Is Earth Currently Undergoing a Sixth Mass Extinction?

The five Phanerozoic mass extinctions were central in shaping biodiversity on Earth today. Due to increasing biodiversity losses, there is debate about whether we are currently undergoing a sixth mass extinction. To help students better understand these issues and explore the ongoing debate, we developed a lesson that uses active learning approaches including small-group work, poll questions, and whole-class discussion. This lesson provides an overview of major events in Earth’s history, an introduction to extinction and mass extinction, and past and present conservation efforts. Students were assessed using two short take-home assignments, in-class poll questions, and quiz questions. Here we provide detail about the lesson and summarize student performance on the assessments. Any opinions, findings and conclusions, or recommendations expressed in this material are those of the authors and do not necessarily reflect the view of the NSF.