<P> "I suppose that some of the variability exhibited in these wolves could have resulted from crossings in the wild with dogs . Such crosses in the wild have been reported and the wolf in captivity crosses readily with dogs . Some years ago at Circle, Alaska, a wolf hung around the settlement for some time and some of the dogs were seen with it . The people thought that the wolf was a female attracted to the dogs during the breeding period . However, considerable variability is probably inherent in the species, enough perhaps to account for the variations noted in the park and in skins examined . The amount of crossing with dogs has probably not been sufficient to alter much the genetic composition of the wolf population ." </P> <P> In 2008, Dr. Gregory S. Barsh, a professor of genetics and pediatrics at the Stanford University School of Medicine used molecular genetic techniques to analyze DNA sequences from 150 wolves, half of them black, in Yellowstone National Park, which covers parts of Wyoming, Montana and Idaho . It was discovered that a gene mutation responsible for the protein beta - defensin 3, known as the K locus, is responsible for the black coat color in dogs . After finding that the same mutation was responsible for black wolves in North America and the Italian Apennines, he set out to discover the origin of the mutation . Barsh and his colleagues concluded that the mutation 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 . At the University of California, Los Angeles, 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 . </P> <P> Cases of accidental breeding of wolfdogs are known (though this is very rare), where a domestic dog female in oestrus strays and is mated by a male wild wolf . </P> <P> The wolfdog hybrid has been the center of controversy for much of its history, and most breed - specific legislation is either the result of the animal's perceived danger or its categorization as protected native wildlife . The Humane Society of the United States, the RSPCA, Ottawa Humane Society, the Dogs Trust and the Wolf Specialist Group of the IUCN Species Survival Commission consider wolfdogs to be wild animals and therefore unsuitable as pets, and support an international ban on the private possession, breeding, and sale of wolfdogs . </P>

What is the closest breed of dog to a wolf