Question

Industrial melanism as observed in peppered moth proves that:-

• A. Melanism is a pollution-generated feature
• B. The true black melanic forms arise by a recurring random mutation
• C. The melanic form of the moth has no selective advantage over lighter form in industrial area
• D. The lighter-form the moth has no selective advantage either in polluted industrial area or non-polluted area

Answer 1

The Correct Option is B

Industrial melanism in peppered moths is an excellent example of natural selection and adaptation. The phenomenon was observed during the 19th century in Britain, where two forms of the peppered moth existed: the light-colored form and the dark-colored, or melanic, form.

Understanding Industrial Melanism:

• Natural Selection: Before industrialization, the light-colored form was more common because it could blend in with the light-colored lichen on trees, which protected it from predators like birds.
• Environmental Changes: With industrialization, pollution led to soot deposits on trees, darkening them and thus giving the dark-colored form of the moth a camouflage advantage over the light-colored form.
• Resulting Changes: As a result, the dark-colored moths increased in number in polluted areas because they were not as easily preyed upon by birds, demonstrating the principle of natural selection.

Explanation of Options:

1. Melanism is a pollution-generated feature: This is incorrect because melanism itself is not directly caused by pollution but is a trait that becomes advantageous due to changes in the environment.
2. The true black melanic forms arise by a recurring random mutation: This is the correct answer. The initial appearance of the melanic form is due to a genetic mutation, which then becomes prevalent through the process of natural selection.
3. The melanic form of the moth has no selective advantage over lighter form in industrial area: This is incorrect because, in polluted areas, the melanic form does have a selective advantage.
4. The lighter-form the moth has no selective advantage either in polluted industrial area or non-polluted area: This statement is partially correct but does not fully address the selection process; lighter forms are less advantageous in polluted areas.

In summary, the presence of black melanic forms in industrial areas is due to recurring random mutations that were favored by environmental changes, providing a selective advantage under specific conditions. This supports the concept of evolution via natural selection.