Detectable Wolf DNA in Two-Thirds of Dog Breeds, Including Chihuahuas, Study Reveals

The small, furry Chihuahua you pass on the street may be part wolf.

Nearly two-thirds of all dog breeds have detectable amounts of wolf DNA, according to a new study led by scientists at the American Museum of Natural History and the Smithsonian National Museum of Natural History.

This wolf lineage revelation was published Proceedings of the National Academy of Sciences On 24th November.

“Overall, most dogs today have low detectable levels of wolf ancestry after domestication, which has shaped their evolution and provided unique advantages for their survival in diverse human environments,” the study’s introduction says.

According to CBS News, the wolf DNA found in two-thirds of the dogs in this study is not genetic material left over from the time they evolved from wolves 20,000 years ago; Instead, scientists have found that it is likely DNA traces from when interbreeding between wild wolves and domestic dogs was common several thousand years ago.

Scientists began the study to determine how much wolf DNA is present in modern dogs, since it is now rare for wolves and dogs to breed together. Their research found that 64 percent of current dog breeds can be traced back to wolf DNA from a few thousand years ago. Even the Chihuahua was a tiny wolf, with studies showing that 0.2 percent of the breed’s DNA is that of wolves.

Dog breeds with the most wolf DNA include the Grand Anglo-Francis Tricolore Hound – which has about 5 percent wolf DNA – Salukis and the Afghan Hound. Of course, not all breeds were touched by wolf DNA. Saint Bernards tested negative for wolf DNA, which suggests that the recent ancestors of modern Saint Bernards had very little contact with wolves.

CBS reported that the study found that Arctic sled dogs and hunting dogs were the dog breeds most likely to have wolf ancestry, while terriers and scent hounds were the least likely.

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The study’s lead author, Audrey Lynn, a Gerstner Postdoctoral Scholar in Bioinformatics and Computational Biology at the American Museum of Natural History, told Phys.org that the findings suggest that “dog genomes could ‘tolerate’ wolf DNA to unknown levels and still remain the dogs we know and love.”

He added, “Most dogs are a little bit like wolves.”