Darwin's Categories Of Natural Selection

What is natural selection? For Darwin, natural selection is a process when evolution changes from nature in which is consistent and orderly. Darwin explains two different categories that help the theory of natural selection: descent with modification and common descent. Which one of these categories would be better for beings to survive. Darwin uses two different examples to help illustrate the differences between these two categories. Through Darwin’s explains with these two illustrations, descent with modification is the process where many beings have the best chance of surviving longer.
Darwin is well known as the theory of common ancestor or common descent. Darwin explains that every being has a common ancestor. Darwin gives the example