What is the Deep Impact of Plant Domestication

Figure 1. Multiple centers and areas of plant domestication arose, although most staple crops are found in the Mediterranean basin and in Asia.

Plant domestication, which led to agriculture, arguably has had among the deepest or most profound impacts on modern societies relative to all other human innovations. Not only did it lead to greater availability of food, allowing societies to grow in population, but it enabled a large labor force to be freed to pursue other specialties. Additionally, technologies related to agriculture, even today, continue to have profound consequences on all societies, for better and worse. Finally, with domestication, the plant's environment has also profoundly changed.

Initial Impact on Societies

Plant domestication was initially thought to have first appeared in the Fertile Crescent, with later societies in the Nile, Yellow River, and Indus valleys also adopting domesticated plants. However, now it has become evident that various societies have independently discovered how to domesticate given plants for food production. These plant staples have included wheat, barley, rice, lintels, beans, millet, corn/maize, and others (Figure 1).

Several results ultimately developed with the domestication of these plants. First, the benefits of plant domestication was to increase food supplies and make them more predictable. Although plants, as they become domesticate, are susceptible to disease and other detrimental results, over time genetics of plants begin to alter. For wheat, barley, and other grains, these developments can take hundreds of years before fully domesticated varieties form. However, once domesticated varieties form, they now require societies to more fully invest in them. This includes removing weeds, providing fertilizer, and harvesting at appropriate times so that yields are not lost. Thus, one of the first major impacts of domesticated plants is how they required societies to be settled, where labor began to focus on the care of grain production and other domesticated plants. Greater dependence on plant domestication ultimately makes societies live in villages, towns, and even cities. This change led to a change in gender roles, often leading to the emphasis of men being more focused on production and creation of food resources, while women became caretakers of the home. Previously, women likely spend much of their time collecting food for human societies. In effect, domestication led to a major cultural evolution and not just a new mode in obtaining food.

The other major development evident in New and Old World societies is the freeing up of labor. While plant domestication can be labor intensive, the greater output of food allows larger populations to form. Most or if not all settled societies show evidence of families becoming larger, where even social norms and systems evolved so that women began having more children. Once labor increased, then more people were able to focus on other activities, including the production of other goods that supported agriculture. Innovations often lead to other innovations to support them. Agriculture led to many secondary innovations that helped to support it. This included new technologies such as plows, the need for mathematics to calculate field areas, and eventually writing became one result in some societies that needed to account for agricultural goods being produced.

While we often see these impacts, particularly as they spread across different agricultural regions, as having beneficial results for societies, the reality is much more mixed. One major result of domesticated agriculture is that the environment has been greatly altered, to the point where scientists today call the period after plant domestication as the Anthropocene, or when human societies began to have major impact on the plant. Plant domestication leads to the need for clearing more land, including burning of fields to fertilize them and clear them. This, already beginning by 10,000 years before present, began to have an impact on societies and even likely global temperatures through the release of carbon dioxide and methane. While we think global warming has been a modern effect of industry, agriculture arguably helped to create the first significant wave of human-induced climate change or at least increased emissions into the atmosphere.

Intensification of Agriculture

Figure 2. Irrigation and other agricultural technologies have led to a scaling up of population and often led to major social change.

After the initial innovation of plant domestication in many parts of the globe between 12,000-5,000 years ago, the next major wave of development occurred in how plant domestication enabled large cities to develop. Initially, plant domestication and agriculture allowed towns and villages to flourish. However, with increased accumulation of agricultural resources by fewer individuals, cities encouraged greater labor migration to them so that people could work in the new economies that had agriculture at their core. This is evident in the place that first had cities, southern Mesopotamia, but also appears to be the case in the Indus and the New Word. In these cases, social inequality in wealth distribution was closely associated with the rise of cities. However, that wealth was based on unequal ownership of agricultural holding. In effect, domestication helped to create our modern economic institutions that also created more wealth inequality across societies.

Technologies also became more complex as the need to feed larger cities developed further after 5000 years ago. Large-scale irrigation networks, spanning hundreds of miles are found in the Old World, were required to intensify agriculture (Figure 2). These irrigation works not only required large labor forces, but they also required larger control of territory. One goal of now a new form of states, that is empires, was to control the food production process, where the control of water resources became paramount in some of the earliest empires from the 3rd millennium BCE to the 1st millennium BCE. This only continued and intensified in later states and empires. Technologies, on the one hand, enabled larger populations to grow, but they also created new social problems, as they required new social adaptation to enable them. In the case of irrigation technologies, intense labor and upkeep of major irrigation works, including canals, qanats, and aqueducts, required an enormous amount of labor but also led to state control of these resources because of their enormous investment required. The power of governments over people's lives subsequently increased as agriculture and irrigation of domesticated plants became ingrained.

Continued Modern Impact

We think of agriculture and plant domestication as an old technology or development. However, as earlier waves of development have shown, with population increase, new needs arise. Over the last two hundred years, human population has grown at unprecedented scales, as modern medicine, another innovation made possible by agriculture, has allowed people to live much longer. The now much higher populations globally led to the drive in the 1960s to develop new types of fertilizers and hybrid and genetically modified plants. The so-called "Green Revolution" was one development that has led to increased productivity. However, just like the innovation of agriculture had negative effects on the environment, Green Revolution fertilizers and production have led to increased water and air pollution. Some of the productivity by Green Revolution innovations have also not proven to be as sustainable, leading to collapses in productivity or an inability by poorer farmers to maintain the high costs associated with agriculture, in particular the need for petroleum and fertilizers.

Genetically modified plants are also another recent development. These have become controversial in places because it is not clear what the long-term impact of these plants might be. Many such modified plants have similar or the same genes. This potentially makes domesticated crops susceptible to plant disease that can kill many plants. If genetics are similar, and there is a lack of genetic diversity, then hunger could be a result of a major crop-killing disease.

Globally, agriculture is a more than 3.0 trillion dollars industry, where domesticated plants makeup a large-bulk of this business. While agriculture has freed up many people for other pursuits, it is also a major employer around the world, we more than a billion people are involved in agriculture in some way.

Summary

Few developments have affected our societies, cultural development, and environment as much as agriculture. Plant domestication has not only allowed many of us to pursue other interests, as we are freed from the daily need to forage for food, but it has also meant we have chosen a lifestyle we were not initially evolved to. We have become mostly sedentary societies that have increasingly focused on developing technologies to solve many of our problems and enhance our lives. However, this has also made us vulnerable to environmental damage, all the while global population continues to reach record levels. Nevertheless, all of our major technologies and social developments today would have not been possible without plant domestication. Everything from the way we structure our families, to how we build our homes, and even pass on our possessions to our children is dependent on how agriculture became the dominant lifestyle. Agriculture has made it possible for scientists and others to spend their time on endeavours that would have been unthinkable in our early, mobile societies. Today, it is the ever increasing need to develop new technologies or products to increase productivity of agriculture that continue to drive technical and social change, similar to how plant domestication and agriculture did more than 10,000 years ago.