If a mutation is irreversible, then the original allele will eventually go extinct in the population. (True or False)

Question

I said it was false because I think the original allele can be recessive and also I think it means that mutation will become fixed.

Answer 1

False, but not quite for the reasons you're thinking. whether or not the mutation or the original allele survive/become fixed/go extinct just depends on their relative fitness. Without knowing if the mutation is helpful or deleterious, there's not much we can say.

Hope that helps!