The process of natural selection allows the mutation to occur which helps in the evolution of a species. These changes increase the chances of the organism to survive in the environment. There is the development of a species which is more superior and has a better chance of survival. The process of sexual selection helps the organism to find the other organism to mate. These are the changes which help in the breeding of the organisms within the specific groups. There is no guarantee that there will be development of an organism with superior characters.