Selective breeding of maize Figure 1. The ancestor of modern corn had tiny kernels, each protected by a tough husk. Domestication of maize, which began thousands of years ago, selected for large sheathed cobs containing large kernels without husks. SELECTIVE BREEDING OF MAIZE. Courtesy of Robert S. Peabody Museum of Archaeology, Phillips Academy, Andover, Massachusetts. Related Links Online Textbook: Genetically Modified Organisms: Introduction Related Terms: None Related Images: None Related Animations: None