
I'm myopic and I'm slowly balding. Basically, these two things suck. I don't want to have to wear glasses or have worry about what I'll look like in few years when the fragile few hairs that currently cover the crown of my head finally give way. Yet, I'm not terribly troubled by these things. They're just a part of life for us humans (at least for a significant minority of us), minor genetic defects. But the word defect is so harsh. It's not like myopic people are seriously disadvantaged, are we? Certainly not in modern times with all our technology like: glasses, contacts and laser eye surgery. But what about in the past? How could humankind continue to pass on such undesirable genetic features to so many people? I've had a few thoughts that may shed some light.
For one, if a genetic feature is so widespread then it must absolutely be related to a structure within our physiology that was advantageous at some point in our evolution. Otherwise it would be bred out rather quickly. Somewhere, there must be a reason that baldness and myopia exist. There must have been a silver lining at some point in human evolution.
My wild theories for what these positive relationships are are as follows. It's beneficial for a minority of humans to be myopic because it makes them more introspective and individualistic. This creates a superior social and intellectual balance for the whole of society. I can defend this radical statement with two arguments. Humans evolved in tribes of a few dozen to a few hundred people. We have had, for maybe for a million years, the support system necessary to keep alive a small myopic minority. My guess is that even though these individuals were disadvantaged in some ways physiologically, they had one significant psychological freedom, they never worried about the expressions on other people's faces because they couldn't see them. Freedom from the social worry that comes with seeing what other individuals are thinking, based on the expressions of their faces, is a powerful thing. In other words, the function of myopia was basically social. It freed its sufferers from social worry and ensured that they focused inwardly more easily, thus allowing them to have deep and more radical intellectual, spiritual and philosophical thoughts. They therefore provided an advantage to society as a whole which was greater than their obvious disadvantages. Think about it, don't people who wear glasses just seem more intelligent and introspective? Could we ever have made it this far as a species without our stereotypical nerds and geeks? I don't think so.
I can't believe that to this day we still haven't come up with a proper cure for baldness. There's no advantage to being bald and I don't think that there has been for a very long time. But, if the aquatic ape hypothesis is correct, there might have been a very obvious reason why every single man would have once benefited from going bald. Here's a link to the Wikipedia page for this hypothesis: http://en.wikipedia.org/wiki/Aquatic_ape_hypothesis. In case you aren't familiar with the theory and don't want to read a whole article about it, I'll give you a brief rundown. First, our early ancestors became bipedal and learned to run very efficiently. In fact, we became the greatest runners on the planet and are still theoretically capable of outrunning every single species over a long enough distance. Don't believe me? Check out this cool article from Discover Magazine, http://discovermagazine.com/2006/may/tramps-like-us. Anyways, later on some folks got tired of having to run after their food and found an abundant source of food in the ocean. They figured out that by diving for shelfish they could thrive on a protein rich diet without working as hard. It's also posited by some that during this phase in our evolution our brains first started to grow significantly bigger than our chimp-like ancestor's. In support of the theory are several physical characteristics that make humans better swimmers than every other species of primate. Things like thin water-friendly eyelids, partially webbed digits and a serious lack of hair. If we spent tens of thousands of years or longer diving and swimming every day, why wouldn't men evolve to bald? Men were likely the primary providers for the tribe and as they got up in years, into their 30s and 40s, it would undoubtedly have been beneficial to lose more and more hair. I once watched a world cup swimming race where every single man on the starting line had a shaved head. I don't know if this provides any support for the aquatic ape hypotesis or the reason behind baldness, but I hope to at least have provided a little food for thought.