The effects of a professional development program on elementary and middle school teachers’ understanding and acceptance of macroevolution and how they teach it

Despite science education reform efforts stressing the importance of understanding evolution, many students receive little to no exposure to the most important unifying concept in biology. Since evolution is basic to the study of biology, its study should begin with the introduction of the life sciences to students in elementary school. However, many teachers lack sufficient evolutionary content knowledge, have limited acceptance of evolution, and have little confidence to effectively teach it. Better teacher preparation is needed to meet the challenges of ensuring students develop conceptual understanding of evolution. While research shows the general public typically accepts microevolution while rejecting macroevolution, few studies have focused on peoples’ understanding of macroevolution. Additionally, little research exists examining the effects of an intervention on elementary and middle school teachers’ acceptance, understanding, and teaching of macroevolution. Using a conceptual framework based on the Cognitive Reconstruction of Knowledge Model, this study reports the effects of a sustained professional development program on 4th through 8th grade teachers’ acceptance of evolution; understanding of macroevolution; and approach to teaching evolution in schools, awareness of challenges to teaching evolution, and pedagogical content knowledge about teaching macroevolution. This study also explores the relationship between teachers’ understanding of macroevolution and acceptance of evolution. Various data sources, including the Measurement of the Understanding of Macroevolution (Nadelson & Southerland, 2010), the Measure of the Acceptance of the Theory of Evolution (Rutledge & Warden, 1999), teacher interviews, and teacher workshop reflections, were used to answer the research questions. Results from the study revealed that after attending the professional development series, teachers’ understanding of macroevolution and acceptance of evolution significantly increased. Acceptance of evolution was positively correlated to understanding of macroevolution. Teachers’ prior understanding of macroevolution was a significant positive predictor of their subsequent acceptance of evolution. Teachers’ prior acceptance of evolution was a significant predictor of their understanding of macroevolution, but only after teachers participated in at least half of the sustained professional development. Finally, teachers demonstrated having increased macroevolutionary pedagogical content knowledge. This effect was strong in those teachers who were initially low acceptors of evolution. The significance of these findings is discussed.