It had been reported that the domestication of dogs began in the late Paleolithic and Mesolithic period [1, 2].
Human selection generated a lot of canine breeds with a wide range of phenotypic variation, except for changes in character, which is a typical domestication sign for all dogs [3]. Furthermore, the archaeological and archaeozoological sources clearly indicate the great phenotypic variation in the early period of dog breeding [1, 3, 4]