Ongoing pedagogical research in the biological sciences has emphasized the importance of student-centered and process-based learning. However, incorporating this philosophy of teaching into content-heavy biology courses is a difficult task. At Indiana University, B300: Vascular Plants is an upper-level plant systematics course which attracts approximately 70 students from a wide variety of backgrounds each Spring semester. Although our students generally perform well with identifying traits and keying plants, concepts and skills related to phylogenetic analysis have consistently proven difficult to grasp, resulting in poor student performance on this topic in end-of-semester assessments. As a result, the graduate teaching assistants (GTAs), under the guidance of the faculty supervisor, have redesigned how phylogenetic analysis is taught to students in the course. This has been accomplished through implementing a series of homework exercises and in-class discussions which focus on introducing conceptual processes in incremental steps. In this study conducted by the GTAs of the course, we ask whether the implementation of a student-centered and scaffolded approach to teaching improves students’ performance and retention of core concepts and skills.

Results/Conclusions

This investigation represents the results of a novel, productive, and inquiry-based collaboration among GTAs. We will share examples of the formal and informal learning assessments developed by the GTAs, including homework exercises, in-class discussions, a pre/post concept survey, and end-of-semester assessments. Then we will present both quantitative and qualitative results to demonstrate the effectiveness of using incremental, student-centered approaches to teaching difficult conceptual processes in undergraduate biology courses. Results from end-of-semester assessments will be compared to data from three previous years. We will also present results from a pre-post survey which we used to examine our students’ changing understanding of phylogenetic concepts over the course of the semester. Finally, student feedback about their experiences with the course will be discussed. This study contributes revised approaches for teaching concepts and skills related to phylogenetics, approaches which are transferrable to similar process-oriented teaching situations in biology, as well as methods for formally and informally assessing student learning in biology courses.