The genetic history of modern domesticated dogs is extremely complex. Scientists have strong evidence that dogs were domesticated from gray wolves at least 15,000 years ago, but exactly where this domestication first occurred and the where the early dogs and their prehistoric human owners migrated to from there is highly controversial.
A new study, published Tuesday in the journal Proceedings of the National Academy of Science, is the most comprehensive genetic study of dogs to date. The genetic material gathered from 5000 dogs across the globe by the researchers suggests that domesticated dogs probably first originated in Central Asia.
More on new research on domesticated dogs
The new genetic research on dogs was undertaken by a team of wildlife biologists at Cornell University including professor Adam Boyko and postdoc Laura Shannon.
The Cornell project was the largest genetic study attempted to date on domesticated dogs, and involved sampling three types of DNA from 161 breeds of 4,500 dogs, together with 549 street and feral dogs (feral dogs actually represent close to 75% of the global dog population). The study involved sampling genetic material from dogs in 38 countries.
This new large scale genetic analysis is by far the strongest evidence to date that modern domesticated dogs originated somewhere in the area of Nepal and Mongolia, becoming the dogs we know today over more than 15,000 years of evolution. The researchers point out that the DNA of dogs in neighboring areas such as East Asia, India and Southwest Asia is also genetically diverse, further substantiating the claim of the Cornell team.
The scientific community as a whole is duly impressed by this study, given its breadth and ambition, but the researchers are being careful to not try to make a definitive statement on the origins of dogs.
A couple of earlier studies placed the first domestication of dogs in other regions such as Siberia and Europe, Boyko noted, and also emphasized that the origins of modern dogs were “extremely messy.” Boyko noted in interviews with the media that it was still quite possible that dogs were domesticated somewhere else before coming to Central Asia and eventually evolving into modern canines.
Researchers note that the earliest domesticated dog fossils are around 15,000 years old, and were found in Western Europe and Siberia. Genetic studies, on the other hand, have produced conflicting answers regarding the origin of dogs, depending on whether they look at modern DNA from dogs or ancient DNA from fossils, where they collect samples from, and whether the research analyzes the full genomes, specific markers, only the Y chromosome, or just mitochondrial DNA (a kind of secondary genome).
No trouble recruiting subjects for the study
“There are millions of dogs in the world and the vast majority of them are not purebred,” Boyko commented in an interview. “And very little is known about these free-ranging, village dogs.” That’s why he and his team took blood samples from 549 stray village dogs in 38 countries on six continents. “I did my Ph.D. work with tropical butterflies; by comparison, working with dogs is fantastic,” he pointed out. “You don’t need to hunt them down with a net. You show up, you have food, there are dogs.”