by Emma J Devereux
Citation: Devereux, E.J., (2021) Ancient Grains: When & where did the domestication of modern crops begin? EcoFoodDev, https://www.ecofooddev.com/the-cultivation-domestication-and-spread-of-cereals-the-real-ancient-grains/
We cannot really think about the future of food until we look at where it has come from. Many modern “diets” and food lifestyle movements are preoccupied with the idea of “getting back” to some way we must have eaten in the past. They look to a time when food was “more natural”, when we must have been more in sync with nature simply because it was the past, and modern infrastructure as we know it did not exist on the scales we now recognise. The suggestion is that the great proportion of the foods that we see on supermarket and grocery store shelves are modified and have only been altered by cultivation relatively recently. These lifestyle movements often pay particular attention to genetic modification (GMO), and make suggestions about the place of meat in our diets. We are repeatedly presented with messages about “natural” foods, and “ancient grains”. Of course, these movements are striving for food that is more sustainably produced, where producers get a better wage, and a way of eating that is better for our health generally- all things that we should strive for.
But what is an “ancient grain”? What is a “natural” food? How did our diet evolve, what are these concepts, and are these food movements necessarily accurate? The answer is: somewhat, maybe, with many caveats.
Before we can talk about the future of food, we need to talk about its past and present. I will describe the beginnings of cereal farming and the domestication of some of our most common grains, such as barley and wheat. This is a huge topic in biology, ecology, environmental archaeology, botany, plant genetics and agronomy among others, that I will endeavour to review. I will also provide links to resources with more details.
An example of work on ancient grain genomic research can be found at: https://www.the-scientist.com/notebook/ancient-wheat-genome-reveals-clues-to-the-agricultural-past-67162
How do we know about the ancient history of plant foods?
Tracing the beginnings and evolution of agriculture is a major preoccupation of fields such as archaeology, anthropology and sociology, as the emergence of farming is akin to the emergence of human society. New insights into the mechanics and technology of early farming are constantly coming to light, due to continued research by archaeologists, archaeobotanists, biologists, and synergies between multiple different sciences.
Archaeologists examine archaeological remains, such as materials used to process foods. Archaeobotanists identify and analyse ancient seed and grain remains, stores, and particular spaces in ancient settlements, and further specialists analyse pollen, starches, phytoliths, and ancient DNA.
Molecular and genetic studies have been of particular importance. Recent genetic studies on the origins and spread of domesticated cereals use molecular analysis to determine the progenitors (ancestors) of modern crops, as well as to trace the paths by which these cereals spread worldwide.
Where did it all begin?
When you talk about the domestication of modern cereals, the area focused on is the Levantine region of modern Israel, Jordan, Lebanon, Syria, and Turkey, as well as parts of Iran and Northern Iraq. This area is known as the “Fertile Crescent” and is the stage on which the domestication of modern cereals took place. The ancestral plant forms of most of our modern domesticated cereals are native to this region. The domestication of cereals in this area, roughly 10,000 years ago, paved the way for the emergence of agriculture, the creation of modern society, and of our modern economic structure.
The Fertile Crescent, region including modern Israel, Jordan, Lebanon, and south-western Syria (https://en.wikipedia.org/wiki/Fertile_Crescent)
However, it is argued that this, logically, is not the only region in which cereal plants emerged, and instead there were many parallel evolutions of the ancient relatives of modern grains which occurred from 10,000 years ago onward. Genetic evidence indicates multiple geographic origins. Of course, the genetic evidence heavily depends on modern germplasm collections that can represent the diversity of wild and cultivated populations of past cereal plants and their associated taxa, and that data is not always perfect. This is where we can use evidence from archaeobotany and environmental archaeology to support the genetic findings, and shed light on why ancient people chose to shift economies in this way, further spreading the techniques and practices of cultivation.
What happens during domestication?
The emergence of domesticated crops was a slow process, and how and where this happened are hotly debated. Cultivation of cereals happened before domestication, but this is not easy to discern from the archaeological record, information about both being gleaned from indirect evidence. Experiments conducted by authors such as Hillman suggest that once wild forms of cereal were domesticated, this new form could spread within a few centuries. This would have depended on the harvesting methods used, as well as environmental factors, disease, false starts, and development issues.
Archaeobotanical (ancient plant) remains reveal the variety of changes that occurred in grains during domestication. Changes such as the toughening of the rachises (the stem of flower of the plant where the seed is located- becoming stronger means the seed was less likely to fall off and be lost to the farmer) and an increase of seed size are common. Naked forms developed, meaning the protective husk covering the grain is slightly less attached, which would have cut the processing time. Naked wheat and barley have been identified in the Levant from the early 7th millennium BC. If cereals were harvested in a certain way, for example by sickle, and next year’s crop sown using these grains, this modification and change in the cereals could occur in a few decades. But one must be careful, as certain features, such as the toughening of rachises, can occur in some wild forms of cereals. Yield was also increased by the enlargement of cereal grains, and also the increase in the number of seeds per head (6-row barley emerging as opposed to 2-row). The earliest morphological evidence (study the change in shape of seeds) for cereal domestication comes from c. 7000 BC sites in the Damascus or Barada Basin and southern Levant, and includes emmer, barley and einkorn.
What led to domestication?
Varying theories exist as to why cultivation and domestication took place. One of the main argument’s points to climate change as a major factor.
Evidence such as ice cores have revealed a trend for gradual warming over the past 25,000 years, from the late Pleistocene to the Holocene, which has been punctuated by cooling events. These events would have had major and profound effects on those occupying the region, their food resources, and subsequently their way of life.
Computer models known as General Circulation Models (GCMs) have shown that seasonality was a feature of the last glacial maximum, with precipitation and cold conditions in winter, and dry summers.
Evidence from sites such as Ohalo II (from c. 17000 BC) provide evidence that large seeded grasses were being manipulated as food resources, with cereal production being linked with expanding settlements and increased sedentism (staying in one place as opposed to a nomadic lifestyle, though any societies were still semi-nomadic) from the 11th century BC (from 1100 BC). Hence, we can see that hunter-gatherers switched their behaviour to favour a way of life that focused on sedentism and cultivation, which eventually led to domestication. This may have been due to the above mentioned climatic changes occurring throughout this time period, making wild food resources less dependable. Foods may have become scarce, or their location and distribution altered. There was also a spread of woodland-steppe habitat, which contained these cereals, which may have contributed to their exploitation. As population increased due to increased sedentism, the dependence on cultivated cereals grew.
In the next post I will take a look at specific cereals, beginning with wheat.
Cover image: carbonized cereal remains. Photo by author.
References
Fuller, D., Willcox, G., Allaby, R., 2012,” Early agricultural pathways: moving outside the ‘core area’ hypothesis in Southwest Asia”, Journal of Experimental Botany, pp617-633
Garrard, A, 1999, “Charting the Emergence of Cereal Domestication in South-west Asia”, Environmental Archaeology 4, pp67-86
Hillman, G. C. (1996) Late Pleistocene changes in wild plant-foods available to hunter-gatherers of the northern Fertile Crescent: possible preludes to cereal cultivation. In D. R. Harris (ed.) The origins and spread of agriculture and pastoralism in Eurasia, 159-203. London, UCL Press.
