for National Geographic News
As every dog-lover knows, canines can sense a meal a mile away. Now, scientific findings suggest that dogs' chow-time cunning could be the oldest trick in the bookand one the animals mastered on their own.
The ability to find hidden food by reading cues in humans' gestures may be precisely what separated the earliest domesticated dogs from their wild kin, according to Brian Hare.
"If you can figure out how to [find food while] stay[ing] out of the humans' way, you can more successfully get garbage out of the heap," Hare said. By "you," of course, he means an ancient dog-wolf, looking to freeload off the throwaway scraps of people living nearby. Domesticated dogs arose from wolves that somehow became accustomed to living among people.
Hare, a graduate student at Harvard University and a researcher for the Max Planck Institute in Germany, and colleagues conducted a series of experiments that tested the cue-reading abilities of dogs, wolves, and chimpanzees. In each test, an animal was allowed to enter a room after food had been concealed inside one of two identical opaque containers. The only clue the animals got as to the hidden meal's whereabouts came from a human experimenter in the room, who stared at, pointed at, or tapped one of the containers.
One could be excused for expecting chimps, as humans' closest animal relatives, to perform best. In fact, dogs consistently outperformed both chimps and their own closest relatives, wolves, regardless of which clues the experimenters provided.
Born To Be Tame?
Interestingly, even young, kennel-reared dogs with little past experience of people displayed this unusual perceptiveness toward human gestures.
At first, said Hare, "we assumed they were learning. It turned out young dogs could do it just as well." That suggests the dogs' ability is inborn, not learned, Hare said.
Now "we're trying to figure out the origin of this ability," he continued. "It's not enough just to say it occurred during domestication."
He speculates that dogs' understanding of human gestures may have evolved thanks to natural selection. Thousands of years ago, semi-wild wolves that could figure out where food was by watching humans gesture to each other might have obtained more food than gesture-illiterate pack mates.
Such selection pressure could have made it "important for dogs to adapt to human societies," said Peter Savolainen, a biologist at the Royal Institute of Technology in Stockholm, Sweden. "There should have been some sort of behavioral evolution."
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