In this study, we examined two types of group presentation assignments for use in a large, introductory biology course. Students were placed into groups of 6 to 8 members, and tasked with researching a topic and preparing a 10-minute inclass presentation. The assignments varied by course section; in the control section, each group's topics were selected to complement the course topic, whereas in the iterative sections, each group's topic would derive from the previous group's presentation. Students' critical thinking skills were assessed before and after the semester's presentations, and exit surveys were conducted. Results show that students in the iterative group performed better than control on exam questions, and overall interest in biology was high in both groups as a result of the presentations. Overall, performing group presentations in an iterative style enhanced learning by mimicking the scientific process of inquiry and discovery.