Classifying the Dog

It is only recently that the original ancestor of the dog has been identified.

As the result of DNA testing in November 2002 on 654 breeds of dogs and 38 types of wolves, it was shown that the ancestor of the dog was the domesticated wolf.

Although it is still not clear when and where this domestication occurred, it was revealed that four strains of wolf were mixed in the bloodlines of the earliest dogs.

Dogs are placed within the order Carnivora, a division of the larger class Mammalia. Carnivores are usually divided into eight families: Canidae (dogs), Procyonidae (raccoons), Felidae (cats), Mustelidae (weasels), Ailuridae (pandas), Ursidae (bears), Viverridae (civets), and Hyaenidae (hyenas).

Domestic dogs are classified under Canidae. The Canidae are generally divided into four groups: the dog group (genus Canis), the fox group (genus Vulpes), the culpeo group (genus Dusicyon), and the bush dog group (all other genera).

The bush dog group includes the bush dog, crab-eating fox, bat-eared fox, raccoon dog, and gray fox, while the fox group covers almost all species of foxes except the gray fox and a few others.

The culpeo group contains in-between species of dogs and foxes, such as the Falkland wolf, culpeo fox, striped-tail dog, Andes wolf, and maned wolf.

Included in the dog group are the dhole, African wild dog, and canis. The first two genera have only dholes and African wild dogs, respectively. The Canis group includes coyote, jackal, wolf, dingo, and the domestic dog.

All in the Canis group have the same skeletal structure, including five digits on the front paws, and four on the rear paws, and have a circular contracting iris. These shared characteristics indicate that the domestic dog may find its ancestor in this genus.