Peppered moth Evolution

http://en.wikipedia.org/wiki/Peppered_moth_evolution

The evolution of the peppered moth over the last two hundred years has been studied in detail. Originally, the vast majority of peppered moths had light colouration, which effectively camouflaged them against the light-coloured trees and lichens which they rested upon. However, because of widespread pollution during the Industrial Revolution inEngland, many of the lichens died out, and the trees that peppered moths rested on became blackened by soot, causing most of the light-coloured moths, or typica, to die off from predation. At the same time, the dark-coloured, ormelanic, moths, carbonaria, flourished because of their ability to hide on the darkened trees

the dramatic change in the peppered moth's population has remained a subject of much interest and study, and has led to the coining of the term industrial melanism to refer to the genetic darkening of species in response to pollutants. As a result of the relatively simple and easy-to-understand circumstances of the adaptation, the peppered moth has become a common example used in explaining or demonstrating natural selection.

In 1924, J.B.S. Haldane calculated, using a simple general selection model, the selective advantage necessary for the recorded natural evolution of peppered moths, based on the assumption that in 1848 the frequency of dark-coloured moths was 2%, and by 1895 it was 95%. 

Biston betularia f. typica, the white-bodiedpeppered moth.

Biston betularia f. carbonaria, the black-bodied peppered moth.