Consider two populations of fish that live in separate ponds and differ in the frequency of alleles at a locus. after a flood, the two ponds become connected by a stream and some fish are able to move between the ponds. what will happen to allele frequencies at this locus in the two populations?

The allele frequencies in the two ponds will become more similar to each other. Migration has two major effects. First it causes the gene pool of populations to become more similar. Second, migration adds genetic variation to population. Different alleles may arise in different populations owing to rare mutational events and these alleles can be spread ti new populations by migration, increasing the genetic variation within recipient population.