Conceptual understandings of biology in pre-service science educators and undergraduate biology students at Colorado institutions of higher education

Pre-service secondary science individuals, future middle or high school instructors training to become teachers, along with both Honors and general first year undergraduate biology students were investigated to determine how they reason about and understand two core topics in Biology: matter and energy flow through biological systems and evolution by natural selection. Diagnostic Question Clusters were used to assess student understanding of the processes by which matter and energy flow through biological systems over spatial scales, from the atomic-molecular to ecosystem levels. Key concepts and identified misconceptions were examined over topics of evolution by natural selection using the multiple-choice Concept Inventory of Natural Selection (CINS) and open-response Assessing COntextual Reasoning about Natural Selection (ACORNS). Pre-service teachers used more scientifically based reasoning than the undergraduate students over the topics of matter and energy flow. The Honors students used more scientific and less improper informal reasoning than the general undergraduates over matter and energy flow. Honors students performed best on both the CINS and ACORNS items over natural selection, while the general undergraduates scored the lowest on the CINS, and the pre-service instructors scored lowest on the ACORNS. Overall, there remain a large proportion of students not consistently using scientific reasoning about these two important concepts, even in future secondary science teachers. My findings are similar to those of other published studies using the same assessments. In general, very few biology students at the college level use scientific reasoning that exhibits deep conceptual understanding. A reason for this could be that instructors fail to recognize deficiencies in student reasoning; they assume their students use principle-based reasoning. Another reason could be that principle-based reasoning is very difficult and our teaching approaches in college promote memorization of content rather than conceptual change. My findings are significant to the work and progression of concept inventories in biology education, as well as to the instructors of students at all levels of biology curriculum, and those of future science teachers.