万物简史 第632期:神秘的两足动物(10)

（单词翻译）

The shortage wouldn't be so bad if the bones were distributed evenly through time and space, but of course they are not. They appear randomly¹, often in the most tantalizing² fashion. Homo erectus walked the Earth for well over a million years and inhabited territory from the Atlantic edge of Europe to the Pacific side of China, yet if you brought back to life every Homo erectus individual whose existence we can vouch³ for, they wouldn't fill a school bus. Homo habilis consists of even less: just two partial skeletons and a number of isolated⁴ limb bones. Something as short-lived as our own civilization would almost certainly not be known from the fossil record at all.

如果这些人类化石能够按时间和空间分布得比较均匀的话，即使缺乏，事情也不至于如此糟糕。实际情况当然并非如此。它们东一块西一块地出现，往往令人备尝可望而不可即之苦。直立人在地球存在了100万年以上的时间，他们居住的范围从欧洲的大西洋沿岸一直到中国的太平洋沿岸，然而如果你将所发现的每一个直立人复活，他们还装不满一辆校车。能人的化石就更加少得可怜：只有两副不完整的骨骼和几根孤零零的肢骨。有一些存在时间和我们自己的文明一样短暂的事物，仅仅根据化石记录，几乎肯定是无从考证的。

"In Europe," Tattersall offers by way of illustration, "you've got hominid skulls⁵ in Georgia dated to about 1.7 million years ago, but then you have a gap of almost a million years before the next remains⁶ turn up in Spain, right on the other side of the continent, and then you've got another 300,000-year gap before you get a Homo heidelbergensis in Germany—and none of them looks terribly much like any of the others." He smiled. "It's from these kinds of fragmentary pieces that you're trying to work out the histories of entire species. It's quite a tall order. We really have very little idea of the relationships between many ancient species— which led to us and which were evolutionary⁷ dead ends. Some probably don't deserve to be regarded as separate species at all."

为了说明这一点，塔特萨尔这样说道： 在欧洲，你在格鲁吉亚发现了大约170万年前的人科动物头骨；接着，在大陆另一端的西班牙发现了一块与之差不多相隔100万年的化石；然后，又在德国发现了一块与之相隔30万年的海德堡人化石。它们彼此之间几乎没有任何相似之处。”他微笑了一下，继续说道，“你就是在根据这样支离破碎的东西想要归纳出整个人类的历史。这是很难办到的事。我们确实对许多古代物种彼此之间的关系了解甚少——这些物种中哪些最终进化成了人类，哪些在进化过程中灭绝了，我们实在不知其详。有些也许根本不应该视为单独的种类。”