Societies don’t change in a vacuum; an influx of new people and ideas inspire locals to start new practices. To figure out when major societal changes happened, archeologists dig up and analyze the items ancient people left behind.
Archeologists previously established an approximate timeline for when society’s practices shifted in the northwestern Siberian Arctic, including when ancient people started to handle metal tools (about 2,000 years ago) and use reindeer for transportation and as livestock (about 800 years ago). But researchers wondered who influenced the ancient Siberians to take up these new ways of life.
Genome sequencing brought archeologists and geneticists together, and the combination of physical and molecular evidence helps them paint a more thorough picture of ancient life. However, researchers performing genetic analyses of ancient Siberians hit a wall; there was little evidence of this community interacting—and mating—with outsiders during the time periods of societal change.1,2 To solve this mystery, an interdisciplinary team led by Laurent Frantz, a professor of paleogenomics at the University of Munich, looked elsewhere in the animal kingdom. In work described in PNAS,3 the researchers analyzed the genomes of ancient Siberian dogs to figure out where their ancestors and their owners had come from.
“Where humans go, so go their dogs,” said Elaine Ostrander, a chief and distinguished investigator in the cancer genetics and comparative genomics branch at the National Human Genome Research Institute, who was not involved in this study. “Studies have shown that in parts of the world where it's very hard to track what ancestral humans were doing, dogs—man's best friend—are a great way to do that.”
brought archeologists and
geneticists together, and the
combination of physical and
molecular evidence helps
them paint a more thorough
picture of ancient life.
To trace the heritage of dogs living in the Siberian Arctic over time, Frantz and his colleagues collected ancient DNA from dog bones, teeth, and preserved hides. They sequenced the genomes of 20 dogs that lived from 11,000 to 60 years ago and compared them to other publicly-available ancient and modern sequences. The dog remains were taken from sites spanning modern-day Europe, the Middle East, and Asia, including the Steppe—a wide region that spans from Central Europe to Manchuria.
Because the ancient Siberian human lineages were stable during the times of societal change, Frantz expected the dog genomes to follow the same pattern. “But what we can tell is that clearly the ancestry has changed,” Frantz said. “In a few hundred years, we see them shifting from being what we think looks more like this really ancient archaic lineage that's been around for thousands of years to something that looks a lot more like the dogs you had from the south in the Steppe.”
Frantz found that the Siberian dogs evolved in isolation until a point after 6,900 years ago, which suggests that dogs from southern and westerns areas started to visit the Arctic. “What's so interesting is that it coincides with changes in terms of what the [human] population was doing. And they know that because they match their data up with archeologic finds,” Ostrander said.
The ancestry data showed that the first visitors came from the Steppe and later traveled from Western Eurasia, areas where people engaged in metal-working and reindeer pastoralism prior to their appearance in the Siberian Arctic. Because the ancient human genomes did not change throughout this time period, Frantz’s team believes that ancient humans from the Steppe and Western Eurasia traded with the Siberians, rather than relocating permanently to the Arctic.
Frantz next plans to decipher how these genetic changes influenced the ancient Siberian dogs. Genes from outsider groups may have led to behavioral and morphological differences, including size and coat color variations. Another remaining question concerns why ancient humans brought dogs along on their journeys. Were they working dogs or simply companions? Frantz will continue to compare genetic data with archeological findings to further clarify the relationship between ancient people and their dogs.
- E.H.M. Wong et al., “Reconstructing genetic history of Siberian and Northeastern European populations,” Genome Res, 27:1-14, 2017.
- K. Tambets et al., “Genes reveal traces of common recent demographic history for most of the Uralic-speaking populations,” Genome Biol, 19:139, 2018.
- T.R. Feuerborn et al., “Modern Siberian dog ancestry was shaped by several thousand years of Eurasian-wide trade and human dispersal,” PNAS, 118:e2100338118, 2021.