The role of Iran as a center of origin for domesticated cereals has long been debated. High stratigraphic resolution and rich archaeological remains at the aceramic Neolithic site of Chogha Golan (Ilam Province, present-day Iran) reveal a sequence ranging over 2200 years of cultivation of wild plants and the first appearance of domesticated-type species. The botanical record from Chogha Golan documents how the inhabitants of the site cultivated wild barley (Hordeum spontaneum) and other wild progenitor species of modern crops, such as wild lentil and pea. Wild wheat species (Triticum spp.) are initially present at less than 10% of total plant species but increase to more than 20% during the last 300 years of the sequence. Around 9800 calendar years before the present, domesticated-type emmer appears. The archaeobotanical remains from Chogha Golan represent the earliest record of long-term plant management in Iran.

The cereal grass barley was domesticated about 10,000 years before the present in the Fertile Crescent and became a founder crop of Neolithic agriculture. Here we report the genome sequences of five 6,000-year-old barley grains excavated at a cave in the Judean Desert close to the Dead Sea. Comparison to whole-exome sequence data from a diversity panel of present-day barley accessions showed the close affinity of ancient samples to extant landraces from the Southern Levant and Egypt, consistent with a proposed origin of domesticated barley in the Upper Jordan Valley. Our findings suggest that barley landraces grown in present-day Israel have not experienced major lineage turnover over the past six millennia, although there is evidence for gene flow between cultivated and sympatric wild populations. We demonstrate the usefulness of ancient genomes from desiccated archaeobotanical remains in informing research into the origin, early domestication and subsequent migration of crop species.

The collapse and resilience of political systems in the ancient Near East and their relationship with agricultural development have been of wide interest in archaeology and anthropology. Despite attempts to link the archaeological evidence to local paleoclimate data, the precise role of environmental conditions in ancient agricultural production remains poorly understood. Recently, stable isotope analysis has been used for reconstructing site-specific ancient growing conditions for crop species in semiarid and arid landscapes. To open the discussion of the role of regional diversity in past agricultural production as a factor in societal development, we present 1.037 new stable carbon isotope measurements from 33 archaeological sites and modern fields in the geographic area of the Fertile Crescent, spanning the Aceramic Neolithic [10,000 calibrated years (cal) B.C.] to the later Iron Age (500 cal B.C.), alongside modern data from 13 locations. Our data show that drought stress was an issue in many agricultural settlements in the ancient Near East, particularly in correlation with the major Holocene climatic fluctuations, but its regional impact was diverse and influenced by geographic factors. Although cereals growing in the coastal areas of the northern Levant were relatively unaffected by Holocene climatic fluctuations, farmers of regions further inland had to apply irrigation to cope with increased water stress. However, inland agricultural strategies showed a high degree of variability. Our findings suggest that regional differences in climatic effects led to diversified strategies in ancient subsistence and economy even within spatially limited cultural units.Holocene climate change | agricultural societies | aridity stress | Middle East | archaeobotanical crop species