2020-03-01

The innovation of agriculture in prehistory

For innovation in agriculture to happen, agriculture itself had to come into existence, that is, it had to be innovated. Where, when, why, and how that innovation happened, and who were the innovators, are questions that people have asked themselves for a very long time. For much of that time people were satisfied with simple answers: Agriculture was given to man (women presumably looked on) by some deity - Isis in Egypt, Demeter in ancient Greece, Ceres in ancient Rome, Shen-nung in China, Quetzalcoatl in ancient Mexico, and so on. Where did that happen? Obviously wherever that deity felt at home. When did that happen? Don't ask. Why did that happen? Here the myths diverge. In many cultures the mythical deities gave agriculture to the people to allow them to flourish and to give farmers a sense of being somehow superior to their hunter-gatherer neighbors. In the Christian myth, in contrast, agriculture is a predicament that befell humans after their grumpy god had evicted them from paradise as punishment for a trifling insubordination. From then on, as the Bible records in Genesis, man was forced to eat bread in the sweat of his face. Both categories of myths, the Christian as well as the non-Christian ones, have in common that they were able to satisfy the curiosity of people about the origin of people for a very long time.

Myths lack conviction outside their narrow group of believers because people are not usually inclined to accept somebody else's deity as the foundation of their own livelihood. In consequence, each of the many deities that were said to be the origin of agriculture was either unknown to most people, or, if known to nonbelievers, rejected by them. Origination myths that involve deities therefore are unsuitable as generally accepted explanations of the origin of agriculture.

One strategy to enhance the acceptance of an explanation that involves deities, is to replace that deity with an anonymous process. For explaining the origin of agriculture, processes involving stages of progress have been fashionable since the ancient Greeks. An example of such a process-explanation of the origin of agriculture is the story that Adam Smith told his students in 1763. According to Smith, the development of humanity passes through four distinct states: The Age of Hunters, the Age of Shepherds, the Age of Agriculture, and the Age of Industry. He told his students, "when a society becomes numerous they would find a difficulty in supporting themselves by herds and flocks. Then they would naturally turn themselves to the cultivation of land and the raising of such plants and trees as produced nourishment for them. They would observe that those seeds which fell on the dry bare soil or on the rocks seldom came to anything, but that those[s] which entered the soil generally produced a plant and bore seed similar to that which was sown. These observations they would extend to the different plants and trees they found produced agreeable and nourishing food. And by this means they would gradually advance into the age of agriculture" (Smith 1982, p. 15). At the time when Smith lectured to his students no one knew where this might have happened, when it happened, and how long it took. Moreover, Smith's process story simply assumes that agriculture was there to be taken up. Where did it come from? Don't ask.

Archaeology became a science about a century after Smith had lectured his students, and it became a quantitative science after 1949 when the chemist Willard Libby had developed radiocarbon dating. Thanks to botanists such as Nikolai Ivanovich Vavilov, Jack R. Harlan, and many others, we now know where the crops on which agriculture is based have been domesticated. And thanks to new methods, in particular radiocarbon dating, we now know when the domestications happened. Fig 1 provides an overview of the answers that we can presently give when asked where and when agriculture has been innovated. It happened in eleven regions, some small, some huge, on all continents of the world with the exception of Australia and Antarctica. The time periods when the domestications of crops happened range from 10,000 years before present (B.P.) for wheat and squash to 2,000 years B.P. for African rice. The world-wide geographical dispersion of crop domestications and the wide time span of their occurrences hardly supports the notion that the origin of agriculture was a single event.

https://www.journals.uchicago.edu/na101/home/literatum/publisher/uchicago/journals/content/ca/2011/658481/659964/production/images/large/fg1_online.jpeg

(Source: Price and Bar-Yosef 2011)

How has agriculture been innovated? The answer from archaeology is evasive: "Explaining the origins of agriculture is still one of the most contentious issues for social scientists. Few dispute that the interplay of climate, human demography, and social systems through time and space played a significant role. Although some consider the primary driving factors to be patterns of climatic and ecological change, others argue for the primacy of social imperatives and changes within social systems. More generally, some scholars have claimed that no explanations are likely to be universally applicable, whereas others have adopted an explicitly comparative approach, identifying parallel processes and exploring common underlying patterns" (Larson 2014, p. 6145).

The difficulty of providing a more determinate answer than the one cited, lies, in my opinion, in the combination of three things. For one, archaeology is a sparse-data science whose theories are tied to reality by few solid data with huge gaps between them, where bold assumptions stand in for missing data, and where elaborately spun arguments tie sparse data and bold assumptions into coherent theories. When new data arrive, they often falsify assumptions, arguments lose their support, and theories may collapse. Second, hunting-gathering and agriculture are different subsistence strategies that are linked to different habitation strategies. Unless forced by governments, hunter-gatherers rarely live in fixed settlements. Some are nomads and others move from time to time according to the readiness of a meal and a drink at a given location. Only very few hunter-gatherers, such as the Natufians who lived in the Levant from about 12,000 to 9,500 B.P., have settled into villages with fixed buildings. Farmers, in contrast, were, with very few exceptions, always settled. A satisfactory explanation of the origin of agriculture therefore also ought to explain how farmers became sedentary. Finally, and perhaps most importantly, we know that agriculture is a complex innovation that was brought about by hunters and gatherers. We also know that humans can achieve little without first imagining what they want to achieve. Imagining is a mental activity and, in the absence of any symbols that have recorded their thoughts, we don't know, and are unlikely to ever be able to know, the minds of prehistoric hunter-gatherers - what they knew correctly and incorrectly, how they reasoned, how they coped with risk, what their skills were, and so on. A major ingredient into a satisfying explanation of how agriculture came about is therefore unavailable to us, and accounts of how agriculture was innovated must remain highly speculative.

Who was involved in the innovation of agriculture? We know it must have been hunter-gatherers because that was the only group of people around at the time the innovation happened. But that means anybody or any subgroup could have done it. Perhaps we can be a bit more precise. Among modern hunter-gatherers a clear division of labor prevails: men do the hunting and fighting, women do the gathering and most of the food preparation. If the division of labor that prevails among today's hunter-gatherers also prevailed among prehistoric ones, their women were likely to know more about edible plants than the men, and they would have been more skilled in tending plants. If so, the bet is on the women as the innovators of agriculture.

Not knowing the minds of the innovators, there is no hope to answer definitively the question why agriculture has been innovated in different parts of the world sometime between 10,000 to 2,000 B.P. Several answers have been rejected, among them a whole category that has been popular in the past. This category are answers that suggest single causes for the origins of agriculture, such as a change in climate, or population growth, or scarcity of food, or religious beliefs, or whatever. Mono-causal explanations of why agriculture has been innovated have failed in the past and, given the complexity of agriculture and its diverse origins, have a high chance of failing in the future too.

Not being able to say how and why agriculture was innovated, nor being able to identify the innovators, leaves a huge void in our knowledge about agriculture. The mind abhors voids. So let me suggest an innovation story that may fill the void until you hear a better story of how agriculture was innovated. The gist of my rough sketch is taken from James Scott.

Imagine a new app, 'TimeTravel', which can show you the earth as it is believed to have been in prehistory. You tell your assistant on your smart device, "call up TimeTravel"' and the assistant asks back: "where to go?" You can name a region, a place, or when you want to be precise, the coordinates of a place. You tell your smart assistant, "go to Samawah in Iraq." TimeTravel shows you in satellite view a dusty city on the banks of the Euphrates. You zoom in and out of the picture. You see that Samawah is located about halfway between Baghdad and Basra, and about 300 km upstream from the Persian Gulf. A desert lies a short distance to the west of the city and much of the country surrounding Samawah appears to be rather dry. But you are not interested in what the area is like today. You are interested in what it was like in about 8,000 B.P.

You tell your smart assistant, "go to period 8,000 B.P." The city disappears from the screen, the Euphrates wriggles as it changes its course over the millenia, the dominant color changes a few times from dusty brown to lush green and back, another city shows up at around 2,000 B.P. and vanishes again whilst the shore of the Persian Gulf moves upstream until it stops about 50 km away from where Samawah is now. The dominant colors of the satellite view are the green of the land, the blue veins of channels and rivulets that pervade the land, the dark green of the low-lying meadowlands along the Euphrates, the dark-blue-green band of the meandering river, and the deep blue of the Gulf. Other than the river, there are no interesting details to be seen in satellite view and you tell your smart assistant, "switch to bird's-eye view, 200 meters."

The app gives you a view of the terrain as you would have it when sitting in a helicopter overflying the country at a height of 200 m. With the tip of your forefinger you direct the app to fly slowly upstream along the Euphrates. From aloft you see a marshland that must have been hunters' paradise: thick flocks of migrating birds along the river, ducks on the rivulets, egrets and storks stalking fish and frogs in flat ponds, deer in the low-lying meadows, herds of gazelles on the flood plains. To the northwest the plain seems to have pimples. You direct your app towards them and you recognize mounts that look like the backs of huge turtles, similar to the terps of Friesland but smaller. Coming closer, you see clusters of huts thatched with reed on some of the turtlebacks. That is when a pop up window in your app tells you that it has a feature video for that place and time, "Cultural niche construction by hunter-gatherers on the Euphrates marshes before the Ubaid period."

You click on the pop-up window and the video starts playing. The video shows you scenes of daily life of a small group of people who have settled on one of the turtlebacks. In the morning a group of men take off with spears, bows, and flint-tipped arrows; the men are followed by a couple of adolescent boys and their dogs. When the men are gone the women take up their daily chores. The video then focuses on one young woman with a young child of about 1 year. We first see the woman walk with her child to a grove of oak trees that borders on a creek. There the woman fetches some water and on the way back to the huts she also picks up some firewood. Back at the huts she gathers some sickles - short flint stone blades attached to a handle smoothed-by-use, a few strings, and a basket made from reeds. Next we see our stone age mother how she - child on her back - and two other women harvest cereal grains which could be emmer or barley. The women skillfully cut the haulms at their base, careful to avoid letting the ripe seeds drop to the ground. Then they tie the harvested haulms into sheaves and cover the heads with baskets to catch any grains that drop from the heads. Whilst the women are cutting the haulms some older children help their mothers to find more cereal plants that are ready for harvesting.

The video then switches back to an older woman who had stayed back at the huts together with a teenage girl. You see the woman and the girl carefully select from various wooden storage vessels seed grains which they put into a pouch. Next you see them arrive at a patch of land that looks like it had recently been flooded, and with the floods having left a thick layer of silt. In that silt are sprouting some young vegetable plants that look like lentils; others seem to be young chickpea plants. The woman then shows the girl how to plant. Depending on the green plants in the neighborhood, she first selects a seed of a certain kind from the pouch. Then she presses with a stick a whole into the moist silt, and places the seed grain into the whole. Finally, she uses her foot to scrape some silt over the grains. The woman and the girl then work side by side for a while putting seeds into the silt. Occasionally, the woman corrects the teenager who seems to be eager to learn.

The video ends with an evening scene. The women grind seeds into flour for dough for damper baked on hot stones. The men roast duck and fish on an open campfire whilst some children play with puppies. After the meal the men pass a pouch around with some herbs and nuts in it. They chew the stuff, they look content. The stars are shining brightly and some men start singing in a low voice.

The video is over. You are curious to find out what became of the place that you have just seen in the video. You tell the app to go into helicopter-panorama mode from a height of 500 meters and to move forward in time in steps of 500 years. You watch what happens to the cluster of huts and to the landscape surrounding it. You see the number of huts increase, huddling around some more fireplaces. As the number of huts grows more planted plots appear around the proto-village. Then spring up some mud-brick houses with a simple T-shape layout. The number of planted plots around the village increases, and, as the plots move ever closer together, their shapes become ever more regular. On the natural canals you see boats that seem to transport merchandise to the village. As the village keeps growing more T-shaped houses spring up and huts disappear. Between the houses there are open spaces where people work, trade, and socialize. The village is now surrounded by a wide belt of regular-shaped cropped fields. The farming belt is intersected by several straight canals which bring water and boats into the village. Then the color of the landscape changes rather abruptly. The fields are still green but beyond the farm belt the dominant color of the vegetation has changed from a lush green to yellow-brown, as we know it from that area today. Also, some sidearms of the Euphrates have turned into a series of billabongs and others have fallen dry all together. The small rivulets, which were many, have disappeared and the farm belt is criss-crossed by small irrigation canals. The village has grown into a town that is surrounded by a wall. The houses still are T-shaped but many now have a walled-in courtyard. The people in the courtyards seem to do specialized work - some spin yarn, others weave cloth, some forge metal, others shape clay into pots. In the center of the town are some larger buildings. In the courtyard of one of them you see people lining up to deliver grain in return for clay tokens into which a scribe has pressed some marks. Right beside this building is one with a huge courtyard and strong walls. You see how several armed men drive a cluster of neck-shackled men and women into the courtyard. You have arrived at Uruk in the year 3,000 B.P. and you have seen how the slaving, taxing state has sprouted from agriculture. You close the app and put your smart device away..

Uruk could not possibly have emerged without agriculture. It is not economical to tax hunters and gatherers who are a fugitive lot. Moreover, for a ruler and tax collector it is difficult to determine a workable tax base that does not threaten the livelihood of hunters and gatherers. Without taxes, however, rulers can’t keep armed men in their service. Without armed men willing to use force it is difficult to extract taxes from recalcitrant subjects, and the ruler’s business model is threatened.

Taxes and slavery are the downside of the state. On the upside are the many benefits of civil society: enforced property rights, deep division of labor, lively trade among strangers, lasting written records and legal texts, and more innovation. It is these benefits - and many others - that enabled agriculture and civilisation to sustain a dance of innovating moves which has led us to where we are today.

Sources:

Larson, G., Piperno, D. R., Allaby, R. G., Purugganan, M. D., Andersson, L., Arroyo-Kalin, M., Barton, L., Climer Vigueira, C., Denham, T., Dobney, K., Doust, A. N., Gepts, P., Gilbert, M. T. P., Gremillion, K. J., Lucas, L., Lukens, L., Marshall, F. B., Olsen, K. M., Pires, J. C., Richerson, P. J., Rubio de Casas, R., Sanjur, O. I., Thomas, M. G. and Fuller, D. Q. (2014). Current perspectives and the future of domestication studies. Proceedings of the National Academy of Sciences of the United States of America 111(17): 6139–6146.

Price, T. D. and Bar-Yosef, O. (2011). The Origins of Agriculture: New Data, New Ideas. Current Anthropology 52(S4): S163-S174.

Scott, J. C. (2017). Against the grain: A deep history of the earliest states. New Haven: Yale University Press.

Smith, A. (1982). Lectures on jurisprudence. The Glasgow edition of the works and correspondence of Adam Smith. Indianapolis: Liberty Fund.



The innovation of agriculture in prehistory

For innovation in agriculture to happen, agriculture itself had to come into existence, that is, it had to be innovated. Where, when, why, ...