2018年经济学人 熊猫遗传学:熊猫的远亲是谁?(2)

 

And most curiously¹ of all, both have a sixth digit² on their forepaws—a kind of ancillarythumb derived³ from one of the bones of the wrist that helps them hold bamboo stalks for consumption.

最令人惊奇的是，它们的前爪上都长有第六指，是从腕骨长出用来帮助它们在进食时拿住竹茎的辅助拇指。

These common features led Hu Yibo of the Institute of Zoology⁴, in Beijing, and his colleagues, to wonder if the two vegetarian⁵ carnivores also shared genetic⁶ modifications⁷ that might explain those features.

基于这些共同特征，北京动物研究所的胡一波和他的同事们设想，这两种食肉目食草动物是否共有一种能解释这些特征的修饰基因。

And, as Dr Hu observes in a paper just published in the Proceedings⁸ of the National Academy of Sciences, they do.

正如胡博士刚刚在《美国国家科学院院报》发表的论文中所说的，它们确实共有。

To search for such genetic commonalities, Dr Hu and his colleagues compared the DNA⁹ of the two pandas with that of four other members of the Carnivora:

为了找到这样的遗传共性，胡博士团队将两只熊猫的DNA与另外4种食肉目动物

polar bears (close relatives of giant pandas), ferrets(close relatives of red pandas), and tigers and dogs (close relatives of neither).

（北极熊（大熊猫的近亲），白鼬（小熊猫的近亲），老虎和狗（非两者近亲））的DNA进行比较。

If pandas share features of their DNA with each other, but not with the four comparison species, he reasoned,

如果熊猫们有相同的DNA特征，而四种对照物种没有熊猫所共有的DNA特征，

then it is likely that those features encode recent adaptations common to the two of them.

他则推理很有可能这些DNA特征编码了它们两者间近代的共同特性。

Altogether, the team identified 70 genes¹⁰ (out of the 20,000 or so that mammals have) which sport bits of DNA that seemed to be shared.

研究小组从哺乳动物约20000个基因中，确定了可以共有的70个DNA片段。

They also found ten genes which have been disabled by crippling mutations in both of the pandas, but not in the other four species.

他们也在两种熊猫中找到了十个因严重突变而丧失功能的基因，而其他四个物种中并未发现。

Not all of the shared genetic features obviously tied in with the shared peculiaritiesof pandas, but some did.

尽管哺乳动物共有遗传特征并不都与熊猫的特性一致，但有些确实具有一定的关系。

These fell into three categories: genes affecting anatomy¹¹, genes affecting appetite and genes affecting the digestion¹² and metabolism¹³ of nutrients¹⁴.

这分为三类：影响动物体结构的基因，影响食欲的基因和影响营养物质消化和新陈代谢的基因。

1 curiously   

adv.有求知欲地；好问地；奇特地

参考例句：

• He looked curiously at the people.他好奇地看着那些人。
• He took long stealthy strides. His hands were curiously cold.他迈着悄没声息的大步。他的双手出奇地冷。

2 digit   

n.零到九的阿拉伯数字，手指，脚趾

参考例句：

• Her telephone number differs from mine by one digit.她的电话号码和我的只差一个数字。
• Many animals have five digits.许多动物有5趾。

3 derived   

vi.起源；由来；衍生；导出v.得到( derive的过去式和过去分词 )；（从…中）得到获得；源于；（从…中）提取

参考例句：

• Many English words are derived from Latin and Greek. 英语很多词源出于拉丁文和希腊文。 来自《简明英汉词典》
• He derived his enthusiasm for literature from his father. 他对文学的爱好是受他父亲的影响。 来自《简明英汉词典》

4 zoology   

n.动物学，生态

参考例句：

• I would like to brush up my zoology.我想重新温习一下动物学。
• The library didn't stock zoology textbooks.这家图书馆没有动物学教科书。

5 vegetarian   

n.素食者；adj.素食的

参考例句：

• She got used gradually to the vegetarian diet.她逐渐习惯吃素食。
• I didn't realize you were a vegetarian.我不知道你是个素食者。

6 genetic   

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。

7 modifications   

n.缓和( modification的名词复数 )；限制；更改；改变

参考例句：

• The engine was pulled apart for modifications and then reassembled. 发动机被拆开改型，然后再组装起来。 来自《简明英汉词典》
• The original plan had undergone fairly extensive modifications. 原计划已经作了相当大的修改。 来自《简明英汉词典》

8 proceedings   

n.进程，过程，议程；诉讼(程序)；公报

参考例句：

• He was released on bail pending committal proceedings. 他交保获释正在候审。
• to initiate legal proceedings against sb 对某人提起诉讼

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 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

11 anatomy   

n.解剖学，解剖；功能，结构，组织

参考例句：

• He found out a great deal about the anatomy of animals.在动物解剖学方面，他有过许多发现。
• The hurricane's anatomy was powerful and complex.对飓风的剖析是一项庞大而复杂的工作。

12 digestion   

n.消化，吸收

参考例句：

• This kind of tea acts as an aid to digestion.这种茶可助消化。
• This food is easy of digestion.这食物容易消化。

13 metabolism   

n.新陈代谢

参考例句：

• After years of dieting,Carol's metabolism was completely out of whack.经过数年的节食，卡罗尔的新陈代谢完全紊乱了。
• All living matter undergoes a process of metabolism.生物都有新陈代谢。

14 nutrients   

n.（食品或化学品）营养物，营养品( nutrient的名词复数 )

参考例句：

• a lack of essential nutrients 基本营养的缺乏
• Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》