***20th Anniversary Edition - With a New Introduction*** How could such an intricate object as the human eye - so complex and so precise - have come about by chance? In this masterful piece of popular science, Richard Dawkins builds a powerful and carefully reasoned argument for evolutionary adaptation as the force behind all life on earth. The metaphor of 'Mount Improbable' represents the combination of perfection and improbability that we find in the seemingly 'designed' complexity of living things. And through it all runs the thread of DNA, the molecule of life, responsible for its own destiny on an unending pilgrimage through time. Evocative illustrations accompany Dawkins' eloquent descriptions of astonishing adaptations in the living world.