Comment Re:How long before... (Score 2) 105
If it wasn't, that mutation would have been selected out of existence a long time ago.
OK, smartass, what is the evolutionary advantage for stupidity?
Because you'd think we'd have selected that away a long time ago as well.
Hell, we have an appendix. Why do we have an appendix? Why hasn't evolution made that go away?
Evolution is awesome, but it can do some silly things that stick around.
Most people think of evolution as "survival of the fittest", but this is a gross simplification. In a population bottleneck, genetic diversity can shrink rapidly if a large portion of the population dies out. Imagine what would happen if everyone in the world died except a small and distinct group- lets say the Vietnamese people just for example. If the population recovered and repopulated the world, humans would have lost a tremendous amount of genetic diversity which may or may not be beneficial to survival.
Evolution in the traditional sense also only affects characteristics which affect the ability to reproduce. For example, it is impossible for humans to evolve the problem of cataracts or alzheimer's out of our genetic code. By the time these problems show up, the children of those affected have already become self-sufficient. Evolution is about "reproduction of the fittest" not the more general "survival of the fittest".