Physical traits can be size, strength, color, and more, which allow an animal to survive.
For instance, a white rabbit doesn't live long in a green forest. Genes and physical traits change from one generation to the next. Since, the NSES suggest that biological evolution be taught in every biology classroom it is important to find ways to teach the students in a non-offensive manner. The KEY is to have students perform this lesson. At the end of each interval students who took a breath are instructed to go and stand in a corner of the room.