section_path: History/Domestication
section_name: Domestication
paragraph_text: Domestication
  
  Hunter-gatherers in West Asia harvested wild wheats for thousands of years before they were domesticated, perhaps as early as 21,000 BC, but they formed a minor component of their diets. In this phase of pre-domestication cultivation, early cultivars were spread around the region and slowly developed the traits that came to characterise their domesticated forms.
  
  Repeated harvesting and sowing of the grains of wild grasses led to the creation of domestic strains, as mutant forms ('sports') of wheat were more amenable to cultivation. In domesticated wheat, grains are larger, and the seeds (inside the spikelets) remain attached to the ear by a toughened rachis during harvesting. In wild strains, a more fragile rachis allows the ear to shatter easily, dispersing the spikelets. Selection for larger grains and non-shattering heads by farmers might not have been deliberately intended, but simply have occurred because these traits made gathering the seeds easier; nevertheless such 'incidental' selection was an important part of crop domestication. As the traits that improve wheat as a food source involve the loss of the plant's natural seed dispersal mechanisms, highly domesticated strains of wheat cannot survive in the wild.
  
  Wild einkorn wheat (T. monococcum subsp. boeoticum) grows across Southwest Asia in open parkland and steppe environments. It comprises three distinct races, only one of which, native to Southeast Anatolia, was domesticated. The main feature that distinguishes domestic einkorn from wild is that its ears do not shatter without pressure, making it dependent on humans for dispersal and reproduction. It also tends to have wider grains. Wild einkorn was collected at sites such as Tell Abu Hureyra (c. 10,700–9000 BC) and Mureybet (c. 9800–9300 BC), but the earliest archaeological evidence for the domestic form comes after c. 8800 BC in southern Turkey, at Çayönü, Cafer Höyük, and possibly Nevalı Çori. Genetic evidence indicates that it was domesticated in multiple places independently.
  
  Wild emmer wheat (T. turgidum subsp. dicoccoides) is less widespread than einkorn, favouring the rocky basaltic and limestone soils found in the hilly flanks of the Fertile Crescent. It is more diverse, with domesticated varieties falling into two major groups: hulled or non-shattering, in which threshing separates the whole spikelet; and free-threshing, where the individual grains are separated. Both varieties probably existed in prehistory, but over time free-threshing cultivars became more common. Wild emmer was first cultivated in the southern Levant, as early as 9600 BC. Genetic studies have found that, like einkorn, it was domesticated in southeastern Anatolia, but only once. The earliest secure archaeological evidence for domestic emmer comes from Çayönü, c. 8300–7600 BC, where distinctive scars on the spikelets indicated that they came from a hulled domestic variety. Slightly earlier finds have been reported from Tell Aswad in Syria, c. 8500–8200 BC, but these were identified using a less reliable method based on grain size.