This book provides an overview of human-plant interactions and their social consequences, from the hunter-gatherers of the Palaeolithic Era to the 21st century molecular manipulation of crops. It links the latest advances in molecular genetics, climate research, and archaeology to give a new perspective on the evolution of agriculture and complex human societies across the world. Even today, our technologically advanced societies still rely on plants for basic food needs, not to mention clothing, shelter, medicines, and tools. This special relationship has tied together people and their chosen plants in mutual dependence for well over 50,000 years. Yet despite these millennia of intimate contact, people have only domesticated and cultivated a few dozen of the tens of thousands of edible plants. Crop domestication and agriculture then led directly to the evolution of the complex urban-based societies that have dominated much of human development over the past ten millennia. Thanks to the latest genomic studies, how, when, and where some of the most important crops came to be domesticated can now be explained, and the crucial roles of plant genetics, climatic change, and social organization in these processes. Indeed, it was their unique genetic organizations that ultimately determined which plants eventually became crops, rather than any conscious decisions by their human cultivators.