ABSTRACT
Since the beginning of agriculture 10,000 years ago, the human diet has depended primarily on the deficit spending of ecological capi tal. All of the important cereal seeds that sustain us-wheat, rice, corn, beans, and others-are annuals that require disturbance of the soil and sowing every growing season. That disturbed soil is vulnerable to the forces of wind and rain. Yet without the calories from annual grains, humanity would lose more than 70% of its diet and most of us would quickly starve. Wild plants, the ancestors of the high-yielding annual crops in our food inventory, made it possible for our ancestors to launch the agri culture revolution. Although the world’s population was far smaller in ancient times, even then we were spending our ecological capital. From the beginning, soil erosion has been linked repeatedly to the collapse of ancient civilizations (Lowdermilk, 1953; Runnels, 1995).
