2018年经济学人 进化生物学:古人类异血缘交配的证据 (1)

 

Set aside romantic sentiment. Sex is a biological insurance policy.

除了浪漫调情，性也是一份生物保险单。

By chaotically¹ mixing their genetic² information, animals generate extraordinary diversity.

通过将基因信息杂乱混合，动物繁衍出了特别的多样性。

In general, the more different the genomes of the partners are,

总的来说，伴侣的基因组差异越大，

the greater the diversity in their offspring and the more likely it is that some of the combinations will survive.

他们后代的多样性越大，这样的杂交结合也越有可能存活下来。

Early humans had no inkling of evolutionary³ theory.

早期人类并不知晓进化论。

But the discovery of a teenage girl with a Neanderthal mother and a Denisovan father shows they were happily participating in the practice.

但是一位少女（她的母亲是尼安德特人，父亲是丹尼索瓦人）的发现表明早期人类愉快地参与到了进化论的实践中。

A team led by Viviane Slon and Svante Paabo of the Max Planck Institute for Evolutionary Anthropology⁴, in Leipzig, Germany,

由德国莱比锡城马普进化人类学研究所的维维亚娜·斯隆和斯凡特·派伯领导的团队

carried out genetic analysis on a fragment of bone, more than 50,000 years old, found in a cave in Russia.

对在俄罗斯一处洞穴中发现的五万多年前的一块骨头碎片进行了遗传分析。

It came from a girl, aged⁵ about13, who seemed to belong to the Denisovans,

这块骨头碎片来自于一个年纪约13岁的女孩，她似乎是丹尼索瓦人，

a poorly understood cousin of modern humans who evolved in Eurasia around 390,000 years ago

现代人类的表亲，进化于约39万年前的欧亚大陆，

and then were driven into extinction⁶ some 40,000 years ago.

然后在约4万年前被迫灭绝，人类对这一族系知之甚少。

An analysis of a Denisovan fossil carried out in 2013 revealed that their genes⁷ differed substantially from those of modern-day humans.

2013年对一块丹尼索瓦人化石的分析表明他们的基因和现代人类的基因有着本质上的区别。

Yet what really surprised researchers at the time was the discovery of a little Neanderthal DNA⁸ mixed in.

但那时真正让研究人员惊讶的是他们在其中发现了一些尼安德特人的DNA。

Neanderthals are known to have successfully mated with humans

尼安德特人已经和人类进行了成功的交配

because they permanently⁹ inserted some of their DNA into the human genome.

因为他们将自己的的一些DNA永久地嵌入到了人类基因组中。

The discovery that the genetically¹⁰ distinct Neanderthals and Denisovans had also reproduced with one another

基因差异明显的尼安德塔人和尼安德特人相结合产生了后代

raised the question of whether their interbreeding had been a regular affair.

这一发现也引出了一个问题：他们这种异血缘交配是常态么。

The results of the new study, published this week in Nature, show that,

本周发表于《自然》杂志上的新研究结果表明

instead of having just a little Neanderthal DNA mixed in with lots of Denisovan DNA,

这个少女的基因中并不仅是少量尼安德塔DNA和大量尼安德特人DNA的掺杂，

the girl's remains¹¹ contain a much more balanced split: 38.6% of the DNA fragments matched versions of genes

她的遗骸中含有很多其他平衡分裂：在她的DNA碎片中，38.6%显然是属于尼安德特人基因组，

that clearly belong to the Neanderthal genome, and 42.3% to the Denisovan one. There was no clear match for the remainder.

42.3%属于尼安德特基因组。剩下的基因版本尚未得到匹配。

1 chaotically   

参考例句：

• His thoughts churned chaotically in his brain like snowflakes whirling about in the north wind. 头脑里，情思弥漫纷乱像个北风飘雪片的天空。 来自汉英文学 - 围城
• In metal the atoms are arranged not chaotically but in even rows, forming a crystal lattice. 在金属里，原子并不是杂乱无章地排列而是排成平整的行列，构成一个晶格。 来自辞典例句

2 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。

3 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。

4 anthropology   

n.人类学

参考例句：

• I believe he has started reading up anthropology.我相信他已开始深入研究人类学。
• Social anthropology is centrally concerned with the diversity of culture.社会人类学主要关于文化多样性。

5 aged   

adj.年老的，陈年的

参考例句：

• He had put on weight and aged a little.他胖了，也老点了。
• He is aged,but his memory is still good.他已年老，然而记忆力还好。

6 extinction   

n.熄灭，消亡，消灭，灭绝，绝种

参考例句：

• The plant is now in danger of extinction.这种植物现在有绝种的危险。
• The island's way of life is doomed to extinction.这个岛上的生活方式注定要消失。

7 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

8 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。

9 permanently   

adv.永恒地，永久地，固定不变地

参考例句：

• The accident left him permanently scarred.那次事故给他留下了永久的伤疤。
• The ship is now permanently moored on the Thames in London.该船现在永久地停泊在伦敦泰晤士河边。

10 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

11 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。