Biologist: Researchers believe that dogs are the descendants of domesticated wolves that were bred to be better companions for humans  It has recently been found that some breeds of dog are much more closely related genetically to wolves than to most other breeds of dog
This shows that some dogs are descended from wolves that were domesticated much more recently than others
If one breed of dog is more closely related to wolves than to another breed of dog, then the former breed of dog has more recent undomesticated wolf ancestors than the latter breed has.