Darwin's Theory of Evolution
- Charles Darwin, as a result of observations on a round-the-world expedition, backed by years of experimentation and discussion and linked to developing knowledge of geology and fossils, proposed the theory of evolution by natural selection
- Evolution can be defined as the change in the frequency of a phenotype in a population over many generations
- Darwin’s theory, very simply, is:
- Individuals in a species show a wide range of variation caused by differences in genes
- Individuals with characteristics most suited to the environment have a higher chance of survival and more chances to reproduce
- Therefore these characteristics are passed to their offspring at a higher rate than those with characteristics less suited to survival
- Over many generations, these beneficial characteristics become more common in the population and the species changes (the species evolves)
- This idea of natural selection became known as ‘survival of the fittest’
- Darwin published his ideas in his famous book, On the Origin of Species (1859)