Here's why:
* All living organisms react to their environment in some way. This is a fundamental characteristic of life. Reactions can range from simple (like a plant turning towards the sun) to complex (like a bird migrating for the winter).
* Survival depends on the ability to react to the environment. Organisms that cannot respond to changes in their surroundings (temperature, food availability, predators, etc.) are less likely to survive.
Therefore, it's not just a few organisms that react to their environment and survive; it's a necessity for all living things.
