Stockholm, Nov. 22 (Reuters): From chihuahuas to Saint Bernards, all modern dogs originate from a small number of female wolves living in East Asia some 15,000 years ago, Swedish scientists said yesterday.
By analysing hair samples from more than 500 different breeds from all over the world, the scientists discovered that all dogs share the same genetic pool but that East Asian dogs had a higher genetic variation.
“This makes it probable that dogs originated in East Asia and spread all over the world,” said Peter Savolainen, a senior scientist at the Swedish Royal Institute of Technology.
The main reason why modern dog breeds look so different is the enormous interest in breeding that swept across Europe after the Middle Ages, Savolainen said.
The few dogs which still look almost like their ancestors include the Mexican hairless dog, the Australian dingo and the greyhound, which has been found in the pyramids of Egypt.
In two articles due to be published in US journal Science today, Savolainen and his colleagues report the results of a four-year study of dogs’ genetic codes.
The study looked at dogs’ mitochondrial DNA, genes directly inherited from the mother which present a straight historical lineage. According to Savolainen, it was possible to see genes from at least five female wolves in today’s dogs.
Archaeological findings, the oldest being a 12,000-year-old canine jaw bone found in Israel, had previously led scientists to believe the domestic dog originated in West Asia.
The new research also shows native American dogs used by American Indians originated from East Asia, brought by people over the Bering Straits some 14,000 years ago.
But researcher Carles Vila of Sweden's Uppsala University, who has studied remains of native American dogs found in South America and Alaska, said there were no traces of these native dogs in modern American canines. “It is very clear that the modern American dogs derive from dogs brought by the Europeans,” he said.
The dog is widely believed to be the first domesticated animal, but it is not known why wolves were tamed. Theories include that they were bred for food or were scavengers around human sites and later used as sheep dogs. Per Jensen, professor at the Swedish Linkoping University, believes the question will remain unanswered.