Before November 24, 1859, many people simply believed that species were created byGod in their present forms, or that it was possible for organic matter to be spawned frominorganic matter. However, Charles Darwin used these ideas to create his thesis, On theOrigin of Species by Means of Natural Selection.
The first true theories on evolution arise during the classical Greek period. On ahandful of Greek philosophers believed in the theory of evolution and natural selection. Unfortunately, the two philosophers who influenced western civilization the most, Platoand Aristotle, opposed any theory of evolution. Plato believed that there were twoworlds, one real world, and one imperfect world that we perceive with our senses.
Anyvariations in life were imperfect images of their ideal forms. However, Aristotle didn’tbelieve in two worlds; instead, he believed in a “scale of nature.” Each life form wasarranged on a type of “ladder”. It started at the bottom with the least complex organismand 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 toAccording to Neil Campbell in his book, Biology: Fourth Edition, “Juedo-Christianculture fortified anti-evolution theories.” (p. 400-401) The creationist-essentialist dogmathat species were permanent and created for a specific purpose became deeply embeddedin Western thought. Any person who dared to theorize or believe in theories aboutevolution were instantly labeled heretics.
The medieval church saw evolution as sayingthat God did not exist, that we are not the “supreme creation”, and that humans could justHowever, in the later 1700’s and early 1800’s there was a “scientific revolution”taking place. People began to use scientific experiments to explain what they had alwaysput faith in. According to Campbell, the first big step in the development of the theory ofevolution was made by Carolus Linnaeus. (p.
400-401) Linnaeus was the founder oftaxonomy and developed the naming system for organisms that we still use today. Hegrouped organisms based on similar characteristics. This, for Darwin, would become afocal point of his theory of evolution. When Darwin began his research aboard the H.
M.S. Beagle in 1831, he had somepre-constructed ideas. The first was that he rejected Plato’s, Aristotle’s, and theChurch’s ideas that organism were made the way they are, and will never change.
Thesecond was about Linnaeus’ filing system; Darwin believed that similar species must ofevolved from similar ancestors. During his trip on the Beagle, Darwin collected 13different types of finches that he believed were different species. When he returned toGreat Britain in 1836, he learned from ornithologists that the 13 different types of fincheshe collected, were indeed separate species. This discovery led Darwin to theorize that if aspecies was isolated, then it would adapt to fit it’s surroundings; just like how the finchesadapted new beaks depending on their native types of food.
Finally in 1844, Darwin wrote an essay on his theory of natural selection and theorigin of species. When Darwin finished his book on evolution, The Origin of Species, hehad two major ideas: the first was that evolution was the explanation for life’s unity anddiversity; the second was that natural selection is the cause for adaptations. Darwinprovided numerous example of his theories, but he was still doubted. However, on of hismodern day supporters named Ernst Mayr has provided his own theories and proof ofWith respect to Darwin’s ideas on natural selection and adaptation, Mayr used anclosely related group of insect species to prove this point.
In Malaya round, pink flowersare common; so the mantid native to Malya is round and pink. However, in CentralAmerica, most plants have green, oval-like leaves; so the mantid to Central America isgreen and oval-like in shape. This example shows how species of common ancestry haveadapted to fit their individual surroundings. With respect to Darwin’s 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 provethis by focusing on one particular part of the plant to accentuate. The process ofaccentuating the plant parts by breeders is evidence of evolution, except that humans aremanipulating the results to meet their own needs. There really is not much moreinformation on Darwin’s theory of evolution, due to the fact that the majority of his bookfocused on adaptations rather than evolution.
So, as you can see, Darwin’s disbelief in the notions that evolution occurred,caused him to investigate evolution, and led to the creation of Darwinism. Darwin didpresent a great deal of evidence to prove his point, however, his theory still has one majorproblem; the “missing link”. Darwin was able to show evolution from the simplestorganism to the most complex organism as a complete chain; except that he is missing thelink between primates and humans. In spite of all the evidence and the “missing link”,Darwin’s ideas are still being debated to this day; however, most biologists now believe inDarwinism and support Darwin’s ideas on evolution and natural selection.
