Migration occurs at a constant rate between two populations

Migration occurs at a constant rate between two populations of butterfly, 89% of the insects are blue; in the other, only 10% are blue. Both color morphs are equally likely to migrate in both populations. What would you expect to happen to the allele frequencies in the two populations over time? why?

Solution

As the color morphs migrate from one population to the other population at an equal rate, the allele frequencies become nearly equal. Because migration acts as a force of homogenization. If the migration rate is high, the faster that population become homogenized.