Why is it difficult for new dominant alleles to go to fixation in a population, even if they increase in
frequency very rapidly due to selection?
Additive alleles keep them from going to fixation.
Recessive alleles that interact are more dominant, so homozygous recessive individuals are
maintained in the population.
Residual recessive alleles end up being present in a few remaining heterozygous individuals, that
then rely entirely on drift to change their frequency.
Populations with dominant alleles always suffer from high rates of mutation.