Question

a group of small fish live in a lake with a uniformly light - brown sandy bottom. most of the fish are light brown, but about 10% are mottled. this fish species is often prey for large birds that live on the shore. a construction company dumps a load of gravel in the bottom of the lake, giving it a mottled appearance. which of these statements presents the most accurate prediction of what will happen to this fish population? the ratios will not change. the proportion of mottled fish will increase over time. there is no way to predict the result. in two generations, all the fish will be mottled. as the mottled fish are eaten, more will be produced to fill the gap.

Explanation:

Before the gravel - dump, light - brown fish had a camouflage advantage. After the gravel is dumped, the lake bottom has a mottled appearance. Mottled fish will now have better camouflage and thus a survival advantage over light - brown fish. Natural selection will favor the mottled fish, increasing their proportion in the population over time.

Answer:

The proportion of mottled fish will increase over time.