New Hope, Pa.

How deliciously amusing that Trent Lott was forced to eat not only crow but Jim Crow [“A Sorry Lott,” Jan. 13/20].



Amherst, Mass.

In “Sowing Disaster?” [Oct. 28], Mark Schapiro mentions a number of the risks posed by genetically engineered corn, including its surreptitious spread into the world’s center of corn genetic diversity in southern Mexico and Guatemala. As Schapiro reports, crop genetic diversity is the world’s “insurance policy,” protecting our long-term food security by sustaining the bases for adaptation to new plant diseases, insect pests and climate change.

But Schapiro does not mention the possibly greater threat to crop diversity: the global integration of agricultural markets. Traditional Mexican corn farmers, for example, today face increasing competition from cheap US corn imports (genetically modified or not) as a result of NAFTA and the Mexican government’s embrace of the neoliberal creed that market prices are the only measure of value.

If campesinos are forced to abandon their cornfields in search of better livelihoods, it will trigger “genetic erosion”–widespread losses of diversity–in North America’s number-one crop. These small farmers, and others like them around the world who cultivate diversity in rice, wheat and other crops, provide an immensely valuable service to humankind. There is an urgent need to develop strategies to reward these farmers for the fruits of their labor–fruits that ultimately feed us all.


St. Louis

Mark Schapiro highlights the problem of genes engineered into a target species escaping into other cultivars of the same, or related, species. The potential escape of genes from corn engineered for production of pharmaceuticals into the commercial corn population is the most serious scenario he describes. There are plausible technologies aimed at limiting fertilization by transgenic pollen only to transgenic plants of the same cultivar, so that when transgenic pollen lands on plants in neighboring fields, development would be aborted. These strategies are not “terminator technology.” The transgenic seeds are fully viable and can be planted on the same terms as other seed (for more information see an article by H. Daniell in Nature Biotechnology). We should demand intensive research and the adoption of technologies that limit transgene spread–especially when that spread might have serious consequences, as in the case of plants producing pharmaceuticals.

Schapiro also expresses concern for the genetic pollution of isolated, ancient cultivars (land races). A controversial paper in a 2001 issue of Nature reported finding DNA sequences unique to transgenic corn in land races. Land races are vital since breeders rely on them when new traits are needed for contemporary commercial breeding. The authors of the Nature paper note that transgenic markers found only in GE corn provide “a unique opportunity to trace the flow of genetic material over biogeographical regions.” If DNA from relatively recently modified corn has moved to such an area, it seems highly probable that DNA from corn improved by standard breeding techniques would also have been incorporated into land races during the many years that land races and commercial varieties have shared the hemisphere. This probability underscores another policy priority–the urgency of collecting and preserving the genetic diversity still remaining in ancient cultivars.


Nantucket, Mass.

Mark Schapiro relies on a paper appearing in the British science journal Nature, on the purported escape of GM corn genes into the Mexican environment. However, the editors of Nature reported with chagrin on October 24, 2002, that this paper has some very serious problems and concluded that “the evidence available is not sufficient to justify the publication of the original paper.”


Evanston, Ill.

GMOs are problematic because of the lack of transparency and traceability in our food system. People want to know if they’re eating GMOs, yet most have no real way of telling. I am a student at Northwestern University and am working to get the school to use organic food, support local growers and phase out GM products. The dining-services coordinator told me it is essentially impossible to phase out or even label GMOs in our dining halls, because the food suppliers don’t know who grew it or if their products are GMOs. As the supply chain gets increasingly muddled and our food sources get farther away, there are fewer places to turn. If you are lucky enough to have a farmers’ market, community-supported agriculture or other local supplier in your area, you’re off to a good start, but even corporate organic food stores do nothing to let us see where our food comes from. Hope lies in places like the University of Iowa, where most of their banquet food comes from local farmers, or Toronto, where city-catered functions support local growers. I don’t want my food coming from Monsanto, but how am I to know?



New York City

I appreciate the interest my article has generated–coming at a time when a growing percentage of our nation’s food is dependent on genetically engineered technology.

I agree with James Boyce that the issues raised by genetic engineering must be seen in the context of changes in the structure of global agriculture. I will never forget traveling through southern Mexico, where town after town had been emptied of its farmers–who had been driven off their land and out of business by competition from cheap US imports. While in the name of “free trade” America pressures Mexico and other foreign nations to eliminate tariffs and subsidies to protect its own producers, Mexican farmers now find themselves unable to compete with subsidized US farm exports. The ironies are poignant. Many of those former Mexican farmers head north and end up working as farmhands in the cornfields of the Midwest.

Consider an equally poignant image on the other side of the Rio Grande: the dozens of farm auctions across America’s rural heartland each month. Trying with increasingly little success to sustain family farms against the twin forces of corporate competition and declining commodity prices, many US farmers are forced to auction off their farm implements and their land. Mexican and American farmers are on the same highwire, attempting to sustain an ever-more-tenuous living in an era of corporate agriculture.

Danny Kohl makes the correct assertion that some new corn is being engineered to remain sterile in the face of floating pollen. But why is corn being used at all for this next frontier of genetic research, in which medicines are being bred into the genetic fiber of the plant itself? Putting aside whether one agrees with developing biopharmaceuticals in plants, there is growing concern among leading botanists that corn is the wrong choice of crop. Corn is by far the most promiscuous of food crops, sending its pollen into the wind and making it extremely difficult to insulate the new antibodies and vaccines being bred into those plants from pollinating neighboring fields, where corn is grown to be eaten by livestock or people. We have already seen one particularly egregious result of such contamination: The EPA levied a $250,000 fine on the firm leading the research on biopharmaceuticals in corn, ProdiGene, for allowing the vaccine-laden corn into a feed corn and soybean field.

The article to which Russell Seitz refers was written by Ignacio Chapela, a microbial biologist, and his graduate student, David Quist, at UC, Berkeley. They made two assertions: first, that through DNA analyses they had discovered transgenes in the indigenous corn plants of southern Mexico; and, second, that the transgenic material itself was unstable within the genome, potentially leading to an array of unknown synergistic effects within the impacted, or contaminated, plants.

The article provoked a considerable controversy within the scientific community, mostly focused on methodology, and on the second assertion, that the transgenes are unstable. After rising pressure, including criticism from both public and industry-funded scientists–and brought to the public’s attention through an industry-sponsored Internet campaign to discredit Chapela and Quist–Nature did disassociate itself from the findings of their paper. However, the primary assertion–that transgenes had made their way to Mexico–is no longer in dispute, as it has been widely accepted as correct even by Chapela’s critics, several of whom I interviewed, and confirmed in a study conducted by the Mexican government’s Institute of Environment. What remains in dispute is how unstable those genes are within the genome–a matter to which I did not refer in my article, because of space restraints.

For further details on the dispute over the Nature article, I refer readers to the website for PBS’s NOW With Bill Moyers, which aired the television version of my story this past October (www.pbs.org/now/science/genenature.html).



Jersey City, NJ

I am surprised and disappointed that you published the letter by Liz Hrenda in which she argues that Catholic political leaders oppose abortion mostly for unworthy reasons–ignorance, intimidation and fear [“Letters,” Dec. 2]. That some might oppose abortion out of principle, because they see it as a moral evil, escapes her. Without offering evidence, she claims that Catholic schoolteachers give failing grades to the children of Catholic politicians who vote the wrong way in order to punish the parents. I have taught in Catholic high schools and universities since 1965 and have never heard of such a bizarre phenomenon. My colleagues and I have heard hundreds, thousands, of explanations of why junior flunked–from the dog who ate the homework to the remote family tragedy where grandmother’s second husband drove their car off a cliff. For lots of reasons, some parents can’t own up to the fact that their children don’t study. A teacher who failed an otherwise high-scoring student merely to punish that student’s political parent should and would be disciplined.