Natural Selection

Name: _______________________________________ Period: ____________ Date: __________
                                         
                                      Natural Selection Homework

Directions: Read the following situations below and identify the key concepts of natural
selection.
Natural Selection: a natural process resulting in the evolution of organisms best
adapted to the environment.
Part 1:
There are three types of polar bears: one with thick coats, one with
thin coats and one with medium coats. It is fall, soon to be winter. The
temperatures are dropping rapidly and the bears must be kept warm,
or they will freeze to death. Many of the bears have had 2 cubs each
but due to the extreme temperatures, many mothers only have one cub left.
1. Which polar bear will NOT benefit from natural selection?

2. Identify the type of variation in the polar bear population.

3. Who is the most fit for her environment?

4. Predict how the gene pool will change over time with the polar bears?
5. Describe what is happening in figures 1 – 3.
6. Is the population of mice different in figure 3 than in figure 1? Explain your answer.

7. Living things that are well adapted to their environment survive and reproduce. Those
that are not well adapted don’t survive and reproduce. An adaptation is any
characteristic that gives the living thing the ability to survive and reproduce. What
characteristic of the mice is an adaptation that increased their chance of surviving and
reproducing?

8. An inheritable characteristic that helps an animal or plant have more offspring will
tend to become more common in a population as a result of evolution by natural
selection. Explain why a characteristic which helps an animal to live longer will
generally tend to become more common in the population as a result of evolution by
natural selection