What was the first animal to be domesticated?
Goats were probably the first animals to be domesticated, followed closely by sheep. In Southeast Asia, chickens also were domesticated about 10,000 years ago. Later, people began domesticating larger animals, such as oxen or horses, for plowing and transportation. These are known as beasts of burden.
Domesticating animals can be difficult work. The easiest animals to domesticate are herbivores that graze on vegetation, because they are easiest to feed: They do not need humans to kill other animals to feed them, or to grow special crops. Cows, for instance, are easily domesticated. Herbivores that eat grains are more difficult to domesticate than herbivores that graze because grains are valuable and also need to be domesticated. Chickens are herbivores that eat seeds and grain.
Some animals domesticated for one purpose no longer serve that purpose. Some dogs were domesticated to assist people in hunting, for instance. There are hundreds of domestic dog species today. Many of them are still excellent hunters, but most are pets.
Throughout history, people have bred domesticated animals to promote certain traits. Domestic animals are chosen for their ability to breed in captivity and for their calm temperament. Their ability to resist disease and survive in difficult climates is also valuable.
Over time, these traits make domestic animals different from their wild ancestors. Dogs were probably domesticated from gray wolves. Today, dogs are a distinct species from gray wolves.
Domesticated animals can look very different from their wild ancestors. For example, early wild chickens weighed about two pounds. But over thousands of years of domestication, they have been bred to be larger. Larger chickens yield more meat. Today, domestic chickens weigh as much as 17 pounds. Wild chickens only hatched a small number of eggs once a year, while domestic chickens commonly lay 200 or more eggs each year.