Introduction

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Common wheat—also known as bread wheat and botanically named Triticum aestivum—is one of the world’s most important cereal crops. It is grown across vast areas of the planet and provides the flour used for bread, pasta, pizza and countless other foods. Today, common wheat accounts for the great majority of the wheat produced worldwide. [1]

For thousands of years, wheat has helped sustain human societies. Yet common wheat is not simply an ancient crop: it is also an extraordinary genetic story. It originated through natural hybridisation between different wild grasses, followed by chromosome duplication, and was later shaped by human cultivation and selection.

In this article, we will explore the genetic history of common wheat and the remarkable sequence of events that led to its emergence in the Fertile Crescent. We will see how the history of wheat and the history of human societies became deeply intertwined—and why this cereal still matters so much in the food we eat today.

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The origins

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The origins of modern wheat

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The story of common wheat has very deep roots. It begins in the Middle Pleistocene, roughly 300,000 to 500,000 years ago—long before Homo sapiens appeared.

At that time, two diploid wild grasses contributed to the ancestry of modern wheat. One was Triticum urartu, which carried the A genome. The other was an unknown grass closely related to modern Aegilops speltoides, which contributed the B genome. Like other diploid species in this group, each had 14 chromosomes, arranged in seven pairs.

At some point, these two ancestral grasses hybridised naturally. Hybridisation means that two different species reproduce and combine their genetic material. For the hybrid to become fertile, its chromosome sets had to be duplicated. This produced a tetraploid wheat: a plant with four complete sets of chromosomes, 28 chromosomes in total, arranged in seven groups of four.

This early tetraploid lineage gave rise to wild emmer wheat, the ancestor of several important cultivated wheats. The event was remarkable: hybridisation between species is not unusual in plants, but a fertile hybrid with duplicated chromosome sets is much rarer. It was the first decisive step towards the evolution of common wheat. [2]

It is impossible to know exactly when humans first mixed ground seeds with water and cooked the resulting dough. However, it is a plausible hypothesis that this sequence—grinding grains into flour, mixing flour with water, and cooking it—was among the earliest forms of food processing whose basic principle still survives in our kitchens today.

Unlike roasting meat directly over a fire, this process required several deliberate steps: collecting seeds, separating them from their husks, grinding them, adding water and applying heat. It transformed a hard and inedible seed into a new food with a different texture, taste and nutritional value.

From this simple sequence came porridge, gruel and, eventually, flatbread-like products: some of the oldest ancestors of the breads and doughs we still make today. [3]

Around 10,000–12,000 years ago, in the Fertile Crescent, early farming communities began to cultivate and select tetraploid wheat. Over generations, they favoured useful traits such as larger grains, tougher seed heads and plants whose seeds remained attached until harvest. One result was domesticated emmer, Triticum dicoccum, a wheat widely cultivated in the ancient Mediterranean world, including Egypt and Rome.

Other tetraploid wheats were later selected from the same lineage. One of them is durum wheat, Triticum durum, which is still used today to make semolina and pasta. [4]

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The invention of agriculture

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When did humans begin to use cereal grains?

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Homo sapiens appeared in Africa around 300,000 years ago. For much of that time, our ancestors lived as hunter-gatherers: they did not farm crops, but they collected a wide range of wild foods, including seeds from grasses.

Evidence from Ngalue Cave in Mozambique suggests that people were processing wild grass seeds at least 105,000 years ago. Starch granules recovered from Middle Stone Age stone tools show extensive use of sorghum and other plant foods. This does not mean that these people were growing wheat or practising agriculture; rather, it shows that wild cereal grains were already part of the human diet long before farming began. [5]

Agriculture developed much later. In the Fertile Crescent, communities began cultivating and gradually domesticating plants around 10,000–11,000 years ago. This was a turning point: instead of relying only on wild plants, people began to select, sow and harvest cereals in a more systematic way.

Turning hard, dry grains into food required skill and time. Seeds had to be collected, cleaned, crushed or ground, mixed with water and cooked. These techniques made cereals easier to digest and transformed them into nourishing foods such as porridge, gruel and flatbread-like products.

We do not know when people first made dough, but there is direct evidence of bread-like products made from wild cereals around 14,400 years ago in what is now Jordan—several thousand years before agriculture became established. [6]  Over time, the processing of cereal grains helped create the long culinary tradition that eventually led to the many forms of bread, pasta and pizza we know today.

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Ohalo II: cereals before agriculture

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A later site in the Levant offers an unusually vivid picture of how hunter-gatherers were already working with wild cereals long before farming began. Ohalo II, on the south-western shore of the Sea of Galilee, was occupied around 23,000 years ago. The lake is a landscape that would become familiar thousands of years later through Biblical and Gospel narratives; in the Gospels, for example, Jesus is described teaching and calling fishermen by the Sea of Galilee. Ohalo II itself, however, belongs to a vastly earlier world of hunter-fisher-gatherers.

The site was rapidly covered by water after it was abandoned, preserving the floors of brush huts, hearths, plant remains and stone tools with exceptional detail. In one hut, the distribution of seeds was not random. Concentrations of cereal grains and other plant remains occurred around a grinding stone fixed into the floor, while flint-working debris was concentrated elsewhere, closer to the entrance. This pattern strongly suggests that the inhabitants organised different activities in different parts of the hut: one area for preparing plant foods, another for making or maintaining stone tools.[12]

The grinding stone also retained starch grains from wild cereals, including wheat and barley. Together with the spatial distribution of seeds, this is evidence of deliberate gathering and repeated processing—not simply occasional consumption of seeds found in the landscape. Yet it is not evidence that the inhabitants were already farmers. We cannot infer permanent fields, domesticated wheat or a gender-based division of labour from these remains alone.

What Ohalo II does show is a crucial stage in the longer relationship between humans and cereals. Before wheat was domesticated, people had already begun to invest labour, tools and domestic space in its collection and transformation. The path towards agriculture did not begin suddenly with the first cultivated field: it was preceded by thousands of years of increasingly skilled attention to wild plants.​​​​​​​​​​​​​​​​​​​