Corn is numero uno! It’s the number one crop in the United States, and
we use it for an unbelievable number of everyday things. Corn was “made
in America”… Central America to be precise! Geneticists recently
discovered that the ancient peoples of Mexico created corn or “maize”
between 4000 and 6000 years ago from a grass-like plant called teosinteThe ancient ancestor of modern corn. Teosinte is a grass that originated in Mexico and still grows wild in remote mountain areas of the Sierra Madre.
. It’s a little hard to believe because the
two plants look so different: the “ears” of a teosinte plant hold 8-10
hard-shelled seeds while ears of corn contains up to 500 soft kernels.
By selecting seeds from plants with desirable traits, the ancient
Mexican farmers turned the hard shell casings inside out and multiplied
the kernels into the ears of corn we know and love.
The story of corn is a great example of how looks can be deceiving.
Teosinte and corn look very different, but the genomes of the two
plants remain very close. The difference between their genomes is only
1200 out of 50,000 genes!
Corn is now completely human-dependent and cannot survive on its own in the wild.
This sort of evolutionThe process of change in the inherited traits of organisms from one generation to the next. This change is driven by natural selection.
is not unique. Humans have been domesticating
and changing the genetic makeup of plants since the beginning of
civilization. Maize scientist Ed Buckler says, “Domestication stories
like teosinte are really about people and their food crops co-evolving
over the last ten thousand years. Our human culture is really a product
of plant geneticsThe scientific study of heredity
and human beings working and changing together…
becoming people who live in cities, people who can grow large amounts
of grain from small pieces of land. And I think it tells us something
about the close relationship between ourselves and the organisms that
we live on.”