Determine the most likely reason why natural selection may cause prezygotic reproductive isolating mechanisms to evolve if postzygotic reproductive isolating mechanisms are already present, but natural selection can never cause the evolution of postzygotic reproductive isolating mechanisms. Ca Natural selection may lead to the evolution of prezygotic reproductive isolation in organisms that already have postzygotic isolation to prevent wasted reproductive effort. O Prezygotic isolation can evolve if postzygotic isolation has generated genetic variation during earlier periods of anagenesis. O If postzygotic isolation is present, then natural selection is already acting evolution of prezygotic isolation. Prezygotic reproductive isolating mechanisms are the necessary physiological and behavioral precursors for the evolution of postzygotic isolation via natural selection. same