VOA标准英语2012--Scientists Recreate Ancient Mating Call from Dinosaur Age

Scientists Recreate Ancient Mating Call from Dinosaur¹ Age

It was probably a noisy world, with thousands of other animal sounds, rushing streams and the rustle² of giant ferns and coniferous trees.
Fernando Montealegre studies how insects sing and hear.
When he and his colleagues at the University of Bristol got their first look at a fossilized pair of katydid wings found in China, it was obvious that bug³ was a music maker⁴.
Montealegre says Achaboilus musicus, as the new species was named, already displayed features that modern-day katydids use to make sound.
“One wing in extant species has a file vein⁵, modified with a series of pegs⁶ and the other wing has a scraper. So they open and close the wing and during the closing cycle they produce the sound. The scraper hits the file teeth and generates vibrations⁷.”
Montealegre and colleagues compared the pegs on the vein on the 7-centimeter-long katydid wings’ with those of 59 living bush cricket or katydid species. Unlike insects today that have varied⁸ rhythm and call patterns, Montealegre determined⁹ that A. musicus had a simple, single-frequency pulsing tone.
“It’s a primitive¹⁰ condition, just continuous singing. And in this case, the continuity would be a chirp¹¹ every one second.”
The male’s low six-kilohertz tone was especially adapted to carry over long distances at night.
The mating call rose from the forest floor and captivated females, despite other Jurassic distractions¹². Montealegre says that sound marked a new era in acoustic¹³ evolution.
“Many animals developed these acoustic capabilities¹⁴. And it was a noisy environment and so they needed to produce private channels that they would attain¹⁵ with pure tones and tuning¹⁶ the sender and the receiver at the same respective frequencies for each animal.”
But any predator¹⁷ that could have picked up the sound would have been a problem. Mammals may have fed on them. It wasn’t until 100 million years later that bats appeared. By that time katydids had developed ultrasonic¹⁸ mating calls that their enemies could not hear.
The work is reported this week in the Proceedings¹⁹ of the National Academy of Sciences.

1 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。

2 rustle   

v.沙沙作响；偷盗(牛、马等)；n.沙沙声声

参考例句：

• She heard a rustle in the bushes.她听到灌木丛中一阵沙沙声。
• He heard a rustle of leaves in the breeze.他听到树叶在微风中发出的沙沙声。

3 bug   

n.虫子；故障；窃听器；vt.纠缠；装窃听器

参考例句：

• There is a bug in the system.系统出了故障。
• The bird caught a bug on the fly.那鸟在飞行中捉住了一只昆虫。

4 maker   

n.制造者，制造商

参考例句：

• He is a trouble maker，You must be distant with him.他是个捣蛋鬼，你不要跟他在一起。
• A cabinet maker must be a master craftsman.家具木工必须是技艺高超的手艺人。

5 vein   

n.血管，静脉；叶脉，纹理；情绪；vt.使成脉络

参考例句：

• The girl is not in the vein for singing today.那女孩今天没有心情唱歌。
• The doctor injects glucose into the patient's vein.医生把葡萄糖注射入病人的静脉。

6 pegs   

n.衣夹( peg的名词复数 )；挂钉；系帐篷的桩；弦钮v.用夹子或钉子固定( peg的第三人称单数 )；使固定在某水平

参考例句：

• She hung up the shirt with two (clothes) pegs. 她用两只衣夹挂上衬衫。 来自辞典例句
• The vice-presidents were all square pegs in round holes. 各位副总裁也都安排得不得其所。 来自辞典例句

7 vibrations   

n.摆动( vibration的名词复数 )；震动；感受；（偏离平衡位置的）一次性往复振动

参考例句：

• We could feel the vibrations from the trucks passing outside. 我们可以感到外面卡车经过时的颤动。
• I am drawn to that girl; I get good vibrations from her. 我被那女孩吸引住了，她使我产生良好的感觉。 来自《简明英汉词典》

8 varied   

adj.多样的，多变化的

参考例句：

• The forms of art are many and varied.艺术的形式是多种多样的。
• The hotel has a varied programme of nightly entertainment.宾馆有各种晚间娱乐活动。

9 determined   

adj.坚定的；有决心的

参考例句：

• I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
• He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。

10 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。

11 chirp   

v.(尤指鸟)唧唧喳喳的叫

参考例句：

• The birds chirp merrily at the top of tree.鸟儿在枝头欢快地啾啾鸣唱。
• The sparrows chirp outside the window every morning.麻雀每天清晨在窗外嘁嘁喳喳地叫。

12 distractions   

n.使人分心的事[人]( distraction的名词复数 )；娱乐，消遣；心烦意乱；精神错乱

参考例句：

• I find it hard to work at home because there are too many distractions. 我发觉在家里工作很难，因为使人分心的事太多。
• There are too many distractions here to work properly. 这里叫人分心的事太多，使人无法好好工作。 来自《简明英汉词典》

13 acoustic   

adj.听觉的，声音的；(乐器)原声的

参考例句：

• The hall has a fine acoustic.这个大厅的传音效果很好。
• Animals use a whole rang of acoustic, visual,and chemical signals in their systems of communication.动物利用各种各样的听觉、视觉和化学信号来进行交流。

14 capabilities   

n.能力( capability的名词复数 )；可能；容量；[复数]潜在能力

参考例句：

• He was somewhat pompous and had a high opinion of his own capabilities. 他有点自大，自视甚高。 来自辞典例句
• Some programmers use tabs to break complex product capabilities into smaller chunks. 一些程序员认为，标签可以将复杂的功能分为每个窗格一组简单的功能。 来自About Face 3交互设计精髓

15 attain   

vt.达到，获得，完成

参考例句：

• I used the scientific method to attain this end. 我用科学的方法来达到这一目的。
• His painstaking to attain his goal in life is praiseworthy. 他为实现人生目标所下的苦功是值得称赞的。

16 tuning   

n.调谐，调整，调音v.调音( tune的现在分词 )；调整；（给收音机、电视等）调谐；使协调

参考例句：

• They are tuning up a plane on the flight line. 他们正在机场的飞机跑道上调试一架飞机。 来自《简明英汉词典》
• The orchestra are tuning up. 管弦乐队在定弦。 来自《现代汉英综合大词典》

17 predator   

n.捕食其它动物的动物；捕食者

参考例句：

• The final part of this chapter was devoted to a brief summary of predator species.本章最后部分简要总结了食肉动物。
• Komodo dragon is the largest living lizard and a fearsome predator.科摩多龙是目前存在的最大蜥蜴，它是一种令人恐惧的捕食性动物。

18 ultrasonic   

adj.超声的；n.超声波

参考例句：

• It was very necessary for people to take type-B ultrasonic inspection regularly.定期进行B超检查是十分必要的。
• Sounds are classified into two kinds: sonic and ultrasonic.声波分为两类，即普通声波与超声波。

19 proceedings   

n.进程，过程，议程；诉讼(程序)；公报

参考例句：

• He was released on bail pending committal proceedings. 他交保获释正在候审。
• to initiate legal proceedings against sb 对某人提起诉讼