Final answer:
Domesticated corn originated from a wild grass called teosinte through selective breeding initiated by indigenous peoples in Mexico. Genetic differences between the two are minimal but have led to significant morphological changes. Today's corn has larger ears and is crucial to human agriculture for food, feed, and biofuels.
Step-by-step explanation:
Compared with its wild ancestor, domesticated corn, or maize, has undergone significant transformations through a process called selective breeding. This process was initiated by indigenous peoples of what is now Mexico thousands of years ago. Domesticated corn is derived from a wild grass known as teosinte. Despite looking quite different from modern corn, with small fruits encased in rigid structures, genetic studies have shown that they are the same species. The dramatic differences between teosinte and modern corn come down to changes in a small number of developmental genes that have greatly altered the plant's morphology to be more agriculturally beneficial.
Over time, humans selected teosinte with traits that were agriculturally desirable, such as larger ears and seeds that were not enclosed in hard casings, eventually leading to the corn we are familiar with today. This ancient and ongoing collaboration between human innovation and plant biology resulted in a corn plant that does not branch like teosinte and has much larger 'ears', or clusters of female flowers, which make it more suitable for consumption and cultivation. Moreover, corn has become essential to human agriculture and is now used for a variety of purposes including food products, animal feed, and biofuels.