Darwinism

Belief in the theory of evolution by natural selection. The theory in its original form took wing from the observation of Malthus that although living organisms produce multiple offspring, adult populations remain relatively stable in number. Darwin realized that the different chances of survival of differently endowed offspring could account for the natural evolution of species. Nature ‘selects’ those members of a species best adapted to the environment in which they find themselves, just as human animal breeders may select for desirable traits in their livestock, and thereby control the evolution of the kind of animal they wish. In the phrase of Spencer, nature guarantees the ‘survival of the fittest’. The Origin of Species was principally successful in marshalling the evidence for evolution, rather than providing a convincing mechanism for genetic change, and Darwin himself remained open to the search for additional mechanisms, whilst also remaining convinced that natural selection was at the heart of it. It was only with the later discovery of the gene as the unit of inheritance that the synthesis known as ‘neo-Darwinism’ became the orthodox theory of evolution in the life sciences. See also creationism, evolutionary ethics, sociobiology.