In England, the trunks of trees were blackened for many years by soot from factories. After passage of the Clean Air Act in 1959, the trunks became lighter. Scientists in England studied the peppered moth (Biston betularia) which rests on these trees and is preyed upon by birds. They noticed the following change in frequencies over a period of time.

Charles Darwin´s Origin of Species

Explanation:

The way the peppered moth changed (or evolutionised) is in line with

Darwin´s origen of species theory. As its camouflage is vital for surviving, the peppered moth species turned out to be darker when the trees were blackened by soot and lighter after the Clean Air Act in 1959. This made them more difficult to be spotted by the birds and guaranteed them the survival of the best adapted (camouflaged) species.

Explanation:

d