended the Neolithic Period

When researching the genomes of the population that inhabited Britain 4,500 years ago, scientists came across a piece of a prehistoric puzzle with seemingly no real solution. Around the mid-2000s BC, Neolithic communities across Europe seemed to disappear without a trace. These communities had become the first peoples to cultivate European soil, domesticating animals like cows and sheep and growing crops like barley and emmer. Scientific research into population genomes indicates a mass death event among these Neolithic groups, only for them to be replaced by a new group of people that quite literally brought Europe out of the Stone Age. The newcomers that commenced Europe’s Bronze Age originated from the Steppes of modern-day Ukraine and Russia, making their way across a Europe seemingly empty of Neolithic farmers. Scientists have been unable to determine what happened to these Neolithic communities, their genetic strains are missing from the new Bronze Age populations, making integration within the Steppe communities infrequent at best. These Neolithic communities seemingly vanished without a trace, so what (might have) happened?

Well, within the last decade or so, research on the teeth of Neolithic skeletons has indicated a potential contributor to the end of the Neolithic period: yersinia pestis, or the ‘etiologic agent of plague’. The very bacterium associated with some of humanities worst mass death events may have been the perpetrator of the fall of the Neolithic period. In Britain, burial sites at Charterhouse Warren, in Somerset, and Levens Park, Cumbria, both show evidence of the plagues dirty work. At Charterhouse, thirty individuals through a metagenomic process were tested for yersinia pestis, whereby the pulp chamber of the tooth (where there is a blood supply) was analysed for the presence of the bacterium. Now, only two of these individuals, both between 10 and 15 years old, tested positive for yersinia pestis at the time of death. You may be thinking to yourself, hang on a second, only two of the thirty individuals had the plague, how can that indicate a continental wide mass-death event? Your concerns would be reasonable, these results are not the golden ticket to proving a plague like that of the Justinian plague (AD 541-549) or the Black Death (1346-1353) occurred nearly 5000 years ago. However, just because the other individuals didn't test positive, does not mean they did not have the plague. You see, to test positive for the plague an individual needs to have held a very high pathogen load, and even if the individual did, the ‘endogenous microbial DNA’ may have been lost during the thousands of years before they were tested. It is very possible that many of the thirty individuals suffered from the plague and may have possibly died from it. This possible prehistoric plague was not limited to Britain either.

Scientists like Frederick Seersholm have undergone research with a much more robust basis for the prehistoric plague theory. In Scandinavia, it was found that at least 17% of a population spanning a vast area of land, had over a 120-year period contracted yersinia pestis. Around the Swedish village of Falköping, one-hundred and eight individuals were tested with the same process that was used for the Neolithic Britons.  Of these one-hundred and eight individuals, eighteen definitely had the plague, meaning it is likely much of these Neolithic communities also became victims of yersinia pestis. The Neolithic communities of Falköping, like so many populations across Europe, had declined at a time when the plague was present, so surely yersinia pestis had a part to play in the Neolithic people’s downfall? As the great megalithic structures like Stonehenge, Ales Stenar and the Alignments of Carnac were suddenly no longer built, the populations that built them equally ceased to exist. Currently twenty-seven locations have been identified across Eurasia where individuals have tested positive for a similar strain of yersinia pestis. All these burial sites have been dated between five hundred years of each other, indicating that the plague spread quickly. Surely, if an epidemic of plague spread across the Eurasian continent relatively quickly, at a time that coincided with the decline and eventual disappearance of Neolithic communities, then yersinia pestis must have been at least partially responsible?

At the moment scientists and scholars are unable to agree on what happened to the Neolithic peoples of Europe. Some explain this demographic decline as the responsibility of agricultural crisis. Maybe communities simply were unable to sustain themselves with the livestock and crops at hand or were struck by a climatic crisis. Others see some promise in the plague theory, understanding the population decline as the consequence of an early strain of yersinia pestis. With my extremely ignorant and unscientific but enthusiastic two penny’s worth; I would suggest that maybe there is some merit in recent research. It is evident that Neolithic communities across Eurasia were dying or at least infected with yersinia pestis; future strains of the very same bacterium that would go on to wipe out vast swathes of the European population, so why couldn't this have happened earlier. Perhaps it is a culmination of disasters that eclipsed the Neolithic period. People were potentially weakened by malnutrition following an agricultural crisis only then for their immune systems to be ravaged by a plague they were simply too weak to fight. Thus, a group of people from the Steppes with their metal daggers and arrows, and potentially less compromised immune systems, were able to settle on lands that had once been home to these Neolithic farmers.

Ultimately, debates on the disappearance of Europe’s Neolithic population are inconclusive. There just isn't concrete evidence to suggest either theory is correct. However, I hope this article has amiably welcomed you to a field of debate on a period in our history that cannot be so easily read about. It is down to the scientists and archaeologists to uncover this mystery, and I hope that like me, you are eager to wait and see.

Bibliography

Milosavljevich, Stefan, Europe's (Highly Debated) Prehistoric Plague, [Video], YouTube, (2024), <https://www.youtube.com/watch?v=_u3mul4gaPE&t=851s>, [Accessed: 9 December, 2024]

Olalde, I., Brace, S., Allentoft, M. et al. The Beaker phenomenon and the genomic transformation of northwest Europe. Nature Communications, no. 555, (2018), pp.190–196

Seersholm, F.V., Sjögren, KG., Koelman, J. et al. Repeated plague infections across six generations of Neolithic Farmers. Nature Communications, no. 632, (2024), 114–121

Swali, P., Schulting, R., Gilardet, A. et al. Yersinia pestis genomes reveal plague in Britain 4000 years ago, Nature Communications, vol. 14, no. 2930, (2023), pp.114-121

Valtueña, Andrades  A. et al. The Stone Age plague and its persistence in Eurasia. Current Biology, vol. 27, (2017), pp. 3683–3691