100%(3)3 out of 3 people found this document helpful
This preview shows page 1 - 2 out of 3 pages.
Anth. 105 Human Species – Lab 2 Report10/22/18IntroductionEvolution occurs when the alleles in a population change over generations. Alleles, different version of genes, can become more or less common or in rarer cases new alleles can arise. There are four main forces of evolution that effect allele frequency in a population. Mutations increase diversity because new alleles arise through changes in DNA. Genetic drift decrease diversity because alleles are lost through random chance when a group leave. Gene flow increase diversity because alleles are exchanged between a population. In natural selection, alleles that improve fitness, or probability of having surviving offspring, become common. In this experiment, the effect of natural selection when heterozygous allele pairs were favored was investigated. Natural selection works to increase the allele frequency that improves the fitness of an organism. This type of evolution works with what traits are already there. The population size was investigated to evaluate how natural selection would show in bigger and smaller populations. Natural selection that would favor heterozygous alleles would keep both alleles in the population, but the extent of the frequencies of each allele would be expected to be in a constant proportion.The Population Genetics Simulator, a computer simulation program, was used to test the effect of natural selection in a population over generations. The effect of population size on the frequency of heterozygous alleles was the environmental variable tested. The prediction would be the smaller the population, the greater the impact on allele frequency would be because each individual’s alleles would have a bigger influence. The bigger the population, the smaller the impact on allele frequency would be because the number of heterozygous individuals overall would stabilize.