Hormones and antibiotics in nature: a laboratory module designed to broaden undergraduate perspectives on typically human-centered topics.

Bringing discovery-based research into undergraduate laboratory courses increases student motivation and learning gains over traditional exercises that merely teach technique or demonstrate well-documented phenomena. Laboratory experiences are further enhanced when they are designed to challenge student perspectives on topics relevant to their lives. To this end, a laboratory module on antibiotics and hormones, which are generally discussed in the context of human health, was developed for students to explore the multifaceted roles of antibiotics and hormones in nature (e.g. interspecies communication) via reading primary scientific literature and performing discovery-based experiments. The main objective of this module was to increase the general biological literacy of students as determined by their ability to connect the Five Core Concepts of Biological Literacy (American Association for the Advancement of Science, Vision and Change in Undergraduate Education: A Call to Action, 2011) to the topics "hormones" and "antibiotics" in pre- and postmodule surveys. After discussing unpublished research findings, cell biology students performed experiments demonstrating that: 1) fungi may promote fern growth via hormone production, 2) novel bacterial isolates in the genus Streptomyces produce antifungal compounds, and 3) subinhibitory antibiotic concentrations may enhance soil bacterial growth. The third finding provided evidence supporting a hypothesis framed in a scientific article that students read and discussed. Student perspectives on premodule surveys focused on roles of hormones and antibiotics in the human body (e.g. development, fighting infection), but their broadened postmodule perspectives encompassed the roles of these molecules in organismal communication and possibly the evolution of multicellularity.