139. Adaptations Overview

Scientists think plants first appeared about three billion years ago in the form of single-celled green algae. 

Today, we find plants in all sizes, shapes, and colors. Here you can see some fascinating adaptations that may stretch your understanding of what it means to be a plant.

This room highlights several plants that have evolved interesting characteristics in response to their environments. Some of these adaptations evolved in conjunction with animals and other organisms.

Many plant-animal interactions clearly benefit one organism over the other. Other relationships are mutualistic, benefiting both the plant and the organism they depend on. 

Plants can even form mutualistic relationships with bacteria. For example, some bacteria help plants by transforming atmospheric nitrogen into usable nitrogen, a plant nutrient that’s often limited in supply. Bacteria get carbon from the plant in exchange for the nitrogen.