Your Domestic Dog Has But One Ancestor
For centuries, it has been thought that domestic dogs may have been the product of a mix of canine and other species of animals. Brown wolves, foxes, and a host of other animals were considered to be candidates. But then in 1999, and again in 2003, separate international teams of scientists tested hundreds of dogs and wolves, examining their DNA; and the question was answered once and for all. All 150 (or 400, depending who is counting) breeds of domestic dog have but one ancestor--the gray wolf. That is correct, though it is sometimes difficult to believe. The gray wolf was the blueprint, the model if you will, for every one of our pet dogs. That means also that every talent, all of the affection, and the "pack mentality," of dogs was already there in the gray wolf. Every good quality that dogs possess came directly from that one sub-species. When dogs point, and even triangulate prey for hunters, they "learned" that behavior genetically from the gray wolf. When they leap high in canine athletic competitions, that skill comes from the gray wolf leaping into trees to hunt birds. In fact, there are few if any qualities and skills our dogs have that don't come from one animal; and since 2003, it has been indisputable that there would be no Tammy, or Rex or Muffy without the gray wolf--the grandparent of all of our dogs.
(Source: "Wolves: Behavior, Ecology, and Conservation." Edited by David Mech and Luigi Boitani; The University of Chicago )