(单词翻译:单击)
听力文本
This is Scientific American — 60-Second Science. I'm Christopher Intagliata.
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. We've got bigger butt muscles than other primates. We lost most of our fur, too, and sprouted lots of sweat glands, to help us cool off.
Scientists believe our endurance running abilities began to appear two to three million years ago, around the time the genus homo came about. And a new study suggests that a mutation in one key gene had something to do with it.
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.
Researchers have now found that mice bred with that same mutation can run longer without tiring, compared to regular mice. The mice with the gene alteration also logged more miles running on their wheels, apparently for fun. And they had more capillaries in their back leg muscles—which would increase the delivery of nutrients and oxygen during endurance exercise.
The complete stats are in the Proceedings of the Royal Society B.
It's unclear if this small genetic tweak endows humans with the same benefits as the mice. But if it does, it could help explain how early humans got a leg up on their competitors. Or, really, two legs.
Thanks for listening for Scientific American — 60-Second Science. I'm Christopher Intagliata.
参考译文
这里是科学美国人——60秒科学
智人的速度远不及动物界跑得最快的动物 。但我们的耐力优势弥补了我们在速度上的不足 。而且我们还拥有特殊的“装备”帮助我们跑长跑 。我们的臀肌比其它灵长类动物要大 。我们还褪去了大部分皮毛,长出大量汗腺帮助我们降温 。
科学家认为我们的耐力跑能力在200万到300万年前开始产生,大约是人属出现前后 。一项新研究发现,一个关键基因的突变与此有关 。
这种被称为CMAH基因的突变,改变了附着在我们体内每个细胞表面的糖分子的类型 。这反过来可能令我们的肌肉不易疲劳 。
研究人员现在发现,与普通小鼠相比,基因突变的小鼠能跑得更久而不累 。基因突变的小鼠还在轮子上跑了更多距离,这显然是为了好玩 。它们的后腿肌肉中有更多毛细血管,这会在耐力训练中增加营养和氧气的输送 。
这项研究的完整统计数据刊登在《英国皇家学会学报:B辑》上 。
目前并不清楚这种微小的基因变异是否能使人类获得与小鼠一样的好处 。但是如果可以,那将有助于解释早期人类是如何在竞争中占据优势的 。或者,实际上是获得了压倒性的优势 。
谢谢大家收听科学美国人——60秒科学 。我是克里斯托弗·因塔利亚塔 。
译文为可可英语翻译,未经授权请勿转载!
重点讲解
重点讲解:
1. make up for 弥补;补足;
Her beauty can't make up for her stupidity.
她的美丽不能弥补她的愚蠢 。
2. cool off (使)变凉;(使)凉快下来;
Maybe he's trying to co ol off out there in the rain.
可能他是想在雨里凉快一下 。
3. come about 产生;发生;
Any possible solution to the Irish question can only come about through dialogue
任何解决爱尔兰问题的可行方案只能通过对话产生 。
4. in turn 继而;转而;反过来;
Increased production will, in turn, lead to increased profits.
增加生产会继而增加利润 。