Observing populations and testing predictions about genetic drift in a computer simulation improves college students’ conceptual understanding

Abstract

Evolution is a difficult subject for students, with well-documented confusion about natural selection, tree thinking, and genetic drift among other topics. Here we investigate the effect of a simulation-based module about the conservation of black-footed ferrets, a module designed with pedagogical approaches that have been demonstrated to be effective, for teaching genetic drift. We compared performance on the Genetic Drift Inventory (GeDI) of students who completed the module and students who were in classes that used other methods for teaching genetic drift. Students in 19 courses using the simulation-based module improved their understanding of genetic drift significantly after completing the Ferrets module, as measured by the GeDI. Students in five control courses actually performed significantly worse on the GeDI after instruction. The lower scores in the control courses were driven by a decrease in these students’ understanding of key concepts. The Ferrets module appears to be an effective way to teach genetic drift. In the control courses, students’ progress in understanding genetic drift may pass through a stage where their understanding of key concepts is worse than it was prior to instruction. However, students who learned genetic drift in courses that used the Ferrets module showed a more rapid increase in their understanding of key concepts related to genetic drift. This result suggests that the paths that students can take to move from novice to expert understanding may be more varied than was previously predicted.