Investigations into the domestication of the dog

Few people spend their honeymoon catching and drawing blood from village dogs up and down Africa. But Ryan and Corin Boyko, two anthropologists at the University of California, Davis, chose this way to collect valuable genetic data that is casting a new light on the domestication of dogs.

Scientists had thought that dogs, like these in Tibet, were domesticated from wolves in East Asia, but new work calls that into question.

The opportunity to combine love with science arose when Ryan’s brother Adam Boyko, a biologist at Cornell University, was discussing dog genetics with his professor, Carlos Bustamante. Dr. Bustamante, just back from a visit to Venezuela, remarked on how small the street dogs there were.

The two researchers wondered if the dogs carried a recently discovered gene that downsizes dogs from wolves and is found in all small dog breeds. Dr. Bustamante said the idea could be explored by collecting street dogs from up and down South America. Dr. Boyko, knowing his brother was planning a honeymoon in Africa but lacked the money to go far, proposed that the survey be done in Africa instead. “I paid for half their honeymoon,” Dr. Bustamante said.

Ryan and Corin Boyko collected 223 samples of village dog blood from Egypt, Uganda and Namibia. The small gene question has not yet been assessed, but their samples, reported in the current issue of the Proceedings of the National Academy of Sciences, have called into question a finding on the origin of dog domestication from wolves.

The origin is thought to be East Asia, based on a 2002 survey of both village dogs and breed dogs. But most of the village dogs in that survey came from East Asia, which could have tilted the outcome. The African village dogs turn out to have much the same amount of genetic diversity as those of East Asia. This is puzzling because the origin of a species is usually also the source of greatest genetic diversity.