VOA慢速英语--蝙蝠拥有长寿的秘诀吗？

Do Bats Hold the Secret to Long Life?

Bats are the only mammals that can fly a great distance, but they have another ability. Many bats live a very long time for an animal their size.

European researchers are studying bats to understand why they live so long. They hope to make discoveries aimed at fighting the aging process in human beings.

Last week, the group of scientists said they had identified important biological qualities in some bat species.

The group studied bat chromosomes¹, a line of genes² found in the nucleus³ of cells. The scientists were most interested in structures connected to the ends of the chromosomes. They are called telomeres.

Telomeres protect the ends of chromosomes, which shorten each time a cell divides. Scientists believe this shortening process causes cells to break down. They say this is what causes aging.

A report on bats was published this month in the journal Science Advances.

Among the leaders of the study was Emma Teeling, a biologist with University College Dublin in Ireland.

Teeling said studying long-living mammals that have developed ways to fight aging “is an alternative way to identify the molecular⁵ basis of extended ‘health spans.’”

She added that studying bats enables scientists to learn more about the processes “that drive healthy aging.”

The European researchers studied 493 bats from four bat species. The group used information that had been gathered over more than 60 years.

Of these animals, the greater mouse-eared bat generally lived the longest, an average of 37 years.

The scientists said this and a related species, which are grouped together under the name Myotis, had telomeres that did not shorten with age.

Another Myotis bat holds the record for oldest age, reaching 41 years.

The scientists’ findings suggest that these bats’ cells have the ability to maintain and repair their telomeres. This, they said, helps guard against the aging process.

Based on its body size, a bat like the greater mouse-eared bat would be expected to live four years. But, these mammals have been found to live nearly 10 times longer than that.

The scientists found that only 19 species of mammals live longer than humans when their body size is considered. Eighteen of these are bats. The only exception is an unusual African rodent⁶, the naked mole⁴ rat.

I’m Mario Ritter.

Words in This Story

mammals – n. animals that produce milk, have hair and have a high body temperature

alternative – adj. another way or possibility

species – n. a group of people or animals that belong together or have some shared qualities

maintain – v. to keep up or protect in an existing state

1 chromosomes   

n.染色体( chromosome的名词复数 )

参考例句：

• Chromosomes also determine the sex of animals. 染色体也决定动物的性别。 来自《简明英汉词典》
• Each of four chromosomes divide longitudinally. 四种染色体的每一种都沿着纵向分裂。 来自《现代汉英综合大词典》

2 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

3 nucleus   

n.核，核心，原子核

参考例句：

• These young people formed the nucleus of the club.这些年轻人成了俱乐部的核心。
• These councils would form the nucleus of a future regime.这些委员会将成为一个未来政权的核心。

4 mole   

n.胎块；痣；克分子

参考例句：

• She had a tiny mole on her cheek.她的面颊上有一颗小黑痣。
• The young girl felt very self- conscious about the large mole on her chin.那位年轻姑娘对自己下巴上的一颗大痣感到很不自在。

5 molecular   

adj.分子的；克分子的

参考例句：

• The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
• For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。

6 rodent   

n.啮齿动物；adj.啮齿目的

参考例句：

• When there is a full moon,this nocturnal rodent is careful to stay in its burrow.月圆之夜，这种夜间活动的啮齿类动物会小心地呆在地洞里不出来。
• This small rodent can scoop out a long,narrow tunnel in a very short time.这种小啮齿动物能在很短的时间里挖出一条又长又窄的地道来。