Apopulation of short-finned fish and a population of long-finned fish live in a lake. fish with long fins swim faster than fish with short fins, which means they escape predators more often. according to natural selection, which of the following will happen over time? . a. the number of long-finned fish will increase.. b. the number of long-finned fish will decrease.. c. the number of short-finned fish will increase.. d. the number of short-finned fish will not change.