Charles Darwin's Arguments In The Origins Of Species

Word Count: 1766 The Arguments in the Origins of Species Evolution involves organisms developing better adapted traits over time. Darwin explains how these specific traits come about through his “one long argument.” In this paper, I argue that Charles Darwin’s approach to natural selection is the most accurate depiction of our earth’s history. I begin with a breakdown of Darwin’s theory of evolution, then incorporate Darwin’s thoughts on “fitness” and why other scientists may contend against them. Next, I discuss some of the competing ideas of the time, such as William Paley’s theory of an intelligent designer, and I close with how Darwin successfully addressed these opposing arguments. The struggle for existence and natural selection
serve as two main incentives for evolution. At that time, unregulated growth was thought to be the driving force behind the struggle for existence, which means an individuals or species goal to survive and pass on its traits. Malthus’s Law stands behind the ideas of unregulated growth. It explains that species would grow at an astronomical rate, creating a strain on resources. Such a strain means that not only this species, but also co-inhabitants of the environment, would begin to die off. However, Malthus’s law fails to take into account multiple factors, including disease, natural disasters, and so on. Darwin expresses that variations, which help to support the survival of an individual, are typically passed down to that individual’s descendants (Darwin, 42). These variations provide an opportunity for individuals within a species to gain an advantage and triumph over others of their kind. “Therefore during the modification of the descendants of any one species, and during the incessant struggle of all species to increase in numbers, the more diversified these descendants become, the better will be their chance of succeeding in the battle of life” (Darwin, 73). If the likelihood of survival for these individuals increases, so does their chance of procreation and the passing down of their traits. This concept of beneficial traits helping individuals to survive and pass down these traits is known as natural selection. Measuring a trait’s ability to increase an individual’s chance of survival is known as fitness. Traits that improve life expectancy are more fit, while those characteristics that do not aid in survival have little to no fitness. Elliott Sober discusses two ways to determine fitness: one is more exact, and the other is an approximation. The former consists of examining frequencies. Individuals with different traits are monitored, and if a group of individuals with one of those traits tends to survive into adulthood, that trait is said to be “fitter.” When looking at frequencies, Sober tends to use the likelihood principle, which means when noticing a particular effect, the most probable, or likely, cause is probably the best. So the approximation method looks for a change in chance of survival over time, when a particular trait is present, to determine the fitness of that trait. The second method of determining fitness involves “reach[ing] judgments about an organism’s fitness by examining its physical makeup” (Sober, 68). By making inferences based on prior experiences and knowledge, we can decide if a trait logically seems beneficial for an organism’s survival. Sober discusses an example using zebras and how speed seems to affect fitness. If a Zebra is fast, it is more likely to escape predators, therefore increasing its chances of survival. However, Sober informs us of a significant exception as he states, “the rule says that fitter traits evolve, not that advantageous traits always do so” (Sober, 79). If a trait is typically advantageous, but the factor it is providing an advantage for is not present in an individual’s environment, the trait will most likely not be fitter. Skeptics of natural selection argue against the idea of fitness either based on its definition or because of how it is incorporated into evolution.
There are two views, Causalist and Statisticalist, which address how fitness and natural selection are connected to evolution. Causalists believe fitness differences cause evolutionary change and that populations change because of selection. Darwin may at first appear to be whole-heartedly a Causalist, but after addressing Paley and his views, one can tell that Darwin could also be considered a Statisticalist. Statisticalists view fitness as a way to quantitatively track changes in a species; however, they stand by the fact that correlation does not prove causation. Ramsey clarifies this idea when saying, “[Statisticalists] understand core evolutionary concepts like fitness and selection to be mere statistical summaries of underlying causal processes. In this view, evolutionary changes cannot be causally explained by selection or fitness.” From a genetic standpoint, these underlying causes may include pleiotropy, one gene controlling more than one phenotype, or genetic linkage, when alleles in a similar location are usually inherited together. However, from a theistic interpretation perhaps there is a higher power at
play. William Paley’s theory of design explains that rather than life arising from chance, there must be an intelligent designer behind the creation of Earth. He uses a famous example involving a complex watch and its origins to show the difference between an intelligent designer and unplanned causation. Paley asks us to imagine walking down a sidewalk and seeing a rock. Not many of us would find it surprising. He would want us to think about where the rock came from yet we would not spend much time thinking about it and we would probably conclude that it broke off of a larger rock nearby. Now reimagine our stroll, but this time rather than seeing a rock on the sidewalk, picture a watch. After picking up the watch, you notice how intricate its design is and think about it as nearly perfect. If he were to ask where the watch came from, we would be confused. We would question its creation and how it ended up on a sidewalk. Paley has us thinking. We do not know where this watch is from, how it got there, or how it was made. He first uses this elaborate watch to address a timeline, as if the watch appeared overnight. Now imagine that the watch is a well evolved organism. If the watch was created overnight, what created it and how? This question would create a divide between Paley and Darwin. Paley would argue that an intelligent designer would be necessary to create this watch because of its complexity. Furthermore, Paley would say that a watch could never result from random causation: it serves a specific purpose, and each of the watch’s individual components contributes, through its own explicit task, to achieving this purpose. Darwin counters Paley’s theory in his own explanation of how species evolve into well-formed organisms over time, avoiding any periods of “inextricable chaos” during the process, new varieties are very slowly formed, for variation is a very slow process, and natural selection can do nothing until favourable variations chance to occur, and until a place in the natural polity of the country can be better filled by some modification of some one or more of its inhabitants (Darwin, 79).
Most people find it hard to fathom the transition from a reptile to a bird, but the timeline is what they confuse.
Darwin explicitly states that it takes a very long time for these individuals to develop into the organisms they are now. At first there may be minimal differences within the same species, but as time goes on it continues to increase as those organisms with fitter traits survive and pass on their traits. This diversity continues to grow until the varieties among these organisms becomes so distinct that a new species is formed. Although Darwin does not specifically endorse an intelligent designer, he leaves room for a higher power in his explanation of evolution. It is almost as if Darwin sets up evolution, natural selection, and fitness as dominos and in order for those dominos to fall, creating the vast amount of complexity that exists within organisms today, something-- perhaps a higher power-- would have to push the first domino
down.

Darwin does not deny the complexity of organisms, in fact, he supports the idea that individuals move towards perfection as time goes on, but he chooses to support another mechanism. There are many complex organisms in the world, but that does not mean each individual was made separately. Darwin informs us that, “when we see any structure highly perfected for any particular habit, as the wings of a bird for flight, we should bear in mind that animals displaying early transitional grades of the structure will seldom continue to exist to the present day, for they will have been supplanted by the very process of perfection through natural selection” (Darwin, 82).
He is saying that we typically do not see the earlier forms of species and to go even further, what that species originally was. As I previously discussed, species gather variety over time and eventually those distinctions result in a new species. Darwin methodically explained that species transition into other species with time, so if species are coming from other species they must be related. He clearly defines his thoughts as he says, “animals have descended from at most only four or five progenitors, and plants from an equal or lesser number” (Darwin, 117). I think Darwin successfully addressed the competing ideas regarding fitness and intelligent design. He explained himself with logic, while still leaving room for a little blind belief in a creator. The domino comparison I used earlier is how I view earth’s creation. We(humans) descended from bacteria in the sea, but some higher power made it plausible. I believe this as a sort of God of the gaps theory because we cannot fully describe “life.” As a scientist-to be, I like to investigate the science behind big ideas such as the creation of earth and life. It seems that although we have identified all of the chemical components of cells, even when mixed in the appropriate ratios, they do not form living cells. Therefore, something else must be acting to enable life. I recognize that the door is wide open for choices, I just choose to fill the gap with a God.