Bell Beaker pottery spread across western and central Europe beginning around 2750 BCE before disappearing between 2200–1800 BCE. The mechanism of its expansion is a topic of long-standing debate, with support for both cultural diffusion and human migration. We present new genome-wide ancient DNA data from 170 Neolithic, Copper Age and Bronze Age Europeans, including 100 Beaker-associated individuals. In contrast to the Corded Ware Complex, which has previously been identified as arriving in central Europe following migration from the east, we observe limited genetic affinity between Iberian and central European Beaker Complex-associated individuals, and thus exclude migration as a significant mechanism of spread between these two regions. However, human migration did have an important role in the further dissemination of the Beaker Complex, which we document most clearly in Britain using data from 80 newly reported individuals dating to 3900–1200 BCE. British Neolithic farmers were genetically similar to contemporary populations in continental Europe and in particular to Neolithic Iberians, suggesting that a portion of the farmer ancestry in Britain came from the Mediterranean rather than the Danubian route of farming expansion. Beginning with the Beaker period, and continuing through the Bronze Age, all British individuals harboured high proportions of Steppe ancestry and were genetically closely related to Beaker-associated individuals from the Lower Rhine area. We use these observations to show that the spread of the Beaker Complex to Britain was mediated by migration from the continent that replaced >90% of Britain’s Neolithic gene pool within a few hundred years, continuing the process that brought Steppe ancestry into central and northern Europe 400 years earlier.

Bell Beaker pottery spread across western and central Europe beginning around 2750 BCE before disappearing between 2200–1800 BCE. The forces propelling its expansion are a matter of long-standing debate, with support for both cultural diffusion and migration. We present new genome-wide data from 400 Neolithic, Copper Age and Bronze Age Europeans, including 226 Beaker-associated individuals. We detected limited genetic affinity between Iberian and central European Beaker-associated individuals, and thus exclude migration as a significant mechanism of spread between these two regions. However, migration played a key role in the further dissemination of the Beaker Complex, a phenomenon we document most clearly in Britain, where the spread of the Beaker Complex introduced high levels of Steppe-related ancestry and was associated with a replacement of ~90% of Britain’s gene pool within a few hundred years, continuing the east-to-west expansion that had brought Steppe-related ancestry into central and northern Europe 400 years earlier.

The cemetery is located in the south-west of Pottenbrunn, on plot "Steinfeld" (15°41´05"/48°13´55"). Discovered in 1930, it had already yielded objects dating to the early La Tène period. In 1981, road construction revealed further finds which initiated rescue excavations by the Bundesdenkmalamt (State Office for Protection of Historical Monuments) under the guidance of J.-W. Neugebauer (Ramsl 2002a(Ramsl , 13) in 1981(Ramsl and 1982. A total of 42 graves with 45 burials (single and double inhumations, and cremations) have been documented. Some burials were severely disturbed (by ancient activities such as grave robbing and/or contemporary construction work), and some were set within fenced enclosures ("Grabgärten"). Three (of 22) samples of charcoal and bone fragments taken by Peter Stadler (Department of Prehistory, Natural History Museum Vienna) in the course of the FWFproject "Absolute Chronology for Early Civilisations in Austria and Central Europe" returned AMS dates of 410-200 cal BCE (grave 520), 550-200 cal BCE (grave 565) and 380-350 cal BCE (grave 1005) (Ramsl 2002b, 359). The cremation burials were not included in the initial osteological analysis, but 31 inhumed individuals were studied (Gerold 2002). Petrous bones from three of these were successfully analyzed for aDNA. Sample I11699 (female) derived from an individual (inv. no. 26.238) aged c. 20 years in grave 89 which, despite disturbance in antiquity, was accompanied by fibulae and ceramic vessels. Sample I11701 (male) derived from an individual (inv. no. 26.249) aged c. 18 years in grave 570, which also included shears, fibulae, and ceramic vessels. Evidence for bone porosity in the mandible and maxilla suggest possible Vitamin C deficiency, while enamel hypoplasia points to malnutrition or illness during childhood. Sample I11708 (female) derived from an individual (inv.no. 26.250) aged c. 25-35 years in grave 574/2, who was richly adorned with fibulae, bronze, iron and silver-rings, an amber ring, a bracelet, a glass bead, and a worked bone artefact.

In European and many African, Middle Eastern and Southern Asian populations lactase persistence (LP) is the most strongly selected monogenic trait to have evolved over the last 10,000 years 1 . While LP selection and prehistoric milk consumption must be linked, considerable uncertainty remains concerning their spatiotemporal configuration and specific interactions 2,3 . We provide detailed distributions of milk exploitation across Europe over the last 9k years using c. 7,000 pottery fat residues from >550 archaeological sites. European milk use was widespread from the Neolithic period onwards but varied spatially and temporally in intensity. Surprisingly, comparison of model likelihoods indicates that LP selection varying with levels of prehistoric milk exploitation provides no better explanation of LP allele frequency trajectories than uniform selection since the Neolithic. In the UK Biobank 4,5 cohort of ~500K contemporary Europeans, LP genotype was only weakly associated with milk consumption and did not show consistent associations with improved fitness or health indicators. This suggests other hypotheses on the beneficial effects of LP should be considered for its rapid frequency increase. We propose that lactase non-persistent individuals consumed milk when it became available, but that under particular conditions and microbiological milieux this was disadvantageous, driving LP selection in prehistoric Europe. Comparison of model likelihoods indicates that population fluctuations, settlement density and wild animal exploitationproxies for these driversprovide better explanations of LP selection than the extent of milk exploitation. These findings offer new perspectives on prehistoric milk exploitation and LP evolution.

Abstract