CORN, WHERE DID IT COME FROM?

The grain that was to change civilization was probably a common weed. It became the major source of food. The plant also provided the base for fermented drinks. The cobs were burned for a heat source. Even the tassels or silks were used. Dried, they could be used for tobacco, sometimes as a medicine. The tassels were also high in protein and were eaten. The stalks were used as walls and fences. Some had a sweet sap that was used as candy. The dried cobs were a primitive toilet paper.

John Doebley believes it came from "a wild and weedy plant called teosinte". Corn and teosinte don't look much alike. Teosinte has a small ear with two rows of well-armored seeds encased in a nut-hard shell. The ear shatters when it's mature letting the seeds fall where they may. Corn on the other hand has at least eight rows with hundreds of kernels. On the outside is a papery husk that comes off easily. When corn is ripe it needs man to plant it. If the cob were to fall over when ripe and the seeds were to sprout, there would be too many new plants tightly crowded in one spot for any of them to survive and mature.

This dramatic change could not have happened over a long period or archaeologists would be finding semi-evolved corn cobs in various stages. Corn, whenever and wherever it has been found has always looked like modern corn except smaller ears.

Hugh Iltis of the University of Wisconsin argues that corn made this big change suddenly when the teosinte tassel, a male flower was suddenly feminized. This can happen when a plant gets infected with the parasite that causes the disease smut.

Doebley believes genetics had a lot to do with it. He and his colleagues Jane Dorweiler, Adrian Stec and Jerry Kermicle did a series of experiments where they crossed corn plants and teosinte plants. The results confirmed an idea proposed by George Beadle. He believed that only a handful of genes were responsible for this dramatic change.

Doebley and his colleagues proved the existence of a gene that controls the sex of teosinte flowers just as Iltis also thought. Doebley agrees that evolution was step by step but he believes it was fast, within a thousand years.

He points to the mutation leading to the soft glume as being particularly critical to that process. Since teosinte's hard glume makes it very difficult to eat, softening of the glume may well have triggered intensive domestication of plants bearing that mutation, thereby attracting a human helping hand to the development of modern corn.

That gene, teosinte glume architecture 1 controls the key difference in ear development. [They] identified a quantitative trait locus (QTL) on chromosome 4 controlling 42 to 50% of the phenotypic variance for outer glume induration and hypothesized that this locus represented a single gene with a dramatic phenotypic effect......To investigate this QTL further, [they] transferred the segment of maize chromosome 4 containing this QTL into teosinte by three generations of backcrossing coupled with positive selection .... After the sixth backcross generation, a true-breeding line (W22-TGA) was recovered that possessed the W22 plant morphology except for the teosinte-like glumes in its ears.

Luther Burbank also experimented several years ago trying to turn teosinte into corn by positive selection. In eighteen generations he appears to have done this. Dr. Paul Weatherwax dissents. He didn't believe that Burbank had started with wild teosinte, but thought he had used a teosinte-corn hybrid.

Paul C. Mangelsdorf said there were two main theories on the origin of corn. The first is that corn is descended from teosinte. In l939 he proposed that corns' ancestor was a wild race of pod corn. He thought that teosinte was a cross from this pod corn and tripsacum a wild grass. This was annual teosinte. Since then it was discovered that another teosinte, this time a perennial existed. Now he believes that both annual teosinte and modern corn are derived from a hybrid of perennial teosinte and primitive pod corn.

In 1948 Herbert Dick excavated a site in New Mexico called Bat Cave. He found stratigraphic layers of corncobs, in evolutionary order from bottom to top. When tested by Radiocarbon the bottom layer proved to be about 5,600 years old.

Paul Sears of Yale University and Kathryn Clisby of Oberlin College found pollen gains while studying drill cores taken from about 200 feet below Mexico City. They were identified by E. S. Barghoorn, of Harvard as being corn pollen. Although at least 80,000 years old, they very closely resemble the pollen of modern corn.

In the Tehuacan Valley, Richard S. MacNeish of the Peabody Foundation for Archaeology found 23,607 maize specimens. They reveal a well-defined evolutionary sequence. The oldest cobs were from the El Riego and Coxcatlan cultural phase, about 5200-3400 B.C.. They are thought to be wild corn because they have a way for the seeds to disperse. About an inch long, they seem to be topped by a male spikelet a little bit longer. The kernels were brown and orange and rounder than corn today.

Corn was a very important crop in the Americas. The remains of prehistoric corn, including some 25,000 cobs, have been found in numerous sites from Arizona to Guatemala; in contrast, not a single cob dating unmistakably from before 1492 has been found in any part of the old world.

There are many myths about corn. Corn to the ancient Maya was embodied in One Hunapu, one of the twin heroes who defeated the Lords of Death. Corn to the Inca was embodied in Manco-Paca, son of the sun and founder of the dynasty of the Royal Lords of Cuzco. Corn to the Totonac of Central America was Tzinteotl, wife of the sun. Corn to the Aztec was the goddess Xilonen and the god Quetzalcoatl. Corn to the Chippewa was Mondawmin. Corn to the Pawnee was the Evening Star, the mother of all things, who gave corn to the people from her garden in the sky.

Blue corn and the Hopi go together. It is their symbol. Yaapa, the Mockingbird, placed many different kinds of corn before the tribes. The Navajo took yellow ears, Sioux picked the white, Havasupai wanted the red, Ute selected the flint, Apache chose the longest ears. [the Hopi] picked up the last and smallest ear, the blue corn meant the Hopi would have a long-lasting but hard life.

Selection of seed has always been an important right of females. Every year the grandmother selects the strongest kernels to plant. The right to select seed is passed on through the female side of the family.

Corn has been a major part of religion in several Indian cultures. When a Hopi child is born he or she doesn't receive a name until the child is twenty days old. At that time, the child's Aunts from the father's side of the family, give the child a name. A perfect ear of white corn called Tsotsmingwu is passed over the baby four times. At the same time a blue corn mash is fed to the baby.

We don't have all the answers to the mystery of corn and where it came from. Maybe someday we will know how it happened that a common weed became a plant that would change the world.