科学美国人60秒 SSS 2013-09-11_在线英语听力室

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In the east African savanna¹, pools of water form during the rainy season only to dry up a few months later. Being a fish in one of these temporary ponds is a challenge. To survive, they race to maturity², with the shortest generation time of any vertebrate.

To monitor the development of the so-called annual fish, researchers raised two different species in the lab.

The fish could grow by almost a quarter of their body length each day. One species could already reproduce at 17 days of age. The other took an additional day. The eggs these youngsters fertilized³ then hatched in as little as 15 days, leaving only a month between generations. The study is in the journal EvoDevo.

Embryonic⁴ annual fish survive the dry season by lying dormant⁵ underground. Once the rains return and the pool forms, they quickly reproduce before the water dries up again. Their short generation time is thus a crucial evolutionary⁶ adaptation. Their temporary ponds force them to live fast, die young and leave a desiccated corpse⁷.

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1 savanna
n.大草原
参考例句：
The savanna is also the home of meat-eaters--the lion,leopard,and hyena who feed on the grasseaters.大草原也是食肉动物的家乡--狮子、豹、鬣狗--它们都是以草食动物维持生命的。 They sped upon velvet wheels across an exhilarant savanna.他们的马车轻捷地穿过一片令人赏心悦目的大草原。

2 maturity
n.成熟；完成；(支票、债券等)到期
参考例句：
These plants ought to reach maturity after five years.这些植物五年后就该长成了。 This is the period at which the body attains maturity.这是身体发育成熟的时期。

3 Fertilized
v.施肥( fertilize的过去式和过去分词 )
参考例句：
The study of psychology has recently been widely cross-fertilized by new discoveries in genetics. 心理学研究最近从遗传学的新发现中受益匪浅。 Flowers are often fertilized by bees as they gather nectar. 花常在蜜蜂采蜜时受粉。

4 embryonic
adj.胚胎的
参考例句：
It is still in an embryonic stage.它还处于萌芽阶段。 The plan,as yet,only exists in embryonic form.这个计划迄今为止还只是在酝酿之中。

5 dormant
adj.暂停活动的；休眠的；潜伏的
参考例句：
Many animals are in a dormant state during winter.在冬天许多动物都处于睡眠状态。 This dormant volcano suddenly fired up.这座休眠火山突然爆发了。

6 evolutionary
adj.进化的；演化的，演变的；[生]进化论的
参考例句：
Life has its own evolutionary process.生命有其自身的进化过程。 These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。

7 corpse
n.尸体，死尸
参考例句：
What she saw was just an unfeeling corpse.她见到的只是一具全无感觉的尸体。 The corpse was preserved from decay by embalming.尸体用香料涂抹以防腐烂。

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科学美国人60秒 SSS 2013-09-11