Evolution

Natural Selection, in biology, the non-random survival of randomly varying hereditary units, resulting in the evolution and maintenance of adaptive improvements. The importance of natural selection was first recognized, independently, by Charles Darwin and Alfred Russel Wallace. They compared it to the breeding of domestic strains by artificial selection and saw it as the tendency for individual organisms of differing heredity to vary in survival and reproductive success. It is often called by Herbert Spencer's name, "Survival of the Fittest". …