時(shí)差N小時(shí):史前的牙簽

If asked to imagine the first prehistoric tools,crafted and used by our early, hominid ancestors,you'd probably think of crude knives or spear heads,chipped from stone.You probably aren't aware ofanother human innovation that might be just asold. Today we'll learn about the two million yearhistory of the toothpick, possibly one of humanity'soldest tools.

如果讓你去想象做工粗糙，人類最早的祖先使用過(guò)的史前牙簽，你可能會(huì)想到由石頭磨成的原始刀具或者矛槍尖。你可能沒(méi)有意識(shí)到另一種同樣古老的革新。今天我們就來(lái)了解200萬(wàn)年的牙簽歷史，這可能是人類歷史上最古老的工具之一。

Early stone tools, like knives and scrapers, are easy for anthropologists to learn aboutbecause these items are still around. Even after two million years, a chipped stone tool is stillgoing to be there when you dig it up. Toothpicks, however, are another story. Made fromsplinters of wood, thorns, or bone fragments, these can rot and crumble away over time,leaving no recognizable trace. If this is so, how can an anthropologist look at a two millionyear old fossil site and claim that these early pre-humans picked their teeth?

早期的石頭工具，如小刀和刮刀，讓人類學(xué)家很容易理解，因?yàn)樵诂F(xiàn)代社會(huì)仍然存在這些東西。即使再過(guò)200萬(wàn)年，這些東西仍然埋在地里。然而牙簽卻是另一回事了。大多數(shù)牙簽由木頭的碎片、荊棘或者骨頭碎片制成，會(huì)隨著時(shí)間的流逝腐爛消失，不留下任何可辨別的痕跡。如果是這樣的話，為什么人類學(xué)家會(huì)只憑著200萬(wàn)年前的化石遺址，就聲稱古代史前人類也用牙簽剔牙?

It's certain that no toothpick will ever last two million years, but this isn't the case withteeth. In fact, fossil teeth are the most durable remnants that anthropologists work with, andsome of these ancient teeth display a curious set of grooves. Although these might have beencaused by tooth decay, a close examination of the marks seems to indicate that the grooveswere worn by repeated toothpicking--probably to alleviate the pain of gum disease. Indeed,these fossil grooves match the toothpick grooves in the teeth of several modern aboriginalpopulations.

可以肯定的是，沒(méi)有牙簽會(huì)保存200萬(wàn)年，但牙齒卻不一樣了。事實(shí)上，牙齒化石是人類學(xué)家所研究的最持久的殘留物。這些古時(shí)人類的牙齒上排列著一道道凹槽，很令人好奇。盡管這可能是由于蛀牙引起的，但經(jīng)過(guò)進(jìn)一步仔細(xì)檢查，證明這些凹槽似乎是因?yàn)殚L(zhǎng)期剔牙而形成，古人類剔牙也可能是為了減輕牙齦疾病引起的疼痛。事實(shí)上，不少現(xiàn)代土著居民的牙齒上也出現(xiàn)了凹槽，并與化石上的凹槽相匹配。

It's enough to warm every dentist's heart: The first tools weren't just for preparing food,hunting, or fighting. They might have been used for dental hygiene as well.

這足以溫暖每一位牙醫(yī)的心：第一個(gè)工具不只是為了準(zhǔn)備食物，為了狩獵或戰(zhàn)斗，也可能是為了保持牙齒衛(wèi)生。