The research reported here documents scientists’ changing practices and attitudes concerning college teaching. Graduate students and postdoctoral scientists participated in long-term, inquiry-based teaching professional development while maintaining an ongoing commitment to research science. Data analysis focused on digital recording and transcription of semi-structured interviews of a representative sample of scientists, as well as ethnographic notes, collected over a period of five years. Interview data were analyzed using a newly developed rubric (Practice, Identity, Community Analysis Tool), which allowed the authors to represent qualitative data quantitatively, and, when combined with scientists’ in-depth reflections both in the moment and over time, informed the development of a proposed trajectory of change. They posit that scientists co-constructed a hybrid community of practice within which participants moved easily between university research and inquiry science teaching practices.