ABSTRACT
Some 10 million species of plants, animals, and microbes are believed to inhabit the Earth, but so far only about 1.5 million of these have been identi¢ed. A mere 15 of the approximately 250,000 known plant species provide the world’s human population with about 90% of its food.1 These crops are wheat, rice, corn, rye, barley, soybeans, and common millet. Although these crops are now grown in nearly every nation, only one or two of these crop species originated in any speci¢c country.
