First
dogs came from East Asia
Researchers at Sweden's KTH Royal Institute of Technology say they
have found further proof that the wolf ancestors of today's domesticated
dogs can be traced to southern East Asia -- findings that run counter to
theories placing the cradle of the canine line in the Middle East.
Dr Peter Savolainen, KTH researcher in evolutionary genetics, says a
new study released November 23 confirms that an Asian region south of
the Yangtze River was the principal and probably sole region where
wolves were domesticated by humans.
Data on genetics, morphology and behaviour show clearly that dogs are
descended from wolves, but there's never been scientific consensus on
where in the world the domestication process began. "Our analysis of
Y-chromosomal DNA now confirms that wolves were first domesticated in
Asia south of Yangtze River -- we call it the ASY region -- in southern
China or Southeast Asia," Savolainen says.
The Y data supports previous evidence from mitochondrial DNA. "Taken
together, the two studies provide very strong evidence that dogs
originated in the ASY region," Savolainen says.
Archaeological data and a genetic study recently published in Nature
suggest that dogs originate from the Middle East. But Savolainen rejects
that view. "Because none of these studies included samples from the ASY
region, evidence from ASY has been overlooked," he says.
Peter Savolainen and PhD student Mattias Oskarsson worked with
Chinese colleagues to analyse DNA from male dogs around the world. Their
study was published in the scientific journal Heredity.
Approximately half of the gene pool was universally shared everywhere
in the world, while only the ASY region had the entire range of genetic
diversity. "This shows that gene pools in all other regions of the world
most probably originate from the ASY region," Savolainen says."Our
results confirm that Asia south of the Yangtze River was the most
important -- and probably the only -- region for wolf domestication, and
that a large number of wolves were domesticated," says Savolainen.
"Since other studies have indicated that wolves were domesticated in
the Middle East, we wanted to be sure nothing had been missed.
We find no signs whatsoever that dogs originated there," says
Savolainen.In their studies, the researchers also found minor genetic
contributions from crossbreeding between dogs and wolves in other
geographic regions, including the Middle East.
- ScienceDaily |