Table 5. Evaluation of instructional materials and assessments according to the Model for the Use of Evolutionary Trees (MUET).
Evolution Education MaterialData SourcesConstruction of TreesRepresentation of TreesReasoning with Trees
Instructional Materials Tested with Undergraduate College Students
Phylogenetics Laboratory: Reconstructing Evolutionary History (Catley & Novick, 2012)Data sources mentioned in Parts I and II include molecular data (HOX gene sequences) and morphological traits (developmental patterns and body structures such as type of skeleton).Students are taught to use cluster analysis of molecular or morphological data to construct a tree.Students are instructed with an example to draw rooted bifurcated trees with nodes and the origin of traits indicated along the branches of the tree. No examples of unrooted trees are provided.Parts IV–VI have students comparing trees based on clustering of molecular or morphological data, to find evidence for homology and homoplasy and to trace the origin of traits on the tree.
Phylogeny Assessment Tool (PhAT) (Smith et al., 2013)In the PhAT, data sources are morphological traits of organisms such as large canine teeth.In Part B of the PhAT, students were expected to use the parsimony principle to decide which tree is a better hypothesis for related organisms in the PhAT.The PhAT shows two rooted bifurcated trees with traits marked along the branches of the trees. No examples of unrooted trees are provided.Based on morphological data, the PhAT assesses students’ ability to consider both gain and loss of traits in chronology for reasoning about homology and homoplasy.
The Great Clade Race (Goldsmith, 2003)Traits are represented using various shapes (e.g., circles, squares, diamonds) without specifying if these are molecular, cell, tissue, or morphological traits of organisms.Cladistics is introduced as a method to examine patterns of shared derived characters to infer a sequence of divergence within groups of organisms. Maximum parsimony is introduced to guide cladistic analysis.Two different correct answers with the same branching order are given as rooted bifurcated trees with traits marked along branches of the tree. No unrooted tree is given as an answer for this exercise.Cladistics, homoplasy, and homology are introduced in this paper.
Instructional Materials Tested with K-12 Level Students
The Lizard Evolution Biointeractive Virtual Lab (HHMI, 2015)Data sources include morphological data, which are the lengths of the lizards’ bodies, hindlimbs, and tails (Module 1), and molecular data, which are mitochondrial NADH dehydrogenase subunit 2 (ND2) DNA gene sequences and five transfer RNA (tRNA) sequences from different populations (Module 2).Module 1 introduces cluster analysis based on animal traits such as appearance and morphology. In Module 2, cluster analysis of eight anole species is done by DNA comparisons using MABL (Dereeper et al., 2008).An unrooted bifurcated evolutionary tree was constructed to depict eight anole species. A distantly related species was introduced to “root” the tree with nodes, branches, and the living species at the tip. Students are able to omit the outgroup to re-root the tree with the midpoint or examine an unrooted tree for the eight anole species.To compare the rooted or unrooted evolutionary trees generated by students with published rooted and unrooted trees provided in worksheets, the students must reason about chronology, trace the origin of traits, cladistics, homology, and homoplasy (convergent evolution).