Where did the chicken come from?

The chicken comes from a jungle bird. It is the domesticated form of the red junglefowl, originally native to Southeast Asia. Today it is one of the most common animals on Earth: as of 2023 there were more than 26.5 billion chickens, and more than 50 billion birds were produced each year for food.

When and where it was first kept has been a real argument. Genomic studies estimated that chickens were domesticated around 8,000 years ago in Southeast Asia and then spread to China and India 2,000 to 3,000 years later. A 2020 study that sequenced 863 chickens from around the world suggests that all of them come from a single domestication of red junglefowl. But when researchers re-examined bones from more than 600 sites and dated those from 23 of them, the earliest probable chicken bones turned up in central Thailand and were only about 3,250 years old.

How might a jungle bird have ended up in a farmyard? Two researchers, Joris Peters and Greger Larson, propose that wild junglefowl were drawn to eat the seeds of rice crops, nested nearby and became domesticated. Humans also took advantage of an ability the red junglefowl already had: it can breed prolifically when its food supply surges.

The result is a bird that looks very different from its ancestor. Wild junglefowl can fly, while domestic chickens are too heavy to fly more than a short distance, and a hen bred for laying can produce over 300 eggs a year.