Wheat

Wheat begins with wild grasses in the hills of Southwest Asia. Each has 14 chromosomes.1 One of them, Triticum urartu, still grows from Lebanon to Iran.8,9

About 800,000 years ago a grass very like it crossed with a relative of the goat grass Aegilops speltoides. The seedling kept both parents' genomes whole. It was wild emmer, with 28 chromosomes. 1,21 That second parent has never been found alive. It is most probably extinct.10,1

Wild einkorn looks much the same as T. urartu, but it is a separate species and it stayed as it was.9,77

Wild emmer is a plant of rocky slopes around the upper Jordan valley.78 At Ohalo II, a camp on the Sea of Galilee about 23,000 years old, wild grasses were the staple food, and wild wheat and barley made up a large part of what was left behind.3 Starch on a grinding stone shows grass seeds being processed there: barley, and possibly wheat.79

Some researchers see more than gathering. Weeds of the kind that grow in tilled fields hint at small trial plots. Others read the same remains as wild stands, cut and carried home. 801

In the Black Desert of Jordan, hunter-gatherers were baking some 14,400 years ago. Charred crumbs from two fireplaces at Shubayqa 1 are bread-like, and the excavators suggest that wild einkorn went into them. 1919

Farming came before the farmed plant. In northern Syria, at Jerf el Ahmar, Dja'de and Tell Qaramel, people of the tenth and ninth millennia BCE were growing wild einkorn and other wild cereals. The plants themselves had not yet changed. 201

A wild ear shatters when ripe and sows itself. Harvesting favors the rare ear that holds on, and the change shows in the chaff. At Nevalı Çori in south-east Turkey, about 10,000 years ago, only 14% of einkorn chaff was of the holding kind. At Çatalhöyük, a thousand years and more later, 95% was. 59,602323 Whether so slow a change means that nobody was selecting on purpose is argued. 8162,70

Einkorn's DNA points to the slopes of Karacadağ, a volcano in south-east Turkey.6,7 Where emmer was tamed is disputed, between that region and the southern Levant, and the oldest fields with a good share of tamed ears lie in southern Syria. 83,6678,7023

Domestication changed the ear in three ways. First, it stopped shattering. In einkorn a single amino-acid change in one gene, Btr1, did it. Emmer has two genomes, so it needed two broken copies. 87,964,1 Archaeologists read the result in the chaff: a wild spikelet breaks away with a smooth scar, a farmed one with a rough, torn one.81

Second, the grain swelled. It did not get longer. It got wider and deeper, and it did so before the ear stopped shattering. 8881

Third, in some wheats the husk let go. Einkorn, emmer and spelt are hulled: threshing breaks the ear into spikelets, and the grain has to be pounded out. Durum and bread wheat thresh free, largely because of one gene, Q. 595989

Somewhere near the Caspian Sea, a cultivated wheat met a weed. The weed was Tausch's goat grass, Aegilops tauschii, which grows from Turkey to China. 12,26,111,12 Their offspring kept every chromosome of both: three genomes, 42 chromosomes. It was bread wheat. 11,70

The usual date is 8,500 to 9,000 years ago, though estimates run from 6,000 to 11,000.1,12,77 No wild bread wheat exists.1,11

The goat grass passed on only about a quarter of its own variety.91,12 Yet a rare lineage, found today only in Georgia, left its mark too, so the cross may have happened more than once. 91,1291 In the ground, DNA from grain about 8,400 years old at Çatalhöyük is of the three-genome kind, and two Georgian villages held bread wheat beside goat grass by about 5900 BCE. 682626

Wheat left its homeland with the people who farmed it. Villagers on Cyprus had cereals from the mainland by about 10,600 years ago.27 Around 6700 BCE newcomers founded farming villages on the Aegean coast of Turkey. Wheat grains from the first of them, Çukuriçi Höyük, have been dated directly. 2828

From the plains of northern Greece, farmers moved up into the Balkans with emmer and einkorn as their staples. By 5400 to 4900 BCE the same two wheats were the main crops at Biskupice in Poland. 343429 Naked wheat kept to the Mediterranean coast.35 Cereals reached Britain about 4000 BCE, and Sweden soon after. 3630

A fourth wheat traveled with them, and then vanished. Archaeologists noticed its odd chaff in 2000 and named it the new glume wheat. Ancient DNA has since tied it to Timopheev's wheat, a separate species with its own pair of genomes. It died out in Europe before the end of the first millennium BCE. 94,95949478,77

South of the Levant, the oldest farmed cereals in North Africa come from the Fayum oasis of Egypt, 4650 to 4350 BCE, where emmer was kept in pits lined with basketry.37,38

Eastward the going was slow. The Zagros mountains held the crops up more than any desert did.98 Mehrgarh in Pakistan, which grew wheat of south-west Asian kinds, was long said to have begun about 8000 BCE. New dates on its burials give 5200 to 4900 BCE. 9839 By 3200 to 2600 BCE wheat of the bread-wheat type grew at early Harappan sites.15,42

Herders took it through the mountains of Central Asia. Naked wheat lay at Tasbas in Kazakhstan by 2840 to 2490 BCE, and at Chap II in Kyrgyzstan, 2,000 meters up, soon after. 4240

China is argued over. One grain from Shandong dates to about 2562–2209 BCE. Some take it at its word. Others call it an anomaly and count wheat as secure there only from about 2100 BCE. 15,9942

The wheat of the first cities was emmer. At Mesopotamian sites it is the commonest wheat, second only to barley, and Sumerian tablets record it going into beer and groats. 1313 The scribes wrote it zíz.13

In Egypt emmer was the wheat, by most accounts the only one, from the start of farming until after Alexander's conquest in 332 BCE. Then durum, which threshes free, replaced it. 1313,44

Rome remembered a hulled wheat as well. Pliny called far the first food of Latium, eaten as porridge long before bread. Whether far was emmer or spelt is still argued. 1413 By Pliny's century the city's grain came by sea, a third of it, in one ancient telling, from Egypt.100

Wheat sailed with Columbus's second voyage, among the seeds for the new town of La Isabela. Whether it grew depends on whom you read. Columbus reported a harvest. A companion wrote that it withered. 4545

On the mainland the first sower may have been Juan Garrido, a free Black conquistador. In 1538 he petitioned the Crown as the first man to try wheat in New Spain. The claim is his own. 46,4746

Farther north, single samples founded whole wheat belts. In 1842 David Fife of Ontario grew on a few grains from a cargo out of Danzig. His Red Fife became the leading wheat of the Canadian prairie, and a parent of Marquis, which ripened a week or more sooner. 484849

Old wheats stood up to a meter and a half tall. Feed them well and they fell over. 5958

The answer came from Japan. In 1917 breeders there crossed a short local wheat, Daruma, with an American one. A descendant was registered in 1935 as Norin 10. 54,5555,54 In 1946 an American agronomist in occupied Japan sent its seed home.56,57

In Mexico, Norman Borlaug's team began crossing it into their wheats in 1953 or 1954. 5858 The short plants put more of their growth into grain. 103104 In 1967 Pakistan, Turkey and India bought 82,000 tons of the seed, and within five years India's harvest had risen from 12.3 to 20 million tons. 5758

The gains were real and uneven. In irrigated Punjab they came with salt, waterlogging and poorer groundwater. 105106,107

Wheat covers more of the Earth than any other crop: 219.5 million hectares in 2024, hardly more than in 1961. The harvest from that land has more than tripled, to 798 million metric tons. 4,544,5 Three countries, China, India and Russia, grow two-fifths of it.4

It gives people about a fifth of their calories and of their protein, and two-thirds of the crop is eaten as food. 5,1065 About 95% is bread wheat. Most of the rest is durum.108 What sets wheat apart is gluten, the stretchy protein that holds the gas in rising dough.108

The old wheats hang on. Emmer is still grown in Ethiopia, India and Yemen.109 And the base is narrow. Modern varieties descend from two of seven old groups of landraces, and a rust race found in Uganda in 1999 could infect about 90% of the world's varieties. 1717110,111111