According to the University of Chicago paleontologist David Raup,
根据芝加哥大学古生物学家戴维.诺普的观点，
the background rate of extinction on Earth throughout biological history has been one species lost every four years on average.
在整个生物史上，地球上的物种灭绝速度一直是平均每年有一个物种灭绝。
According to one recent calculation, human-caused extinction now may be running as much as 120,000 times that level.
理查德.利基和罗杰.卢因在《第六次灭绝》一书中说，现在，人类所造成的物种灭绝数量可能高达那个速度的12万倍。
In the mid-1990s, the Australian naturalist Tim Flannery, now head of the South Australian Museum in Adelaide,
20世纪90年代中期，澳大利亚博物学家、现任阿德莱德南澳大利亚州博物馆馆长提姆.弗兰纳里
became struck by how little we seemed to know about many extinctions, including relatively recent ones.
开始对我们对许多已经灭绝的物种，包括最近灭绝的物种所知甚少而感到吃惊。
Wherever you looked, there seemed to be gaps in the records—pieces missing, as with the dodo, or not recorded at all,
不论在什么地方，你都可以发现记录资料存在很多空白——不是残缺不全，比如关于渡渡鸟，就是根率没有记录。
he told me when I met him in Melbourne a year or so ago.
2002年初，他在墨尔本这样告诉我。
Flannery recruited his friend Peter Schouten, an artist and fellow Australian,
弗兰纳里聘请了他的朋友彼得.斯科顿，他是一位澳大利亚画家。
and together they embarked on a slightly obsessive quest to scour the world's major collections to find out what was lost, what was left, and what had never been known at all.
他们一起对世界的主要收藏标本进行了比较认真的考证，以发现什么东西消失了，什么东西遗漏了，什么东西我们一无所知。
They spent four years picking through old skins, musty specimens, old drawings, and written descriptions— whatever was available.
他们用了4年的时间，从旧毛皮、发出难闻气味的标本、古画、文字描述——总之是从他们找得到的一切东西中寻找资料。
Schouten made life-sized paintings of every animal they could reasonably re-create, and Flannery wrote the words.
然后，斯科顿尽可能地照实物大小为每一种动物画了像，弗兰纳里则撰写文字介绍。其结果是一本名为《自然的缺环》的书的问世。

The result was an extraordinary book called A Gap in Nature, constituting the most complete—and, it must be said, moving— catalog of animal extinctions from the last three hundred years.
这本书最完整地——必须说，最生动地记载了最近300年里灭绝的动物种类。
For some animals, records were good, but nobody had done anything much with them, sometimes for years, sometimes forever.
有些动物，尽管资料还算比较多，但是有时好多年无人去作多少研究，有时根本无人问津。
Steller's sea cow, a walrus-like creature related to the dugong, was one of the last really big animals to go extinct.
施特莱发现的海牛，一种与海象相像、与人鱼有关的动物，就是最后一批灭绝的大型动物之一。