Survival of the fittest, only the strong survive, scientists today still believe, as Darwin did, that natural selection is one of the major mechanisms by which evolution, as least theoretically, occurs. Charles Darwin observed that within a particular animal or plant species, there are various colors, shapes and other traits. Along with this observation, Darwin contended that in nature the weaker varieties of animals and plants are ‘killed off’ by the stronger varieties due to their better ability to compete for