Natural selection

A mechanism of evolution, the dark moth, for example, became increasingly adapted to its industrial surroundings as soot darkened its habitat. The camouflage allowed them to live longer and have more offspring. Over time, the species changed.

Industrial Revolution

The factories produced dark soot that covered the surrounding habitat. Over time due to this, the camouflage of the light moth no longer worked on the darkened trees and buildings and the dark moth thus outnumbered the light moth.