英语听力文摘 驯化狐狸
你与猫或狗玩耍过吗?在远古，狗对我们的祖先来说还是一种比较危险的动物呢。那么，现在为什么它们这么听话?我们的祖先又是如何驯化它们的呢?今天，就让我们一起听听研究人员是怎样驯化狐狸的吧。
Have you ever played with a dog or cat and wondered why they are so tame? How did our ancient ancestors take wild, and potentially dangerous, carnivores and turn them into “man’s best friend”?
In 1959 a Russian geneticist name Dmitry Belyaev began an experiment to try and understand how domestication worked. He started by selecting 130 of the captive wild foxes from a nearby fur farm that showed the least amount of fear and aggression towards humans.
With each successive generation he selected which foxes would breed based solely on tameness. Only the foxes that behaved in the friendliest and tamest manner towards humans were selected to breed.
Amazingly, after only ten years of selected breeding, the team had developed a strain of foxes with dog like tameness towards humans: tail wagging, face licking, playful friendliness. But that’s not all. Although the scientists always selected foxes based only on behavior, the tame foxes have several other traits that differentiate them from wild foxes.
Traits including: white patches of fur on the face, the loss of the fox’s strong musky odor, wagging tails that curl up over the back, drooping ears and dog like barks and whines.
Interestingly, many of these are traits that Darwin noted in the Origin of Species as being common among most domesticated animals.
Now in the 50th year, the research is ongoing. The project’s long term goals are not just to understand the process of domestication, but to identify the genes that influence tame and aggressive behaviors.
The team also hopes that defining the genes important to friendly, outgoing and social behaviors in foxes, might someday lead to genetic discoveries that may help treat or prevent autism and other human neurological disorders in which social reciprocity is impaired.
