Evolution is a process where all the living beings have to change and adapt themselves to their environment in order to survive. Evolution takes place in many ways and natural selection, is one on them. In natural selection, those living beings who are best adapted to the environment, survive and reproduce more aggressively thereby making similar offspring. The mechanism by which natural selection takes place is fivefold: Variation, Inheritance, Selection, Time and Adaptation.
In any organism, no two species are exactly same. Many times the change is small, for example, change in the color on wings of birds, eyes of fish or skin of a chameleon. These minute changes are called variation and are the result of random mutation triggered by environment. When the organism reproduces, the mutation is passed on to the offspring. Thus, the offspring inherits the traits from parents and is born with better adaptability (AMNH.org). As always, nature has limited supplies but, there are organisms in any given population who survive better than others by finding food, camouflaging from predators and mating. These traits get selected in these organisms, which help them adapt and propagate efficiently, hence they survive and others perish. The genetic traits passed on to the next generation gives the offspring an upper hand and a chance to pass the same to yet another generation. Thus, generation after generation, the selected traits are passed and the organism which displays them becomes robust in time (Fisher).
Finally, the process of acquiring new traits by natural selection continues by the mechanism of variation-inheritance-selection-time-adaptation, ending in species which are best adapted to the ever changing environment and evolve to dominate, reproduce and survive.
References
“How does natural selection work?” amnh. n.d. Web. 19 Nov 2014.
Fisher. The Genetical Thory of Natural Selection. Oxford: Clarendon Press, 1930. Web. 19 Nov 2014.
