Explain Darwins theory of evolution by natural selection (5 marks)

A mutation will randomly occur in individuals within a species, providing a larger variation in genes. This mutated gene may produce characteristics which are beneficial for the individual in their environment. This means they are more likely to survive than those without the gene and are therefore more likely to reproduce and pass on the beneficial gene to their offspring. Individuals without the gene however, are less likely to survive and therefore will not be able to pass their genes on to offspring. Over time the advantageous gene will become more common within the species and they will gradually evolve.