In our work with high school students and nonmajors college populations, we have been troubled by wide gaps in experience, confidence, and access to rigorous science content. In order to make science an inclusive community, it is important that all students have experiences that allow them to engage in science practice, while also being developmentally appropriate for students’ age and current understanding. This need is particularly acute in the area of evolutionary biology, where both misconceptions and cultural resistance continue to impede broad public understanding of scientific ideas.

We read with great interest the recent exchange of ideas in this journal regarding tree-thinking. In the March and April 2015 issues of ABT, Davenport, Milks, and Van Tassell presented a set of activities designed to expose high school students to the concepts of phylogenetics. These activities asked students to read and construct evolutionary tree diagrams to support a development of understanding of descent with modification and the relatedness of different species, which strikes at the heart of common misunderstandings about evolution. Brower's commentary (May 2016 ABT) challenges some of the pedagogical choices made in these activities, such as the analogy of pedigrees to evolutionary trees. This critique raises an important issue: when does analogy advance student understanding, and when does it confound it by creating misconceptions? This question has come up in ABT before; Novak (January 1981 issue) uses the example of telling young children the sky is blue. They will eventually learn about concepts of colorless gases and diffraction – but that's a later step in their education, and “the sky is blue” is a developmentally appropriate step that advances their understanding. The idea of high school students using a tree-thinking paradigm seems more directly useful in building evolutionary understanding, regardless of the compromises made in the name of strong pedagogy.

This exchange of ideas – a sharing of a set of activities to support high school students in thinking like evolutionary biologists, a critique attempting to place those activities in the context of the field of evolutionary biology, and a measured response about pedagogical choices – exemplifies the value of a journal like ABT. Davenport et al.'s papers were centered on student experiences and learning goals, whereas Brower's commentary and the authors’ subsequent response provided a deeper look into the pedagogical choices necessary to construct a successful activity that advances student understanding of evolutionary biology.

Are we biologists, or are we teachers of biology? If we wish to improve scientific literacy, we are compelled to be both. We're constantly making tradeoffs between accuracy, complexity, and accessibility – and it is altogether appropriate that we should do this. If our priority is to provide students with appropriately leveled opportunities to engage with rich scientific thinking, then their experiences have the potential to change their perceptions about science and to improve scientific literacy in society at large. The questions of which biological ideas to include, and the pedagogical choices made to convey these ideas, often introduce conflict between current understandings in biology and best practices in teaching.

These conflicts do not have easy or clear answers and deserve thoughtful discussion and debate. We are grateful to The American Biology Teacher for providing a forum for this discourse. This community allows us to be both biologists and teachers of biology, and to honor both of these fields of scholarship as we try to serve the public good by expanding access to scientific ideas and practice. We believe that this is a worthwhile conversation to continue, and we look forward to more of these discussions in the future.


Stephen Traphagen

AP Biology Teacher

Rolling Meadows High School

Rolling Meadows, IL 60008

Julie Minbiole

Assistant Professor of Biology

Columbia College Chicago

Chicago, IL 60605