On the bahamian island of andros, mosquitofish populations live in various, now-isolated, freshwater ponds that were once united. currently, some predator-rich ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds have mosquitofish that can swim continuously for a long time. when placed together in the same body of water, the two kinds of female mosquitofish exhibit exclusive breeding preferences. which two of the following have operated to increase divergence between mosquitofish populations on andros? improved gene flow bottleneck effect sexual selection founder effect natural selection