GAINESVILLE, Fla. — Dogs are traditionally seen as "man's best friend," but an expert on canine cognition says the origin of the species may not have been all that warm and fuzzy: Dogs could have started out as mutant wolves that rooted around in the garbage like rats.
"Those dogs are not our best friends," says Clive D.L. Wynne, who heads up Arizona State University's Canine Science Collaboratory. "They are vermin, along with other nasty things that are in the trash. But then a second phase kicks in."
Humans discovered that dogs could be very useful. And tasty, too.
Wynne, who is writing a book about canine evolution, outlined his scenario for dog domestication this week at the ScienceWriters2013 conference in Gainesville.
Rise of the mutants
His tale begins with wolves — evolutionary cousins that are so closely related to dogs that they're considered variants of the same species (Canis lupus). But here's where the tale wags in a different direction: In Wynne's view, the first dogs weren't just domesticated wolves.
"You couldn't go hunting with a wolf," said Wynne, who has studied wolf behavior as director of research at Wolf Park in Indiana. "That cannot be part of the story of domestication of the dog."
Instead, he favors the view that mutations in the wolf genome gave rise to a population that was willing to come closer to humans — say, 16 feet (5 meters) rather than the wolves' standard 650 feet (200 meters). "As paradoxical as it sounds, wolves are actually scaredy-cats," Wynne said.
Wynne noted that the dog genome shows evidence of a mutation that's linked in humans to a rare disorder known as Williams-Beuren syndrome. People who have that mutation are unusually friendly with strangers. Could the genetic change have had the same effect on mutant wolves? Wynne says he's no geneticist, but he's working with colleagues on that piece of the scientific puzzle.
He suggests that the mutants became scavengers about 15,000 years ago, hanging around human settlements and looking for yummies in the trash. That was the vermin phase of the dog's domestication. The second phase kicked in when humans started to figure out what to do with them: A dog could bark out a warning. It could be trained to help a hunter. And it could be eaten.
"It's big enough to be worth slaughtering," Wynne said. That's taboo in most parts of the world nowadays — but in some countries, ranging from South Korea to Nigeria to Switzerland, dog meat is still on the menu.
No big doggy deal
Are dogs uniquely suited for cohabitation with humans? To some extent, it's worked out that way. For example, Wynne said "dogs are every bit as effective as rifles" when it comes to hunting. He said the average hunting dog can bring in 40 pounds of meat per month — but not without a human handler.
"Dogs need the humans to complete the kill," Wynne said. "It's a beautiful symbiosis."
That doesn't mean dogs have a unique ability to read the actions and intentions of humans, Wynne said. Some experiments have indicated that dogs can figure out when humans are pointing to a hidden treat, while wolves can't. Wynne, however, pointed to research suggesting otherwise.
Brian Hare, co-director of the Duke Canine Cognition Center, said it's a healthy sign that researchers are airing their differences over dog evolution. "Anytime you have a field in its infancy, this is a great thing," he told NBC News. "It's always a little nerve-wracking when everybody agrees."
In any case, dogs haven't taken so big of an evolutionary leap from vermin to best friend that the leap can't be reversed. About 75 percent of the world's 500 million to 1 billion dogs are living as scavengers, much as their ancestors did 15,000 years ago.
"Dogs hanging out on the streets are all over the place," Wynne said.
More about the science of dogs:
Alan Boyle is NBCNews.com's science editor as well as president of the Council for the Advancement of Science Writing. CASW and the National Association of Science Writers presented the ScienceWriters2013 conference in Gainesville, in cooperation with the University of Florida. Wynne's talk was part of CASW's New Horizons in Science briefings.
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