Examining Teaching Assistants’ (TA) Experiences Facilitating Traditional Versus Active-Learning-Based Tree-Thinking Curricula: TA Perceptions, Student Outcomes, and Implications for Teaching and Learning About Evolution

Lack of tree-thinking abilities has been identified as a factor that hampers deep understanding of evolution. In this exploratory study, we compared an innovative curriculum based on the Model of the Use of Evolutionary Trees (MUET) to that of a traditional tree-thinking curriculum with regard to how these curricula were implemented by Graduate Teaching Assistants (TAs) in an introductory undergraduate biology classroom. Specifically, semi-structured interviews were used to examine the TAs’ perceptions about their implementation of these curricula and their students’ tree-thinking abilities. Results indicate that the TAs thought that the MUET curriculum was more effective than the traditional curriculum in teaching evolutionary tree-thinking. Results also indicate that TAs’ lack of teaching experience might hinder their students’ tree-thinking abilities, but that TAs’ lack of previous tree-thinking knowledge did not hamper such abilities with the MUET curriculum. These findings suggest that both the MUET curriculum and MUET professional development training promoted gains in TAs’ knowledge of the nature of undergraduate students’ learning processes as well as their capacity to develop pedagogical knowledge with and without the MUET curriculum. However, especially for those with some pedagogical experience, the MUET curriculum helped TAs overcome barriers related to their lack of prior evolutionary tree-thinking knowledge.