Genetic Drift And Natural Selection

Genetic drift and natural selection both play important roles in shaping the genetic makeup of a population in nature. Although this is true, they have different modes of doing so. Genetic drift, unlike natural selection, is a completely random process. While natural selection tends to improve the fitness of generations to come in the context of a certain environment, the chance events of genetic drift do not necessarily lead to forming positive environmental adaptions. In addition, the effects of genetic drift are much more pronounced in smaller populations compared to larger populations (Bowman, Cain, and Hacker, 2014). In order to support this idea with data, I have utilized a computer model to simulate how genetic drift would affect populations of variable size over time (without the effects of selection). Figures 1 and 2 below depict the results:

With the analysis of these figures, one can conclude that population size truly does play a role in how pronounced the effects of genetic drift are in a population. Figure 1 specifically depicts
Looking at two different population sizes (a population of 10 versus a population of 250), one can see that the smaller population experienced allele fixation much earlier than the larger population: only an average of 11.3 generations until fixation, compared to an average of 78.84 generations until fixation for the larger population. With this being said, one can begin to understand why small populations of vultures have different probabilities and times of fixation compared to larger populations. It is due to the fact that in the case of a small population, each individual represents a larger allele proportion that makes up that particular gene. By contrast, larger populations have numerous individuals that to represent a certain allele's frequency (Wikipedia contributors,