纪录片《狗狗秘闻》 12狗和灰狼相似

Until the advent¹ of molecular² genetics,

在分子遗传学出现前

archaeology³ had few firm answers.

考古学对很多问题都给不出确定的答案

All you have to play with are the bones

你能够做的只有研究动物的骨头

and so when you look at the bones, if you don't have

因此当你观察那些骨头的时候

a very small flat-faced round-headed pug in

如果考古学中没有出现过

the archaeological record,

扁脸圆头哈巴狗的化石

you don't know where that came from.

你就不知道它从何而来

Those are questions that

那些问题在遗传学出现之前

before genetics you really couldn't answer.

真的是难以回答的

To unravel⁴ the evolutionary⁵ origins of dogs,

为了发现犬类的进化原型

molecular Geneticists compared DNA⁶

分子遗传学家比对了

from dogs with that of their wild relatives.

狗与其野生亲属的DNA

Specifically, they looked at mitochondrial dna sequences

他们目标明确的着手于线粒体的DNA顺序

Which are passed unchanged down the maternal⁷ line.

这些DNA完全遗传于母系

What's so useful for scientists

随着时间的推移线粒体DNA只改变了

is that mitochondrial DNA changes little over time

很小一部分 这对科学家来说非常有用

And so acts as a kind of signature

这就如同一个签名

left by an animal's ancestors.

遗传自某类动物的祖先

Those markers in domestic dogs show them to be much more

从这些家狗的线粒体DNA中可以发现

closely related to grey wolves

和其他物种对比

than they are to any other species.

他们与灰狼的基因更加相似

There's no admixture

这里没有任何的基因的糅合

so we never see a mitochondrial signature of saying

我们从未在家狗身上发现任何存在于

An african wild dog, jackal or coyote in a domestic dog.

非洲野狗 豺 山狗身上的线粒体DNA

Of thousands upon thousands of mitochondrial DNA

在成千上万的线粒体DNA中

that has been extracted from domestic dogs,

那些从驯养狗身上萃取下来的DNA

every single one of them just looks just like a grey wolf.

每一部分都与灰狼的DNA非常接近

1 advent   

n.(重要事件等的)到来，来临

参考例句：

• Swallows come by groups at the advent of spring. 春天来临时燕子成群飞来。
• The advent of the Euro will redefine Europe.欧元的出现将重新定义欧洲。

2 molecular   

adj.分子的；克分子的

参考例句：

• The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
• For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。

3 archaeology   

n.考古学

参考例句：

• She teaches archaeology at the university.她在大学里教考古学。
• He displayed interest in archaeology.他对考古学有兴趣。

4 unravel   

v.弄清楚（秘密）；拆开，解开，松开

参考例句：

• He was good with his hands and could unravel a knot or untangle yarn that others wouldn't even attempt.他的手很灵巧，其他人甚至都不敢尝试的一些难解的绳结或缠在一起的纱线，他都能解开。
• This is the attitude that led him to unravel a mystery that long puzzled Chinese historians.正是这种态度使他解决了长期以来使中国历史学家们大惑不解的谜。

5 evolutionary   

adj.进化的；演化的，演变的；[生]进化论的

参考例句：

• Life has its own evolutionary process.生命有其自身的进化过程。
• These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。

6 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。

7 maternal   

adj.母亲的，母亲般的，母系的，母方的

参考例句：

• He is my maternal uncle.他是我舅舅。
• The sight of the hopeless little boy aroused her maternal instincts.那个绝望的小男孩的模样唤起了她的母性。