Historically fishermen kept larger fish and left smaller juvenile fish.Over time the average size of the fish would:

Question

Quizplus · Accepted Answer

The practice of keeping larger fish and leaving smaller ones leads to a higher selection pressure on larger fish, causing a decrease in their population. This selection pressure will also affect the overall genetic makeup of the fish population, resulting in a decrease in the average size of the fish over time. This phenomenon is an example of natural selection.

Historically Fishermen Kept Larger Fish and Left Smaller Juvenile Fish