New research co-led by Cornell University examines thousands of years of Arctic sled dog ancestry and reveals when and how Siberian and Alaskan sled dogs' DNA mixed.
"There was a real concern from Siberian breeders - who were mostly racing their dogs - that they were sending out their dogs' DNA samples for analysis, more for the context of health traits, and they were getting breed ancestry information back that said their dog was not 100% Siberian husky," said Heather Huson, a former sled dog racer who is now associate professor of animal science at Cornell. "Many (ancestry tests) were saying the Siberian huskies were a certain percentage Alaskan husky or Alaskan sled dog.
The massive genomic survey of the Siberian husky has revealed that sled dogs descended from two distinct lineages of Arctic canids and originated in the northeastern Siberian Arctic generations earlier than previously thought. The study also showed that approximately half of all Siberian huskies bred for racing have introgression with European breeds.
Huson is co-corresponding author of "Comparative Population Genomics of Arctic Sled Dogs Reveals a Deep and Complex History," which is under embargo until Sept. 14 in Genome Biology and Evolution. The other corresponding author is Tracy Smith, senior lecturer in the Department of Biological Sciences at the University of Maryland, Baltimore County (UMBC).
Huson said her team's findings on genomic history are an important tool in the effort to sustain ancient lineages, such as the Siberian husky, and their unique evolutionary identity.
"It was thought that there was this one Arctic lineage," Huson said, "but what we identified was that there are these two. One leads to our modern Siberian husky - smaller body size and stature - and the other one leads to this larger body size and to what we see now as Greenland sled dogs, and potentially the Alaskan malamutes."
Understanding the genomic history is essential, the authors wrote, for developing effective policies and best practices for breed management.
"The more genetic diversity you have, generally the better your genetic health," Huson said. "The slightly admixed racing Siberian huskies bring this genetic diversity to the population yet confound the original Arctic lineage which produced early Siberian huskies."
For their research, researchers collected and analyzed DNA samples (or genomic data) from 344 dogs - mostly registered Siberian huskies but also Alaskan malamutes, Alaskan sled dogs, Chukotka sled dogs and one each of German shepherd, golden retriever, German shorthaired pointer, Samoyed and Saluki.
The researchers found that at least two distinct lineages of Arctic dogs existed in ancient Eurasia at the end of the Pleistocene era, which ended approximately 11,700 years ago. This finding pushes back significantly the origin of sled dogs in the northeast Siberian Arctic, "with humans likely intentionally selecting dogs to perform different functions," the authors wrote. That kept concurrent breeding populations relatively reproductively isolated.
This work was supported by funding from UMBC, Neogen Genomics and the Siberian Husky Club of America.
