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Retreat to Subsistence

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The CEC's report, Maize and Biodiversity: The Effects of Transgenic Maize in Mexico, appeared in 2004 and consisted of a workmanlike summary volume and ten beautifully detailed background chapters—a number of which are almost novelistic in their complexity. The background chapters were written by leading biologists as well as experts on the politics and sociology of the Mexican countryside, and they examine the political, social and ecological value of indigenous cornfields and also the ways genetically modified genes might flow through those cornfields. Timothy Wise at Tufts told me that Maize and Biodiversity is "the best study of gene flow to date."

Ex Mex
From Migrants to Immigrants
By Jorge Castañeda
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Sin Maíz, no Hay País
Edited by Gustavo Esteva and Catherine Marielle

NAFTA’s Promise and Reality
Lessons From Mexico for the Hemisphere
By the Carnegie Endowment for International Peace.
Available at carnegieendowment.org

The Impact of Genetically Engineered Crops on Farm Sustainability in the United States
By the National Research Council
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Environmental Effects of Transgenic Plants
The Scope and Adequacy of Regulation
By the National Research Council
Buy this book

Maize and Biodiversity
The Effects of Transgenic Maize in Mexico
By the Commission for Environmental Cooperation
Available at cec.org

Failure to Yield
Evaluating the Performance of Genetically Engineered Crops
By the Union of Concerned Scientists
Available at ucsusa.org


About the Author

Peter Canby
Peter Canby is a senior editor at The New Yorker and the author of The Heart of the Sky: Travels Among the Maya (...

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The CEC report argued that because the ecology of a traditional Mexican cornfield is so much more complicated than that of cornfields in the United States, studies conducted in the United States of the interaction between genetically modified corn and its surrounding environment were useless in Mexico. "Will the introduction of transgenic maize have a positive or negative effect on natural ecosystems in Mexico?" one of the CEC background chapters asked, concluding that "existing data on transgenic maize will not address the question sufficiently."

The report held that "the introgression of a few individual transgenes is unlikely to have any major biological effect on genetic diversity in maize landraces." But it went on to argue that not enough was known about the ways genetically modified plants would behave in the complex environment of a Mexican cornfield to rule out the possibility that an introgression of genetically modified genes would produce a weedy superhybrid that could overrun not just native landraces but also the wild teosinte grass that still grows around indigenous cornfields. One of the background chapters pointed out that such an outcome would be a "catastrophe" that could gravely reduce the genetic diversity of the world's corn.

In the end, the authors of the CEC study unanimously agreed that until the effects of introgressed transgenes could be properly studied, all 6 million tons of US corn then entering Mexico each year should be ground at the border before being transported into the country. In doing so, the report's authors evoked a regulatory category increasingly used in international environmental law and known as the "precautionary principle." The CEC's authors argued that, given the possibility of irreversible damage to the heritage of corn in Mexico, the genetically modified corn industry bore the burden of proving its safety. This was significant for US agribusiness because the logic of the precautionary principle had once been used to bar US corn from the European Union.

The reaction in Washington was furious. Judith Ayres, a Bush appointee and the assistant administrator of the office of international activities for the Environmental Protection Agency, appended comments to the summary report. She attacked the degree to which it combined political and scientific issues and failed to consider the benefits of post-NAFTA agricultural developments—particularly to the growth of the Mexican livestock industry (a market for much imported corn). It ultimately lacked "policy relevance," Ayres declared. It was too late for the summary report to be withdrawn, but the ten background chapters that treated different aspects of the problem in such fascinating detail were never published and effectively suppressed. (They are nevertheless archived at www.cec.org/page.asp?PageID=924&ContentID=2796.)

The underlying worry of scientists concerned about Mexico's landraces is the narrowness of the genetic base of commercial corn. As the effects of climate change become more pronounced, the corn belt in the United States will likely be affected not just by rising temperatures but also changing rainfall patterns. With these altered conditions will arrive plant diseases to which the corn crop has not previously been exposed. The devastation such diseases could wreak is hinted at by the effects of the Southern corn leaf blight in 1970. Before it was controlled, the blight destroyed 50 percent of the crop in some Southern states and 15 percent of the crop nationwide, and it caused $1 billion in damage.

I asked one of the CEC authors, Major Goodman, a professor of crop science at North Carolina State University and one of the nation's leading corn experts, about the condition of commercial corn in the United States. He compared it with that of potatoes in Ireland before the potato famine and then continued, "We're basically looking at the descendants of about seven inbred lines and the derivatives of those lines," he told me. "There are an awful lot of similar hybrids out there." Goodman is concerned about two diseases—one in Argentina and one in Africa. "Each is a virus spread by a leaf hopper" (a piercing insect that can spread plant diseases). "A leaf hopper could cling to a person's luggage or clothing and jump on a plane without trouble. I'm 99 percent certain that not a hybrid on the market has resistance."

The genetic material that the corn industry would use to breed in resistance to such a virus would typically originate in a germplasm bank—a specialized facility that stores the genetic material needed to reproduce important crops (germplasm banks in Mexico contain samples of the seeds of the nation's landrace corn). But as Goodman put it, "If we are to have climate change, it will be hard to meet the problems it presents out of a germplasm bank. Basically, germplasm banks deal in hundreds of kernels. The only way to make them available, in the case of rampant plant disease, would be to grow them out seed by seed."

Monsanto has recently said that it is working to address climate change and has promised to create crops that will require 30 percent less water, land and energy to grow. Specifically, it promises to develop a "drought gene" designed to dramatically reduce a plant's water consumption. Monsanto's drought-resistance work is widely believed to involve "transcription factors," types of master genes that regulate numerous other genes.

Industry critics are skeptical of Monsanto's claims. Goodman explained to me that to date there were essentially only two commercial gene-implant applications—Bt crops and glyphosate-resistant crops—and that each was the result of single-gene engineering. "Drought tolerance is a genetically complex trait," he said, and the present state of genetic modification is confined to implanting "single genes affecting single traits." Paul Gepts agreed with Goodman's point that drought resistance was a genetically complex trait and added that it would require an ability to engineer sequences of genes that had not yet been attained. "They may have something," he said, "but I'm skeptical. They have to please their stockholders. They have to attract capital."

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