The dog is descended from the wolf. True wolves appeared in Europe about one million years ago and in the Americas some 700,000 years later. Dog remains estimated to be about 14,000 years old have been found in Germany, and younger remains have been found in Israel (about 13,500 years old) and Idaho (about 10,500 years old). It is probable that the dog was the first animal to be domesticated, certainly by 15,000 years ago but possibly as long as 40,000 years ago. Domestication may have occurred independently in a number of different areas of the world, but genetic tests show that all dogs are descended from an Eurasian stock, even the now extinct pre-Columbian dogs of the Americas.
It is thought that the earliest domesticated dogs resembled the present-day dingo, the wild dog of Australia. The dingo is believed to have come to Australia as a domestic dog with the aborigines from Southeast Asia. Although more historical information exists on the forerunners of European dogs (such as the British hounds, terriers, and shepherd dogs) than on those of other areas, there is evidence that dogs have existed in most areas of the world throughout the period of recorded history. One of the oldest known breeds is the basenji, which originated in central Africa and is still used as a hunter by certain tribes in that region. Several distinct breeds were known in ancient Egypt and a mastifflike breed (resembling the Kurdish dog in present-day Iraq) is found in Babylonian illustrations of c.2200 B.C.