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Attempting to uncover the history of dog domestication is a complicated task. It oftens seems as though the more information we acquire, the less clear the picture becomes.
A few months ago we reported on the findings of Peter Savolainen, who analyzed mitochondrial DNA and deduced that the long and convoluted trajectory of dogs should be traced back to East Asia. However, a new report to be published tomorow in Science suggests that Savolainen’s thesis may be wrong: modern day dogs might have actually come from Europe.
Robert Wayne, a professor of ecology and environmental biology at UCLA, has found genetic evidence that not only supports a European background for dogs. It also suggests that their domestication happened during the age of the hunter-gatherer rather than after the birth of farming, as the traditional story goes.
To reach these conclusions, Wayne, alongside his former doctoral student Olaf Thalmann and their colleagues, compared the mitochondrial genomes obtained from the fossils of 18 ancient canine specimens and 20 modern wolves, all American or Eurasian, with a collection of mitochondrial genomes from 49 wolves, 77 dogs, four coyotes, and three indigenous Chinese breeds. They found that dogs as we know them today are the descendants of long-gone type of European wolf, and that their domestication occurred somewhere between 19,000 and 32,000 years ago.
Does this, then, discard Savolainen’s powerful, albeit controversial stance?
“I guess every paper on dog genetics relates to his work in one way or the other,” Thalmann said of Savolainen. “He basically uses genetic data of modern dogs and wolves to derive the conclusion that dogs came from China. However, by using only modern dogs or wolves, your results will be affected by hybridization events that happened after the onset of domestication and thus the story might get blurred.”
When Science reached out to Savolainen for comment on Wayne and Thalmann’s work, he said it was “not really an objective study.” His critique refers to one particular weakness in the newest results, which the researchers themselves preemptively cite: The study did not include data from ancient Middle Eastern and East Asian canid specimens.
As these immediate rumblings between camps suggest, the debate over dog domestication will continue. Wayne himself provided evidence in 2010 that dogs came from the Middle East, though obviously has since altered his perspective in light of new research. Wayne told UCLA, “This is not the end-story in the debate about dog domestication, but I think it is a powerful argument opposing other hypotheses of origin.”
But why is this important in the first place? To Thalmann, the answer is simple: “Dogs have become such an important part of our lives that we should have some sort of knowledge that might help to understand the history of man’s best friend.”