Dogs were first domesticated in Central Asia, in an area that is now near present-day Nepal and Mongolia, scientists have said. By analysing the DNA of over 4,000 purebred dogs and 540 village dogs, the team of researchers was able to trace back where the first domesticated canines came from.
It is thought domestic dogs evolved from Eurasian grey wolves at least 15,000 years ago, but where and when this happened has remained a source of debate. Scientists from Cornell University in Ithaca now say they have pinpointed the location of this transition.
The team, publishing their findings in the journal PNAS, analysed over 185,000 genetic markers in the autosomes, Y chromosomes, and mitochondrial DNA of thousands of dogs from 38 countries. "Dogs today consist primarily of two specialised groups − a diverse set of nearly 400 pure breeds and a far more populous group of free-ranging animals adapted to a human commensal lifestyle (village dogs)," they wrote. "Village dogs are more genetically diverse and geographically widespread than purebred dogs, making them vital for unravelling dog population history."
Their findings showed a higher genetic diversity in village dogs compared with the purebreds. Populations in Egypt, Vietnam and India showed few signs of European influence, village dogs in the South Pacific show predominantly European origins. This, the authors say, suggests dogs were probably domesticated in Central Asia.
"Dogs were the first domesticated species, but the precise timing and location of domestication are hotly debated... We find strong evidence that dogs were domesticated in Central Asia, perhaps near present-day Nepal and Mongolia," they wrote.
Researchers note that Central Asia has been considered as a likely domestication origin for dogs for some time, but genetic studies have been lacking. They also say it cannot be ruled out that dogs were domesticated elsewhere and then arrived and diversified in Central Asia at a later date, but they say it would be "difficult to explain" their findings if this was the case. "These populations exhibit a clear gradient of short-range linkage disequilibrium consistent with a Central Asian domestication origin."