Transposons--genes that jump around the genome--were first discovered in corn, and the genome of corn revealed that there are a staggering number of these in the crop. A whopping 85 percent of the corn genome consists of these "transposable elements." As a result of having such a high concentration of movable gene sequences, different strains of corn are hugely different genetically--more than one would predict. Two strains of corn can, for instance, be more different, genetically, than humans are from chimpanzees.