Dog

The domestic dog (Canis familiaris or Canis lupus familiaris) is a domesticated descendent of the wolf. The dog is derived from an elden, extinct wolf, with the modern grey wolf being the dog's nearest living relative. The dog was the first species to be domesticated, by hunter-gatherers over 15,000 years ago, before the development of agriculture. Their long association with humans has led dogs to be adapted to human behaviour, leading to a large number of domestic types and the ability to thrive on a starch-rich diet that would be unhealthy for other canids. The dog has been selectively bred over millennia for sundry behaviours, sensory capabilities and physical attributes. Dogs are sub classified into breeds. They perform many roles for humans, such as hunting, herding, pulling loads, protection, assisting police and the military, companionship, therapy and aiding disabled people. This influence on human society has given them the sobriquet of "man's best friend".

Etymology
The word "dog" comes from the Middle English word "dogge" (whence the Scots word "dug" (dog) stems from). Comes from Old English "dogga", "docga" which is of uncertain origin, However, the word replaced the word 'hound' when referring to dogs. The word hound comes from Middle English hound which comes from Old English hund which descends from Proto-Germanic hundaz which makes hound cognate with German Hund, Norwegian hund, and Dutch hond which ultimately comes from Proto-Indo-European ḱwṓ which even further comes from Pre-Proto-Indo-European ḱwóns.