CATXDOG

Canidae is the family of carnivorous and omnivorous mammals commonly known as canines . It includes dogs , wolves , foxes , coyotes , and jackals. These animals are all digitigrades , meaning they walk on their toes.

Note that the subdivision of Canidae into "foxes" and "true dogs" may not be in accordance with the actual relations, and that the taxonomic classification of several canines is disputed. Recent DNA analysis has shown, however, that Canini and Vulpini are valid clades , which exclude two genera : Nyctereutes and Otocyon . These are basal canids and are not closely related to either vulpines or canines. (Some evidence also suggests the same for Urocyon .)

Speothos and Chrysocyon are primitive members of Canini, but might be placed in their own clade. Cuon and Lycaon may in fact belong in Canis , and there is evidence that Alopex and Fennecus are not valid clades, but are both part of Vulpes .

The Domestic Dog is listed by some authorities as Canis familiaris and others (including the Smithsonian Institution and the American Society of Mammalogists ) as a subspecies of the Gray Wolf (i.e., Canis lupus familiaris ); the Red Wolf may or may not be a full species ; and the Dingo is variously classified as Canis dingo , Canis lupus dingo , Canis familiaris dingo and Canis lupus familiaris dingo . Today it is known that Dingo is not a separate wild dog species as was believed for many years, but rather a unique breed of domesticated dog wich went feral (reverted back to a wild life). Geagrafical isolation kept them clean of other domesticated dogs gene pool, and thus kept them as separate species known today. Although we know now that they were also domesticated dogs, their genes make them quite different from other breeds. At least one subspecies of wolf has recently been listed as a separate species - the Eastern Canadian Wolf , Canis lycaon . This is, however, still a controversial classification; the precise relationships among the Gray Wolf, Red Wolf, Eastern Canadian Wolf, and Coyote have yet to be worked out satisfactorily.

The origin of entire Canidae family is still theorized, because they bear familiarity with various other families such as Felidae (cats) and Ursidae (bears). More detailed information from Dr. Xiaoming Wang can be found here.

	Canidae

Genus Vulpes	Genus Canis	Genus Pseudalopex	Basal Canids
Red Fox (Vulpes vulpes)	Gray Wolf (Canis lupus)	Culpeo (Pseudalopex culpaeus)	Genus Nyctereutes
Swift Fox (Vulpes velox)	Red Wolf (Canis rufus,Canis lycaon)	Darwin's Fox (Pseudalopex fulvipes)	Raccoon Dog (Nyctereutes procyonoides)
Kit Fox (Vulpes macrotis)	Ethiopian Wolf (Canis simensis)	Argentine Grey Fox (Pseudalopex griseus)
Corsac Fox (Vulpes corsac)	Golden Jackal (Canis aureus)	Pampas Fox (Pseudalopex gymnocercus)	Genus Otocyon
Cape Fox (Vulpes chama)	Side-striped Jackal (Canis adustus)	Sechira Fox (Pseudalopex sechurae)	Bat-eared Fox (Otocyon megalotis)
Pale Fox (Vulpes pallida)	Silver-backed Jackal (Canis mesomelas)	Hoary Fox (Pseudalopex vetulus)
Bengal Fox (Vulpes bengalensis)	Coyote (Canis latrans)
Tibetan Fox (Vulpes ferrilata)		Genus Chrysocyon
Blanford's Fox (Vulpes cana)	Dingo (Canis lupus dingo)	Maned Wolf (Chrysocyon brachyurus)
Rüppell's Fox (Vulpes rueppelli)
Fennec (Vulpes zerda)	Genus Cuon	Genus Dusicyon
	Dhole (Cuon alpinus, Canis alpinus)	Falkland Island Fox (Dusicyon australis)
Genus Alopex
Arctic Fox (Alopex lagopus)	Genus Lycaon	Genus Speothos
	African Wild Dog (Lycaon pictus)	Bush Dog (Speothos venaticus)
Genus Urocyon
Grax Fox (Urocyon cinereoargenteus)
Island Fox (Urocyon littoralis)

Genus Cerdocyon
Crab-eating Fox (Cerdocyon thous)

Genus Atelocynus
Short-eared Dog (Atelocynus microtis)

	Domestic Dog (Canis lupus familiaris)		a

Recently, the study of DNA sequences has been used to address the question of the dog's ancestry, and studies using this approach have all pointed to the wolf as being the dog's closest wild relative. For example, a study done by Vila et al. (1997) examined mitochondrial DNA (mtDNA) sequences from several canines to investigate the origins of the domestic dog. mtDNA sequences were obtained from 162 wolves representing 27 populations from Europe, the Middle East, North America and Asia, 140 dogs representing 67 breeds, and 5 coyotes, 2 golden jackals, 2 black-backed jackals and 8 Abyssinian jackals. mtDNA is inherited only maternally, unlike nuclear DNA (which is found in the nucleus of the cell), which is inherited from both the mother and the father. The region of mtDNA sequenced (the control region) region was chosen because it evolves very rapidly, and since dogs are such a young species, only a rapidly evolving region of DNA would show any differences between different dog types. More information by Jessie Zgurski.