摘要：考研英语作为一门考研公共课，虽然大家都学了英语十几年，却仍经常有总分过线挂在英语上的情况，因此英语复习不单单是单词、做题。阅读作为考研英语的大头，仅仅做考研真题或许没法满足你的阅读量，因此帮帮之后会不定时推出一篇英文美文，这些文章都与考研英语阅读同源，多读必有好处。

　　►Homo sapiens are nowhere near the fastest runners in the animal kingdom. But what we lack in speed， we make up for in endurance. And we’re specially equipped to go the distance.

　　在动物王国里，智人的奔跑速度远不如那些跑的最快的动物。速度确实是我们的短板，但我们却以耐力弥补不足。尤其适合远距离跑动。

　　We’ve got bigger butt muscles than other primates.

　　比起其他灵长类，我们有更加强壮的臀部肌肉。

　　We lost most of our fur， too， and sprouted lots of sweat glands， to help us cool off.

　　为此，我们也失去了大部分体毛，长处了发达的汗腺，以给身体降温。

　　Scientists believe our endurance running abilities began to appear two [million] to three million years ago， around the time the genus homo came about.

　　科学家们认为，我们跑动的忍耐力出现在200万到300万年前，大概就在这个时间，智人出现了。

　　And a new study suggests that a mutation in one key gene had something to do with it.

　　新的研究表明，这种忍耐力与一次重要的基因突变相关。

　　The mutation， in what’s called the CMAH gene， altered the types of sugar molecules that decorate the surfaces of every cell in our bodies. Which in turn may have made our muscles less prone to fatigue.

　　有一种称作羟化酶（CMAH）的基因，它的突变改变了我们身体里每个细胞表面上分部的各种糖分子，反过来，这也可能使我们肌肉不易产生疲劳感。

　　Researchers have now found that mice bred with that same mutation can run longer without tiring， compared to regular mice.

　　最近，研究人员发现，和正常的老鼠相比，有同样基因突变的老鼠可以不知疲倦的跑动。

　　The mice with the gene alteration also logged more miles running on their wheels， apparently for fun.

　　这些基因改变的老鼠显然对跑动更加感兴趣，在它们实验跑动的轮子上被记录的奔跑距离更远一些。

　　And they had more capillaries in their back leg muscles—which would increase the delivery of nutrients and oxygen during endurance exercise.

　　它们后腿肌肉里的毛细血管更加密集---在持久的跑动期间，这也提高了它身体内营养和氧气的运输。

　　The complete stats are in the Proceedings of the Royal Society B.

　　完整的统计数据录入到了《英国皇家学会学报B》中。

　　It’s unclear if this small genetic tweak endows humans with the same benefits as the mice.

　　尚不清楚的是，对于这样细微的基因微调，人类是否会和老鼠一样从中受益。

　　But if it does， it could help explain how early humans got a leg up on their competitors. Or， really， two legs.

　　但如果事实的确如此的话，它就可以帮助我们弄清人类是何时在和那些奔跑的赛手比拼的时候，抬起了一条腿，或者，可以确切地说是，两条腿。

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　　帮帮提示：考研英语同源外刊美文赏读汇总

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