Pre-Darwinism Views Essays - Biological Evolution, Sexual Selection

Pre-Darwinism Views Essays - Biological Evolution, Sexual Selection Pre-Darwinism Views Before November 24, 1859, many people simply believed that species were created by God in their present forms, or that it was possible for organic matter to be spawned from inorganic matter. However, Charles Darwin used these ideas to create his thesis, On the Origin of Species by Means of Natural Selection. The first true theories on evolution arise during the classical Greek period. On a handful of Greek philosophers believed in the theory of evolution and natural selection. Unfortunately, the two philosophers who influenced western civilization the most, Plato and Aristotle, opposed any theory of evolution. Plato believed that there were two worlds, one real world, and one imperfect world that we perceive with our senses. Any variations in life were imperfect images of their ideal forms. However, Aristotle didnt believe in two worlds; instead, he believed in a scale of nature. Each life form was arranged on a type of ladder. It started at the bottom with the least complex organism and continued up to the most complex organism. Each organism had a pre-determined rung, which allowed no ability to move up, and no open spaces for a new organism to fill. According to Neil Campbell in his book, Biology: Fourth Edition, Juedo-Christian culture fortified anti-evolution theories. (p. 400-401) The creationist-essentialist dogma that species were permanent and created for a specific purpose became deeply embedded in Western thought. Any person who dared to theorize or believe in theories about evolution were instantly labeled heretics. The medieval church saw evolution as saying that God did not exist, that we are not the supreme creation, and that humans could just be evolutionary mistakes. However, in the later 1700s and early 1800s there was a scientific revolution taking place. People began to use scientific experiments to explain what they had always put faith in. According to Campbell, the first big step in the development of the theory of evolution was made by Carolus Linnaeus. (p. 400-401) Linnaeus was the founder of taxonomy and developed the naming system for organisms that we still use today. He grouped organisms based on similar characteristics. This, for Darwin, would become a focal point of his theory of evolution. When Darwin began his research aboard the H.M.S. Beagle in 1831, he had some pre-constructed ideas. The first was that he rejected Platos, Aristotles, and the Churchs ideas that organism were made the way they are, and will never change. The second was about Linnaeus filing system; Darwin believed that similar species must of evolved from similar ancestors. During his trip on the Beagle, Darwin collected 13 different types of finches that he believed were different species. When he returned to Great Britain in 1836, he learned from ornithologists that the 13 different types of finches he collected, were indeed separate species. This discovery led Darwin to theorize that if a species was isolated, then it would adapt to fit its surroundings; just like how the finches adapted new beaks depending on their native types of food. Finally in 1844, Darwin wrote an essay on his theory of natural selection and the origin of species. When Darwin finished his book on evolution, The Origin of Species, he had two major ideas: the first was that evolution was the explanation for lifes unity and diversity; the second was that natural selection is the cause for adaptations. Darwin provided numerous example of his theories, but he was still doubted. However, on of his modern day supporters named Ernst Mayr has provided his own theories and proof of Darwins ideas. With respect to Darwins ideas on natural selection and adaptation, Mayr used an closely related group of insect species to prove this point. In Malaya round, pink flowers are common; so the mantid native to Malya is round and pink. However, in Central America, most plants have green, oval-like leaves; so the mantid to Central America is green and oval-like in shape. This example shows how species of common ancestry have adapted to fit their individual surroundings. With respect to Darwins ideas on evolution, we will look at the mustard plant. The mustard plant is the evolutional ancestor of six different vegetables: cauliflower, cabbage, brussels sprouts, broccoli, kale, and kohlrabi. Breeder have been able to prove this by focusing on one particular part of the plant to accentuate. The process of accentuating the plant parts by breeders is evidence of evolution, except that humans are manipulating the results to meet their own needs. There really is not much more information on