Where did the first dogs come from?
I love dogs. My partner Randy and I recently acquired a labradoodle puppy, who – now nearly 15 weeks old – has become the best friend of our older dog and the source of a huge amount of family time spent petting dogs, walking dogs, training dogs, selecting and distributing treats, toys and bones to dogs, and, for me, reading about dogs.
So I was fascinated when researchers at the KTH Royal Institute of Technology in Stockholm, Sweden, announced on November 23, 2011, that they have found further proof that the wolf ancestors of today’s domesticated dogs can be traced to southern East Asia.
The wording (further proof) in their press release made me wonder if other scientific studies had shown a different point of origin for domesticated dogs – which everyone for the most part agrees, by the way, descended from gray wolves some tens of thousands of years ago. And indeed another prominent paper suggesting an East Asian origin for dogs by these same Swedish researchers – with lead author Dr. Peter Savolainen, KTH researcher in evolutionary genetics – appeared in the journal Science in 2002. It used mitochondrial DNA evidence to suggest a common origin from a single East Asian gene pool for all dog populations.
In 2010, though, a study led by Bridgett vonHoldt, then at UCLA, contradicted Savolainen’s earlier findings. The 2010 study appeared in the journal Nature and used a larger data set of nuclear markers to suggest that domesticated dogs originated in the Middle East. There’s a very good story about that study here.
So which is it? East Asia? Or Middle East? I don’t have the expertise to evaluate either study, but I can tell you a bit more about Savolainen’s more recent one, suggesting the East Asian origin. It points to an Asian region south of the Yangtze River as the principal region where wolves were domesticated by humans. Savolainen said:
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.
He said the Y chromosome data supports previous evidence from mitochondrial DNA, adding:
Taken together, the two studies provide very strong evidence that dogs originated in the ASY region.
Savolainen rejects the view that dogs originated in the Middle East …
Because none of these studies included samples from the ASY region, evidence from ASY has been overlooked.
Savolainen worked with PhD student Mattias Oskarsson and Chinese colleagues to analyze DNA from male dogs around the world. Their new study can be found 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. Savolainen said:
This shows that gene pools in all other regions of the world most probably originate from the ASY region.
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.
In other words … grrr! It’ll be interesting to see if the UCLA scientists come back with confirmation of their idea that the Middle East is the place of origin of dogs.
Bottom line: Researchers are arguing about whether the DNA evidence supports an origin for dogs in the Middle East or East Asia. The most recent study, published November 23, 2011, in the journal Heredity, suggests the East Asian origin. Peter Savolainen at the KTH Royal Institute of Technology in Stockholm, Sweden, was lead author.