Students’ Conceptions in Determining Evolutionary Relationships of Animals
Mentor:William Hoese, Professor of Biological Science, California State University, Fullerton
The fundamental tenants of evolution are that life is related and that life has changed over time. Understanding the evolutionary relationships among animals is a key skill for introductory college biology majors, yet it can be challenging to master because superficial similarities among distantly related organisms may be confounding. Children (grades 4-8) naturally group animals based on their habitat and mode of locomotion even after learning the appropriate taxonomic categories. Our research question was the following: What cues do introductory college biology majors, who have nearly completed their first semester of evolution and biodiversity, use to determine evolutionary relationships of animals? We used habitat and the paraphyletic grouping of “invertebrates” as distractors to investigate how these students (n=155) determined these relationships. We developed and administered a six-question survey. Each question consisted of four line drawings of animals in which students indicated which two were most closely related, diagrammed the relationships of these animals, and explained why they diagramed the relationships in this way. We selected familiar animals and each question included examples of two animals that shared a habitat (e.g., terrestrial; coyote and roadrunner), and one that did not (e.g., sea turtle); we hypothesized that students using habitat as a cue would group those sharing the habitat together, and students using evolutionary-based features would not. We used a similar strategy to design questions around the presence/absence of a backbone. Following instruction, the average correct score across all six questions was 43.3%. Of the 56.7% of questions answered incorrectly, a substantial proportion used habitat and invertebrate misconceptions to determine relationships. Introductory college students appear to use similar cues as younger children when making decisions about how to group animals. These alternate conceptions negatively impact student learning and should be directly confronted in instruction.