Through an intricate process of trial and error, they selected mutated seeds that (1) _______ at higher elevations and (2) ______ favorable characteristics such as larger cobs and kernels and better taste. By continuing to plant (3) ______ seeds, the Indians eventually produced a new, much larger species—maize—with dozens of varieties. In so doing, geneticist Nina V. Federoff has written, they achieved “arguably man’s first, and perhaps his greatest, feat of genetic engineering.”
