Did bats evolve flight or echolocation first, or did it evolve in tandem?

进化出飞行能力还回声定位能力，或者两者同时进化的？

Toothed whales developed echolocation, a way to use sound waves to explore their surroundings.

齿鲸发展出了回声定位能力，这一种利用声波探索周围环境的方法。

Scientists have found that blind people are almost always a little better at echolocating than sighted people.

学家发现，盲人的回声定位能力几乎总比视力正常的人要好一些。

And those two adaptations -- stronger echolocation and powered flight -- made bats the stealthy aerial predators of insects that many still are today.

而这两种适应性变化——更强的回声定位能力和动力飞行能力——使得为了今天依然存在的那些昆虫的隐形空中猎手。

As its ability to echolocate evolved in power, so too did its ability to make longer jumps, which eventually turned into gliding and powered flight.

随着其回声定位能力的增强，它也逐渐能够进行更远的跳跃，最终演变了滑翔和主动飞行。

Scientists think baleen whales lost the ability to use echolocation when they stopped chasing after large fish and other mammals and started eating tiny fish and plankton, which swim in large, slow-moving schools.

学家认为，当须鲸停止追逐大型鱼类和其他哺乳动物并开始捕食小鱼和浮游生物时，它们就失去了使用回声定位的能力，这些小鱼和浮游生物群结队地游动缓慢。