I remember thinking as a kid that if I try to fly every day by flapping my arms, I will never succeed, but if I had a kid and told him or her to do the same, and they did, and then they teach their kids to do the same... eventually one of my descendants would evolve to the point of success.

It could happen, I reckon. It'd take thousands of years, perhaps millions. And when it happens, my great great great great (repeat a thousand more times) grandson will soar to the sky like a bird, before falling to his death and in the process rendering the flying human extinct an hour after it emerged as a unique species.

Yes I'm smoking.