Describe the process of natural selection

A mutation occurs in the genotype of an organism. This results in a beneficial phenotype being expressed. This organism now has a survival advantage. Therefore, it will live longer. This means it will have more opportunities to reproduce and therefore pass on their beneficially mutated gene. Their offspring will inherit the beneficial gene, and in turn will express it as the advantageous phenotype. These offspring will therefore have more opportunities to reproduce. Eventually, those who inherit the beneficial gene and therefore have a survival advantage, will outcompete those without the gene. This will result in all organisms of a species inheriting this gene. This is natural selection and results in evolution.