Cradle and birthday of dog identified

But now researchers at the Royal Institute of Technology (KTH) in Stockholm have managed to zero in on man's best friend.

"For the first time in world history it is possible to provide a detailed picture of the dog, with its birthplace, point in time, and how many wolves were tamed," says Peter Savolainen, a biology researcher at KTH.

Together with Swedish colleagues and a Chinese research team, he has made a number of new discoveries about the history of the dog.

These discoveries are presented in an article in the scientific journal Molecular Biology and Evolution, where it is claimed that the dog appeared 16,000 years ago, in Asia, south of the Yangtze River in China.

This is a considerably more specific date and birthplace than had previously been put forward.

"Our earlier findings from 2002 have not been fully accepted, but with our new data there will be greater acceptance. The picture provides much more detail," says Peter Savolainen.

The time for the emergence of the dog conforms well with when the population in this part of the world went from being hunters and gatherers to being farmers, which was 10,000 to 12,000 years ago.

According to Peter Savolainen, the research indicates that the dog has a single geographic origin but descends from a large number of animals. At least several hundred tamed wolves, probably even more.

"The fact that there were so many wolves indicates that this was an important, major part of the culture," says Peter Savolainen.

He adds that the research findings provide several exciting theories. For example, the original dogs, unlike their later descendents in Europe, which were used as herders and guard dogs, probably ended their lives in the stomachs of humans.