The head wires of the King-of-Saxony BIrd-of-Paradise are unlike any other feathers in the world. They’ve lost their normal feather structure and become a conspicuously awkward ornament. It may seem difficult to explain the evolution of head wires by the process of natural selection. In fact, they’ve evolved because of sexual selection—an extreme example of female mate choice affecting basic anatomy. Filmed and photographed by Tim Laman. Explore more at