Biologist Nathan Lents joins Science Quickly to explore the vast sexual diversity found across the animal kingdom. His new book, The Sexual Evolution: How 500 Million Years of Sex, Gender, and Mating Shape Modern Relationships, challenges the binary framework that has long shaped biological research, arguing for a more accurate and inclusive view of sex and gender. From alternative reproductive strategies to overlapping traits, this episode reveals how nature defies neat categories—and why science should, too.

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The Sexual Evolution: How 500 Million Years of Sex, Gender, and Mating Shape Modern Relationships, by Nathan Lents. Mariner Books, 2025

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Science Quickly is produced by Rachel Feltman, Fonda Mwangi, Kelso Harper and Jeff DelViscio. This episode was edited by Alex Sugiura. Shayna Posses and Aaron Shattuck fact-check this show. The theme music was composed by Dominic Smith.

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