The impact of evolutionary processes in understanding human health and disease is an important idea for future health professionals to understand. These students, however, typically receive little to no formal instruction in the role of evolution in not only understanding human health, but its impact on how to treat human diseases. To address this issue, we developed and implemented a case-study based learning module designed with a learning cycle implementation as part of a larger evolution across the curriculum program. The module focused on the evolution of skin color to illustrate that natural selection occurs in humans, and that the process of evolution involves tradeoffs (a balance of costs and benefits). Student understanding of the tradeoffs of natural selection was assessed through a pre- post-test design, with students answering a set of questions before instruction and again after. The modules helped improve student comprehension of natural selection, particularly for lower-performing students who were not biology majors, and for those whom reported less interest in evolution.