Agriculture invention and animal domestication caused lasting changes to how humans live and to the physical surface of Earth. A. The transition from hunting and gathering to raising plants and animals was gradual and led to significant changes in the organization of human societies. B. Scholars now believe that agriculture and animal domestication began independently in many separate locations and then spread to new areas. C. As trade in agricultural products grew and social inequalities arose, new crops were developed specifically to feed the labor needed to support societies. D. Although it is now clear that agriculture developed independently in many places, often the most efficient techniques arose by combing practices of different cultures. E. Agriculture became more widespread when human populations realized that an agricultural diet supplemented through trade could provide as much nutrition as the hunter-gatherer diet. F. The earliest reason for raising plants and animals may have been to provide goods for trade, and such trade may account for the rise in social problems such as environmental destruction.