Evolutionary theory is considered a central foundation of biology, but its complexity often makes it difficult for students to understand (Perry et al., 2008). While schools and universities primarily teach concepts of microevolution (e.g., natural selection) (Catley, 2006), macroevolutionary topics such as the analysis of phylogenetic trees receive little attention. However, they are crucial for understanding evolutionary relationships in their entirety (Dees & Momsen, 2016; Phillips et al., 2012).

Phylogenetic trees are graphic representations that use lines and nodes to visualize evolutionary relationships between living organisms (Blacquiere & Hoese, 2016). The ability to accurately read, interpret, and construct these family trees is referred to as Tree Thinking (Halverson, 2011). However, studies show that both learners (e.g., Catley et al., 2013; Halverson et al., 2011) and teachers (Gregory, 2009) have considerable difficulty with this skill.

Previous research has primarily focused on reading and interpreting phylogenetic trees (Tree Reading). Tree Building, on the other hand, has hardly been studied to date, although initial findings suggest that this activity can significantly improve understanding (Dees & Momsen, 2016; Eddy et al., 2013).

This PhD project therefore examines the processes and potential of Tree Building with three central focuses:

1. Systematizing skills and challenges in tree construction:

First, we will examine how learners and teachers proceed in creating phylogenetic trees and the difficulties they encounter. Using qualitative methods (Ericsson & Simon, 1993), we will visualize the thought processes and evaluate them using qualitative content analysis (Mayring & Fenzl, 2019) to systematically capture the challenges of Tree Building.

2. Developing and testing effective learning methods:

Based on the results of the first phase, various learning settings will be developed and empirically tested for their effectiveness in an intervention study. This involves varying didactic approaches with/without biological examples (Goldsmith, 2003) and with/without inquiry-based learning (Perry et al., 2008) in order to specifically promote learning gains in Tree Building.

3. Test teaching and learning options for the university: 

The findings will ultimately be incorporated into the development of a new seminar module for biology teaching students. Future teachers will be trained in how to design teaching materials on phylogenetic trees in a way that addresses the diverse learning needs of heterogeneous learning groups.