A comprehensive genetic analysis of ancient human remains from northwestern Europe maps out the complex population history of the coastal wetlands spanning modern-day Netherlands, Belgium, and western Germany. The research, published in Nature, traces how isolated hunter-gatherer communities gradually integrated early farming populations and eventually sparked a massive migration that reshaped the genetic makeup of ancient Britain.
The study examines the population history and genetic ancestry of groups living in the Lower Rhine-Meuse area over nearly seven millennia. From roughly 8500 to 1700 BCE, this water-rich landscape of river deltas, coasts, and peat bogs supported communities that relied heavily on hunting, fishing, and gathering.
In most of Europe, the period between 6500 and 4000 BCE brought a rapid and nearly complete replacement of local hunter-gatherers. Early farmers arriving from regions near modern-day Turkey expanded across the continent and established widespread agricultural settlements. Later, around 3000 BCE, nomadic pastoralists with genetic roots in the Eurasian steppe expanded westward, fundamentally changing the continent’s genetic makeup a second time.
Archaeologists and geneticists investigate whether these sweeping demographic changes happened uniformly or if specific regional environments experienced different patterns of migration and blending. In a region where hunting and gathering remained viable long after neighbors adopted farming, the exact origins and ancestry of the people who navigated these cultural transitions have remained an open question.
Co-first authors Iñigo Olalde of the University of the Basque Country, Eveline Altena of Leiden University Medical Center, and Quentin Bourgeois and Harry Fokkens of Leiden University led the international research team. They analyzed ancient DNA extracted from the skeletal remains of 44 individuals who lived in the region between 8500 and 1700 BCE.
The researchers enriched the extracted DNA to look for over a million specific single-letter genetic variations, allowing them to map broad ancestry patterns across the genome. They combined this new genetic material with existing data from 69 previously studied individuals, creating a continuous genetic timeline of 112 people over roughly 6,800 years. To confirm recent common ancestors and track community sizes, the researchers analyzed long, identical segments of DNA shared between individuals.
To understand how different communities interacted, the team compared the genetic profiles of the wetland inhabitants with known ancestral populations, including early European farmers, local western hunter-gatherers, and groups migrating from the eastern steppes. They also isolated genetic markers passed down specifically through maternal and paternal lines to trace the sex-specific movement of people across cultural boundaries.
The genetic data provides evidence that people in the Lower Rhine-Meuse wetlands retained unusually high levels of hunter-gatherer ancestry for nearly 3,000 years longer than populations in neighboring regions. While early farmers quickly absorbed or displaced foragers across much of central Europe, the wetland communities maintained roughly 50 percent hunter-gatherer ancestry for millennia.
The isolated maternal and paternal markers indicate that early farming ancestry entered these specific groups primarily through women. The paternal lineages in the area remained overwhelmingly consistent with local hunter-gatherers. This suggests that the foraging communities incorporated female individuals from nearby farming settlements, a process that likely facilitated the slow exchange of agricultural knowledge while leaving the local genetic identity largely intact.
These communities also experienced the later westward spread of the Corded Ware culture differently. In most of Central Europe, the arrival of Corded Ware pottery and burial practices was accompanied by a massive influx of people carrying steppe ancestry. In the western Netherlands lowlands, individuals buried in settlements containing typical Corded Ware artifacts had almost no steppe ancestry. The transmission of this culture in the wetlands appears to reflect an exchange of ideas and goods among neighboring groups rather than a large movement of people. However, one male individual from these sites carried a paternal lineage associated with the Corded Ware expansion, indicating that a small number of migrants did enter the community during this era.
A major genetic shift finally occurred around 2500 BCE with the rise of the Bell Beaker culture, named for its distinctive inverted-bell pottery. The genome sequences show that newcomers carrying high levels of eastern steppe ancestry arrived in the wetlands and mixed with the local population, replacing the previous genetic continuity.
The resulting Bell Beaker population inherited about 13 to 18 percent of their DNA from the distinctive local wetland inhabitants who carried high hunter-gatherer ancestry. This specific mixture of populations then expanded across northwestern Europe. Previous archaeological theories often linked the spread of Bell Beaker populations to the Iberian Peninsula, where the culture’s oldest artifacts are found. Tracking this unique genetic signature instead reveals that the Lower Rhine-Meuse groups were the primary source of a subsequent migration into Great Britain, driving a near-complete replacement of the local British Neolithic population.
Reconstructing ancient demographics relies heavily on the availability and preservation of skeletal remains, which presents persistent challenges. In the sandy uplands east of the wetlands, soil conditions generally destroy bone tissue, leaving archaeologists without genetic data to trace the full geographic range of the incoming populations.
Similarly, documenting the exact population turnover in ancient Britain is restricted by local burial practices. The British Neolithic populations encountered by the incoming Bell Beaker groups predominantly cremated their dead, destroying the DNA needed to map the step-by-step process of interaction and replacement.
Questions also remain regarding the specific points in time and space where the incoming steppe populations first mixed with the local wetland inhabitants. A gap of several centuries in the available human remains leaves researchers to interpret whether the demographic shift happened rapidly or through a steady integration over generations. Future discoveries of preserved human remains in these transitional zones may help clarify the exact pace of this sweeping prehistoric migration.
The paper, “Lasting Lower Rhine-Meuse forager ancestry shaped Bell Beaker expansion,” was authored by Iñigo Olalde, Eveline Altena, Quentin Bourgeois, Harry Fokkens, Luc Amkreutz, Steffen Baetsen, Marie-France Deguilloux, Alessandro Fichera, Damien Flas, Francesca Gandini, Jan F. Kegler, Lisette M. Kootker, Judith van der Leije, Kirsten Leijnse, Constance van der Linde, Leendert Louwe Kooijmans, Roel Lauwerier, Rebecca Miller, Helle Molthof, Pierre Noiret, Daan C. M. Raemaekers, Maïté Rivollat, Liesbeth Smits, John R. Stewart, Theo ten Anscher, Michel Toussaint, Kim Callan, Olivia Cheronet, Trudi Frost, Lora Iliev, Matthew Mah, Adam Micco, Jonas Oppenheimer, Iris Patterson, Lijun Qiu, Gregory Soos, J. Noah Workman, Ceiridwen J. Edwards, Iosif Lazaridis, Swapan Mallick, Nick Patterson, Nadin Rohland, Martin B. Richards, Ron Pinhasi, Wolfgang Haak, Maria Pala, and David Reich.