Natural Selection – a.k.a. Survival of the Fittest

Today, the phrase, survival of the fittest is coupled with the English scientist Charles Darwin and his evolution theory. Contrary to popular belief, however, not only the concept of survival of the fittest predates Charles Darwin’s work on evolution, but also he is not the one who borrowed this phrase to define the mechanism of evolution he proposed in 1859. Yet, he was more than willing to adapt the said catchphrase to describe evolution by natural selection.

From Economics

The English economist Thomas Malthus may not be a household name today, however, he played a major role in the discovery of evolution by natural selection. Thomas Malthus had a major influence on Charles Darwin, and he was an inspiration to Charles Darwin’s works.

In 1798, Thomas Malthus published the book Principle of Population where he made the observations that the humans would be likely to overproduce if the population size was not kept under control.

Malthus then focused his studies on the human race. His calculations and theories produced the idea that the human population would increase geometrically while the food supply and natural resources would only increase arithmetically. This is a potential explanation for the predicted poverty and famine.

The conclusion of Malthus was that as more offspring were born, a more competitive nature would arise. More offspring meant fewer resources would be available for the population. Subsequently, due to a lack of resources would result in the rivalry between the individuals.

According to Malthus the competitive nature of individuals would be necessary for the survival of them within a large population size unable to be supported by the environment. He believed that this uncontrollable population size would eventually be the cause of famine and poverty among humans. His reasoning behind this idea was divine intervention. He believed that this would be the punishment for man if he became too lazy.

Malthus’ Principle of Population caused Darwin to rethink many issues while coming up with his theory of natural selection. Malthus’ work made Darwin realize the importance of overpopulation and how it was necessary to have variability in different populations. Darwin also used Malthus’ ideas to use competition as well as the survival in numbers idea to come up with his full idea of natural selection.

Inspiration to Charles Darwin

Tipped off by an article on economics on the survival of the fittest in a free-market economy, the English biologist Charles Darwin initiated a study on the fish population. Little did he know that he was about to cause a dramatic change in thinking in natural sciences.

It is not the strongest or the most intelligent who will survive but those who can best manage change.

Charles Darwin

The English economist Thomas Malthus, who predates Charles Darwin by a few decades, discovered that the human population grew exponentially as much as the resources allow, and once having reached the peak population stabilizes due to famine, sickness, malnutrition, and so on. Being a religious man, Malthus assumed this phenomenon was divine and what kept the equilibrium in the population. Besides this, Thomas Malthus did not believe in social welfare, interpreted it as an intervention to the free-market, and claimed the only way for the population to grow was to scale up the resources. Eventually, he published his findings in an essay called ‘On Population’ in 1798.

To Evolutionary Biology

Charles Darwin borrowed the mechanism described in the essay ‘On Population’ and with that in mind, he started his studies. His experiments and observations on populations of species lead Darwin to the conclusion that:

• All species have such immense potential fertility that their population size would increase exponentially if all individuals that are born go on to reproduce successfully.
• Populations tend to remain stable in size, except for seasonal fluctuations. Therefore, there must be a mechanism that prevents an exponential increase in population. This mechanism is triggered by environmental factors such as limited resources for things such as food and shelter.
• There is a continuous struggle for existence among individuals. The individuals vary extensively in their characteristics. The individuals that survive are more likely to reproduce and pass on their favorable characteristics to their offspring than those with unfavorable characteristics. In every generation, the population becomes ever so slightly more adapted to its habitat.

In his 1859 book ‘On the Origin of Species’, Charles Darwin called the mechanism that gradually changes the characteristics of species and makes the species more adapted to its environment as ‘natural selection’. It wasn’t before 1864 that Herbert Spencer coined the phrase ‘survival of the fittest’ in reference to ‘natural selection’. Although Darwin was advised to use ‘survival of the fittest’ instead of ‘natural selection’ to make his ideas more clear, he used natural selection and survival of the fittest interchangeably but never abandoned the use of ‘natural selection’.

Survival of the Fittest

The characteristics that make species, including humans, ‘fit’ are not universal. Favorable characteristics change from population to population based on environmental factors. Therefore, the individuals that inherit their characteristics in a given population are not necessarily the smartest, the strongest, the largest of the population, but they are adapted well enough to their environment to survive and reproduce.