This is where my weird weird thoughts start coming in to play. Leave me somewhere on my own without a book, and things start to get odd.
I was waiting to get my hair cut the other day, and I thought something that I hadn't thought of in a while; isn't hair fucking weird? I mean, we're predominantly hairless creatures, and then we have this huge mat right on top of our heads. Not only that, the freaking thing grows indefinitely, and we take so much care with it and pull it and dye it and do all kinds of stuff to it but what is it really? A mop of very long body hair right on top of our heads.
How in the hell did it evolve?
Now I know that we lose a lot of heat from our heads, so of course it would be normal for us to keep hair there. But how did it go from being a patch of body hair to something that grows so freaking long? What other animal has hair that can grow that freaking long? Don't say lion's mane. Even though it can grow quite long, its an exclusively male characteristic, which could be selected for through sexual selection, more analogous to how a man's beard could have evolved. Both sexes of the human race have indefinitely growing hair, and there is nothing to suggest male selection for females with long hair viable, since that really never happens in evolution (except occasionally in those animals that have solely paternal care for young) as it is evolutionarily stable for males to impregnate pretty much any female that will have them. So how was it selected for?
Initially you could say well, more hair more heat retention. OK. But that only really works up to a point. Imagine primitive man trying to get about its day with hair down to its ass, not really all that useful and not any warmer than hair that is shoulder length. Also it would knot up and catch all kinds of nasty dirt and bugs that is in no way helpful. So how could it have come about?
Now to be honest, I haven't even attempted to research any possible theories that evolutionary biologists have come up with, if there are any (and there probably are). This is just the kind of thing that I will often ponder, and then I'll have a eureka moment if I think of something that might work, logic at its best. If anyone knows, or thinks of something, do tell me! Its a great way to flex your reasoning muscles, to hash out what could and could not work and for what reasons, and its even more fun when you're not just doing it by yourself!