I do feel the need to reply. "We have faulty programming. We are basically supposed to be the ones that die early on, and not spread our genes. Same goes for other diseased people". Not entirely true. There is evidence suggesting that CF has a heterozygote advantage. Eg They believe people with CF are somewhat resistant to cholera, typhoid, TB due to the mutated CFTR protein. Same with sickle cell anemia. So nature did it's course and it evolved in response to these outside things unfortunately nature screws up sometimes. And for some reason this reminds me of the x haplotype and mitochondrial eve.
Life/nature/whatever is erased all the time, we had more haplotypes than what we do now, Neanderthals are gone, Homo heidelbergensis etc. etc. etc. Things die out and things evolve whether we're directly involved or not. I expect this will be the case with CF, something will either mutate or it'll cease to exist. Given the rate medicine is going who knows. In any case people are culled out naturally; plagues, natural disasters, famine, etc. Irish potato famine, the bubonic plague in europe, the flu of 1918, etc. Some of the sociology courses that i've taken have covered this question; the answers are always varied and interesting. Population control is something that's being done in China: only so many number of children per household. Heck even depressions affect population numbers. If you're in financial straights you're more likely to put off marriage and starting a family until you can afford it.
Also I might add that unless you believe Charles Dawson, most anthropologists believe bipedalism came before the development of the brain back in the evolutionary chain of things.
