Genomic and strontium isotope variation reveal immigration patterns in a viking age town

Abstract

Abstract: The impact of human mobility on the northern Euro- pean urban populations during the Viking and Early Middle Ages and its repercussions in Scandinavia it- self are still largely unexplored. Our study of the de- mographics in the final phase of the Viking era is the first comprehensive multidisciplinary investiga- tion that includes genetics, isotopes, archaeology, and osteology on a larger scale. This early Christian dataset is particularly important as the earlier com- mon pagan burial tradition during the Iron Age was cremation, hindering large-scale DNA analyses. We present genome-wide sequence data from 23 indi- viduals from the 10th to 12th century Swedish town of Sigtuna. The data revealed high genetic diversity among the early urban residents. The observed vari- ation exceeds the genetic diversity in distinct mod- ern-day and Iron Age groups of central and northern Europe. Strontium isotope data suggest mixed local and non-local origin of the townspeople..