Teaching and learning evolutionary trees: how cognitive science predicts "better" and "worse" diagram styles

Monday 11:30am-1:30pm UMC Aspen Rooms
Poster Presentation Part of Geoscience Education Research


Andrea Bair, Delta College
A cladogram is a branching diagram commonly used to depict hypotheses of evolutionary relationships, and is a central representation of evolution in the fossil record. Biological education research has identified expert-like skills and student learning difficulties associated with interpreting and constructing cladograms. Cognitive science informs diagram design that reduces or avoids misconceptions, and many common misconceptions and difficulties learning "tree-thinking" skills relate to the design of evolutionary tree diagrams. However, recent research has not been incorporated into teaching and communicating evolutionary trees in geology contexts.

The purposes of this study are to: summarize recent research applicable to teaching and learning evolutionary tree diagrams in geology contexts, test whether modifying a "tree-thinking" assessment explicitly to avoid cognitive interference improves scores, and test whether research-based teaching materials and strategies promote improvement in tree-thinking skills and avoidance of misconceptions.Materials and strategies for teaching evolution and "tree-thinking" in undergraduate geology courses were designed to avoid cognitive interference through diagram design, emphasize the hierarchical structure of cladograms,and reduce common misconceptions about evolution and evolutionary trees.

Specific recommendations from recent research are: 1) use "tree-style" cladograms to support understanding of evolutionary concepts; 2) initial work should not use real organisms in trees to avoid cognitive interference; 3) explicitly teach multiple representations and diagram reading strategies to promote hierarchical thinking; and 4) teach using shared, derived characters (synapomorphies) to support understanding of cladistic analysis and evolutionary relationships.

Modifying the assessment to reduce cognitive interference produced comparable results between post-test scores of students in an upper level majors' paleontology course using partially reformed instruction and pre-test scores of students in introductory courses. A pilot study of reformed teaching materials and strategies shows improved tree-thinking skills and reduction in misconceptions in both an upper level majors' paleontology course and introductory courses.