More Light is Shed on the Origins of Domestic Dogs
We’ve previously talked about the results of a 2011 study published in the journal Heredity that pointed to Southeast Asia, specifically an area south of the Yangtze River, as the part of the world where dogs were first domesticated.
The researchers looked at the genetic structure of 151 dogs from around the world. The most genetic diversity (which takes time to develop) was seen in dogs from Southeast Asia. The results indicate that these dogs were the first dogs (originating from 13-24 wolf founding mothers and fathers), and subsequent breeds developed when subsets of this group were removed and bred only to one another. In the past, other researchers had asserted that the Middle East or Europe was the most likely site of dog domestication, but their work did not include DNA analysis of samples from Southeast Asia.
Well … new research brings these findings into question. A different group of scientists published a paper in the November 14, 2013 issue of the journal Science. They make reference to this previous study and the confusion associated with determining the origin of dogs in the paper’s abstract, stating, “The geographic and temporal origins of the domestic dog remain controversial, as genetic data suggest a domestication process in East Asia beginning 15,000 years ago, whereas the oldest doglike fossils are found in Europe and Siberia and date to >30,000 years ago.”
In this study, the scientists analyzed mitochondrial DNA sampled from modern dogs and wolves and 18 fossil “canids” and the results suggest “that an ancient, now extinct, central European population of wolves was directly ancestral to domestic dogs” and that domestication occurred approximately 20,000 years ago while our ancestors were still hunter-gatherers, not beginning to farm as was previously suggested.
This latest study is not definitive (neither was the last one, obviously). Critics are arguing that major failings center on the scientists’ inability to include DNA taken from fossil “canids” from the Middle East and Asia and an overrepresentation of modern European wolves. But, it does offer a tantalizing look into a possible scenario that led to dogs becoming “(wo)man’s best friend.” As one of the authors, Robert Wayne from the University of California, Los Angeles, puts it in a Science podcast:
[Proto-dogs] probably began following humans around taking advantage of carcasses potentially that they left behind. It puts domestication in that kind of context, which is much more easy for me anyway to understand because dogs are the only large carnivore ever domesticated. And it’s hard for me to envision how you would just bring a large carnivore into the confines of human society very easily. But if it was a long process of acclimation where the first dogs were just living in the kind of human niche and alongside humans and at some distance from them and taking advantage of carcasses and then gradually being incorporated into human society more closely over time, then I can stomach it much more easily. I can’t really take the scenario where they were just readily domesticated as we’ve done say with horses or even the kind of cat scenario.
For more information on this fascinating subject (at least I think it is!), listen to the whole Science Podcast or take a look at their News and Analysis piece called Old Dogs Teach a New Lesson About Canine Origins.
Dr. Jennifer Coates
Image: Pakawat Suwannaket / Shutterstock