Genes, Mutations, Evolution, and Sickle Cell

In Part 1, students follow the inheritance of a hemoglobin mutation through two generations. Students identify patterns in their data and investigate the cause-and-effect relationship between environmental conditions (incidence of malaria, survival rates, and resource availability) and the frequency of a trait in a population. Based on their data collection and analysis, students construct explanations for how changes to a gene influence an organism’s ability to survive and reproduce. Specifically, students use the example of hemoglobin to explain how structural changes to genes (i.e., mutations), lead to changes in protein structure and function, and how this can lead to changes in the function of red blood cells which, in turn, can affect survival of individuals with the mutation. In Part 2, students use a computer simulation to extend their investigation of the hemoglobin mutation. Initially, the simulation extends their data from the previous activity through 30 generations. Then students are able to adjust the environmental conditions to see how access to resources and the prevalence of malaria influence the distribution of the hemoglobin gene over time.