NOT SAYING “EVOLUTION” MAY BE THE KEY TO TEACHING EVOLUTION
The survey containing the term “evolution” yielded a mean score of 10 (out of 15), and the survey without the term yielded a mean score of 9, which was a significant difference (p = 0.002). The difference in scores suggests that participants may respond to the term “evolution” in ways unrelated to true conceptual understanding. For example, we asked, “Which of the following processes is the mechanism responsible for the evolution of the many varieties of domestic dog alive today?”. Participants were more likely to answer correctly—artificial selection—when “evolution” was removed from the question. When “evolution” was included, participants were more likely to select the distractor “natural selection”; we suggest this results from natural selection and evolution being closely tied together during the instruction of evolutionary theory. In addition, Rasch-based response option analysis indicates that response patterns differ for items between the surveys with and without “evolution”, further supporting the idea that the term “evolution” triggers specific types of responses. The knowledge that the term “evolution” can affect perceived understanding of the theory itself indicates that educators and scientists should be careful in interpreting standard assessment results. Perhaps, too, this indicates that the term “evolution” is not a requirement for, and may even hinder, the teaching of evolutionary processes and concepts.