经济学人53:羽毛化石 并非鸟类独有

 　　Science and Technology

　　科技

　　Fossil feathers

　　羽毛化石

　　Not just for the birds

　　并非鸟类独有

　　A trove¹ of fossils sheds light on the evolution of feathers

　　珍贵羽毛化石的发现能够更好地阐释羽毛的进化过程

　　THE fossil record is, famously, full of holes.

　　众所周知，化石记录总是漏洞百出。

　　One such lacuna has been the absence of well-preserved feathers from the Cretaceous-the period between 145m and 65m years ago that ended with the mass extinction² that wiped out the dinosaurs³.

　　一个漏洞就是由于人们无法找到白垩纪时期保存完好的羽毛，因而该时期羽毛化石的记录一直处于空白状态。白垩纪是距今1.45亿年到6500万年的一段时期，末期发生了导致恐龙消失的物种大灭绝。

　　Now, this gap has been partly filled.

　　如今，这段空白得到了部分填充。

　　In this week's Science, a team led by Ryan McKellar from the University of Alberta report the discovery of eleven feathers preserved in amber⁴ from the latter part of the Cretaceous, about 70m-85m years ago.

　　本周，瑞安?麦凯乐领导的研究小组在《科学》杂志上发表报告称，他们发现了11种白垩纪后期（距今约7000至8500万年）封存在琥珀里的羽毛。

　　Intriguingly⁵, not all of them seem to come from birds.

　　有趣的是，这些羽毛并不都属于鸟类。

　　The origin of feathers is a mystery.

　　羽毛的起源一直是个谜。

　　The earliest known bird, Archaeopteryx, lived during the Jurassic, the period before the Cretaceous.

　　人类所熟知的最古老鸟类始祖鸟生活在白垩纪时期之前的侏罗纪时期。

　　But fossils from China suggest the precursors⁶ of feathers-simple, filament-like structures possibly used for insulation⁷-evolved in land-lubbing dinosaurs and were only later adapted for flight.

　　中国出土的化石表明羽毛的前身呈简易的丝状结构，可能具有隔离热量的功用，这些简易丝状羽毛在陆地恐龙身上不断进化，直至后来才具备了飞行功能。

　　The top picture shows similar filaments⁸ discovered by Dr McKellar and his team, suggesting flightless dinosaurs sporting such protofeathers were still around in the late Cretaceous.

　　上图所示为麦凯乐博士及其研究小组发现的类似丝状的羽毛，表明长有这些原生羽毛的“非鸟”恐龙在白垩纪后期仍然存活着。

　　Not all the feathers found by Dr McKellar were so primitive⁹, though.

　　不过，McKellar博士发现的羽毛并不都是远古时代的。

　　The second picture shows one similar in shape to those sported by modern birds.

　　第二幅图显示的羽毛形状与现代鸟类羽毛相似。

　　Modern feathers consist of thousands of fibres held together by tiny hooks.

　　现代鸟类羽毛由成千上万束靠细钩聚拢在一起的纤维构成。

　　The details of that design can be tweaked to change a feather's characteristics, offering waterproofing¹⁰, insulation, streamlining and so on.

　　通过改进羽毛构造的细节可改变它的特性，如防水、隔热、流线造型等功能。

　　The third picture shows feathers that have just such a specialisation: coiling reminiscent of that seen in the feathers of modern divers¹¹.

　　第三幅图显示的羽毛就具备这样的特殊功能：螺旋造型与现代潜鸟的羽毛相似。

　　Such coiling allows a feather to absorb water, which streamlines¹² and insulates the owner.

　　这种螺旋形状的羽毛能够吸水，并使该鸟类身形更加精巧同时起保温作用。

　　These feathers, then, presumably adorned¹³ a diving bird-perhaps Hesperornis, a flightless North American diver from precisely¹⁴ this period.

　　这些羽毛想必当时是归潜鸟所有——也许是“黄昏鸟”，一种恰好生活在这一时期不会飞翔的北美潜鸟。

　　The final picture shows pigmentation preserved in a fossil feather.

　　最后一幅图显示了封存在羽毛化石里的色素沉着。

　　Different feathers have different patterns of colour, suggesting that Cretaceous dinosaurs-flying or otherwise-used their feathers for display.

　　不同的羽毛有不同的颜色样式，这表明白垩纪时期的会飞恐龙和陆地恐龙都利用羽毛来炫示自己。

　　Charles Darwin once said that contemplating¹⁵ a peacock's tail made him sick, such was the difficulty of explaining its complexity¹⁶.

　　查尔斯?达尔文曾说过研究孔雀尾让他有头晕的感觉，可见想解释清楚其复杂性有多难了。

　　Dr McKellar's finds suggest, at least, that that complexity began to evolve a long time ago.

　　不过，麦凯乐博士的发现至少表明这种复杂性在很久以前就开始进化了。

1 trove   

n.被发现的东西，收藏的东西

参考例句：

• He assembled a rich trove of Chinese porcelain.他收集了一批中国瓷器。
• The gallery is a treasure trove of medieval art.这个画廊是中世纪艺术的宝库。

2 extinction   

n.熄灭，消亡，消灭，灭绝，绝种

参考例句：

• The plant is now in danger of extinction.这种植物现在有绝种的危险。
• The island's way of life is doomed to extinction.这个岛上的生活方式注定要消失。

3 dinosaurs   

n.恐龙( dinosaur的名词复数 )；守旧落伍的人，过时落后的东西

参考例句：

• The brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
• Dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》

4 amber   

n.琥珀；琥珀色；adj.琥珀制的

参考例句：

• Would you like an amber necklace for your birthday?你过生日想要一条琥珀项链吗？
• This is a piece of little amber stones.这是一块小小的琥珀化石。

5 intriguingly   

参考例句：

• Intriguingly, she gave to the music a developed although oddly malleable personality. 最神奇的是，她的音乐具有成熟却又很奇怪地极富可塑性。 来自互联网
• Intriguingly, the patients brains were riddled with tangles, but not amyloid plaques. 有趣的是，患者的大脑中充满了各缠结，但并没有粉斑。 来自互联网

6 precursors   

n.先驱( precursor的名词复数 )；先行者；先兆；初期形式

参考例句：

• Phenyl (or polyphenyl) substituted epoxides serve as excellent precursors to phenyl (or diphenyl) carbenes. 某些苯代（或多苯）环氧乙烷是制取带苯环（或二苯）碳烯的极好原料。 来自辞典例句
• Note the presence of megakaryocytes, erythroid islands, and granulocytic precursors. 可见巨核细胞，红细胞岛和粒细胞前体细胞。 来自互联网

7 insulation   

n.隔离；绝缘；隔热

参考例句：

• Please examine the insulation of the electric wires in my house.请检查一下我屋子里电线的绝缘情况。
• It is always difficult to assure good insulation between the electric leads.要保证两个电触头之间有良好的绝缘总是很困难的。

8 filaments   

n.（电灯泡的）灯丝( filament的名词复数 )；丝极；细丝；丝状物

参考例句：

• Instead, sarcomere shortening occurs when the thin filaments'slide\" by the thick filaments. 此外，肌节的缩短发生于细肌丝沿粗肌丝“滑行”之际。 来自辞典例句
• Wetting-force data on filaments of any diameter and shape can easily obtained. 各种直径和形状的长丝的润湿力数据是易于测量的。 来自辞典例句

9 primitive   

adj.原始的；简单的；n.原(始)人，原始事物

参考例句：

• It is a primitive instinct to flee a place of danger.逃离危险的地方是一种原始本能。
• His book describes the march of the civilization of a primitive society.他的著作描述了一个原始社会的开化过程。

10 waterproofing   

v.使防水，使不透水( waterproof的现在分词 )

参考例句：

• The company will come up with a new technique for waterproofing walls. 该公司将推出防止墙壁渗水的新技术。 来自辞典例句
• Large scope of heat-resistant, waterproofing and the anti-chemical properties. 耐温范围大，具防水及抗化学性。 来自互联网

11 divers   

adj.不同的；种种的

参考例句：

• He chose divers of them,who were asked to accompany him.他选择他们当中的几个人，要他们和他作伴。
• Two divers work together while a standby diver remains on the surface.两名潜水员协同工作，同时有一名候补潜水员留在水面上。

12 streamlines   

把…做成流线型( streamline的名词复数 )； 简化使效率更高； （系统、机构等）效率更高； （尤指）使增产节约

参考例句：

• In a junction, there is no fixed pattern of streamlines. 在接头中，流线没有固定图形。
• Small droplets tend to follow the streamlines of the air. 小水滴顺着气流运动。

13 adorned   

[计]被修饰的

参考例句：

• The walls were adorned with paintings. 墙上装饰了绘画。
• And his coat was adorned with a flamboyant bunch of flowers. 他的外套上面装饰着一束艳丽刺目的鲜花。

14 precisely   

adv.恰好，正好，精确地，细致地

参考例句：

• It's precisely that sort of slick sales-talk that I mistrust.我不相信的正是那种油腔滑调的推销宣传。
• The man adjusted very precisely.那个人调得很准。

15 contemplating   

深思，细想，仔细考虑( contemplate的现在分词 )； 注视，凝视； 考虑接受（发生某事的可能性）； 深思熟虑，沉思，苦思冥想

参考例句：

• You're too young to be contemplating retirement. 你考虑退休还太年轻。
• She stood contemplating the painting. 她站在那儿凝视那幅图画。

16 complexity   

n.复杂(性)，复杂的事物

参考例句：

• Only now did he understand the full complexity of the problem.直到现在他才明白这一问题的全部复杂性。
• The complexity of the road map puzzled me.错综复杂的公路图把我搞糊涂了。