All domesticated animals have their origins in wild ancestors, but it takes hundreds of years for an animal species to be completely domesticated. Humans had already been domesticating animals for thousands of years before anyone began recording history. The first domesticated animals were probably raised as pets, for sports, or for religious purposes. Archaeologists believe people did not begin to domesticate animals until they had settled into communities and established reliable food supplies through farming or fishing.
The dog was the first animal to be domesticated, probably 10,000 to 12,000 years ago. Sheep and goats came next, around 7,000 BC, in the Middle East and Central Asia. Cattle were domesticated in South Asia, the Middle East and Europe by 4,000 BC. Pigs were domesticated at about the same time. Present-day cattle derive from the wild aurochs (or-oks), a huge beast which sometimes stood five feet at the withers, had horns three feet long and weighed a ton.
The easiest animals to domesticate were herd animals. Herd animals follow the lead of a dominant member. They stay close together and move together. Early farmers could use surplus grains to attract hungry animals, especially in times of drought. They watched the animals and learned their food and water needs. They would lead them to suitable pasture and water and protect them from predators. The animals grew accustomed to having humans around and gradually became tame.
Although farmers would kill some of the tame animals for food, they would save the youngest and the tamest. The farmer would kill the animals that were most difficult to manage and save those that were more tame. The animals that ate the most would be killed as well. The smaller, tamer animals would reproduce, and eventually the entire herd would become smaller and more tame. This was the beginning of the practice we know now as selective breeding.
At first the tame animals were used only as an easy source of meat. Later the farmer noticed that crops grew better on plots where animals had grazed and realized the value of animal manure as fertilizer. Through more observation, the farmer realized the animals’ milk could provide another food source.
Eventually humans discovered they could weave the hair of animals like sheep and goats to make cloth for clothing. The Sumerians were the first to develop sheep and goats with the woolly coats we use for making cloth today.
Sometime before 3300 BC, farmers in Sumer and nearby Egypt started using animals as beasts of burden. Wooden plows were invented and drawn by oxen or asses to turn over the irrigated fields. Farmers also found they could harness animals to haul carts loaded with the harvest, making it possible to move large amounts of grain to a storage point or canal boat for further transport. In the New World, the alpaca, llama, duck, turkey and dog were all domesticated by the time of the first European explorers. Early European settlers brought their domesticated animals with them when they came to the New World. These included cattle, sheep, goats, pigs and chickens. Horses were introduced to the New World by the Spanish in the 15th Century. Many of them escaped to form the wild mustang herds in the West.
In the past 100 years, farmers and ranchers have begun to domesticate some other species of wild animals. On the Great Plains of North America, the bison, a herd animal, had roamed the grasslands for thousands of years. Prehistoric humans living on the plains hunted the bison but did not make any serious efforts to domesticate them. In the late 1900s, when hunters threatened the bison with extinction, some ranchers and other conservationists began rounding up small herds. Over the past 100 years these small herds have grown into large ones, and in some parts of the Great Plains, cattle ranchers have begun replacing their cattle with bison herds. Since the bison are native to the Great Plains they are better adapted than cattle to the conditions present there.
