Figure 23.8 Genetic diversity of crops. (a) Corn originated from a wild plant in Mexico and looks very different from the modern cultivated corn plant. This photo shows an ear of teosinte on the left, an ear of maize on the right, and an ear of their F1 hybrid in the center. (b) From the teosinte ancestor, humans have bred a wide range of genetic varieties to perform well under different conditions, including these varieties grown in Oaxaca State, Mexico. Today, the tremendous variety of genetic crops is at risk of being lost.

Photos by (a) John Doebley and (b) Philippe Psaila/Science Source.