After sequencing the genomes of over 50 wolves and dogs from around the world, researchers have traced the origins of domestic dogs back to southern East Asia. Their findings are published in Cell Research this week.
Domestic dogs, Canis lupus familiaris, have followed us to every continent on the planet, but researchers can’t agree on their origin and evolution. The results of recent DNA studies have ranged from a European origin to a Central Asian one, near what is now Nepal or Mongolia. But one key element was missing from many of these previous studies: dogs from the southern part of East Asia. "If dogs actually originated in this region it would not have been detected," Peter Savolainen from the KTH-Royal Institute of Technology explains to IFLScience.
So Savolainen, together with Ya-Ping Zhang from the Kunming Institute of Zoology and an international team of researchers, sequenced the whole genomes of 58 members of the dog family, Canidae. These include a dozen gray wolves, 23 indigenous dogs from northern and southern East Asia, four village dogs from Nigeria, and 19 breeds from around the world, including Afghan hounds, Siberian huskies and Alaskan malamutes, Chihuahuas and Peruvian naked dogs, Tibetan mastiffs, and the sloughi of northern Africa.
For many organisms, their geographical origin typically exhibits the greatest genetic diversity. The team found that dogs from southern East Asia have a much higher degree of genetic diversity than any of the other dogs studied, and they were the most closely related to gray wolves. That means domestic dogs likely originated in southern East Asia, and a population genetic analysis puts it at about 33,000 years ago.
The team thinks that sometime around 15,000 years ago, a subset of dog ancestors began migrating from South China towards the Middle East and Africa, and they reached Europe about 10,000 years ago. While this dispersal was linked with the movement of humans, the first migration of the domestic dog out of southern East Asia was likely initiated by the dogs themselves. They may have been driven by environmental factors, such as the retreat of glaciers some 19,000 years ago. Later on, dogs from one of these ancient, out-of-Asia groups traveled back east, towards northern China. There, they encountered dogs that had migrated from southern East Asia, and after these two groups interbred, they went on to the Americas.
Images in the text: Some of the dogs sampled in the study. Ting-Ting Yin and Yan-Hu Liu
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