Significant (Z|-4|) admixture signal with a source from ancient Wusun observed in contemporary Bulgarians.
We report the presence of significant Central Asian ancestry in both contemporary Bulgarians and in early medieval population from SMC (Saltovo Mayaky Culture). The existence of Chalcolithic Iran (Hajj Fruz) and Wusun related ancestral component in contemporary Bulgarians comes as a surprise and sheds light on both migration route and ethnic origins of ProtoBulgarians. We interpret these results as an evidence for a Central Asian connection for the tribes, constituting the population of SMC and Kubrats Old Great Bulgaria in Pontic steppe from 6th and 7th century AD. We identify Central Asian Wusun tribes as carriers of this component on the base from the results from f3 and D statistics. We suggest that Wusun related tribes must have played role (or might have even been the backbone) in what became known as the Hunnic migration to Europe during 3rd 5th century AD. Same population must have taken part in the formation of the SMC (Saltovo Mayaki Culture) and Great Old Bulgarian during 6th 9th century AD in Pontic Caspian steppe. We also explore the genomic origins of Thracians and their relations to contemporary Europeans. We conclude that contemporary Bulgarians do not harbor Thracian-specific ancestry, since ancient Thracian samples share more SNPs with contemporary Greeks and even contemporary Icelanders than with contemporary Bulgarians.