Sorry, but I haven't read it on some website.
It stands to reason that if today's biologists state the cheetah's are in danger of becoming extinct because of not enough DIVERSITY in the gene pool (NOT too few individuals) then actually GETTING 'diversity' in the gene pool to begin with is VERY suspicious as well.
Where is the fallacy?
the fallacy is that you propose that the cheetah had no evolutionary advantage over the pre-cheetah which is the basis for evolutionary theory.
It sort of like your proposing that the automobile is a failure since it sinks everytime you drive it into a river.