User:Faulty Logic

http://rationalwiki.org/wiki/Mutation#Beneficial_mutations

It is safe to say that the vast majority of mutations in an organism are not beneficial.

Despite the odds against an individual mutation being beneficial, the driving force of natural selection means that when one does appear, it can quickly dominate a population. This is the entire point of natural selection, which invalidates any argument that "beneficial mutations" are too rare to ever have any effect.