I Can Hear the Ocean

This is interesting:

Your ability to hear relies on a structure that got its start as a gill opening in fish, a new study reveals.

Humans and other land animals have special bones in their ears that are crucial to hearing. Ancient fish used similar structures to breathe underwater.

Scientists had thought the evolutionary change occurred after animals had established themselves on land, but a new look at an old fossil suggests ear development was set into motion before any creatures crawled out of the water.