Biodiversity good enough to eat.

Last January, over an enlightening meal of quinoa and amaranth, garnished with assorted exotic legumes (exotic, at least, to a palate accustomed to the durable nothingness of iceberg lettuce and hothouse tomatoes), I began to understand the future of the ecology of food. We were gathered to celebrate the publishing of Seeds of Change by Kenny Ausubel, a book devoted to rescuing agriculture from multinational corporations. The setting was sort of an Explorer's Club of the botanical world--hunters of rare legumes and grains mingled with writers and entrepreneurs over heaping plates of exotic plant species.

Quinoa and amaranth are New World grains, staples of the original inhabitants of Central and South America. Absent from the North American diet for centuries, they are now reappearing in health food stores and certain seed catalogs. The National Academy of Sciences has dubbed them "critical" to the future of global nutrition. They taste good, too.

This criticality bestowed by the Academy on otherwise unassuming plants only makes sense if you know what has happened to food in the last hundred years. The evolution of global agriculture has been a process of winnowing and refining, removing parts that do not contribute to the imperatives of shape, yield and appearance that communities and markets generally impose. For the first few millennia, this was okay. Markets were dispersed and diverse, and ancient peoples did what ancient people tend to do: by remaining interested in hundreds of different food plant varieties and continually rejuvenating their genetic stock by borrowing from the wild, they saved all the pieces.

Now, things are different. According to Jack Doyle of the Washington, DC-based Friends of the Earth, 15 companies provide some 60 percent of farm supplies. Six companies handle 95 percent of wheat and corn exports. This concentration of influence means that "agri-culture"--the interwoven set of social, political, economic and spiritual relationships that have evolved around humanity's daily effort to feed itself--is rapidly giving way to corporate agriculture, and important pieces of our biological heritage are being lost.

Down on the farm, this means that, of the thousands of plant species that might provide nutrition to humans, just three--corn, rice and wheat--account for nearly half our sustenance. Even worse, whereas nature has seen fit to evolve hundreds of thousands of varieties of these three staples, adapted to myriad ecological niches, agribusiness devolves itself to one, or at best a handful of varieties. Fully 97 percent of the food plant varieties available to our grandparents no longer exist, except perhaps as a handful of seeds in a seed bank or a corner of some thoughtful gardener's backyard.

In this way, the gene pool is drained. First through breeding, and now through genetic engineering, agribusiness has taken the few plant species settled on for our table and altered them beyond recognition, reaching into Nature's diverse genetic soup and marshalling the talents of genetic engineers to pick out a few characteristics of little interest to anyone except Monsanto, John Deere and Cargill. The goal is to produce seeds that promise a predictable crop of genetically consistent, laboratory-bred vegetables that meet certain idiosyncratic standards: a tomato square enough to be stacked conveniently and tough enough to withstand the rigors of mechanical harvesting; a barley that tolerates salty soil; a broccoli that can survive a drenching in Monsanto's best-selling herbicide.

The result is a class of genetic freaks--uniform agricultural products that excel in color, size and convenience, but which are bereft of nutrition, genetic robustness, fertility and taste.

This weakness became apparent in 1972, when a fungus latched onto an anomaly that had been bred into U.S. farmers' preferred variety of corn, and a fifth of that year's harvest was ruined. If such an attack had occurred in Peru, a fifth of the country might have starved. Besides species vulnerability, continuing down this road promises further reliance on pesticides, the elimination of the Third World farmer's way of life, further depletion of the Earth's genetic pool, less nutritious food and myriad other subtle denials and distortions of a fundamental part of what it means to be alive.

Seeds of Change may be just the first of many new books detailing the ecology of food. Read it for an alternative to agribusiness-as-usual. It's $21 postpaid from: Harper San Francisco, 1160 Battery Street, San Francisco, CA 94111-1213/[phone].