Question

Describe ‘Industrial Melanism’, explain theory of natural selection?

Answer 1

Industrial melanism:

1. Prior to the industrial revolution in England, light grey-colored moths were more abundant. Before industrialization, the tree trunks were covered with light grey-colored lichens. The grey-colored moths successfully hid among the lichens. Black-colored moths were rarely seen because could be easily spotted by predators.
2. During the industrial revolution, smoke polluted the environment and lichens disappeared. The tree trunks became black and the white-colored moths were replaced by the black-colored variety. This phenomenon is called industrial melanism.
3. Industrial melanism is an example of natural selection.

Theory of natural selection:

1. According to Darwin, variations occur naturally in all individuals of a species. These variations can be harmful, neutral, and useful.
2. In the struggle for existence, individuals with useful variations survive. This is called natural selection.
3. Useful variations present in the existing Individuals are passed on to the next generation. In this way, useful variations are accumulated over time which ultimately leads to the formation of a new species.