Theory on origin of domestic dogs challenged
The theory that the domestic dog originated in East Asia has been challenged by an international group of researchers who say African dogs are just as genetically diverse.
The huge genetic diversity of dogs found in East Asia had led many scientists to conclude that it was where the domestication of the dog began.
But newly published research, based on analyzing blood samples from dogs in Egypt, Uganda and Namibia, shows the DNA of dogs in African villages is just as varied, according to the New York Times.
The research was originally aimed at tracking down a newly discovered “small gene” that led to wolves being downsized in their transition to dogs. Instead, as reported in the current issue of Proceedings of the National Academy of Sciences, the researchers found information they say calls into question where wolves were first domesticated.
Lead scientist, Adam Boyko of the Department of Biological Statistics and Computational Biology at Cornell University, says he decided to look at village dogs at least partly because his brother, an anthropologist as the University of California-Davis, was head there on a honeymoon. Also there are more mutts there — dogs more genetically diverse than bred dogs.
It’s the mutts that may hold the key to the learning the origins of dog domestication.
The team analysed DNA from 318 dogs from villages and measured their genetic diversity. They also analysed the genetic make up of dog breeds thought to be of African origin, such as the Saluki, the Rhodesian Ridgeback, and the Pharoah Hound .
The team found genetic diversity among African village dogs is just as diverse as that of East Asian dogs, leading them to question the hypothesis of an East Asian origin for dog domestication.
Boyko told BBC News: “I think it means that the conclusion that was drawn before might have been premature. It’s a consequence of having a lot of street dogs from East Asia that were sampled, compared to elsewhere. The reason that East Asia looked more diverse than elsewhere was not because East Asia as a continent had more diverse dogs than elsewhere but because non breed street and village dogs are more diverse than breed dogs.”
He said he was not ruling out East Asia as a location for the origin of the domestic dog, but said but it could just as likely have happened anywhere else on the Eurasian landmass where there were both grey wolves and humans. Today’s dogs are believed to have descended from Eurasian grey wolves, domesticated between 15,000 and 40,000 years ago.
Co-author Paul Jones of The Waltham Centre for Pet Nutrition, UK, said: “It’s interesting to know the answer to the question of where dogs were first domesticated and this paper goes someway to giving us an answer.”
The team are now in the process of sampling street and village dogs across Europe and Asia from Portugal to Papua New Guinea to pinpoint the areas of greatest genetic diversity.
Boyko said that all the dogs sampled in the study have grey wolf DNA so he is not questioning the hypothesis that dogs descended from Eurasian wolves.
Posted by John Woestendiek August 4th, 2009 under Muttsblog.
Tags: africa, diversity, dna, dogs, domestication, east asia, eurasian, gene, genetics, humans, location, origin, research, science, small ene, study, villages, wolf, wolves