Maize
Maize is often called corn. It originated in Mesoamerica where native people began to domestically cultivate it roughly 5,000 years ago. Climates that are too dry for rice or too wet for wheat produce can sustain maize. Corn requires small acreage while it produces high yields in a short amount of time. This makes the crop desirable for famine-prone areas as well as feed for livestock. While much of the corn cultivated in the twenty-first century is genetically modified in some way, it remains a staple food crop throughout the world.
Native Americans have been cultivating corn for centuries. When the Spaniards arrived in the New World, they believed corn to be inferior for several reasons. Catholics believed that only wheat flour could be used to make bread that would be used in the sacrament of Holy Communion. The belief that wine and bread undergo transubstantiation and actually become the blood and body of Christ meant that corn flour could not be used for such a holy purpose.
Documents left by the Conquistadors noted that corn was an inferior crop because the Native population in the New World relied upon it. Europeans believed that they were at the top of a human hierarchy. They believed that it was their responsibility to spread Christianity throughout the world. This meant that they were a stronger and more important people. Native Americans, on the other hand, were viewed as weak, and the only way to save their souls was to be conquered by the Spaniards. The Spaniards believed the Native people of the New World to be weak because they ate maize. As such, Europeans refused initially to eat maize.
Over time, of course, the Spaniards in the New World had no other choice but to eat maize. When Europeans planted wheat, it could not survive the hot, humid, and often dry conditions. The wheat crops rotted while the maize crops flourished. If Spaniards were going to continue their conquest of the New World from the fifteenth century onward, they had to embrace corn.
Maize contributed to a worldwide population boom in the years after the voyages of Columbus. As returning sailors introduced corn to Europeans, diets improved. Corn, along with the Old World crops such as wheat, rice, and fruits, introduced new vitamins to Europeans. As diets improved and varied from consuming only meat and bread, people began living longer. When farmers in present-day China began cultivating corn at the end of the seventeenth century, the Asian population began to increase substantially.