Lab report on natural selection.
Problem: The purpose of this investigation is to simulate natural selection in a population.
Hypothesis: If there are five colored rocks, then the green color rocks will not be picked as much.
- Laminated wrapping paper (environment)
- Aquarium rocks of various colors (insects with coloration differences)
- Colored pencils
- Graph paper
1. Students should work in groups of 4, assigning the following roles:
1 game warden: distributes the insects randomly and keeps time
3 predators: “eaters” of the prey
2. Examine the rocks that will represent your insect population.
3. Examine the wrapping paper that will represent the environment in which the insects live.
4. Assume that the population begins with 20 members of each color and write your hypothesis for how natural selection may be observed in this population after a simulation of several generations of predation and reproduction.
5. Count out 20 of each color of rock, trying to select rocks that are close in size to one another.
6. Have the game warden spread the rocks out evenly and randomly over the wrapping paper environment while the predators look away.
7. The game warden will serve as official time keeper and will tell the predators to “start” and “stop.” All predators will “eat” at the same time for 20 seconds, eating randomly as a rock catches their eye. Try to avoid picking or avoiding colors on purpose or skewing data deliberately.
8. After the “eating” has stopped, students should collect and count the survivors (those still on the wrapping paper environment). Record this data on your chart.
9. Simulate reproduction in the surviving population by adding 3 rocks of that color for each survivor (ex: if 11 pink rocks remain, then 44 pink rocks will be placed in the environment for the next predation). Record this data on your chart.