Answer:
they can make the organism better suited to the environment.
Step-by-step explanation:
often when an organisms environment changes, the organism will change with it in order to survive...it's the survival of the fittest theory...you either adapt to your changing environment or the species will die off. this is shown in the way that different species of birds have differently shaped beaks based on the types of seeds and flowers available for them to eat. some eat big seeds and some eat small ones ...the humming bird has a certain flower it collects nectar from as food....when the flower gets larger, making the near further down and harder to reach, the humming birds beak will become slightly longer over a few generations making the better equipped to reach the nectar again ....