Darwin’s Theory of Evolution argues that we are related in some way because we come of a common ancestor (Darwin, 1959). Darwin explains in his theory that all forms of life, animals, birds, fishes, and plants, are related. One of the examples he gives to prove his theory is the existence of a tailbone in humans. Monkeys have tailbones, and the only reason why humans also have them is that humans and monkeys have common roots. But people must have evolved and lost their tails. He also explains that diversity among all forms of life is caused by evolution. Darwin’s theory involves three essential ideas. One of the ideas is that the species living on the earth undergo changes with the course of time which implies that the species that live today differ from those that were in the past. The other idea is that all living beings have a common origin, common ancestry. For instance, humans have common roots with the apes, and the whales are similarly related to the kangaroos. The last idea is that evolutionary change is a slow and steady process. By the way, Darwin explains that natural selection contributes to the diversity among living beings. Natural selection is responsible for the preservation of valuable genetic mutations. It ensures that undesirable characteristics in a given species are eliminated living only the desirable traits (Reece et al, 2010). Thus, the natural selection gets rid of the inferior species steadily in a similar way over some time.
References
Darwin, C. (1959). On the origin of species by means of natural selection, or, the preservation of favoured races in the struggle for life. London: J. Murray.
Reece, B. et al. (2010). Campbell biology. New York: Benjamin Cummings.