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Bubonic Plague: A Genetic Analysis

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Genetic drift is essentially a process in which the frequency of alleles change randomly due to sampling error between generations. It can lead to major changes in a population over a short period of time and can also lead to a fixation of alleles in that population, increasing homozygosity. Heterozygote advantage is the potential advantage that could arise out of having a single allele of a gene, even if that gene is “bad”. With a heterozygote advantage, heterozygote carriers of a certain disease will be more likely to survive than with people without the disease allele. Since it helps survival, the gene spreads more throughout the population, which is why genetic diseases are occurring more often. Hemochromatosis is most common genetic variant in people of the Western European descent because of the bubonic plague. …show more content…

Macrophages is a type of white blood cell that hemochromatosis does not tend to distribute any iron to which causes the cells to lack iron, providing an advantage to those during the bubonic plague. This directly relates to heterozygote advantage--because Europeans survived carried this mutation, natural selection caused the gene to spread throughout the population, which is why it is common among them. Similarly, with cystic fibrosis, heterozygote advantage played an important role here as well, as carriers of this mutation helped protect people from tuberculosis. Tuberculosis caused of 20% of European deaths between the 1600’s-1900’s, which is why this gene spread among the European population over the years. With both these genetic mutations that provided some form of protection from the plague and tuberculosis, genetic drift also has a chance to increase frequency of alleles and homozygosity, which helps explain why more people would carry two alleles over the years, thus making the diseases apparent and ultimately

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