Two-Thirds Of Dog Breeds Discovered To Have Detectable Wolf DNA

A new study published in Proceedings of the National Academy of Sciences has uncovered that two-thirds of dog breeds have detectable wolf DNA, from chihuahuas to Arctic sled dogs. Studies on wolves have made steady progress in the 2020s. One of the biggest achievements is Colossal Biosciences’ dire wolves, Romulus, Remus, and Khaleesi, who brought the species back from extinction.

Dire wolves were an early species of canine, believed to have thrived around 125,000 years ago during the Late Pleistocene era. They went extinct around 10,000 years ago, during the Early Holocene era. While Colossal Biosciences has brought the extinct predators back to life, a study indicates just how much history modern, domesticated dogs share with wolves.

A report from People reveals a new study from the American Museum of Natural History and the Smithsonian’s National Museum of Natural History discovered two-thirds of modern dog breeds have detectable wolf DNA. Their detailed findings were published in the Proceedings of the National Academy of Sciences on November 24, 2025. The discovery challenges long-believed scientific evolutionary ideas about dogs.

While dogs evolved from wolves 20,000 years ago, the genetic material found in the majority of breeds suggests wolves and domesticated dogs were interbreeding just a few thousand years ago. This DNA can be found in 64% of living dog breeds, indicating the majority of them hail from interbreeding much more recent than when dogs first evolved.

The study indicated the Grand Anglo-Francais Tricolore hound shares some of the most DNA with wolves, at 5%. However, even smaller dogs have detectable wolf DNA in them — the chihuahua, for instance, has 0.2% of detectable wolf DNA, signifying their ancestors were interbreeding just several thousand years ago. Other dogs, though, like the Saint Bernard, have no traceable wolf DNA.

While dogs can trace their ancestry back to species like the dire wolf, the study emphasizes how the evolution of dogs is much more complex than previously considered. Even though 20,000 years is a sensible amount of time for most dogs to evolve, interbreeding between various canine species and wolves was still happening for much longer than expected.

The Proceedings of the National Academy of Sciences study makes a compelling case that dogs have more wolf in them than previously thought. With so many different breeds processed in the study, it seems like the majority of domesticated dogs are more wolf-like than expected, something that could lead to more evolutionary studies down the road.