<human>:  Explain the concept of natural selection
<bot>: Natural selection is the process by which traits that are favorable to an organism's survival and reproduction become more common in a population over successive generations. It is one of the main mechanisms of evolution, where genetic variants that increase the ability of individuals to survive and reproduce are selected and passed down to their offspring. As the environment and the organisms within it change, those who are unable to adapt are eliminated, while those who possess the desired traits become more common, resulting in the gradual transformation of a species over time.