Hello!
Natural selection is believed to be how evolution occurs. It follows the idea of "survival of the fittest." This means that animals that are least 'fit' to survive in their environment are likely to die. The best 'fit' animals will likely survive. This then leads the animals who survive to pass their traits onto their offspring. The offspring will then be born with the traits needed to survive. The animals that were not fit to survive are not likely to have offspring. Because of this, less animals will be born without the traits needed to survive.
I hope this helps you! If you have any additional questions, feel free to comment or PM me!
