Survival of the Fittest

Charles Darwin has long been associated with the phrase, “survival of the fittest.” For a century and a half people have used it to refer to their understanding of his explanation of how species evolved.

But it wasn’t his. And it has obscured the understanding of Darwin’s own theory.

It came from a contemporary, Herbert Spencer. Spencer was a contemporary of Darwin – an English polymath:  philosopher, biologist, anthropologist, sociologist, economist liberal political theorist, utilitarian – and, by some accounts, an early libertarian. His ideas came from people like Malthus and Adam Smith (read more about his philosophy here). Wikipedia tells us:

For many, the name of Herbert Spencer would be virtually synonymous with Social Darwinism, a social theory that applies the law of the survival of the fittest to society; humanitarian impulses had to be resisted as nothing should be allowed to interfere with nature’s laws, including the social struggle for existence. Spencer desired the elimination of the unfit through their failure to reproduce, rather than coercion or state intervention to initiate their physical annihilation.

He wrote his interpretation of Darwin’s ideas in an 1864 textbook of biology:

“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.”

Spencer was really trying to apply Darwin’s ideas to his own ideas about economics, class struggle, competition and politics. He also believed in Lamarckism – the inheritance of attributes gained in one generation by the next – which has long since been discredited. But whether you agree with Spencer’s views, his reduction of Darwin’s theory to a convenient axiom did the theory an injustice.

In the public mind, Darwin’s ideas about natural selection were confusing and challenging. They became conflated with Spencer’s ideas and somehow the phrase stuck – the Victoria era equivalent of a bumper sticker phrase. It became wildly popular, and was soon applied to social and political phenomena, not simply biological.

It was so popular as a catch phrase that in the 1869  fifth edition of his book, On the Origin of Species, Darwin – unfortunately – added this line:

“But the expression often used by Mr. Herbert Spencer, of the Survival of the Fittest, is more accurate, and is sometimes equally convenient.”

The problem is really in how the word “fittest” is defined. Like its sister term, theory, it has both a common and a scientific meaning.*

Fittest, in Darwin’s sense, doesn’t mean the biggest, best, toughest, strongest or even the most competitive. It’s not the macho concept of superiority. It isn’t about power, control or brute force.

It means the “best suited for the immediate environment.” It has also been described as a “property of the relationship between the organism and the environment.” That might be a different colour, smaller size, less active. Whatever offers the best opportunity to survive and breed. Having offspring is key.

It’s a far more subtle notion than commonly used. As Wikipedia says:

Modern evolutionary theory defines fitness not by how long an organism lives, but by how successful it is at reproducing. If an organism lives half as long as others of its species, but has twice as many offspring surviving to adulthood, its genes will become more common in the adult population of the next generation.

However, the axiom “survival of the fittest” has taken on a life of its own, and continues to be used in relationship to a melange of ideas and popular cultural notions. Social Darwinism, for example:

Social Darwinism is not any single well defined concept, but various ideologies that seek to apply biological concepts associated with Darwinism or other evolutionary theories to sociology, economics and politics, often with the assumption that conflict between groups in society leads to social progress as superior groups outcompete inferior ones.
The name social Darwinism is a modern name given to various theories of society that emerged in England and the United States in the 1870s, which, it is alleged, sought to apply biological concepts to sociology and politics. The term social Darwinism gained widespread currency when used in 1944 to oppose these earlier concepts. Today, because of the negative connotations of the theory of social Darwinism, especially after the atrocities of the Second World War, few people would describe themselves as social Darwinists and the term is generally seen as pejorative.

Darwin is well known today, although hardly read by the general public. His masterwork, On the Origin of Species (the full title is a mouthful: On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life), may be the most commented-upon book that has not been read by its detractors in the entire history of publishing. It’s hardly even read by people who claim to support evolution and science.

It’s certainly not read by the creationists or ID believers looking to make magic the agent instead of a natural, observable agent.**

Sure, it’s not an easy book to read: written 150 years ago in a florid, yet classically beautiful style. It takes a circuitous route to presenting its core ideas, like a shy man courting a beautiful woman. It doesn’t rush into things; it dances to it, slowly. Carefully; each step laid out. And done in an elegant, reserved manner.

There are many good definitions of natural selection online today, and many reduced to the basic, non-technical elements for everyone to understand. Berkeley University has one that lists five steps:

1. There is variation in traits. For example, some beetles are green and some are brown.
2. There is differential reproduction. Since the environment can’t support unlimited population growth, not all individuals get to reproduce to their full potential. In this example, green beetles tend to get eaten by birds and survive to reproduce less often than brown beetles do.
3. There is heredity. The surviving brown beetles have brown baby beetles because this trait has a genetic basis.
4. End result: The more advantageous trait, brown coloration, which allows the beetle to have more offspring, becomes more common in the population. If this process continues, eventually, all individuals in the population will be brown.

The late Stephen Jay Gould described natural selection in a 1994 article in Scientific American:

Natural selection is an immensely powerful yet beautifully simple theory that has held up remarkably well, under intense and unrelenting scrutiny and testing, for 135 years. In essence, natural selection locates the mechanism of evolutionary change in a “struggle” among organisms for reproductive success, leading to improved fit of populations to changing environments. ( Struggle is often a metaphorical description and need not be viewed as overt combat, guns blazing. Tactics for reproductive success include a variety of non-martial activities such as earlier and more frequent mating or better cooperation with partners in raising offspring.) Natural selection is therefore a principle of local adaptation, not of general advance or progress.

(NB: Michael Shermer’s review of Gould’s magnum opus, The Structure of Evolutionary Theory is also worth reading).***

The phrase, by the way, was also preferred by Darwin’s contemporary, Alfred Lord Wallace,  who used both “survival of the fittest” and “struggle for existence” to describe his theory of evolution.

The bottom line is that “survival of the fittest” is a mis-attribution if credited to Charles Darwin.

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* In common parlance, theory means any idea or notion, regardless of proof, logic or relevance. Hence: conspiracy theory. The term has a somewhat pejorative effect in common parlance, as if theories are worthless. Anything unproven or speculative gets called a “theory.” But in scientific usage, a theory is a rock-solid proposition: “A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on knowledge that has been repeatedly confirmed through observation and experimentation.” It’s not unlike the difference between truth and the whingings of local bloggers about council “conspiracies.”

** To be fair, they don’t actually read the Bible they allegedly quote, either, just a translation of it.

*** I first wrote about natural selection back in 2006.