Tracing the Bell Beaker phenomenon through ancient DNA studies

The period of the Bell Beaker phenomenon (BBP) falls amidst a time of major cultural and genomic transformations in Europe spanning the 3rd millennium BC. Preluded by the arrival of ‘steppe-related’ ancestry mediated through Corded Ware and Yamnaya-associated pastoralist groups, individuals associated with the BBP show - in addition - an increase in early European farmer-related (EEF) ancestry, which attests to a certain extent of local admixture. At the same time, BBP groups were the carriers of a further westward spread of ‘steppe-related’ ancestry. This is accompanied by distinct shifts in genomic ancestries and Y haplogroup profi les, resulting in nearly complete turnovers of Y haplogroup profi les in Central Europe, the Iberian Peninsula, Britain and Ireland, the reasons for which are not well understood. Critically, these genetic changes contrast with the proposed western origin and chronological developments of the material cultural elements within the BBP itself. Here, we present and discuss the currently available archaeogenomic data associated with the BBP and compare it with preceding Late Neolithic and Copper Age groups as well as contemporaneous and subsequent Early Bronze Age (EBA) groups. Our synthesis ranges from broader population genetic affinities to recent methodological advances that can elucidate cross-regional connections via identity-by-descent analyses and parental background relatedness that informs on eff ective population sizes, and also includes the fi rst insights into kinship structures and social organisation. We showcase the new insights the archaeogenomic data offer by focusing on specific regions (Iberia, Northern Italy, Central Europe-Bohemia), but also address the ensuing complexities and challenges for the interpretation at a broader scale. The finer characterization of the main trends in changes of genomic ancestry are as important as the integrated regional aspects, involving the analyses of various ‘outlier’ individuals or individual life histories, all of which contribute to a more nuanced picture of the major transformations in prehistoric Europe.