Daily News Archive
From October 3, 2001

Genetically Engineered DNA Taints Native Corn in Mexico

Corn is viewed with near religious reverence in Mexico, with seeds of native varieties passed down from generation to generation. Scientists assumed that these varieties, some of which are grown only by subsistence farmers in remote areas, were pristine - until now.

According to an article in the New York Times on October 2, the Mexican government has discovered that some of Mexico's native corn varieties have been contaminated with genetically engineered DNA. The contaminated seeds were collected from a region considered to be the world's center of diversity for corn, which is exactly the kind of repository of genetic variation that scientists had hoped to protect from contamination. Genetically modified corn, the presumed source of the foreign genes, is not approved for commercial planting in Mexico.

Scientists said the results indicate that crop genes might be able to spread across geographic areas and varieties more rapidly than researchers had guessed. They also expressed concern that the new, foreign genes could act to reduce genetic diversity in the country's native corn varieties. If any of the foreign genes are very advantageous, plants carrying those genes could begin to dominate the population, resulting in a loss of genetic variation.

"These are the extremes, the places where you would really not expect to find contamination," said Dr. Ignacio Chapela, a microbial ecologist at the University of California at Berkeley, saying that the results are an indication of widespread contamination. "The only reason that they found it there is because that's the only place they've looked."

Though scientists may eventually be able to quantify the biological effects of the contamination, the culture lost in a country where corn is a symbol of the people may be harder to measure.