A little more than a decade ago, when ancient DNA studies began to gain attention, the idea took hold among geneticists that much of what we knew about the people of Europe by modern humans was wrong. The story was simpler than one might expect: Europe was settled in only three mass migrations from the East.
The first hunter-gatherers arrived more than 40,000 years ago. Then, 9,000 years ago, farming people expanded across Anatolia Neolithic Age.
Ultimately, 5,000 years ago, Corded Ware people expanded beyond the Russian Plain to inaugurate the European Bronze Age. Corded Ware was named after the cord-like impressions in their pottery and had a distinctive genetic signature that was previously absent in much of Europe. Genetically, most present-day Europeans have some of these.
However, this was always an over-simplification. our new paperProduced with collaborators from the US and across Europe, the study has shed light on some of the more complex relationships between ancient populations that occurred in north-west Europe.
Our research unravels the origins of prehistoric populations in Belgium and the Netherlands, as well as identifies the source populations for migration into Britain during the Neolithic period, which appears to have replaced 90% of Britain’s Neolithic farmers.
Ancient DNA research has already suggested a much more nuanced picture. For example, when early Neolithic farmers first arrived in Europe, they had little interaction with local hunter-gatherer peoples. As a result, although they now lived far from their homeland, their genomes still resembled those of their ancestors from Anatolia.
But after 1,000–2,000 years, they had assimilated significant local lineages. their hunter-gatherer lineage increased From only 10% to 30-40% in some areas. Hunter-gatherers apparently did not disappear because of the expansion of farmers.
northern wetlands
The new research takes us further than the simple picture. Almost a decade ago, our research group at the University of Huddersfield began a collaboration with archaeologist Professor John Stewart of Bournemouth University and archaeologists from the Université de Liège, Belgium. We analyzed the genomes of Neolithic human remains from approximately 5,000 years ago, excavated along the Meuse River in Belgium.
The work formed part of a larger project led by Professor David Reich and Dr. Iñigo Olalde at Harvard University, involving geneticists and archaeologists from across Western Europe. It focused on other sites around the Lower Rhine-Meuse region – wetlands and coastal areas as well as rivers – which span late hunter-gatherer cultures to the Bronze Age.
The fertile soils south of the Rhine-Meuse wetlands attracted pioneering Neolithic farmer-colonists as early as 5,500 BC. However, the rich resources of the northern wetlands were more suitable for the lifestyle adopted by hunter-gatherers. Nevertheless, the results, prepared by our research student Alessandro Fichera in collaboration with Harvard, came as a big surprise.
The genome of later Neolithic people in Belgium contained the expected Anatolian farmer ancestry as well as at least 50% local hunter-gatherer ancestry. Discussing these results with our colleagues led to a “eureka” moment: The same pattern appeared at other sites located in similar water-rich environments throughout the region.
In particular, many of the earlier Neolithic Dutch samples from the far north – such as the Swifterbant culture, which is famous for adopting agriculture as well as maintaining a hunter-gatherer economy – are of almost 100% hunter-gatherer ancestry.
Role of women in spreading agriculture
We then compared the Y-chromosome and mitochondrial DNA, which track the male and female lines of descent, respectively. The Y chromosomes in the Belgian remains were characteristic of all hunter-gatherers, but three-quarters of the mitochondrial DNA lineages came from Neolithic farmers living in the south. The implication was clear: agricultural knowledge was imported by women into “waterworld” hunter-gatherer communities.
Our findings support a version of the “marginal mobility” or “availability” model for the spread of the Neolithic, Proposed by archaeologists Marek Zvelebil and Peter Rowley-Conwy in the 1980s. He envisioned “leapfrog colonization” and a contact zone between pioneer farming groups coming from hunter-gatherer areas.
In the model, the “availability” phase involved cross-border contacts and small-scale movements where, for example, business relationships and marriage alliances were gradually formed. This would be followed by a “replacement” phase where farming would develop along with pastoralism in the hunter-gatherer area, and Ultimately a “consolidation” phaseWhen farming is predominant.
Our results suggest that the range was more permeable to women than men, and it may have been the marriage of Neolithic women into forager communities that ultimately helped hunter-gatherers adopt full-time farming. Eventually, due to the predominance of farming throughout Europe, the long-term potential option had disappeared.
Perhaps such a model could also apply to other parts of Europe where we do not have evidence of how hunter-gatherer lineages increased in the later Neolithic. In any case, the fact that, here, “more advanced” farming women married into hunter-gatherer groups runs counter to the expectations of many archaeologists that hunter-gatherers. Women will “marry”Suggests that perceptions need to change.
Beaker, the Bronze Age and Britain
However, by about 4,600 years ago, people were on the move again. A new wave of settlers – shepherd-farmers who eventually came from the Russian Plain – began to infiltrate the Rhine region in the form of the Corded Ware culture. As increasing numbers of people arrived from the East, they transformed – we still don’t understand exactly how – into what is known as the Bell Beaker culture.
Within a few centuries, the genetic landscape of the Rhine-Meuse region, including the wetlands, was completely reshaped. Our colleagues found that, 4,400 years ago, less than 20% of the ancestry of the people living there was linked to earlier farmers and hunters. At least 80% of their ancestry was now from the steppe.
The Bell Beaker people expanded rapidly and spread in all directions, creating the Bronze Age in Central Europe. And not just in Central Europe – they also spread across the English Channel and across Britain as far north as Orkney.
It’s as if British farmers were building Stonehenge from centuries past but everyone disappeared – Again, for reasons that are unclear.
But did they really disappear? As we learn more, perhaps this clear picture will become more nuanced fine details What happened with archeology and ancient DNA.