One of the most important developments in the existence of human society was the shift from a subsistence economy based primarily on terrestrial or maritime foraging to one based primarily on plant and animal food production. This profound transition in human ways of life occurred independently in at least seven or eight regions of the world, namely, the eastern United States, Mesoamerica, South America, the Near East, China, New Guinea, probably mainland Southeast Asia and possibly India (for recent updates of the evidence, see Barker 2006; Zeder et al. 2006; Cohen 2009; and Price & Bar-Yosef 2011). In most of these places, including South America, the transition occurred shortly after the Pleistocene ended. Within a few centuries to millennia of the first domestication of plants, people began living in sedentary communities that derived a significant portion of their diet from agriculture. With the dispersal of agriculture to other parts of the world, such communities developed in new regions, although the processes of their establishment varied. Where agriculture spread through colonisation, a sedentary way of life usually appeared immediately, but where agriculture was adopted by local hunters and gatherers, there was often a gradual reliance on crops. Nonetheless, almost everywhere crops appeared, eventually important subsequent demographic, economic, social and technological changes in society took place.