how did kettlewell test his hypothesis?
How did Kettlewell test his hypothesis?
Answer:
In 1953, Bernard Kettlewell conducted a series of experiments to test his hypothesis of industrial melanism in peppered moths. His main hypothesis was that the changes in moth coloration were due to natural selection, with darker moths having a survival advantage in industrial areas where tree bark was darkened by pollution.
Kettlewell’s experiments involved releasing light and dark colored moths in both polluted and non-polluted woodlands to observe their predation rates. He used a method called mark-release-recapture to track the moths and record their survival rates.
Through his experiments, Kettlewell found that dark moths had higher survival rates in polluted woodlands due to their camouflage against the darkened tree bark. Conversely, light-colored moths had higher predation rates in these areas. This supported his hypothesis that natural selection was driving the changes in moth coloration.
These experiments provided strong evidence for the theory of natural selection and the concept of industrial melanism in peppered moths as a classic example of evolution in action.