Passage:
Recent archaeobotanical excavations at Chogha Golan in the central Zagros Mountains have fundamentally altered longstanding hypotheses regarding the rate and geographic uniformity of cereal domestication in the Fertile Crescent. Previous models, heavily reliant on sites in the western Levant, posited a rapid, single-origin transition to agriculture around 10,200 BP, wherein selection pressure for non-shattering rachises—the structural stems holding seeds to the stalk—yielded morphologically domestic barley and emmer within a few centuries.
However, high-resolution flotation recovery from Chogha Golan demonstrates an uninterrupted 2,000-year sequence of plant exploitation spanning the Pre-Pottery Neolithic A (PPNA) to the Pre-Pottery Neolithic B (PPNB). Crucially, while wild barley (Hordeum spontaneum) constituted a primary subsistence staple from the earliest occupational strata (c. 11,700 BP), fully non-shattering domestic phenotypes (Hordeum vulgare) did not achieve statistical dominance in the assemblage until approximately 9,800 BP. Throughout this prolonged interim, inhabitants actively cultivated wild morphotypes alongside gathered pulses such as lentil and grass pea, employing intensive weed-management and soil-tilling practices long before indelible genetic mutations manifested in grain morphology.
This temporal lag indicates that phenotypic domestication was not an immediate, inevitable byproduct of cultivation, but rather a protracted evolutionary trajectory mediated by variable harvesting methods. For instance, harvesting grain by beating ripe stalks into baskets favored the survival of shattering wild genotypes, thereby delaying the fixation of tough rachises despite centuries of deliberate planting. Consequently, the Chogha Golan evidence refutes the notion of a Levantine monopoly on agricultural origins, supporting instead a multi-centric, non-linear model where cultivation techniques long predated morphological speciation across diverse microenvironments.
Statement: Based on the passage, the prolonged temporal lag in the fixation of non-shattering domestic barley phenotypes at Chogha Golan indicates that early inhabitants failed to engage in active soil-tilling and weed-management practices prior to 9,800 BP.
Answer: Answer