Centering Biodiversity: Integrating the Complexity of Sex into a Developmental Biology Course

In biology, variation is the norm, not the exception. This particularly holds true for the concepts of sex and sex determination, which we refer to here as biology of sex. Unfortunately, biology of sex topics are often taught using oversimplified content, situating sex as a simple, genetically determined binary, and that mammals are the predominant model for biology of sex across organisms. Teaching using these oversimplifications leads students to develop a limited understanding of biology of sex topics, which limits their capacity as future researchers and also harmfully and erroneously supports discriminatory social norms and legislation. To work towards developing effective pedagogical strategies that teach the complexity of biology of sex topics, we used the knowledge in pieces (KiP) theoretical framework to explore the question, how did students' knowledge of sex and sex determination change after a revised unit that centered biologically diverse examples and biological mechanisms in an advanced undergraduate level developmental biology course. Twenty-five of the 48 enrolled students participated in our study. We analyzed students' responses to a reflection and a pre/post assessment using reflexive thematic analysis and compared students' exam responses to multiple choice questions about biology of sex topics and other topics. Our qualitative and quantitative results demonstrated that the expanded unit had mixed effectiveness. From their reflections, students indicated that they thought learning about biology of sex topics was important as part of their biology education and identified the current cultural climate as a reason for discussing, not avoiding, these topics. However, students disproportionately struggled with learning this content. On the exam questions, students performed more poorly on the biology of sex topics than on the other topics covered on the same exam. Their pre/post assessments revealed that student responses changed to responses aligned with the course content more easily for subtopics that were more likely to be novel than for more familiar and often socially charged subtopics. These results demonstrate that seemingly simple topics that are societally entrenched, such as defining the concept of sex, may be more difficult to shift than more conceptually complex concepts that are less entrenched.