雅思哥经济学人精读
原 文 译 文
Science and technology: Panda genetics
科技：熊猫遗传学
Hey dude. Give me six!
嘿，伙计。用六指击个掌吧！
Two strange mammals illuminate the process of natural selection.
两种不同的哺乳动物阐明自然选择的过程。
Convergent evolution—the arrival, independently, by different species at the same answer to a question posed by nature—is a topic of great interest to biologists. One aspect of the phenomenon which has not yet been much looked at, however, is its underlying genetics. In particular, an issue not previously addressed is how often such changes arise from similar mutations in the two convergent lines, and how often they have different genetic causes that happen to have similar effects on the organisms’ forms and functions. That has now been rectified by an examination of two creatures which, though only distantly related, share an unusual feeding habit, an unusual anatomical feature and an unusual name: panda.
趋同进化是生物学家们有着极大兴趣的话题，它是指在自然作用下，不同物种独立的共同进程。然而该现象在潜在基因方面尚未得到许多的关注，尤其是在两条趋势线中来自相似基因突变引起趋同变化的频率，以及不同基因对生物的形态功能起到相似作用的概率方面的问题，尚未得到解决。如今,通过对两种动物的研究，这一问题已得到到纠正。虽然这两种动物是远亲，但他们都具有与众不同的饮食习性、解剖特性以及一个不寻常的名字：熊猫。
The giant panda is a black and white bear. The red panda is related to weasels, raccoons and skunks. Their habitats—mountainous areas of southern China and its neighbours—overlap, but their last common ancestor lived 43m years ago. They do, though, share a limited kinship, for both are members (along with dogs, cats, hyenas, mongooses, seals and so on) of the mammalian order Carnivora. Which is curious, because both are vegetarian. More intriguing still, both subsist almost entirely on bamboo (some etymologists think their mutual name is derived from the Nepali phrase nigalyaponya, meaning “bamboo-eater”). And most curiously of all, both have a sixth digit on their forepaws—a kind of ancillarythumb derived from one of the bones of the wrist that helps them hold bamboo stalks for consumption.
大熊猫是一种黑白相间的熊。小熊猫与鼬鼠，浣熊和臭鼬有亲缘关系。他们的栖息地在华南山区及其邻近地区，在4300万年前，他们有着共同祖先。尽管如此，由于它们都是食肉目哺乳类动物（像狗，猫，鬣狗，猫鼬，海豹等），所以确实有一些相同的血缘关系。令人好奇的是它们都是食草动物。更有趣的是，它们几乎完全以竹子为食（一些词源学家认为它们的共同名字源于尼泊尔语nigalyaponya，指“食竹者”）。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 Zoology, in Beijing, and his colleagues, to wonder if the two vegetarian carnivores also shared genetic modifications that might explain those features. And, as Dr Hu observes in a paper just published in the Proceedings of the National Academy of Sciences, they do. To search for such genetic commonalities, Dr Hu and his colleagues compared the DNA of the two pandas with that of four other members of the Carnivora: polar bears (close relatives of giant pandas), ferrets(close relatives of red pandas), and tigers and dogs (close relatives of neither). If pandas share features of their DNA with each other, but not with the four comparison species, he reasoned, then it is likely that those features encode recent adaptations common to the two of them.
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。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。为了找到这样的基因共性，胡博士团队将两只熊猫的DNA与另外4种食肉目动物（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。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，他则推断很有可能这些DNA特征编码了它们两者间近代的共同特性。
Altogether, the team identified 70 genes (out of the 20,000 or so that mammals have) which sport bits of DNA that seemed to be shared. They also found ten genes which have been disabled by crippling mutations in both of the pandas, but not in the other four species. Not all of the shared genetic features obviously tied in with the shared peculiarities of pandas, but some did. These fell into three categories: genes affecting anatomy, genes affecting appetite and genes affecting the digestion and metabolism of nutrients.
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。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，而在其他四个物种中并未发现。尽管这些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。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。
精 读 解 析
P1：解释趋同进化概念以及趋同进化在熊猫（大熊猫和小熊猫）身上得到了验证
P2: 大小熊猫和鼹鼠，浣熊和臭鼬之间存在相似之处
P3: 胡一波及其同事对熊猫以及其它四种动物的DNA进行比较，以确定它们是否有相似的修饰基因。
P4: 研究发现熊猫与这些动物之间，确实有共同的DNA片段。
mammal /'mm()l/ n. 哺乳动物
【例句】
Marine mammals generally swim with the current.
海洋哺乳动物一般顺洋流方向而游。
illuminate /'l(j)umnet/ vt. 使明亮; 照亮；装饰；说明, 阐明
【例句】
The street was illuminated by streetlights.
街灯照亮了街道。
He illuminated his statement with many examples.
他用许多实例阐明自己的论点。
Convergent /kn'vd()nt/ adj. 会合的, 会聚的； 逐渐减小的; 趋同的；(思维)幅合的, 聚合的, 求同的
【短语】
convergent evolution趋同进化
【例句】
a convergent boundary.
相交的国界。
There are a number of convergent reasons for the growth of interest in pragmatics.
对语用学兴趣的提高有许多类似的原因。
underlying adj. 根本的, 基础的；含蓄的, 潜在的
【同根】
Underlie vt. 位于或存在于(某物)之下；构成…的基础(或起因); 引起
【例句】
I have no idea about the underlying meaning of this poem.
我对这首诗隐含的意义不了解。
mutation /mju'te()n/ n. 突变；变化；元音变化
【同根】
Mutate vt. & vi. (使某物)变化, 转变, 突变, 变异
【短语】
gene mutation基因突变
genetic mutation基因突变
【例句】
This mutation appears to have originated just 8,000 years ago.
该突变起源于8,000年前。
anatomical /n'tmk()l/ adj. 结构(上)的; 解剖的
【同根】
Anatomize v. 解剖,解析
anatomy n. 解剖, 解剖学
【例句】
He made careful anatomical drawings of the body.
他画了精细的人体解剖图。
rectify /'rektfa/ vt. 改正；[电]整流；[化]精馏
【短语】
rectify the economic order整顿经济秩序
rectify the market order整顿市场秩序
【例句】
I want to rectify my error before it was too late.
趁还来得及我想纠正我的错误。
overlap /v'lp/ n. 重叠；重复v. 重叠；同时发生
【例句】
there are many overlaps between the approaches.
这些方法有不少相同之处。
Tiles on the roof overlap one another.
屋顶上的瓦片相互交搭在一起。
subsist /sb'sst/ v. 存在；维持生活；供养
【同根】
subsistence n. 存活, 生存, 维生之道
subsistent adj. (独立)存在的,现存的
【短语】
subsist on靠…生存
【例句】
People in the far north subsist chiefly on fish and meat.
住在北极地方的人主要以鱼和肉为生。
He subsisted on welfare and casual labour.
他靠救济金和当临时工维持生活。
etymologist /et'mldst/ n. 语源学；语源学家
【例句】
Although Samuel Johnson was celebrated for his dictionary published in 1755, he didn't have a great reputation as an etymologist.
尽管塞缪尔约翰逊以他1755年出版的词典而出名，但他未获得作为一个语源学家而受到的尊敬。
derived from 来源于
【例句】
The word" perfume" is derived from a Latin phrase which means" through smoke" .
“香水”这个词来源于拉丁语“透过烟雾”。
vegetarian /ved'tern/ n. 吃素的人；素食主义者；食草动物adj. 素食者的
【同根】
vegetarianism n. 素食;素食主义
vegetate vi. 生长；植物似地生长；茫茫然地过日子
vegetation n. 植物(总称); 草木
【例句】
I won't forsake my vegetarian principles.
我不会放弃素食原则。
She became a strict vegetarian two years ago.
两年前她成为严格的素食主义者。
carnivore /'kɑnv/ n. 食肉动物；食虫植物
【例句】
Predators are either carnivores or omnivores.
捕食者要么是食肉动物，要么是杂食动物。
Danger in the wild comes from the carnivores.
荒野地带的危险来自食肉动物。
modification /mdf'ke()n/ n. 缓和,限制,减轻；更改,改变,修改
【同根】
modify v. 修改，修饰；更改
【例句】
The design requires considerable modification.
这个设计需要作大的修改。
The original plan had undergone fairly extensive modifications.
原计划已经作了相当大的修改。
Commonality /km'nlt/n. 共性
【同根】
Common adj. 共同的
【例句】
The explanations show a high degree of commonality in their reasoning.
这些解释在论证方面显示了高度的共性。
encode /n'kd/ vt. 编码，译码
【例句】
We should encode the message for security reasons.
为了确保安全，我们应该对信息进行编码。
disable /ds'eb()l/ vt. 使残废；使失去能力；使无资格
注：这个词中包含动词前缀dis-表示否定，如dislike，disclose等
【例句】
It's an injury that could disable somebody for life.
这种伤害可能会造成终身残疾。
cripple /'krp()l/ vt. 使跛, 受伤致残; 严重削弱, 使陷于瘫痪
【例句】
She was crippled in the car accident.
她在汽车出事时把腿伤成了残废。
peculiarity /p,kjul'rt/ n. 古怪, 怪癖; 特色, 特性
【例句】
One of the peculiarities of his is that he writes instead of talking.
他有一种怪癖, 就是用写字来代替说话。
metabolism /m'tblz()m/ n. 新陈代谢
【例句】
As people start to slim down, their resting metabolism can slow down.
当人们开始瘦下来时，他们的休息代谢可能也会变慢。
坚持就会有收获！
特别声明：以上内容(如有图片或视频亦包括在内)为自媒体平台“网易号”用户上传并发布，本平台仅提供信息存储服务。
Notice: The content above (including the pictures and videos if any) is uploaded and posted by a user of NetEase Hao, which is a social media platform and only provides information storage services.
