Tree squirrels can have different fur colors.
Squirrels live in forests where foxes also live. Foxes hunt squirrels for food. Squirrels that have fur the same color as the trees are harder for the foxes to see and catch.
[IMAGE ONE]
The diagram above shows a population of squirrels that lived in a forest. Scientists had previously only seen brown and gray squirrels in this forest; they had never seen squirrels of any other color.
The diagram below shows how the population changed after many generations.
[IMAGE TWO]
How did the color of the trees in the squirrels’ environment change? Explain what happened to the squirrels over many generations.

