Rock Pocket Mouse Simulation

Manipulate the habitat (background) in this simulation and watch the characteristics of a rock pocket mouse population shift over time.

This activity is meant to start students thinking, not teach them everything about natural selection. If students don’t understand what’s going on, that’s ok. The lessons that follow will explore natural selection in more detail, and you can visit the simulation again later on.

1. Project the simulation or have students explore it individually.
2. As a whole class, summarize what you saw in the simulation.
   • Optional: To help your students understand more about these mice and their environment, show them the Rock Pocket Mice video linked below.

• If an individual has an advantageous trait, then it is more likely to reproduce.
• Since traits pass from parents to offspring, then offspring are likely to inherit advantageous traits.
• Over time, advantageous traits become more common in a population.

People have all kinds of interrelated misconceptions about natural selection and evolution. Keep these misconceptions in mind as you move through the module’s activities:

• “All members of a population are nearly identical; any differences are superficial.” In reality, all populations vary in their traits, and this variation is the fuel for natural selection.
• “Evolution (or natural selection) happens when individual organisms gradually get used to new conditions.” In reality, natural selection can only happen when trait differences lead to differences in reproductive success.
• “Evolution (or natural selection) is random.” While genetic variation is generated at random (through mutation and recombination) natural selection is, by definition, non-random.
• “Natural selection creates new traits.” In reality, natural selection can only act on heritable trait variations that already exist in a population.
• “Survival of the fittest means the strongest survive; fitness means physical fitness.” In reality, fitness in this case is reproductive fitness. The fittest individuals are the ones that are most successful at reproducing.

Student devices with internet access

Rock Pocket Mouse Simulation
Rock Pocket Mice (video)