system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are our ears shaped the way they are with all their weird ridges? Why aren't they more simply shaped like a funnel?
gpt
Part of the shape is to allow the ear to efficiently collect sound waves. However, part of it is also to disrupt the collection - allowing the angle of sound to have a greater effect on what you hear, allowing you to use your ears to sense the direction sound is coming from.

Other shapes are there to keep water from pooling into your ears (from sweat) and to drain efficiently at the same time. Plus, the shape needs to be strong enough to not easily be damaged (heat, cold, fights etc) yet not be a massive resource drain to build them. Additionally, the shape has to be formed by evolution - so each bump and twist and turn has to come about by random mutations that happen to work better for one thing, but maybe worse for another.