时差N小时 变性的青蛙（在线收听）

As you may have heard, frogs and toads have had a rough time over the past several years.

就如你听说的那样，青蛙和蟾蜍在过去的数年中都过得很艰难。

Some populations have vanished entirely, while others suffer disease and gross deformities likeextra or missing limbs.

有些种群已经完全消失了，有些患上了疾病，有些严重畸形，如多长了或是失去了四肢。

And now there's more bad news for the spring-legged amphibians

现今佛罗里达大学科学家们的研究带来了更坏的消息，

maletoads living near farms are likely to develop female sex organs and other female features,according to scientists at the University of Florida.

他们发现生活在农田周围的这些拥有弹簧腿的两栖雄性动物，极有可能演变生长出雌性性器官，并表现出其它雌性的特征。

What is it about farming that causes toads to gender jump?

是什么样的农田耕作让青蛙有如此的性别跳跃呢？

The Florida researchers aren't certain,but one likely culprit is atrazine, a weed killer used widely by sugar cane farmers.

佛罗里达大学的研究人员还不确定，但其中可能的罪魁祸首之一就是阿特拉津，一种被种植甘蔗的农民广泛使用的除草剂。

Other farm-related chemicals could also play a role.

其它与农田有关的化学物质也有可能。

In order to probe the possible causes of frog and toad deformities, the researchers collected specimens from various sites.

为了查明引起青蛙和蟾蜍畸形的原因，研究人员从多个地点搜集了样本。

Some of the toads lived nearsuburban development, some near farms.

一些青蛙生活在城郊郊发展地带，一些生活在农田附近。

The male specimens collected near farms were mostlikely to show signs of feminization.

在农田周围搜集的雄性样本也多半表现出雌性化的迹象。

For example, of the male toads living near large farms, forty-percent had both testes and ovaries.

例如，在大农场附近居住的雄性青蛙，百分之四十同时拥有睾丸和卵巢。

Another twenty-percent of these toads had a developing Bidder's organ—an organ that'snormally without function in male toads,

其余的百分之二十拥有正在进化中的毕氏器官—在雄性青蛙体中中并没有任何功能，

but that can change into an ovary if the testes stop working.

但是一旦睾丸停止工作，这个器官就会转变为卵巢。

Some of the male toads were found with Bidder's organs full of eggs.

一些雄性青蛙被发现拥有装满卵的毕氏器官。

Part of the problemis that the feminized toads are most likely sterile.

问题的一部分就是雌性化的青蛙有可能会不孕。

Without virile male toads, the females are left high and dry, and toad populations dwindle.

如果没有阳刚的雄性青蛙，雌性青蛙就会处于孤立无援的境地，青蛙的数量就会减少。