万物简史 第485期:多灾多难的生命进程(5)
For all the trouble they take to assemble and preserve themselves, species crumple and die remarkably routinely. 尽管物种们费了九牛二虎之力聚集起来保存自己，但它们经常崩溃和死亡。 And the more complex they get, the mo
万物简史 第486期:多灾多难的生命进程(6)
So competition was fierce. 于是，竞争很激烈。 There was also an omnivorous and unsettling new type of predator on the scene, 而且，出现了一种新的无所不吃的、令人不安的捕食者。 one so perfectly designed for attack tha
万物简史 第487期:多灾多难的生命进程(7)
And how, you may reasonably wonder, can scientists know what oxygen levels were like hundreds of millions of years ago? 你也许有理由想知道，科学家们怎么会知道几亿年以前的氧气浓度？ The answer lies in a slightly obscure b
万物简史 第488期:多灾多难的生命进程(8)
By combining their isotope findings with other fossil residuespollen levels and so on, 把对同位素测量的结果和能够说明其他情况（如花粉浓度等）的别的化石残留物结合起来， scientists can, with considerable confiden
万物简史 第489期:多灾多难的生命进程(9)
Then, as now, dragonflies could cruise at up to thirty-five miles an hour, 当时和现在一样，蜻蜓能以每小时50多公里的速度飞行， instantly stop, hover, fly backwards, and lift far more proportionately than any human flying machin
万物简史 第490期:多灾多难的生命进程(10)
Dinosaurs, whales, birds, humans, even fish all are tetrapods, which clearly suggests they come from a single common ancestor. 恐龙、鲸、鸟、人甚至鱼都是四足动物。这显然表明，它们出自一个共同的祖先。 The clue to th
万物简史 第491期:多灾多难的生命进程(11)
But come we did, though reaching our present state of eminence has not of course always been straightforward. 但是，我们毕竟还是来了，虽然达到我们目前这样的卓越状态肯定不总是一帆风顺的。 Since life on land began,
万物简史 第492期:多灾多难的生命进程(12)
Unfortunately for the therapsids, their cousins the diapsids were also productively evolving, 兽孔目爬行动物的运气不佳，它们的表亲双孔亚纲在进化过程中也繁殖力很强， in their case into dinosaurs (among other things),
万物简史 第493期:多灾多难的生命进程(13)
For complex organisms, the average lifespan of a species is only about four million yearsroughly about where we are now. 对于复杂动物来说，一个物种的平均寿命只有大约400万年大致相当于我们人类迄今存在的时间。 Ex
万物简史 第494期:多灾多难的生命进程(14)
Earth has seen five major extinction episodes in its time the Ordovician, Devonian, Permian, Triassic, and Cretaceous, in that order and many smaller ones. 地球已经目睹了5次大的灭绝事件依次在奥陶纪、泥盆纪、二叠纪、三叠纪
万物简史 第495期:多灾多难的生命进程(15)
Two points need to be kept in mind. 我们需要记住两点。 First, these are all just informed guesses. 第一、这些都仅仅是根据资料作出的推测。 Estimates for the number of animal species alive at the end of the Permian range fro
万物简史 第496期:多灾多难的生命进程(16)
Even after stripping out the more crackpot notions there are still more theories for what caused the extinction events than there have been events. 即使去掉了不大切合实际的观点以后，解释灭绝事件原因的理论依然多子事件本
万物简史 第497期:多灾多难的生命进程(17)
What all this leaves us with, as one researcher has put it, is tons of conjecture and very little evidence. 这一切留给我们的，正如一位研究人员所说，是大量的猜测和很少的证据。 Cooling seems to be associated with at lea
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
万物简史 第499期:多灾多难的生命进程(19)
These are difficult inconsistencies. 这些都是难以解释的矛盾地方。 As Richard Fortey observes: Somehow it does not seem satisfying just to call them 'lucky ones' and leave it at that. 正如理查德福泰所说：仅仅把它们称做幸运
