Graduation Year


Document Type




Degree Name

Master of Science (M.S.)

Degree Granting Department

Biology (Integrative Biology)

Major Professor

Luanna Prevost, Ph.D.

Committee Member

Christina Richards, Ph.D.

Committee Member

Sarah Sheffield, Ph.D.


abstract diagrams, cognition, evolution, pedagogy


Phylogenetic trees are common tools used to visualize evolutionary concepts such as historical patterns of ancestry, divergence of species, and descent of species. However, students have misconceptions when reading these abstract diagrams. The purpose of this study was to compare student performance and evolutionary thinking when using two styles of phylogenetic trees: cladograms and phylograms. The study also assessed the validity of a hierarchal theoretical framework evaluating student phylogenetic tree interpretation. Introductory biology students from two research universities were assigned to two groups, one solely given assessments with phylograms, and one solely given assessments with cladograms. One-on-one student interviews were conducted to further explore/examine student interpretation of phylogenetic trees. Results reveal that surprisingly, students used language associated with pedigree charts when describing taxa on the trees, a misconception not previously studied. Students exhibited fewer misconceptions when using cladograms than when using phylograms. Students also used multiple levels of reasoning in their responses, revealing that students cannot be classified on one hierarchal level of tree analysis and a less hierarchal format may reveal a more in-depth analysis of student skills when interpreting phylogenetic trees.