If I am correct it is when the weaker individuals or mutated individuals are killed of by other predators or by nature. Because they cannot survive this is natural selection because they are killed of by nature. Then if they are weak their species will go extinct, thus they are naturally selected to die and only the strong species remain.
Answer: The process by which organisms that are better suited to their environment than others produce more offspring. As a result of natural selection, the proportion of organisms in a species with characteristics that are given environment increases with each generation
