Materials

• 8 identical mousetraps • 8 balls (3 different sizes) • Paper plates • Pencils and markers

Instructions

1. Place one mousetrap on each paper plate and explain to students that they will attempt to demonstrate the process of natural selection with this activity.

2. Challenge students to explain how the mousetraps will be “selecting” for certain traits in the balls. Explain that the different sizes of the balls indicate different levels of “fitness” for the environment.

3. Divide the students into groups of two and give each team a set of balls. Instruct them to place the balls on the mousetraps and determine which size ball will be the most successful in setting off the trap.

4. Allow the students to test their ideas by releasing the balls on the mousetraps and observing which size ball sets off each one. After they complete their tests, encourage them to record their observations.

5. Discuss the results and explain that this is an example of natural selection. Explain that the balls with the right size and mass for the mousetrap environment were the most successful and were therefore “selected for”. Explain that this is similar to how organisms with certain traits are selected for and thrive in different environments.

6. Encourage the students to draw conclusions regarding their results and draw connections to the evolutionary process.