Between 8,000 and 12,000 years ago, people in Alaska kept reinventing dogs with mixed results.
The dogs that share our homes today are the descendants of a single group of wolves that lived in Siberia about 23,000 years ago. But for thousands of years after that split, the line between wolf and dog wasn’t quite clear-cut. A recent study shows that long after dogs had spread into Eurasia and the Americas, people living in what is now Alaska still spent time with—and fed—a bizarre mix of dogs, wolves, dog-wolf hybrids, and even some coyotes.
We just can’t stop feeding the wildlife
University of Arizona archaeologist François Lanoë and his colleagues studied 111 sets of bones from dogs and wolves from archaeological sites across the Alaskan interior. The oldest bones came from wolves that roamed what’s now Alaska long before people set foot there, and the most recent came from modern, wild Alaskan wolves. In between, the researchers worked with the remains of both wolves and dogs (and even a couple of coyotes) that span a swath of time from about 1,000 to around 14,000 years ago. And it turns out that even the wolves were tangled up in the lives of nearby humans.
“The terminal Pleistocene in interior Alaska may have been a time of experimentation in terms of human-canid relationships,” write Lanoë and his colleagues. “People may have domesticated canids that left no trace in later dog lineages. Alternatively, some wild canids may have been kept as pets and others hunted.”
The researchers compared the animals’ DNA to that of modern dogs and wolves, as well as much older wolf populations from Siberia. They also measured the ratio of nitrogen isotopes in the canids’ bones and teeth, which can suggest whether an animal mostly hunted other animals that grazed on land or ate a diet high in fish. Since wolves aren’t much for fishing, the presence of fish in a wolf’s diet usually suggests that it’s being fed by, or scavenging from, humans.
The story that data reveals is complicated—but somehow very human.
Until about 13,600 years ago, any wolf living in what is now Alaska would have lived on the usual wolf diet: rabbits, moose, and a whole range of other land animals. But starting around 13,600 years ago, the nitrogen isotopes locked in ancient wolves’ bones suggest that something changed. Some wolves still made their living solely by hunting wild game, but others started living almost entirely on fish. Since it’s unlikely that Alaskan wolves had suddenly taken up fly fishing, the sudden change probably suggests that some wolves had started getting food from people.
They’re good dogs, Brent
The fact that we kept trying to befriend wolves is starkly clear at a site called Hollembaek Hill, where archaeologists unearthed the 8,100-year-old remains of four canines. Their diets (according to the nitrogen isotopes locked in their bones) consisted mostly of salmon, so it’s tempting to assume these were domesticated dogs. But their DNA reveals that all four—including a newborn puppy—are most closely related to modern wolves.
On the other hand, the Hollembaek Hill canines didn’t all look like wild wolves. At least one of them had the large stature of a modern wolf, but others were smaller, like early dogs. And some of their DNA suggests that they may be at least part dog but not actually related to modern dogs. Lanoë and his colleagues suggest that people at Hollembaek Hill 8,000 years ago were living alongside a mix of pet wolves (do not try this at home) and wolf-dog hybrids.
All modern dogs trace their roots to a single group of wolves (now extinct) that lived in Siberia around 23,000 years ago. But sometime between 11,300 and 12,800 years ago, the canines from Hollembaek Hill and another Alaskan site called Swan Point had dog DNA that doesn’t seem related to modern dogs at all. That may suggest that dog domestication was a process that happened several times in different places, creating several branches of a dog family tree, but only one stuck around in the long run.
In other words, long after humans “invented” dogs, it seems that people just kept repeating the process, doing the things that created dogs in the first place: allowing the friendliest, least aggressive wild canids to live near their villages and maybe adopting and feeding them.
