Traditionally the calculus-based introductory physics course has focused on connections to the lower-level engineering curriculum. For students in the rapidly evolving biological sciences, however, inclined planes and pulleys may be less relevant. Because biologists need to understand how to apply ideas from physics to highly complex and dynamic systems, an introductory course that focuses on the development and exploration of physical models could provide an important foundation for students in this area. Engagement in the process of modeling, including idealizing complex systems, making atomic-level models, applying fundamental principles, exploring the behavior of model systems (including computationally), and observing the emergence of complex behavior from the interaction of even a small number of objects, could be central components of students' experience in physics. Examples of such activities (intended to be suggestive, not comprehensive) will be shown.