Survival of the fittest" is a phrase which is shorthand for a concept relating to competition for survival or predominance. Originally applied by Herbert Spencer in his Principles of Biology of 1864,
Although Darwin used the phrase "survival of the fittest" as a synonym for "natural selection", it is a metaphor, not a scientific description.
It is not generally used by modern biologists, who use the phrase "natural selection" almost exclusively.
[B][I][U]An interpretation of the phrase to mean "only the fittest organisms will prevail" (a view common in social Darwinism) is not consistent with the actual theory of evolution
.Any organism which is capable of reproducing itself on an ongoing basis will survive as a species, not just the "fittest" ones
. A more accurate characterization of evolution would be "survival of the fit enough
", although this is sometimes regarded as a tautology.