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Man's Best Friend 人类的朋友
They come in all shapes, sizes and temperaments. But scientists believe all the dogs in the world evolved from just a handful of wolves living in Asia less than 15,000 years ago. In fact, DNA test indicated 95% of all dogs living today are descendants of just three original females. Harvard anthropologist Brian Hare studies evolution and dogs.
\"To a lot of people, it seems completely obvious why dogs would be man's best friend, but if you think about the origin of dogs, it's actually a little bit of a puzzle because dogs evolved from wolves. And wolves, they are kind of terrifying predators- they are very large and people don't generally like to welcome them into their homes or have them as fireside companions.\"
It's not known exactly how or why humans domesticated the first dogs. But once tamed, people found them useful and they learned how to selectively breed for certain traits to create animals fit for specific task. Most likely, the first dogs were used for hunting and protection. Some were bred to chase down prey, others to herd livestock. Today's most popular breed, the Labrador, was originally bred by fishermen to haul nets and retrieve fish. But at some point, humans also started to breed dogs for looks and for companionship. Brian has wondered why of all domesticated animals, dogs seem closest to their owners.
\"To anyone who's interacted or, or had a dog for any amount of time knows the dogs are really good at reading your behavior and trying to figure out what you want.
So he devised a simple but striking experiment.
\"The test that we generally use is, it's, it's very simple.\"
Food is placed under one cup. The other is empty. The researcher gestures which cup has the treat by placing a block on top of it.
\"By, you know, moving my body, I'm essentially giving what, you know, a lot of people like to call social cue or signal or gesture.\"
Chimps are closest to humans genetically, but they don't get the hint.
\"And then when we did this with dogs, what we found was the exact opposite. Dogs are really, really good at using human social cues. If you point or you look at the location where the food is, the dogs, er, are really good at finding food. They're very skillful.\"
Brian thought perhaps dogs had inherited the skill from their ancestors- the wolves.
\"So we tested wolves to see if wolves share the ability with dogs, and what we found was that wolves were like the chimpanzees. \"
Somehow during the long relationship together, dogs learn how to communicate with humans.
\"Good job.\"
And they pass the skill down to each succeeding generation. It turns out puppies can understand human gestures even if they've been raised in the wild while wolves raised in captivity just don't get it. It's a unique skill that perhaps only dogs possess.
word：domesticate: tame (an animal) and keep it as a pet or for farm produce |
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发表于 2007-10-8 10:42:59
