The domestic dog is a domesticated wolf. The dog descended from an ancient, extinct of 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 uniquely adapted to human behavior, leading to a large number of domestic individuals and the ability to thrive on a starch-rich diet that would be inadequate for other canids.