Greger Larson, a research fellow at Uppsala University in Sweden and at Durham University in Britain, said yellow-skinned chickens have a different version of a gene than their white-skinned cousins.

Darwin believed that all chickens came from a wild species known as the red junglefowl but when the research team looked for a yellow-skin gene in the red junglefowl they found only the genetic variant that codes for white skin. The yellow-skin version of the gene, however, was present in grey junglefowl, the journal Public Library of Science (PLoS) Genetics said Friday in a release.

"Darwin recognized the importance of studying domestic animals as a model of evolution and this insight has proved enormously influential," Larsen said. "The ironic thing is that he believed that dogs were hybrids of several wild ancestors but that chickens only had one, and he was wrong on both counts."