Ancient DNA shows dogs joined human migrations and trade

As human groups migrated and settled across Holocene Eurasia, dogs often traveled with them, researchers report in a new genomic study – and sometimes dogs were traded among populations. The study reveals the integral role these animals played in culture and exchange. For at least the last 11,000 years, dogs and humans have lived side-by-side. However, the true antiquity of their association with humans remains elusive. Some evidence suggests that major dog lineages in different parts of the world appear to have diversified thousands of years earlier, suggesting that these dogs may have traveled with humans as they colonized different parts of Europe, Asia, and the Arctic, forming integral parts of the cultural and biological exchanges of early migrations. To explore how dogs and humans moved together, Shao-Jie Zhang and colleagues sequenced 17 ancient dog genomes dated between 9,700 and 870 years ago from sites across Siberia, the Central Eurasian Steppe, and northwest China, regions that experienced major shifts in human ancestry and culture during the Holocene. These new genomes were analyzed alongside 57 previously published ancient dog genomes, 160 modern dog genomes, and 18 ancient human genomes, which allowed Zhang et al. to explore how ancient dog lineages intersected with human migrations and cultural exchanges. The findings show that the movement of domestic dogs across the Eurasian Steppe, East Asia, and Eastern Siberia often coincided with the migrations of hunter-gatherers, farmers, and pastoralists, suggesting that dogs very commonly travelled alongside humans and were integrated into diverse societies. Some mismatches between dog genetic lineage and human population histories indicate that communities with different ancestries likely exchanged dogs with one another. This was particularly true for Arctic-lineage dogs, which were found among hunter-gatherer groups with differing ancestries across Eurasia.