Evolution as Both a Process Over and a Theory Across Time
Evolution: a Process Over and a Theory Across Time
I always believed that evolution, while an ongoing process, was a concept used only to explain the past. It seemed to be solely a logical scheme for explaining and deriving relationships between preceding and modern organisms. Evolution, as I saw it, was constrained by the boundary set forth by the beginning of existence up to the now. Typically, when one looks at the relationship between evolution and time, several concepts emerge. The relationship is positive and linear, with evolution increasing over time. The relationship is unidirectional, confined by our current understanding of time. The relationship is direct, with evolution occurring only through the passage of time. Thus, the process of evolution is dependent on time, only persisting with time’s persistence. However, looking at it as a theory rather than a process, evolution encompasses all three known time frames; the past, present, and the future. It is this true application that creates and maintains the credibility of evolution, arguably making it a more convincing theory than Creationism.
Evolution is classically seen as an explanation of the past; it is the story of biologically based changes over the vast span of time. When one thinks of evolution often the branched phylogenic image (Figure 1) comes to mind. This image depicts how in a linear and unidirectional time frame, a single species diverges into various states of being. It is important to note that Figure 1 does not explain why these changes occur, but simply maps them. As Darwin proposed, one of the driving forces of evolution is natural selection. Natural selection stems from the facts that organisms vary, and these traits are heritable. As proposed by Thomas Malthus, essential recourses are limited, and this provokes competition among the individuals of a species. Through this competition only the fittest of the species are likely to reproduce, thus creating similarly fit offspring. In his book The Origin of Species Darwin supports the notion of evolution through natural selection by demonstrating the linear progression of certain traits in an organism over time. Unavoidably, all of Darwin’s evidence is based off of fossils and bones of extinct species, things of the past. By examining how these structures change over time Darwin was able to derive an explanation for evolution, the theory of evolution.
While the process of evolution and the theory of evolution are clearly related, it is important to consider them as separate entities. The process of evolution is simply the observation of an organism adaptively changing over time; it is the statement that species develop. The theory of evolution explains why the process of evolution happens. As a theory, evolution not only explains the past but it serves as a set of guidelines for life. In a technical sense the theory of evolution parallels other theories such as the theory of gravity. Like evolution, gravity is a phenomenon for which an explanation was formed based on the knowledge of the past and present. Simple observations such as the constant rate of an object falling served as evidence of gravity, and by using such observations Newton’s theory of gravitation emerged. His theory of gravitation, while now known to be only an approximation, became applicable in not only explaining past and current circumstances, but also in predicting unknown facts about the past, present, and future. An example of this, is the discovery of Neptune. Originally, astronomers noted that Uranus’s orbit deviated from Newton’s theory, this lead to the conclusion that there must be another planet disrupting it’s orbit (Discovery). Through further use of Newton’s theory scientists were able to logically locate Neptune, showing how a theory can be used to predict the undiscovered truthof now. In general theories not only explain past evidence, but the serve as a mathematical function. By plugging in hypothetical circumstances the theory can go beyond explaining evidence to predicting evidence or outcomes in the past, present, or future. (Creationist Claims)
Thus, while the process of evolution is
temporally constrained,when used as a theory the concept may then transcend these initial temporal boundaries extending its applications into the past, present, and future. Even in his book On the Origin of Species Darwin makes a few predictions about the past. One of the issues he emphasis in Chapter X is the necessary, yet complete lack, of strata and fossils beneath the Cambrian system. Showing how important such an existence is to his theory Darwin writes, “the case at present must remain inexplicable; and may be truly urged as a valid argument against the views here entertained.” (Darwin, 440) In the 1950’s Precambrian fossils were indeed found, demonstrating how through the use of the theory of evolution Darwin was able to foretell that there must fossils from this earlier period (Schopf). Through the theory of evolution scientists have been able to work backwards, predicting and then finding evidence for how the past was.
In a similar fashion the theory of evolution can also be used to evaluate the present, which can therefore lead to the discovery of new concepts happening in the present time. One of Darwin’s notorious predictions, based off of his theory of evolution, is that of the Madagascar hawkmoth. When studying the Madagascar Star orchid (Figure 2), a modern day plant, Darwin was surprised by the plant’s excessively long spur of 22 cm (this is the area of the plant containing nectar), (Whittal & Hodges). He proposed that such a long spur was evolutionarily adaptive in that in order for insects to reach the nectar they would be forced to come in contact with the pollen, ultimately enhancing the plant’s reproductive success. Based off of the fact that this particular variant of orchid was thriving, Darwin concluded that an organism must have evolved acquiring a tongue long enough to reach the nectar. Such a feature would benefit the organism by reducing its competition for food. While no such organism was known at the time, over 40 years later a moth, later named the Madagastcar hawkmoth, was discovered in the region. Upon further study it was found to have a tongue around 22 cm, the length of the plant’s spur.
Finally, while the notion may be somewhat controversial, evolution can be used to predict events in the future. Because the circumstances of the future involving genetic variation and the environment are unknown, these predictions, inevitably, are less specific. They are still useful, however, in giving a general idea of what the future entails. One common example of future prediction, once again derived from the theory of evolution, is found in studying virulent strains bacteria. One of the main concerns of today, which was predicted by evolution and is being observed now, is the emergence of disease resistant bacteria strains. In such a case the theory of evolution would propose that in the future bacteria will continue to vary genetically and that those who develop traits enabling them to survive a specific antibiotic will then transfer their genes and multiply creating an entire resistant strain.
The fact that the theory of evolution can not only be used to explain the past, but also be applied to real life in order to suggest unknown facts about the past, present, and future, which can then be confirmed, strongly enhances the credibility of the theory of evolution. Creationism, a rivaling theory of evolution, centers on the belief that an intelligent creator produced the organisms found today (Ruse). The creator is responsible for their flawless design, which has not and will not randomly change genetically and additionally is not subject to the supposed pressures of natural selection. Creationism is a widely believe theory, and is actively taught in many American institutions. However, given the above examples, which demonstrate how the application of evolution is not strictly limited in explaining, but also in predicting circumstantial life, Creationism is found lacking. Nothing in the theory of Creationism allows for it to be applied to real circumstances in order to logically predict the facts regarding past, present or future. Creationism is a story that can tie together the evidence of the past, but it cannot provide new information like the theory of evolution, making it an inferior and less useful theory. Thus, when the question arises as to why evolution should be taught in schools over Creationism, one compelling argument is that evolution is applicable in predicting life, as the theory serves as a set of natural laws and constants.
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