Ancient Wolf's Diet Suggests He Was a Pet

When did wolf become dog? It's a debated question and central to a new study presenting what appears to be the earliest evidence of the human-dog relationship in the Americas. It comes from the 12,000-year-old bones of a canid—a wolf, coyote, or dog—found at Swan Point in interior Alaska. This canid, living far from the coast, ate salmon on the regular, and researchers think it was getting the fish from humans. Other ancient canids in the region did not eat salmon. This suggests, according to researchers, that the animal was living with and being fed by humans, or at least that there was some kind of mutually beneficial relationship, some 2,000 years earlier than previously known, per a release.

Researchers compiled 111 large canid specimens from Alaska, including 76 spanning from about 1,000 to 14,000 years ago, and analyzed their diets by measuring the ratio of nitrogen isotopes in the bones and teeth, per Ars Technica. The diet of the Swan Point canid stands out, along with that of four 8,100-year-old canids, dubbed the Hollembaek Hill canids, whose bones revealed a diet likewise heavy in salmon. None of these canids are related to modern dogs, who descended from a single group of wolves in Siberia around 23,000 years ago. And it's not entirely clear if they were wolves, or dogs, or hybrids.

But if the Swan Point canid was a wolf, "it was a tame wolf" who "probably behaved like a dog" and was "most likely fed by people directly," study author François Lanoë of the University of Arizona tells the Washington Post. Others disagree, arguing the salmon consumption could be a natural behavior. But for Lanoë and colleagues, the findings suggest the dog domestication experiment that resulted in the modern dog was not the only one—that these experiments were carried out widely, not so much deliberately, but with humans "allowing the friendliest, least aggressive wild canids to live near their villages and maybe adopting and feeding them," per Ars Technica. The study, published Wednesday, can be read in full in Science Advances. (More domestication stories.)