The dog (Canis lupus familiaris, pronounced /ˈkeɪ.nɪs ˈluːpəs fʌˈmɪliɛərɪs/) is a domesticated form of the Gray Wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The domestic dog has been one of the most widely kept working and companion animals in human history. Amongst canine enthusiasts, the word "dog" may also mean the male of a canine species, as opposed to the word "bitch" (the female of the species).

The dog quickly became ubiquitous across culture in all parts of the world, and was extremely valuable to early human settlements. For instance, it is believed that the successful emigration across the Bering Strait might not have been possible without sled dogs. Dogs perform many roles for people, such as hunting, herding, protection, companionship, and, more recently, assisting handicapped individuals. Currently, there are estimated to be 400 million dogs in the world.

Over the 15,000 year span that the dog had been domesticated, it diverged into only a handful of landraces, groups of similar animals whose morphology and behavior have been shaped by environmental factors and functional roles. As the modern understanding of genetics developed, humans began to intentionally breed dogs for a wide range of specific traits. Through this process, the dog has developed into hundreds of varied breeds, and shows more behavioral and morphological variation than any other land mammal. For example, height measured to the withers ranges from a few inches in the Chihuahua to a few feet in the Irish Wolfhound; color varies from white through grays (usually called "blue'") to black, and browns from light (tan) to dark ("red" or "chocolate") in a wide variation of patterns; coats can be short or long, coarse-haired to wool-like, straight, curly, or smooth. It is common for most breeds to shed this coat, but non-shedding breeds are also popular.

The dog is a mammal in the order Carnivora. Dogs were first domesticated from wolves at least 17,000 years ago, but perhaps as early as 150,000 years ago based upon recent genetic fossil and DNA evidence. In this time, the dog has developed into hundreds of breeds with a great degree of variation.

Contents

• 1 Sourced
• 2 Unsourced
• 3 See also
• 4 External links

Sourced

• Yet the dogs eat of the crumbs which fall from their masters' table.
  • The Bible, Matthew xv. 27.

• Cry Havoc! and let slip the dogs of war.
  • Antony; in William Shakespeare's Julius Caesar, Act III, Scene i (1599)

• Turn, hell-hound, turn!
  • Macduff; in William Shakespeare's Macbeth, Act V, Scene viii (c. 1605)

• A dog will make eye contact. A cat will, too, but a cat’s eyes don’t even look entirely warm-blooded to me, whereas a dog’s eyes look human except less guarded. A dog will look at you as if to say, “What do you want me to do for you? I’ll do anything for you.” Whether a dog can in fact, do anything for you if you don’t have sheep (I never have) is another matter. The dog is willing.
  • Roy Blount, Jr., "Dogs Vis-A-Vis Cats,” Now Where Were We?, Random House (1989)

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Wed Oct 14 00:56:20 2009