The Theory of Evolution is the idea that living things have changed over time and continue to change. It’s all thanks to two things: natural selection and genetic diversity. Natural selection is when certain traits are helpful in a particular environment, so animals or plants with those traits are more likely to survive and have offspring. Genetic diversity is when there are variations in traits within a population, which can allow some individuals to better adapt to changing environments and outcompete others. Over millions of years, these small changes can add up and lead to the creation of new species.