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This is Scientific American's 60-second Science, I'm Christopher Intagliata.

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。

You're probably not too interested in what some people call ABC gum—already been chewed. But for archaeologists, such gum—a?s long as it's really old—is a genetic¹ gold mine.

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”。

"It's a bit like Jurassic Park." Natalija Kashuba, a graduate student in archaeology² 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 amber³, "and bingo, dino DNA⁵."

“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。”

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 detritus⁶ is black, sticky tar⁷ distilled⁸ from birch bark. Kashuba has tasted modern-day versions and isn't eager to try it again. "Not unless I'm paid for it."

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。”

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.

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。

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.

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。

The results are in the journal Communications Biology.

研究结果发表在《通讯·生物学》期刊上。

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?

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？

"No, I still think this one should not be spatted¹⁰ out anyplace just like that. So I think you should definitely throw it in the bin⁴. But I won't blame these guys... who spat⁹ it out 10,000 years ago. They did a good job then."

“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。”

Thanks for listening for Scientific American — 60-Second Science. I'm Christopher Intagliata.

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。