The effects of diagram format on students' interpretation of evolutionary diagrams

Abstract

The present study researches university students' understanding of different forms of evolutionary diagrams. It is important to look at students' understanding of evolution so that teachers can use the most effective instructional method possible. College students demonstrate a very poor understanding of evolutionary processes, particularly when asked to interpret evolutionary relationships. Evolutionary biologists traditionally employ cladograms to demonstrate such relationships, but textbooks often give students other types of diagrams, which I label as "textbook" diagrams. The diagrams to be used in this study were found in contemporary high school and college textbooks. Subjects' ability to reason from these "bad" diagrams was compared to their ability to reason from two types of cladograms. Subjects were presented with three sets of evolutionary relationships, each in a different format- either as a textbook diagram, a cladogram tree, or a cladogram ladder and asked to reason from them. Subjects were divided into two groups based on the strength of their biology background. It was hypothesized that subjects with a stronger biology background would exhibit a better understanding of evolutionary relationships than subjects with a weaker biology background