Students’ model-based explanations about natural selection and antibiotic resistance through socio-scientific issues-based learning

ABSTRACTAntibiotic resistance (ABR) is a significant contemporary socio-scientific issue. To engage in informed reasoning about ABR, students need to understand natural selection. A secondary science unit was designed and implemented, combining an issues-based approach and model-based reasoning, to teach students about natural selection and ABR. This sequential explanatory mixed methods study explored students’ explanations of natural selection. Students created model-based explanations (MBEs) about ABR and verbally explained generalised natural selection during semi-structured interviews. Students’ MBEs significantly increased in natural selection content, and misconceptions about natural selection and ABR significantly decreased after the unit. However, students’ explanations of generalised natural selection differed from ABR explanations. Students struggled to include mutation as the cause of initial variation when explaining generalised natural selection, whereas students included mutation when explai...