Mr. Darwin supposes that natural-selection acts by slight variations.
natural selection n.
The process in nature by which, according to Darwin's theory of evolution, only the organisms best adapted to their environment tend to survive and transmit their genetic characters in increasing numbers to succeeding generations while those less adapted tend to be eliminated.
natural selection |
The process by which organisms that are better suited to their environment than others produce more offspring. As a result of natural selection, the proportion of organisms in a species with characteristics that are adaptive to a given environment increases with each generation. Therefore, natural selection modifies the originally random variation of genetic traits in a species so that alleles that are beneficial for survival predominate, while alleles that are not beneficial decrease. Originally proposed by Charles Darwin, natural selection forms the basis of the process of evolution. See Notes at adaptation, evolution. Compare artificial selection.
A process fundamental to evolution as described by Charles Darwin. By natural selection, any characteristic of an individual that allows it to survive to produce more offspring will eventually appear in every individual of the species, simply because those members will have more offspring.
Note: The expression survival of the fittest was used to describe this process in the nineteenth century but is not favored by modern scientists.