Biologist Joan Roughgarden examines gender and sexuality through a biological lens, addressing key concepts such as the definition of male and female based on gamete size, the prevalence of hermaphroditism in plants and animals, and the distinction between biological sex and gender expression. This video also explores historical and cross-cultural perspectives on gender diversity, providing a scientific framework for understanding the variation observed in human societies. This discussion is particularly relevant for researchers, educators, and students in biology, anthropology, and gender studies.