22 Good-bye To All That
第二十二章 多灾多难的生命进程
When you consider it from a human perspective, and clearly it would be difficult for us to do otherwise, life is an odd thing. It couldn't wait to get going, but then, having gotten going, it seemed in very little hurry to move on.
要是你从人的角度去考虑生命这个问题，显然我们也很难不这么做，生命是个古怪的东西。它迫不及待地起步，但起步以后又似乎不大急着往前走。
Consider the lichen. Lichens are just about the hardiest visible organisms on Earth, but among the least ambitious. They will grow happily enough in a sunny churchyard, but they particularly thrive in environments where no other organism would go—on blowy mountaintops and arctic wastes, wherever there is little but rock and rain and cold, and almost no competition. In areas of Antarctica where virtually nothing else will grow, you can find vast expanses of lichen—four hundred types of them—adhering devotedly to every wind-whipped rock.
想一想地衣。地衣大概是地球上最坚强的可见生物，也是最没有雄心壮志的生物之一。它们会很乐意生长在阳光明媚的教堂墓地里，但它们尤其乐意在别的生物都不愿意去的环境里茂盛生长——在风吹雨打的山顶上，在北极荒原，那里除了岩石、风雨和寒冷以外几乎什么也没有，也几乎没有竞争。在南极洲的许多地区，那里实际上别的什么也不长。你却可以看到大片大片的地衣——有400种——忠诚地依附在每一块风吹雨打的岩石上。

For a long time, people couldn't understand how they did it. Because lichens grew on bare rock without evident nourishment or the production of seeds, many people—educated people—believed they were stones caught in the process of becoming plants. "Spontaneously, inorganic stone becomes living plant!" rejoiced one observer, a Dr. Homschuch, in 1819.
在很长时间里，人们无法理解它们是怎么办到的。由于地衣长在光秃秃的岩石上，既没有明显的营养，也不结出种子，许多人——许多受过教育的人——认为它们是变成植物过程中的石头。“无生命的石头自动变成了有生命的植物！”一位名叫霍恩舒克的博士观察者在1819年高兴地说。
Closer inspection showed that lichens were more interesting than magical. They are in fact a partnership between fungi and algae. The fungi excrete acids that dissolve the surface of the rock, freeing minerals that the algae convert into food sufficient to sustain both. It is not a very exciting arrangement, but it is a conspicuously successful one. The world has more than twenty thousand species of lichens.
要是更仔细地观察一下，你便会发现，地衣与其说是具有魔力，不如说是很有意思。它们实际上是真菌和藻类之间的一种伙伴关系。真菌分泌出酸，溶解岩石表面，把矿物质释放出来；藻类将矿物质转变成足够的食物来维持二者。这不是个很激动人心的安排，但显然是个成功的安排。世界上有2万多种地衣。