PALEoRIDER generated genomic data from ~1500 individuals from key sites in prehistoric Europe that span the chronological horizon from the 5th to the 2nd millennium BCE, resulting in good quality genome-wide data for >1000 prehistoric individuals. This data is fully compatible with other ancient and modern-day population genetic data and thus constitutes a substantial contribution to the aDNA community. By applying a new standard procedures for the parallel detection of endogenous human and pathogen DNA, we produced time transect in various regions of Europe, resulting in a time-stamped record of the states before, during and after critical events, which were reconciled with archaeological contexts. We also generated hundreds of new radiocarbon dates, which are a critical resource for the refinement of regional archaeological chronologies.
Generating a regionally nuanced account of the dynamic shifts in Europe's prehistory was the main focus of the PALEoRIDER project. PALEoRIDER generated time transect data, which allowed pan-European comparisons and is available via public, international data repositories. At the time of this project report 95% of the datasets of sub-projects are completed and/or fully contextualised, resulting in over a dozen high-profile publications, and the team members presented these results at various international conferences and/or internal workshops with collaboration partners.
PALEoRIDER targeted the transitions from the Eneolithic or Copper Age to the Bronze Age in various regions spanning from the North Caucasus in the East to southern Iberia in the West. The presence, expansion, and distinction between genetic ‘steppe’ and ‘forest steppe’ ancestry, primarily associated with pastoralist groups from the Eurasian steppe zones constituted a prominent feature. By studying zones of early contact and exchange between late farming and pastoralist groups also through the study of dairy proteins in dental calculus, we could shed light of the formative periods and economic changes during the 4th millennium BCE, which enabled the economic exploitation of the steppe zone and establishment of nomadic pastoralism as main subsistence strategy, which in the 3rd millennium BCE ultimately led to an expansion of these groups. Importantly, we observe that these processes had led to further transformations of the genetic and social structures in central and western parts of Europe.
Overall ,we documented an unprecedented level of dynamism across all time transects in Europe. We find that the expansion of steppe-related ancestry across Europe from the East, previously seen as a unified turnover event of the early 3rd millennium BCE, involved two or more streams with regional differentiation and variable timing, linked to varying population densities and socio-economic characteristic of the prehistoric societies involved. In the centuries following these expansions, we observe a complex interplay of various groups, indicating a long process of assimilation and continuous population dynamics. Intra-site studies estimating biological relatedness and uniparentally inherited lineages revealed striking patterns of virilocality and patrilineality alongside a strong reduction in Y-diversity, which suggest isolated mating networks under strict social norms. This pattern is dissolved in the 2nd millennium BCE in line with new burial customs and potentially reformed social organisation.
With respect to pathogens as potential driver or critical parameter, the PALEoRIDER project was able to contribute a large number of positive cases, corroborating previous evidence for the presence of a range of pathogens, in particular two early forms of the plague-causing agent of Yersinia pestis during the early Bronze Age alone. The regular detection and presence of other pathogens such as Salmonella enterica and recent advances in the detection of prehistoric viruses such as Hepatitis B (HBV) added further to the complex entanglement of human-pathogen interaction in parallel/contrast to human agency alone.
