In A Short History of the World J. M. Roberts argues, “The Coming of Agriculture changed life so much and so deeply that nothing since would have been possible without it” (Roberts 1993, 22). Prior to the emergence of agriculture, and "for most of human history, people lived in relatively small groups, gathering, fishing, and hunting what they needed from their immediate environments" (Goucher and Walton 2013, 36). Because of the unpredictable nature of this way of life, hunting, gathering and fishing could not sustain large groups of people for extended periods of time. Seasonal influences, animal migrations or even human pressures on the environment often forced people to move their settlements to areas that could sustain their survival. On a larger scale, migrations were typically precipitated by factors including: changes in climate such as recession of glacial ice, population increases that exhausted or stressed natural resources, sudden ecological changes caused by floods and volcanoes and the emergence of technologies such as communication, use of tools and metals, and the advent of agriculture.
Over time, as humans' relationships to their environment changed, their subsistence strategies had to change. Climatic changes that produced droughts in once fertile and productive areas made it impossible for hunting and gathering people to maintain their mobile way of life. Being forced to stay close to any source of water they could find, they began planting fields of wheat and barley around them (Guns, Germs and Steel, 2005). Increased production of grain required the development of storage technologies which would then permit people to store their grains for long periods of time. Production and storage of grains allowed people to remain stationary. Over time, stationary farming communities were able to become selective in their harvesting of only choice grains. The domestication of plants resulted from this prolonged planting and harvesting of choice grain. As populations increased, the pressure grew to become even more productive as farmers. The domestication of animals as well as the introduction of iron technology and the harness allowed for greater productivity (Goucher and Walton 2013, 51). These technological innovations contributed to the societies' ability to sustain their growing populations with greater ease.
Though early agriculture was degrading on the environment and more difficult and labor intensive than previous hunting, gathering and fishing strategies, the benefits far outweighed the costs. The emergence of agriculture allowed formerly mobile, small groups of people to lay down roots and become settled communities. Increased agricultural productivity led to the specialization of occupations including "woolen textiles, metal goods and pottery" (67). Specialization fostered the development of complex networks for trade which created greater diversity in resource availability and consumption.
Early settled societies...