In the early 1950's, Kettlewell studied the changes in England's peppered moth population. Over a hundered year time period, the peppered moth population shifted from predominantly light-colored moths to predominantly dark-colored moths.
Kettlewell reasoned that predatory birds fed on more light-colored moths than on dark-colored moths because the light-colored moths were more easily spotted against pollution-darkened tree bark. This meant that the dark-colored moths survived in greater numbers, and the genes for their dark coloring were passed down to future generations. Using Kettlewell's study as the basis for experimentation, students conduct two simple quantitive lab activities that demonstrate the effects of environmental pollution on nature. Kit includes reusable supplies for 30 students.
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