[swingdoc]

The ear is an incredibly good example of an organ that combines ridiculous complexity with sturdy solidity. A simple membrane is actually inferior in both categories. I think it's safe to say that a simple membrane would not give anywhere near the same amount of information that our cochlea does to our brain. A simple membrane hooked to a nerve would also be insanely easy to damage beyond repair. Hearing was obviously very important to survival so a sturdy ear that can withstand trauma, infection, environmental exposures, etc is critical.

Inability to sleep at will is sort of dependent on the person. Some of us certainly can do this. I suspect earlier man was able to do this even more easily. I think at least two factors have made it more difficult. (1) electricity - melatonin levels are important in allowing us to go to bed and these get screwy with conflicting messages of whether it is light or not, (2) decrease in physical activity on average - when we were busy chasing rabbits and other animals all day or fighting off the bigger animals, we experienced physical tiredness. Many, many people today simply don't have this sort of physical exertion as a normal part of their life.

Stuff that doesn't make a lot of sense:

1. Trachea starts in a crazy bad place. Why couldn't the opening somehow be higher in the throat, up more in the nasopharynx, so that choking when swallowing isn't an issue?

2. Limited number of eggs for the ladies. Why in the world do women have a limited number of eggs while men have unlimited aquamen? I really don't see any advantage to having a truncated period of fertility. Many asexual organisms don't have this same limitation.