The theory of evolution by natural selection is about the changes that occur in all living things on earth over time. This process of change, which started on the first day of life on earth and continues up to the present, is what fortifies living things and enables them to survive and perpetuate their species. Detailed in a 500-page book entitled “On the Origin of Species by Natural Selection” published by Charles Darwin in 1858, the theory of evolution by natural selection essentially holds that on this earth, only the brawny and the brainy remain standing as a result of a perpetual struggle for survival.
It follows, therefore, that only the stronger and the smarter of the species get the opportunity to reproduce and keep their kinds endure. As a further result of this process of natural selection, the descendants of the surviving species only exhibit the traits (whether physical strength, size, agility, quick-wittedness, or the ability to change appearance) possessed by their ancestors that permitted them to stay alive in their particular habitats. It further follows, that as a result of this perpetual process of change, the creatures of the present are vastly different from the original or earlier creatures that lived on this earth.
(Regents of the University of Michigan. , 2005) Let us take as an example the case of the “peppered moth (Biston betularia)” in England. This particular species of moth that were found living among lichens in the trunks of trees before 1800 had a generally light coloring. Its coloring, therefore, enabled it to camouflage its presence among the lichens, thereby avoiding the predating birds. With the advent of the industrial revolution, the black smoke (soot) emitted by the industrial plants obliterated the lichens and darkened the trunks of trees.
This development exposed the moth to their predators, resulting to a decrease in their population. In order to survive, the moth metamorphosed and by 1819, a darker variant of the moth appeared – one that was able, once again, to escape the eyes of the predating birds. (Regents of the Univ. of Michigan, 2005) Reference Regents of the University of Michigan. (2005). Evolution and Natural Selection. Retrieved June 22, 2007, from http://www. globalchange. umich. edu/globalchange/current/lectures/selection/selection. html