Natural Selection - process by whch populations become adapted to the environment.
             The fitness of an individual is measured by how well its offspring reproduce - i.e. how many offspring that survive and reproduce does an individual produce
             Charles Darwin studdied and closly watched peppered moths (Biston Betularia) in their natural habbitat. The peppered moths are light colored with darker areas of color. Like humans, however, these moths can be found in a range of pigmentation from very black to very white and all shades in between.He watched durring the Industrial Revolution in the middle of the 18th century. Soot from the factories was starting to discolor the trees making the moths visable to passing predators.
             The different colored moths all belong to the same species; they reproduce with each other, and the color difference depends primarily on alternate alleles for a single gene. The black moths were presumably produced by mutation: biochemical change in DNA that makes up the genes for a trap. Under the Hardy-Weinberg Principle it is stated that the frequencecy of dominat and resessive alleles is the same from generation to generation. This was not he case.
             Peppered moths rest during the day on tree trunks, where they are vulnerable to being eaten by birds. In pre-industrial England, tree trunks were gray. Gray moths are well camouflaged on gray tree trunks; black moths stand out. It has been shown experimentally (by Kettlewell) that in areas with gray tree trunks, black moths are much more likely to be eaten by birds than are gray moths (presumably because black moths are much easier for the birds to see.)
             In industrial areas, because black moths avoided being eaten by birds, they survived better and therefore reproduced more (had higher fitness.) As a result, each generation, more and more of the offspring born came from black parents and inherited the black coloration, since the color differences between moths (gr...