How did dr kettlewell determine if moths lived longer than others
The Correct Answer and Explanation is :
Dr. Bernard Kettlewell conducted groundbreaking experiments in the 1950s to investigate the survival rates of different color variations of the peppered moth (Biston betularia) in England. His research aimed to understand the impact of natural selection on these moths, particularly in relation to their coloration and the industrial revolution’s effect on their habitats.
Kettlewell’s experiments primarily focused on two color morphs of the peppered moth: the light-colored form, which blended in with the lichen-covered trees, and the dark-colored form, which became more prevalent in polluted areas due to the soot covering the trees. To determine which color variation had a higher survival rate, Kettlewell conducted two main types of experiments: marking and release, and predation studies.
In the marking and release experiment, Kettlewell captured both light and dark moths, marked them with a unique identifier, and released them back into their natural habitat. He then observed how many of each color were recaptured over time. This process allowed him to assess the survival rates of each color morph.
For the predation studies, Kettlewell placed both light and dark moths on tree trunks in contrasting environments (light and dark backgrounds) to simulate natural conditions. He then released birds into the area to observe their predation behavior. He found that in polluted areas where the trees were darkened, dark moths had a higher survival rate, while light moths were more vulnerable to predation. Conversely, in cleaner areas with lighter trees, light moths thrived better.
Through these experiments, Kettlewell demonstrated that the coloration of moths significantly affected their survival rates due to predation, providing a clear example of natural selection in action. His work not only enhanced our understanding of evolutionary biology but also highlighted the dynamic relationship between organisms and their environments.