What is the process of natural selection?

Natural selection is able to occur due to variation within a species. Individuals with certain mutations/alleles may be better adapted to their environment than other members of their species, meaning they will survive longer and be more successful. This is described by Darwin as “survival of the fittest” - describing the greater success of the individuals who are most fit for their environment. A greater likelihood of survival means that these individuals are more likely to reproduce, and so more likely to pass their characteristics onto their offspring.This process means that certain characteristics are selected to be passed on more regularly by the environment a species inhabits. Over many generations, the effects of this can accumulate, resulting in the gradual evolution of the species as a whole.