美国科学60秒 SSS 2013-01-31_在线英语听力室_免费在线英语听力学习网站

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　　When you think about dog food, you probably picture more meet than potato. But a new study finds that unlike wolves, dog have genes¹ allow them to digest starch².

　　That evolutionary³ adaptation may help fuel domestication⁴. The report is in the journal nature.

　　Dogs and wolves hail from a common canine⁵ ancestor and though you can still see the strong resemblance, many traits distinguished⁶ two today.

　　Wolves have large teeth and skulls⁷ than dogs do.

　　And they are far less like to bring your newspaper and slippers⁸. To figure out how such difference might have evolved. Researchers compare the DNA⁹ of dozen wolves and 14 different dog breeds from Cocker Spaniels and German Shepherds.

　　And they found 36 places where dog genes stray from those of the wolf.

　　Some of these genes have to do with brain, but a surprising number help pooches process carbs.

　　That metabolic¹⁰ trick may have made it easier for dog to stomach hanging around with humans, particularly once people start farming.

　　The left over grains in the scrap¹¹ may have attracted animals that over time evolved in the ability of carbo-load, and ultimately convinced them to stay.

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1 genes
n.基因( gene的名词复数 )
参考例句：
You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。来自《简明英汉词典》 Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。来自英汉非文学 - 生命科学 - 生物技术的世纪

2 starch
n.淀粉；vt.给...上浆
参考例句：
Corn starch is used as a thickener in stews.玉米淀粉在炖煮菜肴中被用作增稠剂。 I think there's too much starch in their diet.我看是他们的饮食里淀粉太多了。

3 evolutionary
adj.进化的；演化的，演变的；[生]进化论的
参考例句：
Life has its own evolutionary process.生命有其自身的进化过程。 These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。

4 domestication
n.驯养，驯化
参考例句：
The first was the domestication of animals. 第一个阶段是驯养动物。来自《简明英汉词典》 In northwestern China, there is no evidence for endemic domestication of any animals. 在中国西北，没有任何当地动物驯化的迹象。来自辞典例句

5 canine
adj.犬的，犬科的
参考例句：
The fox is a canine animal.狐狸是犬科动物。 Herbivorous animals have very small canine teeth,or none.食草动物的犬牙很小或者没有。

6 distinguished
adj.卓越的，杰出的，著名的
参考例句：
Elephants are distinguished from other animals by their long noses.大象以其长长的鼻子显示出与其他动物的不同。 A banquet was given in honor of the distinguished guests.宴会是为了向贵宾们致敬而举行的。

7 skulls
颅骨( skull的名词复数 )；脑袋；脑子；脑瓜
参考例句：
One of the women's skulls found exceeds in capacity that of the average man of today. 现已发现的女性颅骨中，其中有一个的脑容量超过了今天的普通男子。 We could make a whole plain white with skulls in the moonlight! 我们便能令月光下的平原变白，遍布白色的骷髅！

8 slippers
n. 拖鞋
参考例句：
a pair of slippers 一双拖鞋 He kicked his slippers off and dropped on to the bed. 他踢掉了拖鞋，倒在床上。

9 DNA
(缩)deoxyribonucleic acid 脱氧核糖核酸
参考例句：
DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。 Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

10 metabolic
adj.新陈代谢的
参考例句：
Impressive metabolic alternations have been undergone during embryogenesis.在胚胎发生期间经历了深刻的代谢变化。 A number of intoxicants are associated with metabolic acidosis.许多毒性物质可引起代谢性酸中毒。

11 scrap
n.碎片；废料；v.废弃，报废
参考例句：
A man comes round regularly collecting scrap.有个男人定时来收废品。 Sell that car for scrap.把那辆汽车当残品卖了吧。