Why the chicken crossed the road is a question that'll never be answered. But the circumstances of the domesticated chicken's ancestry should be discoverable.

And a new study suggests Charles Darwin had it wrong. Darwin maintained that the domesticated chicken derives from the red jungle fowl. That seems at least partly true, but new research from Uppsala University now shows that the wild origins of the chicken are more complicated.

The researchers mapped the genes that give most domesticated chickens yellow legs and found the genetic heredity derives from a closely related species, the gray jungle fowl. The study is being published today in the Web edition of PLoS Genetics.

"Our studies show that even though most of the genes in domesticated fowls come from the red jungle fowl, at least one other species must have contributed, specifically the gray jungle fowl," said Jonas Eriksson, a doctoral student at Uppsala University.

The gray jungle fowl was probably crossed with an early form of the domesticated chicken, Eriksson's team figures.




"Our study is a clear example of the importance of regulatory mutations in the course of evolution, said Professor Leif Andersson, who directed the project. "What we don't know is why humans bred this characteristic. Maybe chickens with bright yellow legs were seen as being healthier or more fertile than other chickens, or were we simply charmed by their distinct appearance."
