In 2008 it was discovered that a gene mutation responsible for the protein beta-defensin 3 is responsible for the black coat color in dogs. The same mutation was responsible for black wolves in North America and the Italian Apennines, with the mutation having arose in dogs 13,000 to 120,000 years ago, with a preferred date of 47,000 years ago after comparing large sections of wolf, dog, and coyote genomes. Robert K. Wayne, a canine evolutionary biologist, stated that he believed that dogs were the first to have the mutation. He further stated that even if it originally arose in Eurasian wolves, it was passed on to dogs who, soon after their arrival, brought it to the New World and then passed it to wolves and coyotes. Black wolves with recent dog ancestry tend to retain black pigment longer as they age.