Description

Case studies can be a great way to connect students with primary research literature. Ideally, papers should be selected that not only fit with course content, but are also interesting, relevant and accessible. One approach, especially for first year students, is to use only parts of a research article, perhaps even a single figure. Context can be provided before the class discusses the case by way of videos or other on-line resources ("flipped" case). In this example, two case studies were developed based on a 2014 Nature paper on the evolution of human biting preference in Aedes aegypti mosquitoes.1 The first case, published in the National Center for Case Study Teaching in Science, uses a preassigned video to introduce the basic research questions. The case is presented as a fictional lab group meeting. Students take on roles and the dialog introduces "James," an undergraduate research student who has just joined the Vosshall research group at Rockefeller University. (With permission, profiles are presented of the first author and the research lab PI, Leslie Vosshall). This case has students exploring concepts of evolution (speciation), as well as the important elements of constructing a hypothesis, and experimental design. Students spend time annotating and understanding the first figure from the Nature paper, discussing possible hypotheses, and proposing follow up experiments to address potential flaws in design. The students then get to see how the authors themselves followed the same process. Later in the semester, the case and the characters are revisited as students learn how the researchers discovered the genetic mutation in human-preferring mosquitoes, and how this mutation (an olfactory receptor) specifically responds to a distinctly human volatile chemical from skin emissions. Both cases are presented in the second semester of a year-long Introductory Biology course for life science majors, initially introduced during a unit on evolution, with the second part presented in the context of neurobiology and sensory biology. Other concepts that arise include chemical separation of molecules, electrical recording of neural activity and transgenic methods for gene expression. Introducing the authors as part of the cases may additionally promote science identity in the students. 1 McBride, CS, Baier, F, Omondi, AB, Spitzer, SA, Lutomiah, J, Sang, R, Ignell, R and Vosshall, LB. Evolution of mosquito preference for humans linked to an olfactory receptor. Nature, 515: 222-227, 2014

Cite this work