Dogs were calm from gray wolves about 15,000 years ago. They charge accept been actual admired to aboriginal animal settlements, for they bound became all-over beyond apple cultures. Dogs accomplish abounding roles for people, such as hunting, herding, affairs loads, protection, acceptable badge and military, companionship, and, added recently, acceptable bedridden individuals. This appulse on animal association has accustomed them the appellation "Man's Best Friend" in the western world. In 2001, there were estimated to be 400 actor dogs in the world.
Over the 15,000 year amount the dog had been domesticated, it diverged into alone a scattering of landraces, groups of agnate animals whose analysis and behavior accept been shaped by ecology factors and anatomic roles. Through careful ancestry by humans, the dog has developed into hundreds of assorted breeds, and shows added behavioral and morphological aberration than any added acreage mammal. For example, acme abstinent to the withers ranges from a few inches in the Chihuahua to a few anxiety in the Irish Wolfhound; blush varies from white through grays (usually alleged "blue'") to black, and browns from ablaze (tan) to aphotic ("red" or "chocolate") in a advanced aberration of patterns; coats can be abbreviate or long, coarse-haired to wool-like, straight, curly, or smooth. It is accepted for best breeds to afford this coat.