Answer to Question #86853 in Evolution for Kush sharma

Question

Explain industrial melanism and genetic repatterning during isolation with examples.

Answer 1

Industrial melanism is the emergence of melanistic forms of animals as a result of their natural selection in habitats with the intensive development of the industry.

Dozens of species of butterflies are described in areas with large industrial centers in Europe (especially England) and North America, in populations of which melanistic forms have been found. The most famous example of this phenomenon is the peppered moth (Biston betularia).

Until the middle of the XIX century, all specimens of the peppered moth had a white-grayish color of the wings with dark spots, which ensured a dominant color on the trunks of trees. Now many populations are polymorphic, forming black melanistic forms - Biston betularia carbonaria. The appearance of melanistic forms is the result of directional selection, the main driving factor of which is the selective eating of butterflies by birds. In the forests around industrial conglomerates and cities, tree trunks are often devoid of lichens and can be blackened by soot. In such areas, the dominant color is black, and in non-polluted areas - light spotted color. As a result, the example demonstrates the genetic repatterning associated with the changes in the expression of certain alleles in the population caused by environmental conditions.