What species is the ancestor of the domestic chicken?

The red junglefowl is the primary wild ancestor of the domestic chicken. Scientists classify the chicken as Gallus gallus domesticus, a domesticated form of Gallus gallus, the red junglefowl.

Red junglefowl live across parts of South and Southeast Asia. Their domestication began thousands of years ago, probably in the region where their natural range overlaps with early farming societies. Genetic research indicates that domestic chickens descend mainly from red junglefowl, with domestication occurring in stages and spreading through Asia.

The story is slightly more complex than a single-parent family tree. Domestic chickens later interbred with other junglefowl, including the grey, Sri Lankan, and green junglefowl. For example, the gene associated with yellow skin appears to have come from the grey junglefowl in some chicken populations.

That secondary ancestry does not make the quiz answer wrong: red junglefowl remains the accepted primary ancestor. A common mistake is choosing another junglefowl species because all four look related; only the red junglefowl is the standard answer.