Cattle are among the most useful of all domestic animals. It has been said that modern civilization began when people first began milking cows and using oxen to plow their fields. Cattle have wild relatives in many parts of the world. They must have been domesticated in Asia first, however, for their bones have been found in settlements there earlier than anywhere else. Shorthorn cattle are supposed to have been introduced into Europe from Central Asia when the long-horned urus (now extinct) was still running wild. The urus and the Celtic ox were domesticated later than the Asian breeds of cattle.
Sheep have been so changed by breeding that their wild ancestors are hard to identify. Like the wild sheep, the domestic sheep of Egypt in 3000 BC had coats of coarse hair. The dense wool was gradually developed by selective breeding.
Pigs were derived from the wild boar, which can still be found in Europe, Asia, and Africa. In Egypt their flesh was not eaten. They were instead kept as scavengers. They loosened the soil by their rooting and so prepared it for planting. They were also used to trample down the seeds after sowing and to thresh the grain at harvesttime.
According to archaeological records, chickens were first domesticated in the cities of the Indus Valley in about 3000 BC. The donkey of Mediterranean lands is thought to be a descendant of the wild ass of Western Asia.
The horse was the last important animal to be domesticated. The only species of wild horse still living are Przhevalski's horse, very small numbers of which survive in the wild in western Mongolia, and the Riwoche horse, a few of which survive in northeastern Tibet. The tarpan, a wild horse of Europe and Northern Asia, became extinct in the mid-1800s. These two species were probably the ancestors of the modern horse breeds.
A Semitic people who conquered the Mesopotamian region in about 2300 BC were mounted on horses. The ability of these people to domesticate horses may explain their success in war. The first sight of a person riding a horse must have struck terror into the hearts of people unaccustomed to such a sight. In addition, the myth of the centaur, half horse and half man, probably had its origin in just such an experience.
In North America before the arrival of the Europeans, the only domesticated animal among the Native Americans was the dog. After European settlers brought domesticated horses to the New World, the horse effected great changes for the peoples of the Plains (see Indians, American, or Native Americans).
