万物简史 第644期:永不安分的类人猿(4)（在线收听）

How they got there and why they came are questions that can't be answered. According to most anthropology texts, there's no evidence that people could even speak 60,000 years ago, much less engage in the sorts of cooperative efforts necessary to build ocean-worthy craft and colonize island continents.

他们是怎么到达那里的？他们为什么要去那里？这些问题至今是个谜。大多数人类学文献里说，没有证据显示6万年前人类已经会说话，更不用说进行某种协作，建造横渡海洋到一个岛屿上去开拓新天地的船只的能力。

"There's just a whole lot we don't know about the movements of people before recorded history," Alan Thorne told me when I met him in Canberra. "Do you know that when nineteenth-century anthropologists first got to Papua New Guinea, they found people in the highlands of the interior, in some of the most inaccessible terrain on earth, growing sweet potatoes. Sweet potatoes are native to South America. So how did they get to Papua New Guinea? We don't know. Don't have the faintest idea. But what is certain is that people have been moving around with considerable assuredness for longer than traditionally thought, and almost certainly sharing genes as well as information."

“对于史前人类的迁移情况，我们不知道的东西太多了。”当我在堪培拉遇到艾伦·桑恩时，他告诉我说。“你知道吗，19世纪当人类学家首次到达巴布亚新几内亚的时候，他们发现人们在该地区内陆高地上的一些地球上最难到达的地方种植甘薯。甘薯原产于南美，它是怎样传到巴布亚新几内亚的？我们不知道。一点儿也不知道。但是可以肯定的是，人们信心十足地迁移的时间肯定比以前所认为的要长得多，他们几乎肯定不但彼此分享基因，还彼此分享信息。”

The problem, as ever, is the fossil record. "Very few parts of the world are even vaguely amenable to the long-term preservation of human remains," says Thorne, a sharp-eyed man with a white goatee and an intent but friendly manner. "If it weren't for a few productive areas like Hadar and Olduvai in east Africa we'd know frighteningly little. And when you look elsewhere, often wedo know frighteningly little. The whole of India has yielded just one ancient human fossil, from about 300,000 years ago. Between Iraq and Vietnam—that's a distance of some 5,000 kilometers—there have been just two: the one in India and a Neandertal in Uzbekistan." He grinned. "That's not a whole hell of a lot to work with. You're left with the position that you've got a few productive areas for human fossils, like the Great Rift Valley in Africa and Mungo here in Australia, and very little in between. It's not surprising that paleontologists have trouble connecting the dots."

和以往一样，问题在于化石记录。“世界上哪怕是稍稍适宜于长期保存人类遗骸的地方也并不多，”桑恩说，他是一位目光敏锐的人，留着灰白色的山羊胡，一脸专注而又温和的神情，“要不是在东非的哈达尔和奥都咸发现了大批化石，我们会知道得少得可怜。看看别的地方，我们知道得确实少得可怜。整个印度只发现了一块大约30万年前的古人类化石。在伊拉克和越南之间——其间相距5000公里——只发现了两块化石：一块在印度，一块是在乌兹别克斯坦发现的尼安德特人化石。“他笑了笑，“没有多少该死的东西可以研究的。结果，我们只有几个地方有比较多的人类化石，比如东非大裂谷和这里的澳大利亚的蒙戈。而在这两个地区之间，几乎是一无所获，因此古生物学家很难将这些零零星星的东西串联起来，这也就不足为奇了。”