An example of the wild ancestor of an animal bred as a food source is in chickens. The ancestor of the domesticated chicken, the red junglefowl, is believed to have an origin in parts of South and Southeast Asia. Around 8,000 years ago humans started to breed this species for food. A study has shown that the act of domestication for the chickens caused the gene mutation involving a gene known as TSHR, which was found only in domestic populations. This implied that this gene in particular may have some involvement in the domestication of bird species.
