The Success of Agro Evolution

Early farmers, with no modern knowledge of genetics or the biological sciences, achieved triumphs of plant breeding that modern geneticists often begin to match. This was because there were so many of them, and they had virtually unlimited time. Their successes are seen in crops such as banana, pineapple, date palm, yams, cloves, olives, the classic wine grapes, figs, garlic, horseradish, and hops. Modern plant breeding has contributed nothing to either the productivity or the quality of any of these crops. And modern plant breeding has made only minor contributions to crops such as tea, coffee, cocoa, citrus, mango, pyrethrum, cassava, cashews, and many others.

The success of early farmers came from the recognition and preservation of both qualitatively and quantitatively aberrant forms that happened to possess characters valuable to agriculture. Obvious examples of qualitative aberrations are the free-threshing forms of cereals, and the retention of seed by plants that otherwise had an effective seed dispersal mechanism. Early farmers also recognised that the removal of flowers, and the prevention of seed formation, produced an increased yield of the vegetative parts of plants. This is because flowers and seeds are primary physiological sinks that take precedence over other plant parts. In some crops, aberrant forms have lost their flowering ability, often entirely. These sterile forms have been preserved by generations of farmers for centuries, even millennia. They include garlic, horse radish, turmeric, ginger, and yams.

However, most of the antique domestication involved small increments in quantitatively variable characters. This domestication may stretch backwards for up to ten millennia, and the cumulative quantitative changes were often so great that they become differences in kind. Indeed, the original wild progenitors of some crops are so different from their modern descendants that they have proved rather difficult to identify.

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