The Nature of Darwins Contributions to the Study of Evolution - Essay Example

The nature of Darwin's Contributions to the study of evolution Introduction The battle between theories f evolution and those based on creationism has been going on for many years and does not look as if it will be over any time soon. Particularly, this ongoing debate has surrounded the teachings in public schools. As a former public school student myself, I never studied any theories f "creation science;" in fact, to my surprise, it was not until this year, my junior year f college, where I have been first introduced to the idea f creationism. Given this information, I have decided to focus this paper on various creationist ideas, not only to fulfill the requirements for this research paper, but also to further my own knowledge f this personally unfamiliar topic. While beliefs f organic evolution have been the general acceptance f the intellectual elite in the late Victorian era, it is also true that, at this time, the majority f Americans were loyal to the concept f special creation. Most f these masses said nothing, however, some vocally supported such persons as Charles Hodge, a Princeton theologian who preached that Darwinism was atheism. John William Dawson and Arnold Guyot, two f the last reputable nineteenth-century creationists attempted to oblige science by interpreting the days f Genesis "as ages and by correlating them with successive epochs in the natural history f the world" (Ruse, 229). Dawson and Guyot cited several supernatural interventions, particularly in their theories f the first humans; however, they attempted to keep such paranormal citations to a minimum, thus focusing on a maximizing f operations f natural law. Between 1910 and 1915, The Fundamentals was published to rejuvenate and reform Christianity throughout the world. These booklets were mass-produced, and, at the time, posed a bigger threat to orthodox faith than did evolution. According to Numbers, "Although one contributor [to The Fundamentals] identified evolution as the principal cause f disbelief in the Scriptures and another traced the roots f higher criticism to Darwin, the collection as a whole lacked the strident anti-evolution that would characterize the fundamentalist movement f the 1920s" (249). William Jennings Bryan soon became the ideal spokesman for an anti-evolution crusade. He was politically involved and, although lost the bid for presidency three times, had a national reputation, vast prestige, and a strong following. Bryan often preached f the silliness f humans having a biological connection to apes. After the outbreak f World War I, Bryan began to trace the source f trouble to the influence f Darwinism. From the information printed in two published books, one by Vernon Kellogg and one by Benjamin Kidd, Bryan blamed the deterioration f Christianity and democracy on the support f theories f evolution. Each f the two books cited conversations among German officers revealing that Darwin's biology had played a major role in convincing the Germans to declare war. Bryan furthered his crusade by noting that beliefs in evolution were the main cause f students to lose faith in the Bible. In class we learned that "creation science" has, indeed, not been proven as a science, thus should not be taught in schools. However, it is that same claim that was used by many creationists when referring to theories f evolution-- that it is not scientific. The crusade against evolution was given a significant boost in 1921 when British biologist William Bateson declared that scientists had not discovered "the actual mode and process f evolution" (Bateson, 56). Even though Bateson urged creationists not to misinterpret his statement as a rejection f evolution, they ignored him and accepted the statement as a minor triumph. Nonetheless, when it came down to a scientific debate, the creationists had only a handful f legitimate scientists-- including one or two physicians and a few teachers. In 1925 came the famous Scopes trial, where a high school teacher, John Thomas Scopes, confessed to violating the law prohibiting the teaching f evolutionary ideas. Although Scopes was ultimately found guilty as charged, this trial was somewhat f a Phyrric victory for the creationists. They eventually won the court case, however, the bad publicity and near-humiliation f supporters f the creation science theory was overall very detrimental to the crusade. As a result f this court case, it became obvious that the main weakness f the anti-evolutionists was their inability to agree on one theory f creation. This weakness is a longstanding one that is still the main problem among creationists. It is also this weakness that keeps me from being convinced that creationism is the only accurate explanation for the origin f beings. It is true that I have had much more exposure to teachings f evolution as opposed to creation science, however, throughout my research for this paper I have learned a great deal about some various creation beliefs. There have been, and still are, some very intelligent supporters f the creationism theory. William Riley, for example, followed the ideas f John William Dawson and Arnold Guyot. He believed that the evidence f geology necessitated the interpretation f the days f Genesis as ages. Harry Rimmer, a minister and self-titled "research scientist," favored a different "gap theory." This theory "involved two separate creations, in part because his scientific mind could not fathom, given Riley's scheme, how plants created on the third day could have survived thousands f years without sunshine, until the sun appeared on the forth" (Numbers, 238). And George Price, an educated geologist, insisted that the world was created in six literal days. Each f these "creationists" stood strongly behind his own theory and rejected any other. Variation is the source f evolution. In this lab, we took a closer look the variations in two different species that are commonly known. A countless number f factors could have fostered the variations that we examined in this experiment. Most f the reasons for the variations that we see can be accounted for in the following categories: genetically based, environmentally based and sampling technique. Genetically based reasons for variation come from the very source f life itself, DNA. Changes in DNA (genetic mutations) in a species derive variations within a certain species. For example, possibly a small change in an anchovies DNA sequence occurred as a result f an error in DNA replication and this change affected the length f the anchovy. This variation would have been fostered genetically, so the reason for this variation would fall under the genetically based category. Variations could have also been fostered due to environmental reasons. Possibly, a predator might have come along that only ate the larger fish, therefore killing off all f the larger fish in the species. Countless other environmental factors could have influenced the amount f variation that we saw. Also, some f the variation may have arisen from our sampling technique. We had multiple classes measure the lengths f different samples f anchovies and peanuts, so possibly some classes may have measured them differently. This would have created variation in the data. As you can see in the above graphs, each species tended to have a bell curve in the measurements f their lengths. There tends to be a collection f average lengths towards the middle f the graph, with outlying smaller and larger lengths for each species. Why is it that in two completely different species, the same pattern for the length measurements is found in each species This can easily be explained through the application f Darwin's Theory f Evolution. Specifically speaking, a mechanism called "natural selection" explains why we see this common data trend. Natural selection acts to preserve and accumulate minor advantageous genetic mutations. In the center f the bell curve in the graphs, we see the largest amount f samples f that particular size; this tells us that the length f the anchovies or peanuts in the center f the bell curve is best adapted to live longer and pass on its genes to its offspring. The reason we see fewer outlying lengths (really long, or really short anchovies or peanuts) is because those samples are not as well adapted to survive and reproduce as those in the center f the bell curve. Since the sizes in the middle are best adapted to survive, they will reproduce and the amount f those lengths in each species will increase. Likewise, the amount f outlying lengths in each species will slowly diminish because the members f each species with those lengths are not best suited for survival. This is the process f evolution that we are observing right before our eyes. In each species, the sources f variation are exactly the same. In both species, the anchovies and the peanuts, sources f any variation always originate from genetic mutations. All genetic mutations are completely random (although some are occasionally influenced by environmental factors), however, those that are beneficial to the members f the species that posses the genetic mutations are passed down to the next generation. Mutations can also be detrimental to a member f a species. Natural selection takes care f this though. Members f a species that possess a mutation that prevents them from reproducing will not pass that mutation onto the next generation because they will have no offspring. Because f this, all f the members possessing the detrimental mutation will eventually disappear from the species. In our examinations f the lengths f different samples f anchovies and peanuts we found a great deal f variation within each respective species. As previously mentioned, our all f our graphs f the data were bell curves. Although many f the samples in the center f the bell curve were almost the same size, we found quite a few outlying samples for both the anchovies and the peanuts which were either a lot smaller or a lot larger than the average length. This is a demonstration f natural selection. The members f the species without the favored lengths (the lengths towards the middle f the graph) are those who are genetically disadvantaged. Their numbers are diminishing through the process f natural selection. Since they are not the fittest for survival, they do not reproduce as often and therefore do not have as many offspring as those fittest for survival. In both species, the variants (the outlying samples) played vital roles in the development and evolution f each species. At one point in time, the variants were far more common than they currently are. However, some members f the variants developed genetic mutations which made their length more favorable. Those with the favorable genetic mutations reproduced more often than those without them, and slowly the numbers f the variants depleted. This is a perpetuating process; each species is constantly evolving to their environment. There will always be variants in each species, and the bell curve in the lengths f the samples will always exist. Variants are also essential to the survival f a species in another way. Suppose a deadly virus swept throughout a certain species, decimating its population because it exploited a certain weakness that almost all f the members f the species possessed. However, a species with a large amount f variation would not be nearly as vulnerable to an attack such as this. There would be some members f the species that would be immune to the viruses because they would not possess the weakness that the virus exploited. The surviving variants would survive and reproduce, and eventually, through the process f natural selection, the whole species would no longer possess the weakness and would be immune to the virus. Variation is vital to survival. Often times, in experiments such as these, sample bias may exist, although it is impossible to tell. Sample bias does not decrease with sample size and may even increase depending on the source f the bias. In our case, the measurements f the peanuts and the anchovies are quite likely biased for several f the following reasons: most likely the samples came from one certain area and were not collected all over at random. This creates a problem because in one area, a species tends to bear more similarities than samples spread out. Quite possibly, there were measurement problems and instrument problems during the measurement portion f this lab, however it is impossible to tell to what extend this affected the overall outcome f the experiment. Sample bias cannot be calculated in most cases and bears no relation to sample size or variability f the measures being collected. In our lab, the anchovies were smaller than the average wild anchovies. A possible explanation for this could be that ours were grown in an anchovy farm and did not live to their full size because f mass production. (Adler 50-58) In the case f the peanuts, we probably saw less variation than actually contained within the species f peanuts. Peanuts that are sold to consumers are most likely grown to be as large as possible, in order to please the consumers. Therefore, the smaller ones may be sifted out. We have no way f knowing whether this happened in the case f our samples though. Although sample bias most likely exists in our data, the data turned out exactly as expected (in the shape f a bell curve). Over time, I expect the graphs shapes will remain relatively the same to what they are now. My reason behind this theory is simple. Since both species are constantly evolving, and their environments are changing over time, there will eventually be a new size that is fitter for survival than the average size now. The amount f members f each species with this new size will grow in number, while the older sizes will diminish and sink to the sides f the graph. Therefore, the graph will remain in the shape f a bell curve throughout the process f each species' evolution. Conclusion In conclusion, I still believe that the Theory f Evolution is a more believable concept. Although, on the subject f teachings in public schools, I believe that both theories should be addressed. I believe that a true theory on this topic is one that may incorporate both concepts. For example, in a writing f George Frederick Wright, he argued that the Bible demonstrated concepts f evolution, "an orderly progress from lower to higher forms f matter and life." With that, Wright also indicated that even Darwin himself had hypothesized the supernatural creation f some forms f plants and animals. Until creationists can agree on one theory, it would be difficult to teach such inconsistencies in our public schools. While a coexistence f such contrasting creationist and evolutionary ideas would be ideal f the teachings in public schools, it does not appear to be in the near future that such a curriculum would be implanted. The degree f genetic variation greatly affects the evolutionary adaptability f a particular species. The more variation a species contains, the more adaptable it is to its environment. This lab helped me better understand the role that intra-species variation plays in evolution. From examining the results f this experiment, we can logically conclude that variation is vital to the survival f any species. Works Cited Adler, Jerry; Underwood, Anne; Adams, William Lee., Charles Darwin Evolution f a Scientist. Newsweek, 11/28/2005, Vol. 146 Issue 22, p50-58 Berra, Tim M. Evolution and the Myth f Creationism. Stanford: Stanford University Press, 1990. Numbers, Ronald L. "Science Falsely So-Called: Evolution and the Adventists in the Nineteenth Century." Journal f the American Scientific Affiliation 27 (March 1975): 150-160. Ruse, Michael. But isn't it Science The Philosophical Question in the Creation/Evolution Controversy. Buffalo, New York: Prometheus Books, 1988 Read More