Bronze and Iron Age genomes from the West Eurasian steppe reveal genetic heterogeneity and origins in the southern Urals.

Ancient genomes reveal a complex demographic picture since the post-LGM in northeast Asia and report the presence of Y. pestis .

The impact of human mobility on the northern European urban populations during the Viking and Early Middle Ages and its repercussions in Scandinavia itself are still largely unexplored. Our study of the demographics in the final phase of the Viking era is the first comprehensive multidisciplinary investigation that includes genetics, isotopes, archaeology, and osteology on a larger scale. This early Christian dataset is particularly important as the earlier common pagan burial tradition during the Iron Age was cremation, hindering large-scale DNA analyses. We present genome-wide sequence data from 23 individuals from the 10th to 12th century Swedish town of Sigtuna. The data revealed high genetic diversity among the early urban residents. The observed variation exceeds the genetic diversity in distinct modern-day and Iron Age groups of central and northern Europe. Strontium isotope data suggest mixed local and non-local origin of the townspeople. Our results uncover the social system underlying the urbanization process of the Viking World of which mobility was an intricate part and was comparable between males and females. The inhabitants of Sigtuna were heterogeneous in their genetic affinities, probably reflecting both close and distant connections through an established network, confirming that early urbanization processes in northern Europe were driven by migration.

During the Final Eneolithic the Corded Ware Complex (CWC) emerges, chiefly identified by its specific burial rites. This complex spanned most of central Europe and exhibits demographic and cultural associations to the Yamnaya culture. To study the genetic structure and kin relations in CWC communities, we sequenced the genomes of 19 individuals located in the heartland of the CWC complex region, south-eastern Poland. Whole genome sequence and strontium isotope data allowed us to investigate genetic ancestry, admixture, kinship and mobility. The analysis showed a unique pattern, not detected in other parts of Poland; maternally the individuals are linked to earlier Neolithic lineages, whereas on the paternal side a Steppe ancestry is clearly visible. We identified three cases of kinship. Of these two were between individuals buried in double graves. Interestingly, we identified kinship between a local and a non-local individual thus discovering a novel, previously unknown burial custom.

Background: After over a decade of developments in field collection, laboratory methods and advances in high-throughput sequencing, contamination remains a key issue in ancient DNA research. Currently, human and microbial contaminant DNA still impose challenges on cost-effective sequencing and accurate interpretation of ancient DNA data. Results: Here we investigate whether human contaminating DNA can be found in ancient faunal sequencing datasets. We identify variable levels of human contamination, which persists even after the sequence reads have been mapped to the faunal reference genomes. This contamination has the potential to affect a range of downstream analyses. Conclusions: We propose a fast and simple method, based on competitive mapping, which allows identifying and removing human contamination from ancient faunal DNA datasets with limited losses of true ancient data. This method could represent an important tool for the ancient DNA field.

The demographic history of East-Central Europe after the Neolithic period remains poorly explored, despite this region being on the confluence of various ecological zones and cultural entities. Here, the descendants of societies associated with steppe pastoralists form Early Bronze Age were followed by Middle Bronze Age populations displaying unique characteristics. Particularly, the predominance of collective burials, the scale of which, was previously seen only in the Neolithic. The extent to which this re-emergence of older traditions is a result of genetic shift or social changes in the MBA is a subject of debate. Here by analysing 91 newly generated genomes from Bronze Age individuals from present Poland and Ukraine, we discovered that Middle Bronze Age populations were formed by an additional admixture event involving a population with relatively high proportions of genetic component associated with European hunter-gatherers and that their social structure was based on, primarily patrilocal, multigenerational kin-groups.