In his book entitled Restructuring Science Education: The Importance of Theories and Their Development (1990), science educator Richard A. Duschl presented an equiposed triadic model of the growth of scientific knowledge that is based upon the work of philosopher of science, Larry Laudan (1984). Stage 1 of our study tested that model against the research practices of 10 accomplished life scientists employed at a Carnegie Research 1 university, via purposive sampling, a carefully sequenced model-based interview schedule, face-to-face questioning, and propositional analysis of the interview transcripts. In Stage 2, a revised research-based graphic version of Laudan's model was presented to two experts on the nature of science (Drs. Richard Duschl and Nancy Nercessian) during an extended interview. From that interview, further data collection and analysis, and an extensive literature search, our Stage 1 graphic was elaborated. In response to the interview, 5 novice graduate students and 5 advanced graduate students or new Ph.D's of the original 10 life scientists were interviewed, using the same methods, to ascertain if their research perceptions and practices will differ from that of their mentors. Implications for the teaching of biological science were derived from the research findings.