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Going to the Dogs
Some scientists acquired their fascination with dogs directly, but Hare's grew out of his research on chimpanzee cognition in the late 1990s, when he was part of a team of primatologists led by Michael Tomasello, now at Max Planck. A chimp can follow the gaze of other chimps and figure out what they can and cannot see. That's a skill that seems to be limited to great apes and humans. Tomasello and his team wondered if such a rare ability extended to hand gestures and tested chimps to see if they could understand pointing. To their surprise, the chimps did badly, able to learn the meaning of a pointed finger only after lots of training.
The apparent explanation for these results was that pointing--and the social smarts behind it--required a humans-only level of intelligence and evolved in our ancestors only after they branched off from the ancestors of chimpanzees some 7 million years ago. When Tomasello suggested this idea to Hare, however, Hare demurred. "I said, 'Um, Mike, I think my dogs can do that,'" Hare recalls.
Hare's later research revealed that while chimps and even wolves lack an innate ability to understand what pointing means, dogs come by the knowledge naturally. They're not limited to reading hands and fingers alone. Dogs understand what Hare means if he points with his foot or sets a piece of wood on top of a container with food inside. Even puppies understand, which means it can't be a skill they need to learn. "This is something that dogs just do," says Hare.
To understand how dogs evolved this skill, Hare traveled to Siberia. In the 1950s, Soviet scientists set up an experiment on a farm outside the city of Novosibirsk to understand how animals were domesticated. They decided to study foxes, which are closely related to wolves and dogs.
The Russians began by breeding a group of foxes according to one simple rule: they would walk up to a cage and put a hand on the bars. Foxes that slunk back in fear and snapped their teeth didn't get to breed. Ones that came up to the scientists did. Meanwhile, the scientists also raised a separate group of foxes under identical conditions, except for one difference: they didn't have to pass a test to mate.
More than 40 generations of foxes have now been bred in Novosibirsk, and the results speak for themselves. The foxes that the scientists bred selectively have become remarkably doglike. They will affectionately run up to people and even wag their tails. In 2003, Hare traveled to Novosibirsk and ran his pointing test on baby foxes. The ordinary ones failed miserably. As for the doglike ones, "they did just as well as puppies right out of the box," Hare says. As the animals were bred for their affability, a new side of their social intelligence was apparently awakened.
If foxes are a guide, dog evolution may have begun with a similar shift in personality. Ancestors of dogs could cooperate to hunt, but the cooperation had limits. Wolves are fiercely competitive, as each one tries to claw its way to the top of the pack. Hare proposes that aggressive wolves evolved to have an easygoing personality thanks to a new opportunity: trash.