Survival of the fittest

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For other uses, see Survival of the fittest (disambiguation).

Herbert Spencer coined the phrase survival of the fittest

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".

1 History of the phrase
2 Is "survival of the fittest" a tautology?
3 "Survival of the fittest" and morality
4 External links

[edit] History of the phrase

While the British economist Herbert Spencer is often credited with introducing the phrase "survival of the fittest" in his 1851 work Social Statics (relating to free market economics) or his First Principles of a New system of Philosophy of 1862, he actually did not use the phrase until after reading Darwin's Origin of Species. and introduced it in his Principles of Biology of 1864, vol. 1, p. 444, writing "This survival of the fittest, which I have here sought to express in mechanical terms, is that which Mr. Darwin has called 'natural selection', or the preservation of favoured races in the struggle for life."

In The Man Versus The State of 1884 Spencer used this phrase to reinforce his social theories, writing "Thus by survival of the fittest, the militant type of society becomes characterized by profound confidence in the governing power, joined with a loyalty causing submission to it in all matters whatever." Companies which offer better goods and services survive better in the marketplace and tend to accumulate an ever-growing market share. Poorly-adapting companies will be forced out by better-adapting ones: "killed" by the competition.

In the first four editions of The Origin of Species, Charles Darwin used the phrase "natural selection" [1] and preferred that phrase. However, Spencer's Principles of Biology drew parallels between his economic theories and Darwin's biological ones and made first use in print of the phrase "survival of the fittest". Darwin agreed with Alfred Russel Wallace that this phrase avoided the troublesome anthropomorphism of "selecting", though it "lost the analogy between nature's selection and the fanciers'." It was used by Darwin in the 5th edition of The Origin published on 10 February 1869, in a secondary header of Chapter 4 about natural selection [2] and at several places in the text, mostly using the phrase "Natural Selection, or the Survival of the Fittest". He gave full credit to Spencer, writing "I have called this principle, by which each slight variation, if useful, is preserved, by the term natural selection, in order to mark its relation to man's power of selection. But the expression often used by Mr. Herbert Spencer, of the Survival of the Fittest, is more accurate, and is sometimes equally convenient." At this time the word "fittest" would have primarily meant "most suitable" or "most appropriate" rather than "in the best physical shape".

In modern times, however, the phrase is widely used in popular literature as a catchphrase for any topic related or analogous to evolution and natural selection. It has thus been applied to principles of unrestrained competition, and it has been used extensively by both proponents and opponents of Social Darwinism. Its shortcomings as a description of Darwinian evolution have also become more apparent (see below).

Evolutionary biologists criticize how the term is used by non-scientists and the connotations that have grown around the term in popular culture. The phrase also does not help in conveying the complex nature of natural selection and modern biologists prefer and almost exclusively use the term natural selection. Indeed, in modern biology, the term fitness measures reproductive success and is not explicit about the specific ways in which organisms can be "fit" as in "having phenotypic characteristics which enhance survival and reproduction" (which was the meaning that Spencer had in mind).

[edit] Is "survival of the fittest" a tautology?

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Please see the discussion on the talk page.

"Survival of the fittest" is sometimes claimed to be a tautology. The reasoning is that if we take the term "fit" to mean "endowed with phenotypic characteristics which improve chances of survival and reproduction" (which is roughly how Spencer understood it), then "survival of the fittest" can simply be re-written as "survival of those who are better at surviving". The same criticism applies if we use the most widely accepted definition of "fitness" in modern biology, namely reproductive success itself (rather than any set of characters conducive to this reproductive success). This reasoning is sometimes used to claim that Darwin's entire theory of evolution by natural selection is fundamentally tautological, and therefore devoid of any explanative power.

However this criticism fails to consider that the expression "survival of the fittest", when taken out of context, is actually a very incomplete account of Darwinian evolution. The reason is that this expression does not mention a key requirement for Darwinian evolution, namely the requirement of heritability. Darwin's mechanism of evolution through natural selection implies that heritable variations lead to differential reproductive success, and therefore (precisely because they are heritable) become over-represented in the next generation. If the characters which lead to differential reproductive success are not heritable, then no meaningful evolution will occur, "survival of the fittest" or not. In other words, Darwinian evolution by natural selection does not simply state that "survivors survive" or "reproducers reproduce"; rather, it states that "survivors survive, reproduce and therefore propagate any heritable characters which have affected their survival and reproductive success".

When the full picture is considered, no tautology exists: the complete mechanism leading from heritable fitness-impacting differences, through differential reproductive success ("survival of the fittest"), to actual adaptive evolution (change in the makeup of lineages toward better adaptation) is a valid, informative reasoning, hinging on the testable hypothesis that such fitness-impacting heritable variations actually exist.

[edit] "Survival of the fittest" and morality

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.