(单词翻译:单击)
听力文本
This is Scientific American's 60-second Science, I'm Christopher Intagliata.
You're probably not too interested in what some people call ABC gum—already been chewed. But for archaeologists, such gum—as long as it's really old—is a genetic gold mine.
"It's a bit like Jurassic Park." Natalija Kashuba, a graduate student in archaeology at Uppsala University in Sweden. She's referring to that famous clip from the movie, about how Jurassic Park scientists extract blood from a mosquito trapped in amber, "and bingo, dino DNA."
Except in this case it's human DNA, and it's trapped not in amber, but in exceptionally old chewing gums found at the site of an ancient hunting and fishing village on the west coast of Sweden. The samples look just like chewed-up wads of modern-day gum. But don't think Wrigley's—this detritus is black, sticky tar distilled from birch bark. Kashuba has tasted modern-day versions and isn't eager to try it again. "Not unless I'm paid for it."
So why chew something so unpleasant? Maybe because their gum wasn't for fresh breath. "You could use it to seal your boat, or like seal your pots ... so it's an everyday-use type of substance." Many of the gums have teeth marks, too—so perhaps they chewed it to help shape it and in turn developed a habit, despite the taste, that today's tobacco chewers might relate to.
Kashuba's team extracted and sequenced DNA from the ancient gum, and they found genetic evidence of three different gum chewers—two women and a man. It's the oldest human DNA found in Scandinavia, dating to about 8,000 B.C. And because it more closely resembles the DNA of hunter-gatherers from western Europe than from eastern Europe, it also provides hints about how people ended up in what's now Sweden.
The results are in the journal Communications Biology.
The gum could still hold other clues about ancient diets or the bacteria these people had in their mouths. So given that we can learn so much from chewing gum, is it really so bad to stick it to the bottom of chairs and tables? You know, for the benefit of future archaeologists?
"No, I still think this one should not be spatted out anyplace just like that. So I think you should definitely throw it in the bin. But I won't blame these guys... who spat it out 10,000 years ago. They did a good job then."
Thanks for listening for Scientific American — 60-Second Science. I'm Christopher Intagliata.
参考译文
这里是科学美国人——60秒科学系列，我是克里斯托弗·因塔格里塔。
你可能对某些人称为ABC口香糖——嚼过的口香糖——不太感兴趣。但对考古学家来说，只要这种口香糖真的古老，那它就是“基因金矿”。
“这有点像侏罗纪公园。”瑞典乌普萨拉大学的考古学研究生娜塔利亚·卡舒巴说到。她指的是电影中那个著名片段，即侏罗纪公园的科学家如何从被困在琥珀中的蚊子身上提取血液……“太棒了，恐龙的DNA。”
不过这个案例中谈论的是人类DNA，其没有被困在琥珀中，而是意外出现在古老的口香糖中，这些口香糖是人们在瑞典西海岸一个古老渔猎村庄的遗址上发现的。样本看上去就像嚼过的一团现代口香糖。但不要以为那是箭牌口香糖——这种残余物是从桦树皮中蒸馏出来的黑色粘性焦油。卡舒巴尝过现代版的焦油，她不急于再次尝试。“除非有人付钱让我尝。”
那为什么要嚼这么难吃的东西呢？或许是因为他们的“口香糖”并不是用来清新口气的。“你可以用它来封船或封罐子，它就是一种日常使用的物质。”许多这种“口香糖”上都有牙印，也许他们咀嚼它是为了帮助其塑形，继而形成了一种习惯，尽管味道并不好，这可能是如今咀嚼烟草的人会有的习惯。
卡舒巴团队从古代“口香糖”中提取并测序了DNA，他们发现了三名不同咀嚼者的基因证据——两名女性和一名男性。这是在斯堪的纳维亚发现的最古老的人类DNA，年代可追溯到公元前8000年左右。因为相比于东欧，这种DNA与西欧捕猎-采集者的更为类似，所以它也为人类如何来到如今的瑞典提供了线索。
研究结果发表在《通讯·生物学》期刊上。
这种“口香糖”还可以提供其它线索，比如古代饮食或古代人口腔中的细菌。既然我们能从口香糖中了解到这么多信息，那把它粘在桌椅下面真的那么不好吗？为了未来古老学家的利益？
“我仍然认为不应该随地乱吐口香糖。我认为绝对应该将它扔进垃圾桶。但我不会责怪一万年前吐口香糖的那些人。他们当时做得很好。”
谢谢大家收听科学美国人——60秒科学。我是克里斯托弗·因塔利亚塔。
译文为可可英语翻译，未经授权请勿转载！
重点讲解
重点讲解：
1. as long as 只要；
I'm not fussed as long as we get where we want to go.
只要我们能到想要去的地方就行，别的我都不在乎。
2. be eager to do sth. 热切的；渴望的；
Robert was eager to talk about life in the Army.
罗伯特很想谈谈陆军生活。
3. in turn 继而；转而；反过来；
That, in turn would increase pressure for higher wages and that, in turn, would impact on inflation and competition.
那样就会增加工资上涨的压力，而那样又会对通货膨胀和竞争产生影响。
4. end up (通常指意外地)最终到达；
The result was that the engine ended up at the bottom of the canal.
结果引擎最终沉到了运河底。
