Teaching and Learning Cladistics

The application of phylogenetic systematics (cladistics) to paleontology and evolutionary biology has led to fundamental revisions in the way that scientists view relationships between organisms. Despite the significance and ubiquity of phylogenetic systematics, students, particularly in large class settings, have a difficult time learning cladistic methods because it is unfamiliar to them and because conceptual change is required. Since students already think of the relationships of organisms within a familiar framework based upon superficial similarities that dates back to the pre-evolutionary ideas of Linnaeus, they need to change their basic scheme of understanding organismic relationships, and this conceptual change, like all conceptual changes, is difficult to achieve. Given its importance to reconstructing the evolution of and relationships among organisms, students need to become familiar with phylogenetic systematics. Dinosaur courses, such as the Evolution and Extinction of the Dinosaurs, a cladogram-based freshman-level course taught at the University of Rhode Island, are attractive vehicles by which these concepts can be introduced in large classes.

To help students learn cladistic methods we created Lecture Tutorials which are short, interactive worksheets for students to complete in pairs during a large lecture class. The Lecture Tutorials allow students to apply cladistic methods to familiar groups of organisms. Students that used Lecture Tutorials in the Evolution and Extinction of the Dinosaurs performed slightly better in the course than did students in previous lecture-only courses. To see a larger increase in student learning, additional interactive, well-designed materials are likely needed for students to overcome well-entrenched ideas about organismic relationships. Our study has implications for teaching other topics in geology that require conceptual change.