Many people know dogs have descended from wolves, but not many know the true origin of ‘man’s best friend.’ A research project led by a University professor and the Illinois State Archaeological Survey made discoveries on dogs’ arrival to America.

Ripan Malhi, professor in anthropology, and his team have been studying and transcribing the genetic codes of about 50 fossilized dogs discovered at a site in southern Illinois near St. Louis.

Kelsey Witt Dillon, who was a doctoral student while Malhi was working on this project, said these DNA results proved North American dogs were descendants of Siberian wolves.

“We started by comparing the ancient dogs to many modern and ancient dog populations,” Dillon said. “These ancient dogs from the Americas aren’t closely-related to modern dog populations, and their closest relative is a population of ancient Siberian dogs. This tells us that dogs likely traveled to the Americas with humans.”

Some of the dogs’ remains date back to over 10,000 years ago, making them the oldest domesticated dog remains discovered in America, the study said.

The ancient dog DNA was eventually traced back through maternal ancestry not to wolves in North America, but to Siberia, showing that dogs accompanied humans as they crossed the land bridge that once connected Siberia and Alaska tens of thousands of years ago.

However, these ancient canines largely disappeared once they came into contact with European explorers and migrants, largely mirroring the population decline of the Native Americans after similar contact.

Many theories exist that attempt to explain this sharp decline, Dillon said. These could include the dogs being eaten during times of famine or being wiped out along with many Native Americans due to diseases introduced by new populations.

“We found that the dogs did travel with humans to the Americas, rather than being domesticated separately in North America,” she said. “We also found that modern dogs have almost none of this ancient dog ancestry, demonstrating that a lot of the genetic diversity found in ancient dogs is now lost.”

Dillon said the genetic diversity is the result of the killing of the dogs by European colonists indirectly through the introduction of new diseases, and replaced them with European breeds.

Currently, Dillon is looking at data to further understand how dogs moved across the Americas by comparing different populations to see how the relate to each other.

“We’re comparing different populations to see how they relate to each other, and also comparing patterns of relatedness between dog populations and ancient Native American populations, to see if we can use dogs to learn more about human populations in the America too,” she said. “This is really the first time we’ve looked at the whole genome of ancient American dogs, and so we’re really getting a better picture of how dogs got to the Americas, and what happened to these dogs as a result of European colonization.”

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