Anth. 105 Human Species – Lab 2 ReportEmily Chiu10/16/17IntroductionEvolution occurs when the alleles in the population change over time, usually over thecourse of many generations. Either new alleles arise or the existing alleles become more or lesscommon There are four forces of evolution—mutation, genetic flow, genetic drift, or naturalselection.Mutations are new genetic sequences that were not in the parents and new alleles arisethrough the changes in DNA, producing new variation. Therefore, more allele frequencies arise.Genetic flows are alleles that are exchanged between populations. Diversity increases, causingallele frequencies to increase as more come into the population. Genetic drift causes randomchanges in the frequency of alleles in a population. Alleles can be lost through random chanceand therefore loses diversity in the population or they can be fixed in the population. Naturalselection causes alleles that improve fitness to become more common.In this project, we investigated one of the four types of evolution and how they affect theallele frequencies. In particular, I had investigated how genetic drift affects allele frequenciesbased on changes in the population size. This was investigated using the computer stimulationprogram, “Populations Genetics Stimulator”. We tested different population sizes to see if theyhad contributed towards the change in allele frequencies.HypothesisI hypothesized that genetic drift will have a greater effect on allele frequency in smallerpopulations and larger populations will have lower effect on allele frequencies.
