The History of dogs
Dogs belong to Canid family (Canidae).
Dogs first appeared about 40 million years ago, before any other carnivore families like bears or cats.
Carnivores have a pair of teeth similar to blades that are called carnassials. These teeth are like scissors and can slice through skin and muscle.
Thirty five living species are included in Canid family tree. There are three main groups.
1. South American foxes 2. Wolves, including jackals, wolves, coyotes, and dogs 3. Foxes including red fox and his relatives. The dog that we commonly know is closest kin to gray wolf.
There is genetic evidence and fossils that confirm that all dogs are direct descendants of wolves. Skeletons of earliest dogs and their wolf cousins are very hard to find differences.
There are around 400 domestic breeds of dogs and they all belong to same species, Canis familiaris.
A group that can successfully reproduce with one another is known as a species. A sub-group of species is a breed. This has been made by human interaction. All individuals in a breed can reproduce with each other, but features of breed can be altered or lost when one breed is crossed with another.