What is Industrial melanism ?

Explanation

**Step-by-Step Solution:**

1. **Definition of Industrial Melanism:**
- Industrial melanism refers to the phenomenon where animals, particularly moths, develop darker coloration in response to environmental changes caused by industrial pollution, specifically industrial smog.

2. **Historical Context:**
- The concept of industrial melanism was notably observed in England during the 19th century, particularly before and after the onset of industrialization.

...