An established ecosystem may remain stable over hundreds of years because *
A. species interdependence is absent
B. there is a lack of variety in the species
C. no competition exists between the species
D. there are natural checks on species

The image shows the evolution of a species of fish. a few fish from a population developed different social behaviors and evolved into different species. two fish according to the image, the fish underwent . the new species of fish had mating seasons that were different from that of the original fish. because of the differences in mating seasons, the fish underwent reproductive isolation. this mode of isolation would be .