Peppered Moth Assignment Natural Selection PDF

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Summary of the Peppered Moth assignment on how naturral selection works to change a population of species....

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BIOL 154-12 Peppered Moth Assignment : Natural Selection

Fig 1: Graph of Allele Frequency in High Pollution Environment

Fig 2: Graph of Allele Frequency in Low Pollution Environment

The simulation of high pollution and low pollution environment was done to see how natural selection works in Peppered Moths. The null hypothesis was that the level of pollution does not influence the frequency of moth phenotypes. During the simulation polluted environment, five homozygous dominant moths (BB), ten heterozygous moths (Bb) and five homozygous recessive moths (bb) were taken. With a starting of 0.5 allele frequency for each allele in both simulated environments the experiment was conducted in two of the environments-the high pollution environment and the low pollution environment. After putting the moths in the environment, the most possible moths to be killed were picked and the allele frequency was calculated. The remaining moths were bred, and the same process was repeated in the other generations. The gradual change in the allele frequency was noted and graphed as in Figures 1 and 2. Figure 1 contains the graph of the moths in the high pollution environment. In the high pollution environment, the trees where moths camouflage are covered with soot making it easy for dark colored moths to hide easily while making the light-colored moths more vulnerable to the predators. So, the allele frequency of the recessive allele slowly decreases in the upcoming generations. In the graph we can see that the allele frequency remains the same till the second generation but there is change in the allele frequency in the further generations. The allele for the dominant Black color increases as the pollution increases. Similarly, the allele for the recessive white color decreases with increase in pollution. Figure 2 contains the graph of the moths in the low pollution environment. In the low pollution environment there is less soot on the bark of the trees and therefore it is easier for light colored moths to easily camouflage to escape from the predators. At the generation of moths pass by there can be seen a distinct increase in allele frequency of the recessive allele and

decrease in the dominant allele frequency since the population of the darker moths gradually decreases. With the graphs above it can be clearly seen the influence of pollution in the allele frequency of the moths. So, the null hypothesis can be rejected. This is caused due to Natural Selection. It is a process by which the individuals which are beneficial to the environment and heritable are better able to survive and reproduce....