Dogs Likely Descended From Middle Eastern Wolf
Modern dogs are descended from wolves, but the question has been: which wolves? Now, scientists at the University of California, Los Angeles say they have the answer. By comparing the DNA from both dogs and wolves, the UCLA researchers say the first place that domesticated dogs called home was somewhere in the Middle East.
Robert Wayne, who led the research team, says he was somewhat surprised by the result. "Previous papers have suggested it was East Asia," he says. But Wayne says those papers focused on a small subset of DNA called mitochondrial DNA, instead of looking across all 2.4 billion letters that make up the dog genome.
To come up with their results, Wayne and his colleagues studied DNA from more than 200 wild gray wolves. "We looked at wolf populations in Europe, the Middle East and East Asia and from China," he says. In each case, they sought out and found genetic markers that were unique to these different wolf populations. So, for example, there were some markers that were only found in Chinese wolves, and others only found in Middle Eastern wolves.
'Dominant Signal Comes From The Middle East'
Then they analyzed DNA from more than 900 dogs from 85 breeds, and looked to see which of the wolf markers dogs most closely resembled. It turns out that most dogs shared markers unique to Middle Eastern wolves, although there were some dog breeds that were closer to other wolf populations.
"Many wolf populations may have contributed to the genomic diversity of dogs, but the dominant signal comes from the Middle East," says Wayne. The new research appears in the journal Nature.
"I can't say that I am surprised by the results," says Tamar Dayan, a zoologist at Tel Aviv University in Israel. "I would have been surprised if they were different."
Dayan says dog skeletons 12,000 or 13,000 years old have been found in what is now northern Israel. "They're found in burials with humans in a very clear human context."
This is probably not the final word on the subject of dog domestication. Some scientists think Wayne and his colleagues are barking up the wrong tree, so to speak. But Wayne plans to gather more genetic data that he hopes will fill in any gaps in the history of dog domestication.
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RENEE MONTAGNE, host:
Scientists dont know the moment when dogs learned to like people, but they might know where dogs first became our best friends.
NPR's Joe Palca has more.
JOE PALCA: Dogs are the domesticated descendants of gray wolves. Gray wolves are carnivores. Evolutionary biologist Robert Wayne says domesticating wolves was no easy task.
Professor ROBERT WAYNE (UCLA): It's difficult to domesticate a large carnivore; they tend to eat your children and bite you.
PALCA: But, somehow, humans managed it. Wayne says scientists have been using genetic tools to study the origins of dog domestication for a decade or more.
Prof. WAYNE: Previous papers had suggested it was East Asia.
PALCA: But Wayne and his colleagues at the University of California, Los Angeles decided to look for themselves. First, they gathered DNA samples from more than 200 wolves.
Prof. WAYNE: We looked at wolf populations in the Middle East and Europe and East Asia, from China.
PALCA: Then they looked for what are called genetic markers that could distinguish one population from another.
Prof. WAYNE: So markers that are only found in Middle Eastern wolves and only found in Chinese wolves.
PALCA: Then he analyzed the DNA of more than 900 dogs from 85 breeds, and looked to see which wolf populations were most closely related to which dogs. Some dogs, like the Chinese shar-pei and the chow chow, were most similar to East Asian wolves, and some were closer to European wolves. But there was one wolf population that stood out.
Prof. WAYNE: Many wolf populations may have contributed to the genomic diversity of dogs, but the dominant signal comes from the Middle East.
PALCA: And that suggests it was the Middle East where dogs were first domesticated. Wayne's results appear in the journal Nature.
Tamar Dayan is a zoologist at Tel Aviv University in Israel.
Professor TAMAR DAYAN (Tel Aviv University): I can't say that I'm surprised by the results. I would have been surprised if they were different.
PALCA: She says Wayne's genetic data fits with the archeological data. Dayan says dog skeletons 12,000 or 13,000 years old have been found in what is now northern Israel.
Prof. DAYAN: They're found in burials with humans in a very clear human context.
PALCA: Of course, if humans hadn't domesticated wolves, Groucho Marx would've been denied this famous line: Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read.
Joe Palca, NPR News, Washington. Transcript provided by NPR, Copyright National Public Radio.
