Fruit Fly Lab Report

For this lab we conducted a population genetics study on the frequency of wild and apterous flies within a small population of fruit flies. The fruit fly Drosophila works well for genetic and evolutionary geared studies because they have a relatively short generation time but are intricate enough to reveal some biological principles that are parallel to many different kinds of eukaryotic organisms. When exposed to artificial selection in laboratory experiments, fruit flies have experienced dramatic changes behavioral and evolutionary traits within ten generations or less (Goldsmith, 1991). It is important to note that wild flies have wings and apterous flies do not. The purpose of artificial selection is for humans to modify species over generations by intentionally breeding two organisms with the objective of acquiring a specific trait. In the case of this lab, we began by artificially selecting a group of heterozygous Drosophila for the first cross. On the other hand, natural selection occurs without human interference from humans and organisms acquire …show more content…
Because of the relatively small population size, our flies more than likely experienced some genetic drift. Genetic drift is a chance change in genetic variation resulting from small population sizes. In some cases, alleles can be underrepresented in succeeding generations. Additionally, small population sizes can cause allele frequencies to change randomly. By causing allele frequencies to fluctuate rapidly, genetic drift can eliminate alleles from a population as well. It can also cause harmful alleles to become fixed, which can threaten a population’s survival. (Hedrick,