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科学美国人60秒 SSS Cold Snap Shapes Lizard Survivors

时间:2017-08-21 09:24:33

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(单词翻译)

Cold Snap Shapes Lizard1 Survivors2

南方寒潮中的幸存者后来都怎样了

In January 2014, an epic3 cold wave swept across the southeast—a "snowpocalypse" so severe that thousands of drivers in Atlanta abandoned their cars on icy highways and Interstates.

2014年1月,一场史诗般的寒潮席卷了整个东南地区——严重到堪称“末日暴雪”,以至于亚特兰大数千名司机在结冰的高速公路和州际公路上弃车而去。

"And I'm from the south, I was raised in South Carolina, and I can tell you that in the South we do not do cold—at all."

“我来自南方,我是在南卡罗来纳长大的,我可以告诉你,在南方我们从来没冷过——一点都没有。”

\Shane Campbell-Staton was watching it all unfold from Harvard, where he was getting his PhD. He'd just wrapped up his last field season in Texas, studying the green anole lizard. And as he was scanning photos of the storm, he came across something unexpected: a photo that included his research subject.

肖恩·坎贝尔·斯塔顿在哈佛看到了这些资料,他也是在这里拿到了博士学位。肖恩刚刚结束了在德克萨斯州野外对绿色变色龙蜥蜴的研究课题。他在扫描那次风暴的照片时,偶然发现了意想不到的状况:一张照片中竟然出现了他的研究课题。

"There was this one picture of a green anole that was upside down, dead in the snow. And it was sort of a Eureka moment. And I thought to myself, well maybe I should go back out and see if these populations I'd been studying, if they showed any sort of response to this pretty extreme weather event in the south."

“有一张照片中出现了一只颠倒的、死在雪地里的绿变色蜥。那一刻有种终于找到某物想欢呼的感觉。我当时想,也许我应该回去看看我一直在研究的这个群体,看看它们对这次南方的极端天气事件是否有何反应。”

And so that's what he did. Because here's the bit of serendipity4: he'd actually been studying the cold tolerance5 of different populations of these lizards6. And the cold snap had just delivered the perfect experiment—a chance to see natural selection in action.

然后他就那样做了。这次研究有点意外收获的意思:实际上,他一直在研究这种蜥蜴中不同种群的耐寒性。而这次寒流恰巧做了一次完美的实验——一个看到自然选择发生作用的机会。

"So I went back in April right after these winter storms had subsided7. And I noticed that in the south, the southernmost population, the survivors of the storm were able to maintain function at significantly colder temperatures than the population before the storm. And this ability to maintain function at colder temperatures is something we typically see much farther north."

“因此,4月份当这些冬季风暴消退之后,我就立刻回到那里去了。我注意到,在南部最南端的种群中,与风暴来临之前相比,经历过风暴的幸存者能够在温度显著降低的环境中维持其功能。而这种在更冷的温度下保持功能的能力,我们通常只在更偏北的种群中见到。”

He did genetic9 analyses too: and found that the genes10 switched on in the surviving southern lizards overlapped11 with genes more typically turned on in their cold-hardy northern cousins. And the survivors also carried variations in their DNA12 that more closely matched northern lizards. So three things: cold tolerance, gene8 expression, and even the gene variants13 the southerners carried, suggested this winter storm had indeed caused selection on the southern lizards. The analysis is in the journal Science.

他还做了基因分析:他发现,在幸存的南方蜥蜴身上开启的基因与更典型的表现在抗寒能力更强的北方蜥蜴身上的基因一致。而且,幸存的南方蜥蜴还携带了更接近北方蜥蜴基因的基因变异。因此,耐寒性、基因表达、甚至是南方蜥蜴携带的基因变体——这三种表现,表明这场冬季风暴确实导致南方蜥蜴做出了自然选择。这项分析报告发表在《科学》杂志上。

Campbell-Staton, now at the University of Illinois and the University of Montana, is quick to mention that this isn't quite evolution yet. It's just one generation—he hasn't yet seen these traits passed down to another set of lizards. That's his next investigation14.

目前在伊利诺伊大学和蒙大拿大学的坎贝尔·斯塔顿很快就指出,这还不算是进化。这种变化只表现在一代蜥蜴身上——他还没有看到这些特征被传到另一代蜥蜴身上。而这将是他的下一个研究项目。

As for whether this is a good thing, the fact that some lizards were able to summon the ability to survive cold? "The answer is both yes and no potentially." Yes, because if another cold wave rolls through, the surviving southern population will be better prepared—more cold-tolerant.

至于一些蜥蜴拥有了能够在寒冷环境中生存下来的能力,这是不是一件好事?“答案既有可能是肯定的,也有可能是否定的。”是的,因为如果再发生一次寒潮侵袭,幸存下来的南方蜥蜴将做好更好的防御——因为耐寒性更强了。

But: "We know that selection comes at a cost. Which is death. So the individuals that died during this event may have had genetic variants that would have allowed them to survive a heat wave, or a drought, or some other extreme event. And now those lineages are essentially15 gone."

但是:“我们知道自然选择是要付出代价的,即死亡。因此,在这次事件中死亡的那些个体可能携带一些能使它们在热浪、干旱或其他极端事件中生存下来的遗传变体。而现在这些血统基本上消失了。”

The long term forecast for the 21st century includes more of these extreme events—and more severe ones at that. So species that lose their genetic Swiss army knife of adaptive tools may, again, be left out in the cold.

对21世纪的长期预测中包含了更多的这些极端事件——而且其中还有更为严重的。因此,那些失去了基因中的“瑞士军刀”自适应工具的物种,可能会再次在寒冷的环境中被抛弃。


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点击收听单词发音收听单词发音  

1 lizard P0Ex0     
n.蜥蜴,壁虎
参考例句:
  • A chameleon is a kind of lizard.变色龙是一种蜥蜴。
  • The lizard darted out its tongue at the insect.蜥蜴伸出舌头去吃小昆虫。
2 survivors 02ddbdca4c6dba0b46d9d823ed2b4b62     
幸存者,残存者,生还者( survivor的名词复数 )
参考例句:
  • The survivors were adrift in a lifeboat for six days. 幸存者在救生艇上漂流了六天。
  • survivors clinging to a raft 紧紧抓住救生筏的幸存者
3 epic ui5zz     
n.史诗,叙事诗;adj.史诗般的,壮丽的
参考例句:
  • I gave up my epic and wrote this little tale instead.我放弃了写叙事诗,而写了这个小故事。
  • They held a banquet of epic proportions.他们举行了盛大的宴会。
4 serendipity jDyzZ     
n.偶然发现物品之才能;意外新发现
参考例句:
  • "It was serendipity all the way,"he says.用他的话说是“一直都很走运”。
  • Some of the best effects in my garden have been the result of serendipity.我园子里最珍贵的几件物品是机缘巧合之下意外所得。
5 tolerance Lnswz     
n.宽容;容忍,忍受;耐药力;公差
参考例句:
  • Tolerance is one of his strengths.宽容是他的一个优点。
  • Human beings have limited tolerance of noise.人类对噪音的忍耐力有限。
6 lizards 9e3fa64f20794483b9c33d06297dcbfb     
n.蜥蜴( lizard的名词复数 )
参考例句:
  • Nothing lives in Pompeii except crickets and beetles and lizards. 在庞培城里除了蟋蟀、甲壳虫和蜥蜴外,没有别的生物。 来自辞典例句
  • Can lizards reproduce their tails? 蜥蜴的尾巴断了以后能再生吗? 来自辞典例句
7 subsided 1bda21cef31764468020a8c83598cc0d     
v.(土地)下陷(因在地下采矿)( subside的过去式和过去分词 );减弱;下降至较低或正常水平;一下子坐在椅子等上
参考例句:
  • After the heavy rains part of the road subsided. 大雨过后,部分公路塌陷了。 来自《简明英汉词典》
  • By evening the storm had subsided and all was quiet again. 傍晚, 暴风雨已经过去,四周开始沉寂下来。 来自《现代汉英综合大词典》
8 gene WgKxx     
n.遗传因子,基因
参考例句:
  • A single gene may have many effects.单一基因可能具有很多种效应。
  • The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。
9 genetic PgIxp     
adj.遗传的,遗传学的
参考例句:
  • It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
  • Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
10 genes 01914f8eac35d7e14afa065217edd8c0     
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
11 overlapped f19155784c00c0c252a8b4dba353c5b8     
_adj.重叠的v.部分重叠( overlap的过去式和过去分词 );(物体)部份重叠;交叠;(时间上)部份重叠
参考例句:
  • His visit and mine overlapped. 他的访问期与我的访问期有几天重叠。 来自《现代汉英综合大词典》
  • Our visits to the town overlapped. 我们彼此都恰巧到那小城观光。 来自辞典例句
12 DNA 4u3z1l     
(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。
13 variants 796e0e5ff8114b13b2e23cde9d3c6904     
n.变体( variant的名词复数 );变种;变型;(词等的)变体
参考例句:
  • Those variants will be preserved in the'struggle for existence". 这些变异将在“生存竞争”中被保留下来。 来自辞典例句
  • Like organisms, viruses have variants, generally called strains. 与其他生物一样,病毒也有变种,一般称之为株系。 来自辞典例句
14 investigation MRKzq     
n.调查,调查研究
参考例句:
  • In an investigation,a new fact became known, which told against him.在调查中新发现了一件对他不利的事实。
  • He drew the conclusion by building on his own investigation.他根据自己的调查研究作出结论。
15 essentially nntxw     
adv.本质上,实质上,基本上
参考例句:
  • Really great men are essentially modest.真正的伟人大都很谦虚。
  • She is an essentially selfish person.她本质上是个自私自利的人。

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