Darwin's Finches and Natural Selection

Darwin's Finches And Natural Selection Polymorphism pertains to the existence of two distinctly different groups of a species that still belong to the same species.

Alleles for these organisms over time are governed by the theory of natural selection, and over this time the genetic differences between groups in different environments soon become apparent, as in the case of industrial melanism." (Biology Online, 2000) Darwin's finches are an excellent examples of such polymorphism, "of the way in which species' gene pools have adapted in order for long-term survival via their offspring." (Biology Online, 2000) The finches Darwin studied were a species of small Galapagos finches and were only found on the Galapagos Islands.

They were geographically isolated and without competition from similar species but these finches developed distinctive anatomy. Darwin noted how finches in some areas had completely different shaped beaks than other finches. Even though all were of the same species, natural selection in particular environments favored one kind of finch over another, depending on which finch's offspring had the beak most amenable to surviving in a particular ecological niche.Their beaks had evolved over time to be best suited to their function.

For example, in areas with many grubs, the finches who survived in greatest number were those with thin extended beaks. These birds could more easily poke their beaks into holes in the ground and extract the grubs. Finches with claw like beaks were less sucessful at this. But,.