Dog Domestication Was a Dirty Process, Claims Study of 76 Prehistoric Canines

Who let the dogs out? It’s still unclear, but researchers are now one step closer to knowing how humans’ canine companions began.

Dog breeding has a bad past. Humans have had furry friends for thousands of years, but a precise timeline of the domestication of canids to modern dogs is difficult to establish. The study, published today in Advances in Scienceprovides precise domestication time stamps—or something like it—from 76 ancient canid fossils found across Beringia.

“The general assumption was that domestication occurred once and clearly separated canids that interacted with humans (dogs) from those that did not (wolves),” said François Lanoë, an archaeologist at the University of Arizona and lead author of the study, in an email to Gizmodo. “Our research instead shows that the relationship between caid people was complex, continues to be today, and involved more than just domestication, but also things like wild wolf taming and respect (wolves hanging out in human settlements).”

In other words, domestication occurred to varying degrees, in different places, and at different points in the prehistoric past. That ambiguity has been confirmed by some previous research, which suggested that prehistoric humans used early dogs as hunting partners, but other canids were drawn to humanity by our piles of garbage and food.

In the new study, the team investigated 76 canid specimens—hybrid dogs and wolfdogs, but also wolves and coyotes—from late Pleistocene and Holocene sites in central Alaska. The team also included modern wolf remains from Alaska in their morphological and genomic analysis, which showed that some ancient canids in certain river basins had more salmon in their diet than other specimens in the dataset. Some canids in the data set had a diet that included fish and game.

“This is a smoking gun because they actually don’t follow salmon in the wild,” said Ben Potter, an archaeologist at the University of Alaska Fairbanks, in a University of Arizona release. “It begs the question, what is a dog?”

Although domestication has produced such diverse breeds as the chihuahua and the great dane, some modern dogs still bear a strong resemblance to their ancient counterparts; in 2020, a separate research team found that sled dogs have an unbroken genetic record that dates back to the end of the last ice age. Since ancient canids could not have hunted salmon regularly, the findings of the fish are a useful measure of when some of the animals started to warm to humans.

“I really like the idea that, in the text, however long ago, it’s a repeated tradition that I had this relationship and this level of love with my dog,” said Evelyn Combs, a Healy Lake member and archaeologist. National cultural preservation office, Arizona release. “I know that throughout history this relationship has always existed. I really like that we can look at the record and see that thousands of years ago, we still had friends.”

Some research into the history of dogs and their domestication has revealed everything from the origins of dog coats to how the creatures are related to wild dogs today. A study published in 2021 found that yellow dog coats, seen in species such as the shiba inu, were derived from an ancient canid that split from Pleistocene wolves two million years ago. While some ancient bonds remain unbroken, the more recent bond between dogs and their closest living relatives today—the Australian dingo—is less strong.

Lessons from the latest paper can also be applied to early interactions between human groups and other animals, including foxes—which are not dogs, despite their striking similarities—and chickens, which evolved from junglefowl in southeast Asia. Archaeological evidence provides some insight into domestication, but so does genetic analysis—as evidenced by a 2022 paper in which researchers analyzed the genomes of 238 donkeys to trace back domestication to wild donkey domestication. The recent use of a food analysis function is a clever take on a domesticated question—we’re human, after all, and we’re always incapable of the sad look in the eyes of a dog begging for lox.

The jury’s always out on who let the dogs loose, eh, but recent research is offering new clues about how human-canine relationships begin—even if those beginnings don’t have a clear answer.