No more playing god

Survival of the fittest is a phrase which is a shorthand for a concept relating to competition for survival or predominance. Originally applied by Herbert Spencer in his Principles of Biology of 1864, Spencer drew parallels to his ideas of economics with Charles Darwin's theories of evolution by what Darwin termed natural selection. The phrase is a metaphor, not a scientific description; and it is not generally used by biologists, who almost exclusively prefer to use the phrase "natural selection". "Survival of the fittest" is sometimes claimed to be a tautology Many critics of evolution argue that "survival of the fittest" is a justification for violence and cruelty by premising human "rights" on the perceived quality of an individual by an arbitrary measure of "fitness". Evolution proponents often consider this to be an example of the naturalistic fallacy (or more specifically the is-ought problem), which states that prescriptive, moral statements cannot be derived from purely descriptive premises. On this view, while some have tried to use evolution as a justification for pseudoscientific ideas such as some forms of well known eugenics, these ideas are not actually supported by evolutionary theory.