What is Industrial Melanism?
Industrial melanism is where natural selection pressures due to the man-made influences led to colour changes in various species. With the advent of the industrial revolution, many areas in North America and Europe started getting covered with black carbon. The species that relied on camouflage to avoid predators either adapted to the changing circumstances or got extinct. The process of industrial melanism refers to micro-evolution due to the changes in the species.
Also read: Human Evolution
Industrial Melanism in Peppered Moth
The peppered moth Biston betularia f.typica is a light coloured species with dark patches, that helps them to camouflage against the lichens on the barks of the trees. F.carbonaria which is a sub-species of f.typica had undergone some mutation and changed to a dark coloured moth with light patches. In the polluted areas, the light coloured species could not protect themselves from the predators. This was because the lichen population had reduced due to pollution and the light coloured species were easily visible on the tree barks. This replaced the f.typica species with the f.carbonaria species.
Since Europe has started using environment-friendly modern technologies, the selection pressure from predation has reversed and the moth is returning to its typical variety. This process is slower than the initial change because the allele is recessive for light colour and the copies from both the parents are required. This is called reverse industrial melanism. In Australia, one species of snakes living in water, with black and white stripes has become completely black due to urban pollution.
Industrial Melanism in Marine Dwellers
Industrial melanism had been observed in the turtle-headed sea snake. These snakes have black and white bands on their bodies, but the researchers have come across snakes living in polluted water that are completely black. This is the evidence of animals evolving with respect to change in the surrounding environment.
A.1. It is the appearance of dark melanic forms of some organisms like moths in the industrial region where the heavy emission of carbon from the burning coal has coloured the background.
Q.2. Which phenomenon does Industrial Melanism exhibit?
A.2. Industrial melanism exhibits Natural Selection.
Q.3. In which two organisms is industrial melanism observed?
A.3. Industrial melanism is observed in Biston betularia (peppered moth) and turtle-headed snake.
Q.4. What is Natural Selection?
A.4. Natural selection is a fundamental process of evolution in which any characteristic of an individual that allows it to survive and reproduce with the changing environmental conditions will be selected by nature and will gradually appear in all the individuals of that species.