Botanical Drawings (IMAGE) Penn State Caption These are drawings of teosinte and maize show large differences in the two plants, but the origin of maize occurred with changes in only a few teosinte genes and hybridization and backcrossing occurred frequently. Credit A'ndrea Elyse Messer/Penn State Usage Restrictions non commercial use only License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.