Dog is a domesticated wild dog
It's amazing to think that dogs have similar ancestors to wolves.
Dog
The domestic dog ("Canis lupus familiaris" when considered a subspecies of the wolf or "Canis familiaris" when considered a distinct species) is a member of the genus "Canis" (canines), which forms part of the wolf-like canids, and is the most widely abundant terrestrial carnivore. The dog and the extant gray wolf are sister taxa as modern wolves are not closely related to the wolves that were first domesticated, which implies that the direct ancestor of the dog is extinct. The dog
due to gene flow with the wild European Mouflon. 
The sustained admixture between different dog and wolf populations across the Old and New Worlds over at least the last 10,000 years has blurred the genetic signatures and confounded efforts of researchers at pinpointing the origins of dogs. None of the modern wolf populations are related to the Pleistocene wolves that were first domesticated, and the extinction of the wolves that were the direct ancestors of dogs has muddied efforts to pinpoint the time and place of dog domestication.
Positive selection.
Charles Darwin