bertvan writes:
I was under the impreswsion that both Down's syndrome and sycle cell were defects.
Nobody is denying that mutations often cause a lot of problems. But this doesn't mean that all of them are disadvantageous. It just so happens that heterozygous sickle cell gives you immunity to malaria, which is a prevalent disease in Africa. The African population would have been wiped out by this disease if they didn't gain this mutation. But in a malaria-free environment, heterozygous and homozygous sickle cell cause a lot of problems. It all depends on the environment on what is considered advantageous and what's non-advantageous.
Firthermore, if genetic accidents, somehow turned into biological features by "natural selection" is a strawman, all you have to do is explain the real origin of biological features according to NeoDarwinism.
Somehow? What somehow? Environmental factors made sure that the sickle cell mutation was just advantageous enough to keep it alive within the population. That's not "somehow".
Look at it this way. It sure beats trying to get a miracle out of your god.
I'm trying to see things your way, but I can't put my head that far up my ass.
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