Dogs passed traits to wolves
Mutation turned gray coats black, researchers say
WASHINGTON - Today's dogs are descendants of ancient wolves. Now, it turns out, at least some of today's wolves inherited traits from ancient dogs.
Gray wolves have that name because of their color, but in North America many of them have dark or black coats instead of the standard gray.
The genetic mutation producing dark coats appears to have occurred in dogs, and then spread from them to wolves when the species mated, according to researchers led by Gregory S. Barsh of Stanford University.
The dark-coated wolves are almost exclusive to North America and are much more common in forested areas where they make up 62 percent of the wolf population, compared with 7 percent in open tundra, the researchers noted.
But wildlife biologists don't think wolves rely much on camouflage, Barsh said. "It's possible there is something else going on here."
"It's sort of intuitively appealing, when you see animals that sort of blend in with their environment, to say . . . that explains natural selection, that somehow they are better camouflaged either as predator or prey," Barsh said in a broadcast interview made available by the journal Science, which published his research in today's edition.
But wolves don't have a lot of predators, and there's no evidence to suggest that a black coat color leads to any increase in a wolf's ability to capture its prey, he said.
Also, Barsh added, black wolves, like humans, turn gray with age, "so you would think that if the black coat-color mutation was being selected because it caused the black coat color, you wouldn't get these older gray wolves. They would stay black."
The same protein responsible for coat color differences in dogs and wolves is associated with fighting inflammation and infection in humans. Thus, it "might give black animals an advantage that is distinct from its effect on pigmentation," Barsh said in a statement.