The development of Maize (corn) by early Mesoamerican geneticists probably happened sometime between 10,000 and 6,000 BC in southern Mexico. This development has done more to enable a population explosion to six billion than any other human invention.
From the 1938 to the 1960s, Mangeldorf's 'Tripartite Hypothesis' on the origin of corn was widely accepted. He believed that corn was developed from a cross between an undiscovered wild Maize and the plant Tripsacum.
In 1968, George Beadle, in retirement, began to provide convincing evidence for his own 'Teosinte Hypothesis', which simply believed that Maize was developed from the plant Teosinte. Today scientists generally accept the Teosinte Hypothesis because of advance in the study of genomes.