纪录片《恐龙灭绝真相》 第24期 碰撞冬天（在线收听）

This little tree frog, like all amphibians, is very susceptible to acid rain.

这种小树蛙和所有的两栖动物一样，很容易受到酸雨的影响。

They have problems with their metabolism and finally they can't breed in the water.

它们的新陈代谢会出现问题，以至于最后不能在水中繁殖。

If acid rain had occurred at the end of the Cretaceous, all amphibians should have disappeared.

如果酸雨出现在白垩纪晚期，那所有的两栖动物都应该消失。

They don't, almost all of them survived,

但是它们没有，它们几乎都还活着，

as do all the turtles, the crocodiles, their cousins the alligators and most fishes.

所有的海龟、鳄鱼和它们的近亲短吻鳄，还有大多数鱼类也都活着。

This says that there can not have been battery acid strength acid rain at the end of the Cretaceous.

这就说明在白垩纪晚期没有出现像电池酸那样强的酸雨。

If there was no significant acid rain, it seemed another killing mechanism had been disproved.

如果至关重要的酸雨不存在，那么另一种引起大灭绝的事件也将难以立足。

And what about the so called impact winter?

那就是所谓的碰撞冬天。

Dust was meant to have blocked out the sun...

烟灰封住了太阳，

that could have plunged the world into deep freeze for months or years, but again those little frogs got in the way.

这种情况会使全世界陷入数月甚至数年的冰冷之中，但是这些存活下来的小青蛙又如何解释呢。

Amphibians like all cold blooded creatures have problems dealing with sudden drops in temperature,

像所有的冷血动物一样，两栖动物无法应对气温突然下降的情况，

especially if it lasts for many months or years.

特别是它会持续几个月甚至几年。

If this had happened at the end of the Cretaceous,

要是这样的情况出现在白垩纪晚期，

then many cold blooded organisms should have become extinct, but they did not.

那么许多冷血动物就应该消失，但是它们没有。

This tells us that there could not have been a long term drop in temperature.

这就告诉我们，地球历史上并没有发生过长时间的降温。