字神帝國英語天地

今日主題：Ancient Human DNA Found in Cave Dirt / 獲取DNA新途徑

洪欣老師推薦：托福聽力最好的課外教材：60-Second Science
康康精選托福會考的主題，堅持每天精聽一定會進步的哦!!

建議方法：
1. 先聽兩三遍 (不看文稿)
2. 再一句一句聽寫 (每句都要聽寫數遍，直到寫出85%以上的字)
3. 最後check文稿，看哪聽不出來，單字沒背過，還是發音不熟。
4. 堅持天天聽，就能每天進步哦。

MP3音檔 (按右鍵可下載聽)：喜歡的同學，幫忙推或按讚哦~~
http://online1.tingclass.net/voaspe/2017/20170501sa_tech.mp3

只有音檔怎夠，聽不懂地方，不用怕，
康康幫你準備好中英文稿了：

中英文稿：
Fossilized skulls 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: analyze cave floors to see if it contains any DNA.
在歐洲洞穴發現的頭骨和骨骼化石讓我們第一次瞭解到我們古代的表親尼安德特人.在西伯利亞一個洞穴發現的手指骨,也首次證實了我們另一個親屬丹尼索亞人的存在.但是,化石很難得到.另一種辦法就是分析洞穴層中含有的DNA。

"We find ancient hominins, we find Neandertal mitochondrial DNA, and Denisovan mitochondrial DNA."
“我們發現古人類,發現穴居人的線粒體DNA,和丹尼索瓦人的線粒體DNA。”

Viviane Slon, a geneticist at the Max Planck Institute in Germany.
Viviane Slon,德國馬克斯普朗克研究所的遺傳學家。

She and her team found that molecular evidence by testing teaspoonfuls of sediment from seven different caves. And they screened specifically for mitochondrial DNA—because there's a lot more copies of it in cells compared to nucleus DNA, which has just one set per cell.
她和團隊們,通過檢測7個不同洞穴中的少量沉積物發現了分子證據.他們專門檢測了線粒體DNA——因為與核DNA(每個細胞中僅有一個核DNA)相比，細胞中有多份線粒體DNA。

The researchers uncovered genetic 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.
研究人員在西伯利亞的丹妮索瓦洞中發現了期望中的丹妮索瓦人的基因證據。基因顯示，他們的策略是正確的。因為在那裡也發現了尼安德特人的DNA，在7個洞穴中其他三個洞穴裡——其中有一個洞穴中沒有發現任何尼安德特人的DNA，只發現了工藝品和動物骨骼。

And they found the DNA of some surprise guests, too: "The woolly mammoth, or the woolly rhino. We have cave hyenas and cave bears." The study is in the journal Science.
研究人員還發現了一些意外客人的DNA：長毛象，長毛犀。還有洞穴鬣狗和洞穴熊。該研究結果發表在《科學》雜誌上。

This preliminary success, Slon says, means the method could be a good complement 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 census of our ancient relatives. No bones about it.
Slon 表示，初步的成功意味著這種方法是對傳統檢測方法很好的補充。“我們並不是要取代對化石中古代DNA的研究，”而是要打開基因分析顯示沒有原始人類化石的考古遺址。”希望，這將引領對古代親戚的更廣泛的普查。這一點毫無疑問。