Page "Peppered moth" Paragraph 25

At the start of this period, the vast majority of peppered moths had light coloured wing patterns which effectively camouflaged them against the light-coloured trees and lichens upon which they rested.

However, due to widespread pollution during the Industrial Revolution in England, many of the lichens died out, and the trees which peppered moths rested on became blackened by soot, causing most of the light-coloured moths, or typica, to die off due to predation.

At the same time, the dark-coloured, or melanic, moths, carbonaria, flourished because they could hide on the darkened trees.