科学美国人60秒 洞穴泥土中发现的古代人类DNA

Fossilized skulls¹ and skeletons found in European caves gave us our first glimpse of our ancient cousins, the Neandertals. And a finger bone, found in a Siberian cave, first indicated the existence of another relative—the Denisovans. But fossils are hard to come by. So here's another option: analyze² cave floors to see if it contains any DNA³.

在欧洲洞穴发现的头骨和骨骼化石让我们第一次了解到我们古代的表亲尼安德特人.在西伯利亚一个洞穴发现的手指骨,也首次证实了我们另一个亲属丹尼索亚人的存在.但是,化石很难得到.另一种办法就是分析洞穴层中含有的DNA.

"We find ancient hominins, we find Neandertal mitochondrial DNA, and Denisovan mitochondrial DNA."

“我们发现古人类,发现穴居人的线粒体DNA,和丹尼索瓦人的线粒体DNA。”

Viviane Slon, a geneticist at the Max Planck Institute in Germany.

Viviane Slon,德国马克斯普朗克研究所的遗传学家。

She and her team found that molecular⁵ evidence by testing teaspoonfuls of sediment⁶ from seven different caves. And they screened specifically for mitochondrial DNA—because there's a lot more copies of it in cells compared to nucleus⁷ DNA, which has just one set per cell.

她和团队们,通过检测7个不同洞穴中的少量沉积物发现了分子证据.他们专门检测了线粒体DNA——因为与核DNA(每个细胞中仅有一个核DNA)相比，细胞中有多份线粒体DNA。

The researchers uncovered genetic⁴ evidence of Denisovans where you might expect—at Denisova Cave in Siberia. Which showed that their strategy was sound. They found Neandertal DNA there too, and at three of the other seven caves—including a cave where no Neandertal fossils have ever been found, only artifacts and animal bones.

研究人员在西伯利亚的丹妮索瓦洞中发现了期望中的丹妮索瓦人的基因证据。基因显示，他们的策略是正确的。因为在那里也发现了尼安德特人的DNA，在7个洞穴中其他三个洞穴里——其中有一个洞穴中没有发现任何尼安德特人的DNA，只发现了工艺品和动物骨骼。

And they found the DNA of some surprise guests, too: "The woolly mammoth⁸, or the woolly rhino⁹. We have cave hyenas¹⁰ and cave bears." The study is in the journal Science.

研究人员还发现了一些意外客人的DNA：长毛象，长毛犀。还有洞穴鬣狗和洞穴熊。该研究结果发表在《科学》杂志上。

This preliminary success, Slon says, means the method could be a good complement¹¹ to traditional surveys. "We're not trying to replace working on ancient DNA from fossils, but rather open all the archaeological sites where there are no hominid fossils for genetic analyses." Leading, hopefully, to a broader census¹² of our ancient relatives. No bones about it.

Slon 表示，初步的成功意味着这种方法是对传统检测方法很好的补充。“我们并不是要取代对化石中古代DNA的研究，”而是要打开基因分析显示没有原始人类化石的考古遗址。”希望，这将引领对古代亲戚的更广泛的普查。这一点毫无疑问。

1 skulls   

颅骨( skull的名词复数 )； 脑袋； 脑子； 脑瓜

参考例句：

• One of the women's skulls found exceeds in capacity that of the average man of today. 现已发现的女性颅骨中，其中有一个的脑容量超过了今天的普通男子。
• We could make a whole plain white with skulls in the moonlight! 我们便能令月光下的平原变白，遍布白色的骷髅！

2 analyze   

vt.分析，解析 (=analyse)

参考例句：

• We should analyze the cause and effect of this event.我们应该分析这场事变的因果。
• The teacher tried to analyze the cause of our failure.老师设法分析我们失败的原因。

3 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。

4 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。

5 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。

6 sediment   

n.沉淀，沉渣，沉积(物)

参考例句：

• The sediment settled and the water was clear.杂质沉淀后，水变清了。
• Sediment begins to choke the channel's opening.沉积物开始淤塞河道口。

7 nucleus   

n.核，核心，原子核

参考例句：

• These young people formed the nucleus of the club.这些年轻人成了俱乐部的核心。
• These councils would form the nucleus of a future regime.这些委员会将成为一个未来政权的核心。

8 mammoth   

n.长毛象；adj.长毛象似的，巨大的

参考例句：

• You can only undertake mammoth changes if the finances are there.资金到位的情况下方可进行重大变革。
• Building the new railroad will be a mammoth job.修建那条新铁路将是一项巨大工程。

9 rhino   

n.犀牛，钱, 现金

参考例句：

• The rhino charged headlong towards us.犀牛急速地向我们冲来。
• They have driven the rhino to the edge of extinction.他们已经令犀牛濒临灭绝。

10 hyenas   

n.鬣狗( hyena的名词复数 )

参考例句：

• These animals were the prey of hyenas. 这些动物是鬣狗的猎物。 来自辞典例句
• We detest with horror the duplicity and villainy of the murderous hyenas of Bukharinite wreckers. 我们非常憎恨布哈林那帮两面三刀、杀人破坏，干尽坏事的豺狼。 来自辞典例句

11 complement   

n.补足物，船上的定员；补语；vt.补充，补足

参考例句：

• The two suggestions complement each other.这两条建议相互补充。
• They oppose each other also complement each other.它们相辅相成。

12 census   

n.(官方的)人口调查，人口普查

参考例句：

• A census of population is taken every ten years.人口普查每10年进行一次。
• The census is taken one time every four years in our country.我国每四年一次人口普查。