What can explain the incredible diversity of beauty in nature? Richard O. Prum, an award-winning ornithologist, discusses Charles Darwin's second and long-neglected theory--aesthetic mate choice--and what it means for our understanding of evolution. In addition, Prum connects those same evolutionary dynamics to the origins and diversity of human sexuality, offering riveting new thinking about the evolution of human beauty and the role of mate choice, thereby transforming our ancestors from typical infanticidal primates into socially intelligent, pair-bonding caregivers. Prum's book is an exhilarating tour de force that begins in the trees and ends by fundamentally challenging how we understand human evolution and ourselves. --