Ancient DNA from mastics solidifies connection between material culture and genetics of Mesolithic hunter-gatherers in Scandinavia

The discussion of an early postglacial dual-route colonization of the Scandinavian Peninsula is largely based on associating genomic data to an early dispersal of lithic technology from the East European Plain. However, a direct link between the two has been lacking. We tackle this problem by analysing human DNA from birch bark pitch mastics, “chewing gums”, from Huseby Klev, a site in western Sweden with eastern lithic technology. We generate genome-wide data for three individuals, and show their affinity to the Scandinavian hunter-gatherers, more precisely, to individuals from postglacial Norway and Sweden. Our samples date to 9880-9540 calBP, expanding the temporal range of this genetic group as well as its distribution. Human DNA from mastics provides a clear connection between material culture and genetic data. We also propose that DNA from different types of mastics can be used to study environment, ecology, and oral microbiome of prehistoric populations.