The past life of the earth
原文
Lesson 26
The past life of the earth
What is the main condition for the preservation of the remains of any living creature?
It is animals and plants which lived in or near water whose remains are most likely to be preserved,
for one of the necessary conditions of preservation is quick burial,
and it is only in the seas and rivers, and sometimes lakes,
where mud and silt have been continuously deposited,
that bodies and the like can be rapidly covered over and preserved.
But even in the most favourable circumstances
only a small fraction of the creatures that die are preserved in this way
before decay sets in or, even more likely, before scavengers eat them.
After all, all living creatures live by feeding on something else,
whether it be plant or animal, dead or alive,
and it is only by chance that such a fate is avoided.
The remains of plants and animals that lived on land are much more rarely preserved,
for there is seldom anything to cover them over.
When you think of the innumerable birds that one sees flying about,
not to mention the equally numerous small animals like field mice and voles which you do not see,
it is very rarely that one comes across a dead body, except, of course, on the roads.
They decompose and are quickly destroyed by the weather or eaten by some other creature.
It is almost always due to some very special circumstances that traces of land animals survive,
as by falling into inaccessible caves, or into an ice crevasse,
like the Siberian mammoths,
when the whole animal is sometimes preserved, as in a refrigerator.
This is what happened to the famous Beresovka mammoth which was found preserved and in good condition.
In his mouth were the remains of fir trees--the last meal that he had before he fell into the crevasse and broke his back.
The mammoth has now been restored in the Palaeontological Museum in St.Petersburg.
Other animals were trapped in tar pits, like the elephants, sabre-toothed cats,
and numerous other creatures that are found at Rancho la Brea, which is now just a suburb of Los Angeles.
Apparently what happened was that water collected on these tar pits
and the bigger animals like the elephants ventured out on to the apparently firm surface to drink,
and were promptly bogged in the tar.
And then, when they were dead, the carnivores,
like the sabretoothed cats and the giant wolves,
came out to feed and suffered exactly the same fate.
There are also endless numbers of birds in the tar as well.
译文
第26课
地球的往昔生命
保存任何生物遗骸的主要条件是什么？
最有可能被保存下来的，是那些生活在水中或水边的动植物的遗骸。
其中一个必要的保存条件就是迅速掩埋。
而只有在海洋、河流中，有时也在湖泊里，
在那些泥沙不断沉积的地方……
尸体等物才能被迅速覆盖并保存下来。
但即使在最有利的情况下
只有极少数死亡的生物能够以这种方式被保存下来。
在腐烂开始之前，或者更可能的是，在食腐动物吃掉它们之前。
毕竟，所有生物都是通过摄取其他物质来维持生存的。
无论是植物还是动物，无论是死的还是活的……
只有碰巧才能避免这样的命运。
生活在陆地上的植物和动物的遗骸被保存下来的情况要少得多。
因为很少有东西能将它们覆盖起来。
当你想到那些在空中飞舞的无数鸟类时……
更不用说那些同样数量众多但你看不到的小动物，比如田鼠和鼩鼱。
人们很少能碰到动物的尸体，当然，路上除外。
它们会腐烂，很快被风化或被其他动物吃掉。
几乎总是由于一些非常特殊的情况，陆地动物的痕迹才能得以保存下来。
比如掉进无法进入的洞穴里，或者掉进冰裂隙里。
就像西伯利亚猛犸象一样……
有时整个动物会像在冰箱里一样被保存下来。
这就是著名的贝列索夫卡猛犸象的遭遇：它被发现时保存完好，状态极佳。
它嘴里还残留着冷杉树枝——那是它掉进冰缝摔断背前的最后一餐。
这头猛犸象现已被修复并陈列在圣彼得堡的古生物博物馆中。
还有些动物陷进了沥青坑，比如大象、剑齿虎
以及在兰乔拉布雷亚发现的众多其他生物，那里如今只是洛杉矶的一个郊区。
显然，发生的情况是水在这些沥青坑中积聚了。
那些体型较大的动物，比如大象，便冒险走到了那片看起来非常坚固的地面上去喝水。
结果立刻陷进了沥青里。
然后，当它们死去之后，那些肉食动物……
就像剑齿虎和巨型狼一样……
它们出来觅食，结果遭遇了完全相同的命运。
沥青里还有数不清的鸟类的遗骸。