Molecular data can be used to assess relationships among the major groups of living organisms whose common ancestors lived millions or billions of years ago. Similar techniques can be used to assess relationships among populations within a species. How can molecular techniques be useful for such varied comparisons?

Which of the following is likely not involved in this example of ecological succession? a) the rotting remains of plants add to the fertility of the soil. b)the soil becomes so fertile that eel grass is replaced by other plant species. c) the roots from plants stabilize the sediment, keeping it in place. d) the concentration of salt becomes so high that all plant life is destroyed.