We will start our historical summary of environment-food systems by describing domestication and early farming (10,000 BP – 4,000 BP). Widespread environmental and social impacts occurred during this period. New agricultural ecosystems were created and spread along with the use of domesticated plants and animals. These agroecosystems contained distinctive species and populations of plants and animals including domesticates, as well as characteristic insects, mammals, soil biota, and uncultivated plants (such as weeds). In many places, agroecosystems were increasingly established in areas that previously had supported tree cover. During this period in the Near East, China, and Europe, for example, clearing for agriculture led to increased deforestation.
Jared Diamond, "The Worst Mistake in the History of the Human Race"
As part of this survey, we ask you to read the short and provocative article by Jared Diamond on the impacts of the diffusion of early agriculture. This should prompt a lot of thinking on your part about the way that the emergence of agriculture affected human societies that we describe further below.
Impacts of domestication and early agriculture were notable not just for natural systems but also on human systems. Both a population explosion and a technology explosion occurred in conjunction with early agriculture. The early farming societies grew in the size of their populations and the use of diverse tools and technologies, including ones that no longer needed to be transported as part of highly mobile hunter-gatherer lifestyles. The growth of population was made possible by the increased productivity of food per unit of land area. Impacts on human health and disease were also notable in this period, though they were not entirely positive. As Jared Diamond points out in the required reading above, there were negative impacts on human health traced to larger settlements and denser human populations (e.g. highly infectious “crowd diseases” such as measles and bubonic plague) and also infectious disease involving transmission from domesticated animals (measles, tuberculosis, influenza). Nutritional stress also ironically increased, with life expectancy actually decreased following domestication and the early development of agriculture.
These negative impacts on humans have led Diamond to refer to agriculture provocatively as “The Worst Mistake in the History of the Human Race”. This title is purposefully provocative, and by way of understanding this "mistake", we should realize that early farmers’ switching to agriculture may have become the most viable option in many places. Agriculture becoming the principal livelihood option would have occurred as local hunted-gathered food sources were overexploited and/or required by population pressure. By the end of this period, the evolution of more complex societies also meant the development of deep class divisions. There the social phenomena of deepened class divisions must also be seen as a product, in part, of the evolution of agriculture. In addition, changing social arrangements from agriculture would tend to create a positive feedback (see the end of module 2.1), along with other factors, in maintaining and deepening the pathway of society towards a greater embrace of an agriculture-based food system.
The model of Coupled Natural-Human Systems (CNHS) can be used to reflect on the above impacts through the integrated perspective of human-environment interactions. Here we can highlight a couple of these interactions. First, widespread deforestation occurred as a result of early agriculture. In addition to changing land cover and ecosystems, it has been postulated that the extent of this deforestation at this time was significant enough to release considerable carbon dioxide (CO2) and thus to define the beginning of the Anthropocene epoch. As mentioned below other scientists argue the Anthropocene was created more recently. This scientific debate about the Anthropocene epoch has been productive in our understanding of human dynamics and impacts with respect to the environment.
Humans are presumed to have responded to deforestation by increasing their reliance on agriculture, since the removal of forest cover would have reduced the productivity of hunting-gathering activities, creating a second positive feedback that would have deepened the transition to agriculture. The second form of human-environment interaction involved the selection of a relatively small fraction of utilizable plants and animals that become the cornerstones of early agriculture. Since these plant and animal domesticates produced well relative to others, they became relied upon by early farmers, also acting as a positive feedback towards the adoption of an agricultural lifestyle. The legacy of this initial selection of certain types of plants and animals demonstrates the important role of contingency and positive feedbacks, whereby initial decisions were amplified and exerted a lasting influence on the Coupled Natural-Human Systems of agriculture. The concepts of feedback are considered further in the subsequent pages and in this Module’s Summative Assessment.