VOA标准英语2012--Scientists Recreate Ancient Mating Call from Dinosaur Age
时间：2019-01-14 作者：英语课 分类：VOA标准英语2012年(二月)
Scientists Recreate Ancient Mating Call from Dinosaur 1 Age
It was probably a noisy world, with thousands of other animal sounds, rushing streams and the rustle 2 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 bug 3 was a music maker 4.
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 vein 5, modified with a series of pegs 6 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 vibrations 7.”
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 varied 8 rhythm and call patterns, Montealegre determined 9 that A. musicus had a simple, single-frequency pulsing tone.
“It’s a primitive 10 condition, just continuous singing. And in this case, the continuity would be a chirp 11 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 distractions 12. Montealegre says that sound marked a new era in acoustic 13 evolution.
“Many animals developed these acoustic capabilities 14. And it was a noisy environment and so they needed to produce private channels that they would attain 15 with pure tones and tuning 16 the sender and the receiver at the same respective frequencies for each animal.”
But any predator 17 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 ultrasonic 18 mating calls that their enemies could not hear.
The work is reported this week in the Proceedings 19 of the National Academy of Sciences.
- 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。
- 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。
- 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。
- 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。
- 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。
- 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
- 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》
- 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。
- 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。
- 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。
- 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。
- 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》
- 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。
- 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
- 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。
- 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》
- 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。
- 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。
- 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