Credit: G. VOCKEL/STILL PICTURES

Proc. Natl Acad. Sci. USA doi:10.1073/pnas.0902129106 (2009)

Semi-feral village dogs around the world carry complex mixtures of native and introduced genes, and could point to the origins of man's best friend.

Adam Boyko of Cornell University in Ithaca, New York, and his colleagues analysed mitochondrial and nuclear DNA in 318 dogs from seven areas of Africa and compared them with Puerto Rican street dogs, US mutts and representatives of 126 recognized breeds. They were able to determine the mixture of indigenous and non-native breed-dog genes in each population.

On the basis of mitochondrial DNA diversity, the authors urge closer scrutiny of recent suggestions that domesticated dogs have East Asian origins. The results also suggest that Pharaoh hounds and Rhodesian Ridgebacks, putatively African breeds, have non-African origins.