Lab Summary

In this case‐study based lab students are confronted with an African man who has a child with sickle cell anemia. The child’s mother has passed away, and the father has since remarried. He and his new wife are trying to decide whether or not to have another child. Working in teams, students explore the genetics/molecular biology sickle cell anemia and its relationship to the evolution of resistance to malaria. Students use two kinds of simulated protein electrophoresis (Native PAGE & SDS PAGE) to test hypotheses about the nature of the mutation inherited by individuals in the case.  Additionally students explore how the fitness of individuals with different genotypes with respect to the sickle cell allele differ by regional prevalence of malaria in Africa. Students then explore how these different fitness coefficients influence sickle genotypic frequencies over time. At the end of the lab, students are asked to use what they have learned about the evolution, genetics and molecular biology of sickle cell anemia to make recommendations to the couple regarding their decision to have another child.  The lab is also designed to challenge students' misconceptions about how natural selection is playing out in human evolution and to connect the lab's finding to the history of the enslavement of Africans in America.

Conceptual Learning Objectives

• To explore the relationship between genes and their protein products.
• To explore the effect that mutations have on polypeptide structure and function, and to understand how a mutation results in the characteristic symptoms of a genetic disorder.
• To explore the relationship between genes, mutations and processes of natural selection. 
• To allow students to apply concepts in genetics, molecular biology, evolution and biotechnology as it applies to an important human health-related issue.
• To engender student interest in evolutionary genetics and molecular biology by allowing students to explore these fields in the context of an important human health issue.
  

Scientific Skills  - In this lab students practice and receive feedback on

• generating and evaluating predicted results from protein electrophoresis (SDS-PAGE & Native PAGE) experiments which test hypotheses regarding the different types of a gene mutations.
• using biological knowledge and the results of an experiment to explain and provide guidance on a biology-related societal issue.
• communicating, in writing, complex biological concepts and experimental results to a non-science audience.

Learning Theory & Pedagogy

This case-based inquiry is designed around the premise that students will be more interested and invested in their work if what they are learning has an initial context (an open-ended case-study) which is engaging to the learner, and establishes a goal for learning which is meaningful for the learner. This case-based lab reverses the traditional relationship between content and application in lab by using a compelling scenario to catalyze and drive students’ efforts to construct content understanding.  Moreover the lab facilitates learning often rather abstract molecular biology concepts through scientific inquiry (posing and testing student-generated hypotheses).

• An instructor guide which provide lab instructors with lab preparation instructions, suggested materials, learning theory and pedagogical suggestions.
• An instructor PowerPoint presentation which helps to guide students through the stages of this case-based inquiry, and challenges common misconceptions about human evolution and the relations between genes and populations.
• A link to an interview with Charles Mann, the author of the book 1493: Uncovering the New World Columbus Created, in which he discusses the how the economics of slavery in America was in part driven by the natural resistance that African sickle cell carriers had to malaria.
  

• Electrophoresis equipment
• Student team computers with MS Excel
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