This groundbreaking book dismantles racially based theories of human history by revealing the environmental factors actually responsible for history's broadest patterns. Here is a world history that really is a history of all the world's peoples, a unified narrative of human life even more intriguing and important than accounts of dinosaurs and glaciers. The story begins 13,000 years ago, when Stone Age hunter-gatherers constituted the entire human population. Around that time, paths of development of human societies on different continents began to diverge greatly.