Footnotes

All organisms need to be successful in their environment. This is a major requirement if they want to live. If an inherited trait, instinct, or physical ability helps a species get more food, find better shelter, evade predators, or have more babies it will aid survival.

What helps crocodiles survive in their environment?

The snowshoe hare has white coloring that helps camouflage it in the snow. Would this same white coloring help it in the jackrabbit’s habitat below?

If you were a hungry eagle and saw the snowshoe hare in this habitat, would you leave the snowshoe hare alone?

A trait, instinct or physical ability that gives a species an advantage in one environment can actually be a weakness in another environment.

Wild sunflowers grow in often dry mountains. Their small leaves and small flowers use less water. This variation helps them survive in their mountain environment, but in a wet warm place they would be more successful with big leaves and flowers.