From Tree to Map: Using Cognitive Learning Theory to Suggest Alternative Ways to Visualize Macroevolution

Diagrams can be important tools for communicating about evolution. One of the most common visual metaphors that unites a variety of diagrams that describe macroevolution is a tree. Tree-based diagrams are designed to provide a phylogenetic framework for thinking about evolutionary pattern. As is the case with any other metaphor, however, misunderstandings about evolution may either arise from or be perpetuated by how we depict the tree of life. Researchers have tried various approaches to create tree-based diagrams that communicate evolution more accurately. This paper addresses the conceptual limitations of the tree as a visual metaphor for evolution and explores the ways we can use digital tools to extend our visual metaphors for evolution communication. The theory of distributed cognition provides a framework to aid in the analysis of the conceptual affordances and constraints of tree-based diagrams, and develop new ways to visualize evolution. By combining a new map-based visual metaphor for macroevolution with the interactive properties of digital technology, a new method of visualizing evolution called the dynamic evolutionary map is proposed. This paper concludes by comparing the metaphoric affordances and constraints of tree diagrams and the dynamic evolutionary map, and discussing the potential applications of the latter as an educational tool.