Evolutionary diversification in low density isolated gardens
--Galinat, WC

Maize evolved from teosinte and then diversified at low density in isolated gardens with individual plants and ears judged on their merits. At the time of maize introduction, each garden contained only a few isolated species, like being introduced into an island in the Galapagos Archipelago where it was free from competition with its own related kind and open to an adaptation into an ecosystem with the other inhabitants and with its new environment.

Maize frequently found itself in association with beans and squash, with bean vines twisting up the maize stalks and squash vines spreading around to fill empty space related to large rocks and stumps (Fig. 2). The intercropping of maize, beans and squash with relatively few plants of each kind in small gardens is an extension of their natural ecosystem. The consequence in the thousands of isolated gardens located in diverse environments was an explosion of genetic diversity with over 300 distinct races of maize evolving by the time of Columbus.

The direction of the diversification in an individual garden was in the eyes, hands and mind of the farmer-breeder in charge. He considered factors of beauty, utility and tradition, in contrast now with the industrial maize breeder, whose considerations are yield, profit and market share. The industrial maize grows in an agricultural factory of machines, chemicals and computers. The raw material to achieve industrial maize was generated by the old fashioned farmer breeder. Now that the raw material is endangered, the future is uncertain. 


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