Exam 22: Evolution by Natural Selection

The following questions) are based on information in Hopi E. Hoekstra, Kristen E. Drumm, and Michael W. Nachman, "Ecological Genetics of Adaptive Color Polymorphism in Pocket Mice: Geographic Variation in Selected and Neutral Genes," Evolution 586), 2004: 1329- 41. Figure 22.1 -Refer to Figure 22.1. In their investigation of natural selection on Mc1r alleles the gene that determines coat colour) in Arizona pocket mice, Hoekstra et al. determined the frequency of the D and d alleles in each population. They also determined the frequency of alleles for two neutral mitochondrial DNA genes genes that do not affect and are not linked to coat colour). Why did the researchers include the mitochondrial DNA genes as part of their experimental design?

A patient has finished his treatment for a bacterial infection with an antibiotic and feels better. However, four days later the same bacterial infection returns. The doctor prescribes the same course of antibiotics, but this time these antibiotics do not cure the patient. What would be the most likely reason for this?