The problem for the would-be farmer was that the natural selection pressure for wild plants promotes characteristics that are designed to defeat the farmer. Thus wild grainheads are typically small and shatter easily, thereby seeding themselves. They mature unevenly; their seeds can remain long dormant but still germinate; they have many appendages, awns, glumes, and thick seed coats, all of which discourage grazers and birds. All these features are selected for in the wild and selected against by the farmer. It is diagnostic that the major weeds that plague wheat and barley—one can think of
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