This study analyzes the effect of different instructions on threshold concepts within material covering natural selection on students' use of concepts about evolution. Moreover, it examines students' use of concepts as interconnected networks when reasoning about natural selection and analyzes how these concepts relate to each other regarding…

I describe a quantitative approach to three case studies in evolution that can be used to challenge college freshmen to explore the power of natural selection and ask questions that foster a deeper understanding of its operation and relevance. Hemochromatosis, the peppered moth, and hominid cranial capacity are investigated with a common algebraic…