A groundbreaking study that radically alters our understanding of the Americas before the arrival of the Europeans in 1492. Traditionally, Americans learned in school that the ancestors of the people who inhabited the Western Hemisphere at the time of Columbus's landing had crossed the Bering Strait twelve thousand years ago; existed mainly in small, nomadic bands; and lived so lightly on the land that the Americas was, for all practical purposes, still a vast wilderness. But as Charles C. Mann…Show more