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Agriculture was the basis of the Mesoamerican civilizations. It is estimated to have taken centuries to develop and its final stage - which became known to Europeans in 1500 - is thought to have been the result of an accumulation of practices and materials invented and perfected by the various cultures that had survived wars, famines and natural disasters. It cannot be assumed that this result was a linear process; it must have taken shape slowly in centres of economic and political power, expanding or contracting according to the fate of the human groups. Efforts to improve crops and invent production and utilization practices were undertaken more or less continuously and were perhaps safe from many hazards because activities were in the hands of farmers, who were the least affected by power changes.
From gathering plant products, people went on to protecting and cultivating certain plants. It is thought that fruit-trees, which supplied a good part of the produce gathered, were also the first species to be protected and cultivated. During the expedition to Honduras, the Spaniards of Cortés managed to survive thanks to the sapodillas which they found in the forest. One could imagine that the primitive seed plantings were similar to the ones that can still be seen in the plots of houses in some parts of Chiapas and Guatemala. These plots are a mixture of fruit-trees, edible and medicinal plants, cocoa and ornamental plants, sown and harvested without any order under native trees which serve no other purpose than to provide fuel and shade. There is nothing to indicate that selection was practiced under these conditions, nor that the types chosen were sown. In dry regions, primitive sowings could have been based on plants that produce seeds and require clean soil to grow. Eventually, the system of slash-and-burn clearing developed, and this is practiced in all regions. especially those with alternating seasons.