Chapter 28: Agriculture
What is agriculture? It is an activity whereby an organism actively cultures/cultivates/cares for other organisms with the intent of somehow utilizing these organisms directly or indirectly. While we are focused on the agricultural interactions involving humans, other organisms, specifically numerous ant species, carry out agriculture, culturing fungi, aphids and other organisms. Agriculture generally involves the ‘domestication’, a genetic modification of organisms, both plants and animals, allowing them to be better utilized.
Agriculture involving humans and plants is certainly one of the most significant biotic interactions, an activity that influences vast expanses of land, roughly 12% of the earth’s land surface. Although there is much less agricultural activity in aquatic/marine systems, there is some, and secondary effects from terrestrial activities, e.g. fertilizer run-off, also has an impact. Like all interactions, agriculture involves modifications of both partners. And while we will focus on the non-human component, generally flowering plants, it is important to keep in mind that agriculture has brought about tremendous changes in humans, with probably the most significant ones coming about as agriculture originated and humans altered their patterns of activity, movement and social interactions. It is significant to note that relative to the existence of humans, agriculture is a recent innovation, starting roughly 10,000 years ago. For most of their 200,000 year existence, humans were not involved with agriculture, although they certainly did influence specific plants by their activities. It is also significant that agriculture apparently developed separately in multiple regions. Authorities now list eleven sites of agricultural origin, including the Middle East, Africa, the Far East, and North, South and Central America. In each of these regions distinct species were utilized. The table below lists some of the earliest crops along with their region of origin:
Table 1.
|
crops |
site of domestication |
|
wheat, peas, lentils, flax, figs, chickpeas |
Middle East |
|
potato, tomato, pepper |
South America |
|
corn, squash, beans |
Mesoamerica |
|
banana, sugarcane, taro |
New Guinea |
|
rice, mung beans, soy beans |
China |
|
millet, sorghum, |
Africa |
|
eggplant, mungo bean, pigeon pea |
India |
The majority of crops, and certainly the crops associated with the origin of agriculture, were wild plants that humans had already discovered to have desirable features (most commonly features related to eating but sometimes the features were mechanical, e.g. cotton, or chemical, e.g. a waterproof latex from tree bark). The next step was the appreciation that the plant could yield more product if it were somehow cared for, e.g. planted, pruned, etc. For most crops, the practice of collecting and planting seeds was crucial to crop development. Through time, many plant species were genetically modified by humans through s