how did kettlewell test his hypothesis
How did Kettlewell test his hypothesis?
Answer:
Bernard Kettlewell, a British geneticist, conducted experiments in the mid-20th century to test the hypothesis of natural selection on peppered moths. In his experiments, Kettlewell wanted to show how industrial melanism, which is the darkening of the moth’s wings due to pollution, influenced their survival rates.
Kettlewell conducted his experiments in two main ways:
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Field Experiments: Kettlewell released both light and dark-colored peppered moths into polluted and unpolluted woodlands to observe their survival rates. He did this to determine if the color of the moths provided camouflage against their surroundings and if pollution played a role in predation rates.
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Mark-Release-Recapture Studies: In these studies, moths were captured, marked, released, and then recaptured to see how many were found in subsequent collections. By comparing the proportion of marked moths to unmarked moths in the recaptured samples, he could estimate moth survival rates and understand the impact of coloration on moth predation.
Kettlewell’s experiments provided evidence that darker moths had a survival advantage in polluted woodlands due to camouflage against lichens on trees. This work became one of the classic examples used to illustrate natural selection in action.