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Only about one bone in a billion, it is thought, ever becomes fossilized. 据认为,在10亿根骨头当中,只有大约l根能变成化石。 If that is so, it means that the complete fossil legacy of all the Americans alive todaythat's 270 mill
With his supervisor, Harry Whittington, and fellow graduate student Derek Briggs, Conway Morris spent the next several years making a systematic revision of the entire collection, and cranking out one exciting monograph after another as discovery pil
Dismounting to assist her, Walcott discovered that the horse had turned a slab of shale that contained fossil crustaceans of an especially ancient and unusual type. 沃尔科特跳下马来扶她,却发现马将一块页岩圈了个身。页岩里有
As a boy Walcott discovered that he had a knack for finding fossils, particularly trilobites, 沃尔科特还是个孩子的时候就发现自己具有寻找化石的本领,尤其是三叶虫。 and built up a collection of sufficient distinction t
From time to time certain strains of virus return. 有几种病毒不时重复出现。 A disagreeable Russian virus known as H1N1 caused severe outbreaks over wide areas in 1933, then again in the 1950s, and yet again in the 1970s. 一种名叫H1N1的
As with all extinct creatures, there is a natural temptation to regard them as failures, but in fact they were among the most successful animals ever to live. Their reign ran for 300 million yearstwice the span of dinosaurs, which were themselves one
The most rampantly infectious organism on Earth, a bacterium called Wolbachia, doesn't hurt humans at all, 地球上最具传染性的生物,一种名叫沃尔巴克体的细菌,根本有伤害人类, or, come to that, any other vertebratesbut
One of the odder aspects of infection is that microbes that normally do no harm at all sometimes get into the wrong parts of the body and go kind of crazy, 感染有许多古怪的方面。其中之一是,有些在正常情况下完全无害的微生
We now know that there are a lot of microbes living deep within the Earth, many of which have nothing at all to do with the organic world. 我们现在知道了,有大量微生物生活在地球内部的深处,其中许多与普通的有机世界毫
They have been found living in boiling mud pots and lakes of caustic soda, deep inside rocks, at the bottom of the sea, 我们还发现细菌生活在沸腾的泥潭里和烧碱池里,岩石深处,大海底部, in hidden pools of icy water in t
Bacteria do it all the time without fuss, and thank goodness, for no larger organism could survive without the nitrogen they pass on. 而细菌一直在不慌不忙地干这件事。谢天谢地,要是没有它们来传送氮,大的生物就活不下
Mitochondria manipulate oxygen in a way that liberates energy from foodstuffs. 线粒体支配着氧,释放食物中的能量。 Without this niftily facilitating trick, life on Earth today would be nothing more than a sludge of simple microbes. 没有
Even we can tolerate it only up to a point. 连我们对氧的耐受力也是有限度的。 The oxygen level in our cells is only about a tenth the level found in the atmosphere. 我们细胞里的氧气浓度,只有大气里的大约十分之一。
As one leading biology text puts it, with perhaps just a tiny hint of discomfort, 正如一篇重要的生物学文章所说,说得也许有点儿令人不大舒服: Researchers agree that such reactions would not have been energetically favorabl
There are actually twenty-two naturally occurring amino acids known on Earth, 实际上,地救上有22种天然存在的氨基酸, and more may await discovery, but only twenty of them are necessary to produce us and most other living things. 更多
Particles can come into being and be gone again in as little as 0.000000000000000000000001 second (10-24). Even the most sluggish of unstable particles hang around for no more than 0.0000001 second (10-7). 粒子可以在短达0.000 000 000 000 000 0
Particle physics, in short, is a hugely expensive enterprisebut it is a productive one. Today the particle count is well over 150, with a further 100 or so suspected, but unfortunately, in the words of Richard Feynman, it is very difficult to underst
Hubble realized that this could be expressed with a simple equation, Ho = v/d (where Ho is the constant, v is the recessional velocity of a flying galaxy, andd its distance away from us). Ho has been known ever since as the Hubble constant and the wh
It is all, as you can see, just a little unwieldy, but it is the simplest model that can explain all that happens in the world of particles. Most particle physicists feel, as Leon Lederman remarked in a 1985 PBS documentary, that the Standard Model l
On its website, a history of the company makes no mention of leador indeed of Thomas Midgleybut simply refers to the original product as containing a certain combination of chemicals. 在它的网站上,公司的历史没有提及铅──也没有提