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.

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 spanning 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.