Disputes and reorderings of much the same type can be found in all the other realms of the living, so keeping an overall tally is not nearly as straightforward a matter as you might suppose. In consequence, the rather amazing fact is that we don't have the faintest idea — "not even to the nearest order of magnitude," in the words of Edward O. Wilson — of the number of things that live on our planet. Estimates range from 3 million to 200 million. More extraordinary still, according to a report in the Economist, as much as 97 percent of the world's plant and animal species may still await discovery.
同样的争吵，同样的重新分类，也发生在所有别的生物领域，因此要得出个总数完全不是你想像的那么容易。结果，究竟有多少东西生活在我们这颗行星上，我们心里无数——用爱德华·O·威尔逊的话来说，“连个最接近的大概数”都不知道。这是个非常令人吃惊的事实。据估计，这个数字是从300万—2亿不等。更加不可思议的是，据《经济学家》杂志的一篇报道说，世界上多达97%的植物和动物物种尚待发现。

Of the organisms that we do know about, more than 99 in 100 are only sketchily described — "a scientific name, a handful of specimens in a museum, and a few scraps of description in scientific journals" is how Wilson describes the state of our knowledge. In The Diversity of Life, he estimated the number of known species of all types — plants, insects, microbes, algae, everything — at 1.4 million, but added that that was just a guess. Other authorities have put the number of known species slightly higher, at around 1.5 million to 1.8 million, but there is no central registry of these things, so nowhere to check numbers. In short, the remarkable position we find ourselves in is that we don't actually know what we actually know.
在已知的生物中，100种当中有99种以上只有一个简单的描述——“一个科学名称，博物馆里的几个样品，科学杂志上的零星说明。”威尔逊是这样描述我们的知识状态的。在《生命的多样性》一书中，他估计已知的各类物种——植物、昆虫、微生物、藻类以及一切——为l40万种，但接着说那只是一个推测。别的权威认为已知的物种数量要稍稍多一点儿，大约在150万—180万种不等，但这些东西没有个集中记录的地方，因此无法去哪里核对数字。总之，我们实际上不知道我们实际上知道些什么。这就是我们目前令人不可思议的状态。