Breaking with tradition: Mexico mulls the implications of genetically modified corn.

A scandal is growing in Mexico over controversial claims that genetically modified (GM) corn has been imprudently sown, and is breeding with native strains.

Last year, scientists working in Oaxaca claimed to have found traces of genetic modifications in corn samples taken from remote mountain villages. Scientists Ignacio Chapela and David Quist, from the University of California at Berkeley, were not expecting to find GM corn in the remote sierra. Instead, they were looking for corn free of genetic modifications as part of a project to market Mexican corn to European consumers, who have been skeptical of the new science of designer plants.

The discovery was surprising, since there has been a moratorium on planting GM corn in Mexico since 1998. Only a handful of field projects had been carried out before the ban was put in place.

Soon after Chapela and Quist published their findings in the science journal Nature last November, other scientists attacked the duo's study, claiming that their methodology was highly sensitive and given to false positives. Moreover, Chapela was an outspoken activist in promoting the importance of protecting biological diversity, and a fierce critic of the giant multinationals that control the biotech industry. And so erupted an international debate between scientists, supporters of the biotech industry and environmental activists.

FOOD FIGHT

Chapela and allies say the GM genes threatened the biological diversity of native Mexican corn, or criollo. But detractors say a few more genes among tens of thousands are nothing to worry about.

Meanwhile in Mexico, the Agriculture Secretariat (Sagarpa) and the Environment Secretariat (Semarnat) were engaged in their own squabbles. While Semarnat officials called for swift action and backed up Chapela with their own tests, Sagarpa's first reaction was to maintain that the presence of the GM corn was not scientifically proven.

Welcome to the new Mexican front of the gene wars.

GM foods have had a brief yet tumultuous public life. Biotechnology promises to develop fantastic new yields--drought proof, vitamin enhanced and pest resistant. But the public, especially in Europe, has been skeptical and even fearful of "Frankenfoods."

Genetic modifications are created by inserting specific genes into plants or animals to engineer desired traits, in the case of corn, to confer resistance to insects or herbicides. GM corn has been in development for over 20 years, but wasn't released commercially until 1996. Monsanto, Aventis, DuPont and Syngenta all have GM corn brands on the market.

There is no evidence of health risks from the GM brands approved for human consumption. But the critics of GM corn are more worried about effects on the native corn and its environment. Mexico is where corn was first cultivated over 7,000 years ago from a plant called teosinte. There are at least 60 identified criollo varieties and many more awaiting classification. What if the GM corn, with its engineered advantages, displaced Mexico's genetic storehouse? For one thing, the world would lose a vital genetic reservoir to turn to if a plague struck the increasingly homogenized corn brands of the United States.

QUESTIONING THE SOURCE

"This (discovery) is really serious, Mexico is the first center of origin and genetic diversity for a crop that has been contaminated by transgenic organisms," said Greenpeace Mexico's Liza Covantes. "Maize is an issue of national security. Its contamination puts at risk the diversity of the grain and is a dangerous threat to world food security."

Following the attacks on the credibility of Chapela's science, the Mexican government set out to perform its own tests, aiming to prove definitively whether or not GM corn had invaded Mexico.

While the results of these tests have yet to be officially published, Jorge Soberon, head of Semarnat's Council on Biodiversity, said they were positive. "If this isn't a smoking gun, I don't know what is."

But proving the presence of GM corn is one thing, predicting its effects on the biodiversity of criollo is another. Some scientists hypothesize that GM corn could cross with teosinte, engendering super weeds. Or perhaps the bacterial insecticide designed to kill the European corn borer could poison other organisms, causing unknown effects on the ecosystem. But these are only hypotheses, and there are no scientific studies that definitively provide the answers.

Julien Berthaud, a French population geneticist at the International Wheat and Maize Improvement Center, near Mexico City, says the types of GM corn that may be floating around Oaxaca "look pretty safe." Berthaud argues insect-resistant GM corn is engineered to kill European corn borers, not the types of pests that live in Mexico's southern climate. "It shouldn't have any selective advantage."

But Berthaud warns of the risks from non-food GM corn, constructed to produce results unfit for consumption. Companies have produced such unpalatable corn crosses that produce everything from spermicide to a type of plastic. While these products in development are under tight controls, "It only takes one alien corn, some genes flow into the local (strains) and now we can say all the landraces are contaminated, because we don't know which ones really are. It would be just a catastrophe. We know that corn can cross the U.S. border, and if this occurred it would be a huge crisis, much more serious than what is occurring now."

BOTCHING BORDERS

By law, only controlled, experimental planting of GM crops is allowed, and currently there is a moratorium on planting GM corn, even experimentally. But since Nafta took effect in 1994, exports of U.S. yellow corn have exploded. Last year, Mexico imported around 6 million tons--between 30% and 40% of it transgenic, unlabeled and mixed with non-GM corn. The imports are meant to be used as animal feed or as raw material to make tortillas, corn syrup and other products. But since imports also arrive in the countryside for use as animal feed, it's likely that farmers have unwittingly planted some GM corn in their fields.

So far tests have only been carried out in Qaxaca and Puebla. Where else could this seed have landed?

"The effect will not be so catastrophic or apocalyptic like some groups are warning. It's not the end of genetic diversity or a threat to world food security," Soberon said. "But it is clearly undesirable that there is an uncontrolled form of gene flow like this."

For Soberon, like many other Mexicans, the issue of unwanted corn migrants from the north is not just environmental, it is a matter of cultural and political sovereignty.

Corn is the basic food staple for most Mexicans, and is the nation's largest crop. The total Mexican corn market, 19 billion tons in domestic production plus imports, was worth around US$3.8 billion dollars last year. Besides economic and culinary prominence, corn holds a central cultural significance. Emblazoned on pre-Hispanic ruins and modern murals, corn is regarded as a sacred symbol of life. Indigenous legends tell of how the gods made the first men from corn.

Understandably, such a national emblem has inspired populist lawmakers. Senate commissions are pondering an initiative to ban the import of GM corn from the United States. The Chamber of Deputies has been drawing up a biosecurity law that has made the biotech industry wary.

"Enough regulations are already there," said Dr. Jose Luis Solleiro, technical director for Mexico's biotech trade association, AgroBio, which represents Monsanto, Avantis, Dupont, Syngenta and Savia. "It is not necessary to create new laws, much less the one they have planned, which is totally prohibitive."

Solleiro, who has been lobbying Congress on behalf of the GM industry, says lawmakers are currently planning to declare 120 fruits, vegetables, grains and plants indigenous to Mexico as potentially off limits to biotech experiments. The legislation invokes the "precautionary principle," which says that in the absence of scientific proof about the effects of GM crops on native species or the environment, the option should be reserved to keep the genetic genie in the bottle.

Ricardo Celma, head of the U.S. Grain Council's Central American office, said legislators are caving in to the political pressures mounted by non-governmental organizations like Greenpeace. If public pressure grows, lawmakers could stop the biotech industry from advancing. "It's an aberration to close ones eyes, play the ostrich and stick your head in the ground," Celma said.

Even if Congress turns on the biotech industry, they still have friends in Los Pinos. Mexican President Vicente Fox and his administration in Sagarpa are pushing the nation into an embrace of GM foods.

Whatever stance Congress takes, the border is still open and the rainy season is almost here. And, after months of silence, Sagarpa says they are ready to tackle the problem of the GM corn invasion head on.

"Much of the uncertainty of the effects of transgenic corn could have been avoided if the moratorium had never been in place," said Victor Manuel Villalobos, a top Sagarpa official and a strong proponent of biotechnology. He said the secretariat would soon trash the ban on planting GM corn, so the government can carry out field tests on the effects of GM varieties on native corn and the environment. Then, perhaps, the fears can be settled and Mexican scientists can get around to rearranging the ancient myths, and become the gods making the corn out of man.

Michael O'Boyle is a freelance writer and a finance reporter for a Mexico City daily.