Fleeming Jenkin's On The Origin Of Species

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Charles Darwin, in On the Origin of Species, explains his theory of natural selection and its power to shape the evolution of species with help from the example of how species are shaped through domestication, or rather, artificial selection. With the example of domestication, however, there is a potential obstacle as to the validity his theory. Fleeming Jenkin presents this obstacle by saying Darwin’s theory “rests on the assumption that natural selection can do slowly what man’s selection does quickly” (Jenkin, pg. 3). And further, in artificially selecting traits to be bred in animals, “the rate of variation in a given direction is not constant, is not erratic; it is a constantly diminishing rate, tending therefore to a limit” (Jenkin, …show more content…
Natural selection is “the preservation of favorable variations and the rejection of injurious variations” (Darwin, pg. 81), and those with more favorable traits are more likely to survive and pass their traits to progeny. This cycle of offspring taking after their more adapted parents and also presenting favorable traits may, over time, effect and change the entire species. For, those with injurious traits are less likely to pass their traits to their progeny, as they are more likely to not survive. It is the process of nature selecting those variations that are most likely to help a being survive and procreate, whereas domestication is the process of humans selecting specific traits to then augment. “Man can act only on the external and visible characters: nature cares nothing for appearances, except in so far as they may be useful to any being” (Darwin, pg. 83). Thus, there is already a stark difference between domestication and natural selection, for man cannot know how to further traits that are not visible. Ultimately, man uses domestication for the purpose of changing breeds for the benefit of humans, and not for the good of the being itself (Darwin, pg. 30). If domestication and natural selection were to be directly related, then man would be able to effect more than speed, or size, or color. Man wouldn’t be breeding pigeons with a surplus of tail feathers for the sake of doing so, but they would be changing the whole being so that its physiology made it more apt to survive over its brethren. Darwin says it well when he writes “the key to man’s power of accumulative selection: nature gives successive variations; man adds them up in certain directions useful to him” (Darwin, pg. 30). This is where the problem of limits in domestication are separate, and not comparable, to the process of natural selection. Nature is not

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