万物简史 第498期:多灾多难的生命进程(18)

 The KT meteor had the additional advantage — advantage if you are a mammal, that is — that it landed in a shallow sea just ten meters deep, KT陨石还有一个优势——那就是说，要是你是个哺乳动物的话，那是个优势——它在只有10米深的浅海里着落，

probably at just the right angle, at a time when oxygen levels were 10 percent higher than at present and so the world was more combustible¹. 角度很可能恰好合适，当时的氧气浓度又比现在高10%，因此世界比较容易着火。

Above all the floor of the sea where it landed was made of rock rich in sulfur². 尤其是，着落地区的海底是由含硫丰富的岩石构成的。

The result was an impact that turned an area of seafloor the size of Belgium into aerosols³ of sulfuric acid. 结果，那个撞击把一片比利时大小的海底变成了硫酸气雾。

For months afterward⁴, the Earth was subjected to rains acid enough to burn skin. 在此后的几个月里。地球遭受酸雨的袭击，酸的浓度足以烧伤皮肤。

In a sense, an even greater question than that of what wiped out 70 percent of the species that were existing at the time is how did the remaining 30 percent survive? 在某种意义上，还有一个比“是什么毁灭了当时存在的70%的物种？”更大的问题，那就是“剩下的30%是怎么存活下来的？”

Why was the event so irremediably devastating⁵ to every single dinosaur⁶ that existed, while other reptiles⁷, like snakes and crocodiles, passed through unimpeded? 为什么那个事件对每个存在的恐龙是个灭顶之灾，而别的像蛇和鳄这样的爬行动物却能安然度过劫难？

So far as we can tell no species of toad⁸, newt, salamander, or other amphibian⁹ went extinct in North America. 就我们所知，北美的蟾蜍、水螈、蝾螈，以及别的两栖动物没有一个物种灭绝。

"Why should these delicate creatures have emerged unscathed from such an unparalleled disaster?" “为什么这些纤弱的动物能安然无恙地逃过这场空前的灾难？”

asks Tim Flannery in his fascinating prehistory of America, Eternal Frontier. 提姆·弗兰纳里在他精彩的描述史前美国的著作《永久的边疆》里发问。

In the seas it was much the same story. 海洋里的情况十分相似。

All the ammonites vanished, but their cousins the nautiloids, who lived similar lifestyles, swam on. 菊石统统消失了，但它们的表亲鹦鹉螺目软体动物却存活下来，尽管它们有着相似的生活方式。

Among plankton¹⁰, some species were practically wiped out — 92 percent of foraminiferans, for instance 在浮游生物中，有的物种实际上全部覆灭——比如，有孔虫丧失了92%，

while other organisms like diatoms, designed to a similar plan and living alongside, were comparatively unscathed. 而像硅藻这样的别的生物尽管体形相似，还同有孔虫在一起生活，却受伤害较轻。

 

1 combustible   

a. 易燃的,可燃的; n. 易燃物,可燃物

参考例句：

• Don't smoke near combustible materials. 别在易燃的材料附近吸烟。
• We mustn't take combustible goods aboard. 我们不可带易燃品上车。

2 sulfur   

n.硫，硫磺（=sulphur）

参考例句：

• Sulfur emissions from steel mills become acid rain.炼钢厂排放出的硫形成了酸雨。
• Burning may produce sulfur oxides.燃烧可能会产生硫氧化物。

3 aerosols   

n.气溶胶( aerosol的名词复数 )；喷雾剂；（气体中的）浮粒；喷雾器

参考例句：

• Aerosols are present throughout the atmosphere. 气溶胶存在于整个大气层。 来自辞典例句
• Deodorants are available as aerosols or roll-ons. 除臭剂有喷雾装或滚抹装。 来自辞典例句

4 afterward   

adv.后来；以后

参考例句：

• Let's go to the theatre first and eat afterward. 让我们先去看戏，然后吃饭。
• Afterward,the boy became a very famous artist.后来，这男孩成为一个很有名的艺术家。

5 devastating   

adj.毁灭性的，令人震惊的，强有力的

参考例句：

• It is the most devastating storm in 20 years.这是20年来破坏性最大的风暴。
• Affairs do have a devastating effect on marriages.婚外情确实会对婚姻造成毁灭性的影响。

6 dinosaur   

n.恐龙

参考例句：

• Are you trying to tell me that David was attacked by a dinosaur?你是想要告诉我大卫被一支恐龙所攻击？
• He stared at the faithful miniature of the dinosaur.他凝视著精确的恐龙缩小模型。

7 reptiles   

n.爬行动物，爬虫( reptile的名词复数 )

参考例句：

• Snakes and crocodiles are both reptiles. 蛇和鳄鱼都是爬行动物。 来自《简明英汉词典》
• Birds, reptiles and insects come from eggs. 鸟类、爬虫及昆虫是卵生的。 来自《现代汉英综合大词典》

8 toad   

n.蟾蜍，癞蛤蟆

参考例句：

• Both the toad and frog are amphibian.蟾蜍和青蛙都是两栖动物。
• Many kinds of toad hibernate in winter.许多种蟾蜍在冬天都会冬眠。

9 amphibian   

n.两栖动物；水陆两用飞机和车辆

参考例句：

• The frog is an amphibian,which means it can live on land and in water.青蛙属于两栖动物，也就是说它既能生活在陆地上也能生活在水里。
• Amphibian is an important specie in ecosystem and has profound meaning in the ecotoxicology evaluation.两栖类是生态系统中的重要物种，并且对环境毒理评价有着深远意义。

10 plankton   

n.浮游生物

参考例句：

• Plankton is at the bottom of the marine food chain.浮游生物处于海洋食物链的最底层。
• The plankton in the sea feeds many kinds of animals. 海的浮游生物成为很多种动物的食物。