手机APP下载

您现在的位置: 首页 > 在线广播 > 科学美国人 > 科学美国人科学系列 > 正文

科学美国人60秒:基因突变使早期人类获得优势

来源:可可英语 编辑:aimee   可可英语APP下载 |  可可官方微信:ikekenet
 下载MP3到电脑  批量下载MP3和LRC到手机
加载中..
.z8V9X4%8^RzO

urOcaY1t[)-50lz@Fv

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.

K#b2cL#fY%

跑步.jpg
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.

Lc)BPj.PtRO*d

&SGJjLCvAZ0OPx(.

k#c6~-NG]uX~R3@Dbx#).!2*9Ft6[]gL8BLdk!DorwhH

重点单词   查看全部解释    
stupidity [stju:'piditi]

想一想再看

n. 愚蠢

 
endurance [in'djuərəns]

想一想再看

n. 忍耐,忍耐力,耐性

联想记忆
mutation [mju:'teiʃən]

想一想再看

n. 变化,转变,母音变化

 
cell [sel]

想一想再看

n. 细胞,电池,小组,小房间,单人牢房,(蜂房的)巢室

 
fur [fə:]

想一想再看

n. 毛皮,软毛,皮衣,毛皮制品
vt. 用毛

 
delivery [di'livəri]

想一想再看

n. 递送,交付,分娩

 
decorate ['dekəreit]

想一想再看

vt. 装饰,装修,授予某人奖章或其他奖状

 
tiring ['taiəriŋ]

想一想再看

adj. 令人疲倦的,麻烦的

 
solution [sə'lu:ʃən]

想一想再看

n. 解答,解决办法,溶解,溶液

联想记忆
prone [prəun]

想一想再看

adj. 俯卧的,易于 ... 的,有 ... 倾向的

联想记忆

发布评论我来说2句

    最新文章

    可可英语官方微信(微信号:ikekenet)

    每天向大家推送短小精悍的英语学习资料.

    添加方式1.扫描上方可可官方微信二维码。
    添加方式2.搜索微信号ikekenet添加即可。