Peppered Moth Survey
Introduction: Before the Industrial Revolution, the trees in the forest in Manchester,
England were light grayish-green. Peppered moths, which lived in the area, were colored
light with dark spots. Their coloring served as a protective camouflage against predators.
As the Industrial Revolution progressed, the trees became covered in soot, turning the
trunks dark. As a result, a change in the peppered moths took place. Industrial melanism
is a term used to describe the adaptation of an organism in response to a type of industrial
pollution.
Procedure:
1. Go to the following web address:
http://www.biologycorner.com/worksheets/pepperedmoth.html
2. Read the background information along the left-hand side of the page.
3. Click on the link labeled “Run Lichen (light colored) forest.” Play the part of the
blue jay for 3 minutes, attempting to feed on as many moths as you can by
moving the blue jay so that it is on top of the moth, and clicking the left mouse
button to “eat” the moths.
4. At the end of the three minutes, record the percentage of light and dark-colored
moths.
5. Repeat steps 3 and 4 using the “Run Soot (dark colored) forest.” Be sure to
record your results.
Data:
Percent Dark Moths
Percent Light Moths
Lichen Forest
Soot Forest
Analysis Questions:
1. What happened to the population of light-colored moths in the lichen forest?
2. What happened to the population of dark-colored moths in the soot forest?
3. Explain how the color of the moths increases or decreases their chances of survival
depending on the environment.
4. What variations existed in the moth populations?
5. Explain why those variations would eventually become adaptations.
6. What effect(s) would cleaning up the environment have on the populations of moths?
7. 500 light colored moths and 500 dark colored moths are released into a polluted
forest. After 2 days, the moths were recaptured. Make a prediction about the number of
each type of moth that would be captured.
8. Explain why you made the predictions you did in question #7.
9. Explain why this simulation shows Darwin’s theory of natural selection.