What do mutations do to alleles?

Answer 1

Generally, gene frequency will not change significantly unless the mutation is successful and advantageous enough that it is heavily selected in the population.

Since most mutations result in failure of the organism to thrive (death, reproductive failure, etc.) they have little or no effect on a population's gene frequencies.

Even if the mutation has no apparent detrimental effects it will, itself remain in the population at a low frequency unless it enhances the organism's ability to

reproduce within the population.

Answer 2

Mutation changes the allele frequency.

Say there are two alleles, A and a, and p is the frequency of A and p=0.9, q is the frequency of a and q=0.1.

Say that some A alleles mutated into a, now there would be less A allele than before, thus p will decrease, and q will increase. The new frequencies could be p=0.8, q=0.2.

Answer 3

Mutations introduce new alleles into the gene pool.