The gene responsible for dark coat color in American Gray Wolves and coyotes is a fairly recent addition to these animals’ genomes and most likely arrived through mating with domestic dogs—according to a paper published online in Science Express. The bigger surprise is that the mutation (spread through hybridization) may be helping wolves adapt and survive. Wolves living on the tundra tend to be light-colored, while forest-dwellers are dark. As tundra habitat decreases, a lighter coat is a disadvantage. Listen to a podcast with one of the authors.