The story of how flight evolved. Not just once but four times, and how each time it happened by accident.

Chapters: Advantages of Flight Evolution of Winged Insects Flies andDragonflies From Caterpillars to Butterflies Evolution of Pterosaurs Structure of Pterosaurs Evolution of Birds Birds Versus Insects Convergent Evolution: Hummingbirds and Moths Evolutionary Success of Birds Evolution of Bats Bats Use Echolocation First Insect on Land