【Phat Yeti出品】60-SECOND SCIENCE 官方听力文稿 + 讨论帖 （更新至：2008.03.07）

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Invading Ants Go On Diet

If you’re an invading, meat-eating Argentinian ant, and you run out of prey, there’s only one thing to do if you want to keep invading—become a vegetarian. And that’s just what the carnivorous Argentinian ants that have invaded California did.  They switched and began to eat vegetable matter.  No, these two-millimeter long critters didn’t develop moral qualms about eating meat and they aren’t trying to save the planet.  They just ran out of their first choice, native ants.  Researchers writing in the Proceedings of the National Academy of Sciences say that these ants gobbled up the native ants, which can be ten times their size. The newcomers then had no choice but to carbo-load, switching over to such sweet treats as honeydew nectar produced by aphids. The ants, which are believed to have arrived in California on ships carrying coffee and sugar from Argentina in the 1890s, have caused problems for big creatures as well. The coastal horned lizard, which dined on domestic ants, has declined in numbers by about half recently.  Apparently because the lizard doesn’t particularly care for Argentinian food.

[ 本帖最后由 豆豆～ 于 2008-1-9 14:16 编辑 ]

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发了先
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很喜欢这个节目

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LS强......注册这么长时间居然是第一帖?ORZ......:eek:

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潜水王子

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Founder Mutations Stay In The Family

Some genes that contribute to diseases can be traced back to what’s known as a founder mutation. It’s the first instance of that specific mutation, which then gets carried by all subsequent generations. Mutations in one specific gene are known to give carriers a 69 percent greater risk of colon cancer by the age of 80.  But it can be tough to figure out who has it.  Luckily the Mormon church keeps great family records.

Researchers at the University of Utah were able to figure out that this mutation occurred in only two extended families, one in Utah and one in New York. So they suspected that somewhere in history lurked a founder. They used colonoscopy information, genetic analysis of family members, and genealogical data and Mormon archives to trace the mutation all the way back to one couple.  When Mr. And Mrs. George Fry came to America from England in about 1630 they had no idea that they were bringing along the colon cancer risk gene.  Fortunately, the Frys’ hundreds of 21st century descendants can be monitored and treated at the first sign of the disease.

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