Wednesday, April 8, 2026

Population Discontinuity At The End Of The Neolithic In Paris, France

Bernard's blog, Généalogie génétique, lives. (I had removed it from the blogroll when technical difficulties at the site made it look dead. I'll reinstate it when I have time.)

His latest post examines an ancient DNA paper looks at ancient DNA from a graveyard in Paris, part of which dates to around 3000 BCE in the megalithic Neolithic era, and part of which comes a century later after a long gap in burials there, when the previous megalithic Neolithic civilization there had collapse: forests had regrown, megalithic construction had ceased, and infectious diseases including the black plague had ravaged the population. 

The post-collapse social organization was different too, with the earlier burials reflecting a large extended family/clan social structure of related people, and the later burials reflecting a smaller nuclear family with multiple generations of related people but only a few people in each generation.

In this case, there was population discontinuity in which the prior Neolithic population was replaced by another Neolithic population from the South with a different social organization that moved in after the original megalithic Neolithic culture in Paris collapsed. Both the original group (in brown on the PCA plot below) and the subsequent one (in green) cluster together as European Neolithic populations, distinct from prior European hunter-gather peoples and the later Bronze Age steppe peoples, despite being distinct enough to indicate a population replacement.


This graveyard pins down the timing of this collapse fairly precisely to a single century.

This also makes clear that Neolithic collapse in Western Europe happened before the arrival of Bronze Age people with steppe ancestry. It also illustrates the civilizational vacuum that those Bronze Age people swept into a few centuries later, replacing much of the first farmer wave of people in this part of Europe, in a dynamic distinct from the conquest of a vibrant Neolithic civilization.

The abstract and citation appears below:
At the transition between the third and the fourth millennium BC, there is evidence for a population decline concurrent with the end of megalith building across continental northwestern Europe. In Scandinavia this ‘Neolithic decline’ is followed by a massive population turnover, as farming communities disappeared and were replaced by people with steppe ancestry. In western Europe, however, ancestry associated with Neolithic farmers persisted beyond the Neolithic decline, and it remains unclear whether a similar demographic replacement occurred.

To investigate the population dynamics around the Neolithic decline in present-day France, we sequenced 132 ancient genomes from the allée sépulcrale at Bury. Located in the Paris area, Bury spans two burial phases separated by a hiatus with no burial activity: one phase directly preceding the Neolithic decline in the late fourth millennium BC, ending around 3000 BC, and a later phase some time after the Neolithic decline in the early- to mid-third millennium BC.

Our analysis revealed that the two burial phases at Bury represented largely discontinuous genetic groups of a markedly different social organization as inferred from three large pedigrees. We show that the difference between the two burial phases can be linked to a northwards movement of Neolithic ancestry from the south, which only spread into the Paris Basin after the Neolithic decline, at around 2900 BC. 
Together with genetic evidence of various infectious diseases in the dataset, such as Yersinia pestis and Borrelia recurrentis, as well as evidence for forest regrowth between the two phases, these findings detail a population turnover at the end of the fourth millennium BC, offering a possible explanation for the cessation of megalith building.
Frederik Seersholm, et al, "Population discontinuity in the Paris Basin linked to evidence of the Neolithic decline" Nature Ecology and Evolution (April 3, 2026).

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