The answer is biological evolution.
The theory of biological evolution explains how organisms evolved during the time. It explains how the characteristics of different species changed over generations. According to the theory, most of current species developed from some distinctly different species that have lived a long time ago.
Answer:
the dissolved oxygen of the water decreases.
the fish need the oxygen for respiration, breathing through their gills.
Explanation:
The salinity decreasing doesn't affect the pickerel, because it's a freshwater fish. no salt needed.
more light penetrating the water just means that more aquatic weed or grasses would grow, giving the pickerel more area to spawn their eggs.
temperature increase in the summer has no affect on the fish, since the spawning happens in late winter.
YOU HAVE TWO LOOK AT BOTH
Answer:
your answer is correct. it is option 3
