1. Interaction of Heredity and Environment
-The environment interacts with genes in the development and expression of inherited traits.

2. Identical Twin Studies
Studies show that identical twins may show differences in their phenotype (appearance) as they mature.
These changes have been shown to be dependent upon the environment.

3. Effect of Temperature
The Himilayan rabbit- normally has white hair with black only on the extremities in their normal arctic environment.
In a warm climate, all of their hair develops white.
Ice experiment:

4. When ice is applied to the area where there is normally white hair, it grows back black.

5. Effect of Light
Without light most plants only produce a yellow pigment.
In the presence of light the plant will develop chlorophyll, turn green and perform photosynthesis.