Distinguishing wild and domestic wheat and barley spikelets from early Holocene sites in the Near East

Identifying morphologically domestic cereals is essential to understanding the origins of agriculture. Charred spikelet bases provide the best evidence for distinguishing wild from domestic varieties of emmer, einkorn and barley; however until now, identification criteria have not been agreed upon or well established. We examined more than 20,000 remains of charred spikelets from eleven early Holocene sites in the Near East, classing them into nine groups. We show that damage and fragmentation of wheat spikelets probably due to dehusking makes identification problematic, and only when the abscission scar is well preserved is it possible to distinguish wild spikelets which shatter from domestic spikelets which adhere and separate during threshing. Barley spikelets were found to be less damaged and more easily identified, perhaps because the processing was less damaging. Einkorn was dominant over emmer on early sites, whereas on later sites emmer was dominant. Identifications presented here from eleven sites date from approximately 13000 to 8200 cal b.p. They give an incomplete picture, but no domestic cereals were identified during the PPNA (Pre-pottery Neolithic A). Early PPNB Aswad produced domestic barley but at other sites for this period the evidence is inconclusive. Unequivocal signs of domestic emmer spikelets appear during the Middle PPNB about 10,000 years ago but wild forms continue as part of the crop after this period. These conclusions are based on limited data. Future studies will undoubtedly produce a more accurate picture.