Wheat's DNA points to first farms.

Wheat today is synonymous with bread, but before it became the stuff of the staff of life, people grew an ancient form known as einkorn. The cultivation of einkorn, perhaps for eating as gruel, is thought to mark the origin of agriculture in the Old World.

"If you know where [einkorn] wheat was domesticated, you know where agriculture originated," says wheat geneticist Jan Dvorak of the University of California, Davis.

A new study aims to find those whereabouts. Sifting through and winnowing DNA fragments from wild and cultivated einkorn, a group of European researchers has traced the first sprouts of cultivate einkorn to a stretch of mountains in southeastern Turkey. The group, including Manfred Heun of the Agriculture University of norway in As and Francesco Salamini of the Max Planck Institute for Research on Plant Breeding in Cologne, Germany, reports the finding in the Nov. 14 Science.

Stretching between present-day Turkey and Iran, the Fertile Crescent is well known from archaeological evidence as the home of the first farmers, about 10,000 years ago. Wild einkorn grows abundantly in the crescent and elsewhere. The grain "was a logical choice for neolithic people," says Dvorak.

Heun and his colleagues analyzed the DNA from 270 lines of the wild einkorn, as well as 68 lines of the larger, cultivated grain, which differs genetically only slightly from the wild forms. In the DNA fragments they examined, the cultivated einkorn most closely resembles 11 lines of wild einkorn that grow in the Karacadag Mountains.

"They show that all the cultivated einkorn is related to one specific population in Turkey," says Dvorak. It's an important finding, he adds, and bears repeating with a different genetic technique.

Hard on the seed of cultivated wheat came barley and lentils, then other crops, including another form of wheat that led eventually to the familiar bread wheat. Likewise, sheep, goats, and pigs were domesticated in the Fertile Crescent, along with dogs (SN: 6/28/97, p. 400).

The result, writes Jared Diamond of the University of California, Los Angeles School of Medicine in an accompanying commentary, was a "valuable package" of domesticated plants and animals that quickly spread along the same latitudes, spurring Eurasia's large settlements. In contrast, agriculture in the Americas (SN: 5/24/97, p. 322) expanded more slowly but with more variety, he says, as crops had to be adapted to northern and southern conditions.