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Study Contests Professor's Controversial Paper

By Jennifer Jamall
Daily Californian
August 11, 2005

Ignacio Chapela (center) rallied outside California Hall in December 2004 as part of a high-profile fight to get tenure. A new study challenges the findings of Chapela's controversial 2001 research on genetically modified corn, which he believes hurt his tenure campaign.

After a nearly two-year battle with UC Berkeley over tenure, assistant professor of microbial biology Ignacio Chapela is again facing scrutiny after a study released Tuesday disputed his research that genetically modified corn had spread to native maize crops in southern Mexico.

The study, headed by Ohio State University professor Allison Snow, is the first follow-up to Chapela's study. Chapela's paper, which was written with UC Berkeley graduate student David Quist, garnered worldwide attention when it was first published in Nature in 2001 and later withdrawn from the science journal after journal officials said Chapela's evidence was lacking.

Snow and her co-authors examined about 870 plants in Oaxaca in 2003 and 2004, concluding that there was no evidence to support Chapela's 2001 paper, which claimed genetically modified corn had contaminated local varieties of the crop.

"I am quite surprised," Chapela said. "Mostly because the authors who produced the samples for this are people who a year ago were publicly saying there was contamination."

Following the report, the Mexican government investigated the issue and determined that transgenic corn had ruined some original wild crops.

In the study, Snow accepts that genetically modified corn could have made an impact in 2001 but was not present in their later findings, which spanned more than 150,000 seeds from 125 fields in Oaxaca.

"It's very difficult to believe that contamination has disappeared," Chapela said. "Barely two years after we said we found it, they say it's gone. One of those two statements has to be wrong."

Both critics and supporters of Chapela speculated that the highly contentious paper played a major role in the university's initial refusal to grant him tenure.

"If you look at the report for denying me tenure, it pays so much attention to the paper," Chapela said. "I do think it played an important role."

Chapela fought a high-profile battle against the university for two years. Shortly after being denied tenure in 2003, Chapela began holding his office hours outside California Hall to protest the decision and later picketed in front of the hall with hundreds of supporters in December 2004.

Despite Birgeneau's promise to review his appeal, Chapela filed a lawsuit against the UC Board of Regents in April 2005 alleging conspiracy and discrimination by university officials against his Mexican heritage.

In May, Chapela received an offer for tenure from the university and salary as if he'd been tenured in 2003.

Chapela does not believe the recent findings from this study will affect his new position at the university.

"I really appreciate the fact that at least somebody thinks something about the issue in Mexico," Chapela said. "The 2001 paper was so noisy, it really made the rounds, but after that nobody touched the question ever again. So any research is very much welcome."


Gene-Modified Corn Gone from Mexico, Study Finds

By Maggie Fox
August 9, 2005

WASHINGTON - The Mexican region where modern corn originated shows no traces of a genetically engineered contamination that caused an international uproar and created tension over US corn imports, researchers said on Monday.

"If they were there, they are gone," Exequiel Ezcurra, a former Mexican official who is now with the San Diego Natural History Museum in California, said in a telephone interview.

He said an educational campaign to make farmers in Oaxaca state aware of the issue evidently has worked, and the farmers apparently were able to eliminate the undesirable corn imports.

Ezcurra worked on the original study and the new analysis published in this week's issue of the Proceedings of the National Academy of Sciences.

When the genetically modified corn was discovered in September 2001 deep in mountainous Oaxaca, it raised alarms around the world and sparked protest from global activist groups like Greenpeace.

The culprit was clear -- Mexico imports between 5 million and 6 million tonnes of maize from the United States each year, and close to half of all US corn is genetically modified.

Most is altered to produce a naturally occurring toxin known as Bacillus thuringiensis, or Bt, to ward off pests.

Mexico allows GM cotton and soybeans, but not corn.

The government says it wants to protect the biodiversity of Mexico's corn because the nation is home to the world's richest corn gene pool.

Relief, Surprise

Ezcurra, Allison Snow of Ohio State University and colleagues did another sampling and found no evidence of gene-engineered corn.

"We sampled maize seeds from 870 plants in 125 fields and 18 localities in the state of Oaxaca during 2003 and 2004," they wrote in their report published in the Proceedings of the National Academy of Sciences.

They tested more than 150,000 seeds and found no evidence of transgenes -- the spliced-in genes used to engineer the corn.

"We now know that transgenic maize isn't growing in Oaxaca," Snow said in a statement. "Mexican farmers who don't want transgenes in their crops will be relieved to find out that these uninvited genes seem to have disappeared."

Ezcurra said he also was relieved by the findings.

"We were incredibly surprised when we found nothing," he said.

"If transgenic material had got into the community because people were planting imported grain inadvertently, then from 2001 onwards, the communities were well-informed and they knew how to avoid planting grain of unknown origin."

This finding suggests that even if gene-engineered crops escape the fields they are intended for, the problem can be corrected quickly, Ezcurra and Snow said.

"There is great potential for transgenes to come across the US border, with millions of tons of GM grain imported each year for processed food and animal feed," Snow said.

"If farmers think that their highly revered native plants have been altered by transgenes, they might even stop planting them," she added.

Response to PNAS Article

Pulse of Science
August 10, 2005

Initial statement by Ignacio Chapela and David Quist

Given the large number of requests for comment from us regarding the article recently appeared in PNAS* we would like to make the following statements, preliminary to a deeper commentary.

We were surprised by the results and statements presented in this paper. We had no prior knowledge of the contents or conclusions of the paper until it was being discussed in the media, a few days ago. On first approach, it seems to us highly suspect that transgenic DNA may have been widespread in local landraces of maize in Mexico in 2000-2001, as demonstrated in at least 3 separate studies, would suddenly become absent within a couple of years.

Part of our surprise stemmed also from our knowledge that three of the authors in this paper have made many categorical public representations prior to this paper which lie in diametrical contradiction to the negative results paper presented in PNAS. Although their statements were never published in a peer-reviewed journal, we must presume that those contradictory categorical statements were based on real samples and analyses. We do not know whether the results presented now in PNAS are derived from the same samples, what differences in method they applied, and how much the change in their conclusion is determined not by a biological or social phenomenon, but rather by a change in the author's assumptions and expectations. We reserve our judgement in this regard until these contradictions are explained. We call upon the authors of the PNAS paper to clearly explain the change in their statements from one year to the next.

We continue to be surprised by the interpretation of the significance of this paper as well as by the many representations made about it by the authors for the general public and the media. We are deeply concerned by the conclusions being drawn from those representations in terms of GMO policy and trade, since we feel that these conclusions are not warranted by this paper's results or the interpretation of those results.

We have noticed troubling methodological and technical problems in the PNAS paper which would have deserved close attention before publication, and certainly before any conclusions could be drawn from it. We are writing a first rebuttal of the paper dealing with these questions, and will make this rebuttal public as soon as it is carefully reviewed and considered by our colleagues. News about this rebuttal will be posted at

Given the fact that the paper was published nonetheless, and that conclusions from the biological to the policy and commercial levels are quickly being used in developing policy, we strongly recommend caution in deriving policy from this paper. The scientific community needs the opportunity to apply scrutiny to this work, so that discourse can help guide exactly what can be said about this work.

* [Ortiz-García, S., Ezcurra, E., Schoel, B., Acevedo, F., Soberón, J. and Snow, A.A. 2005. Absence of Detectable Transgenes in local landraces of maize in Oaxaca, Mexico (2003-2004). Proceedings of the National Academy of Sciences.]


The Genetic Shell Game,
or, Now you see it! Now you don't!

News Release by ETC Group -
August 11, 2005

Industry exploits new study on transgenic maize in Mexico

Biotech proponents are using a new scientific study - which finds no evidence of DNA contamination from genetically modified (GM) maize in one area of one Mexican state (Oaxaca) - to claim that Mexico's native maize was never threatened, and even if it was at one time, the issue has now miraculously evaporated. One representative of agribusiness in Mexico, eagerly concluded that, "this study paves the way for the commercial planting of GM maize in Mexico."(1)

According to Silvia Ribeiro of ETC Group in Mexico: "It's no surprise that the industry is using the findings to serve its own interests - as 'proof' that contamination no longer exists and that GM crops should have free reign everywhere, even in the South's centers of crop genetic diversity. Indigenous and farming communities vigorously disagree with the biotech industry's self-serving interpretation of the study."

According to peasant communities in Oaxaca, the new findings are not terribly surprising. Baldemar Mendoza of UNOSJO (Union of Organisations of the Sierra Juarez of Oaxaca) - who lives in the region covered by the new study - said, "We took samples in 3 of the 18 communities that the new report mentions (San Juan Ev. Analco, Ixtlan and Santa Maria Jaltianguis) and our results were also negative in those three communities." Mendoza points out that the geographic area sampled by the new study is small and the 18 communities are predominantly forest communities, which means that their main activity is not planting maize. Mendoza also points out, "The new study doesn't refer to any other part of Mexico where contamination has been found but some in the media are already making the false claim that 'there is no contamination in the whole state of Oaxaca or even all of Southern Mexico.'"

Four years ago the Mexican government first verified that GM maize had contaminated native maize grown and developed by indigenous farmers in at least two Mexican states - including Oaxaca and Puebla. It has been illegal to plant GM maize in Mexico (either for research or commercial plantings) since 1999. The contamination most likely came about after peasant farmers unknowingly planted a small percentage of imported maize (intended for feed - not for seed). Evidence of contamination was confirmed by subsequent studies and has been widely acknowledged. Indigenous peoples, peasant farmers and civil society have sharply criticized the lack of government efforts to prevent GM contamination and protect native maize.

On Tuesday a new study authored by Mexican scientists and US researchers reports no signs of contamination from genetically modified maize (transgenes) in native maize in one area of Oaxaca. "Absence of detectable transgenes in local landraces of maize in Oaxaca, Mexico (2003-2004)" was published in the Proceedings of the National Academy of Sciences (US).(2) The Mexican scientists who authored the report currently or previously worked for the Mexican government and participated in prior government studies confirming DNA contamination in Mexico. However, the Mexican government's earlier studies were not published.

The authors of the study published this week accept the evidence of earlier studies showing contamination, and caution that their results "should not be extrapolated to other regions of Mexico without quantitative data nor is the current situation likely to remain static." The authors also conclude, "we expect that the prevalence and variety of transgenic traits in maize will increase because ... the global area of GM maize cultivation is increasing rapidly."

In October 2003 a network of farmers, indigenous communities and civil society organizations in Mexico ("In Defense of Maize") conducted their own study of GM contamination in nine Mexican states. Using commercial detection kits, community groups sampled 5,000 plants from 134 communities - the results showed contamination in all nine states, to differing degrees.(3)

Baldemar Mendoza of UNOSJO explains, "It is clear to everyone that Mexican native maize is contaminated with GMOs in Oaxaca and many other parts of Mexico. The government has known about it for four years and has done nothing to stop the sources of contamination. In fact, they've done the opposite: they have increased the imports of transgenic maize from the US; they've lifted the moratorium on planting GM maize in Mexico without even consulting with the victims of contamination; and, thanks to the recently approved biosafety law, they have allowed the companies responsible for contamination, such as Monsanto, to proceed with impunity. It is ironic that the only study that governmental sources have published minimizes the problem."

Mendoza continues, "The absence of contamination reported in the new study could mean that the level of contamination has always been very low in that particular area, or it could be that the de-contamination work done by many communities and has been successful - and, of course, that would be good news. If de-contamination efforts have been successful, however, it's not the result of the government's so-called 'education campaign,' it's the result of community efforts to recuperate our seeds by controlling which seeds come into the community and eliminating any strange or deformed plants we see."

Silvia Ribeiro of ETC Group points out that, "The study doesn't explain how the contamination could disappear in such a short amount of time. It could demonstrate that the testing technology is every bit as unreliable as the genetic transformation technology - since the behavior of transformed genes isn't always predictable."

Many observers are uncomfortable with the fact that the editor of the study released this week is Barbara Schaal, who works in the Monsanto Laboratory of Washington University, St. Louis. Monsanto is a major corporate funder of biotech research at Washington University and is the company whose technology accounted for almost 90% of the worldwide area planted in GM seeds in 2004.

Others question the value of the findings. According to Peter Rosset, biologist and former professor of statistics, as well as researcher at CECCAM (Center for the Study of Rural Change in the Mexico), the study is statistically inconclusive: "The researchers did not provide a lot of detail on their methodology, but it seems they erroneously inflated their sample size, thus giving their results an unwarranted appearance of accuracy." He adds that, "because they used commercial testing companies that use conservative, or low resolution tests, they would have been unlikely to detect the levels of widespread, low-level contamination that other researchers found when using higher resolution methods."

For Baldemar Mendoza, "it's profoundly troubling that this study is being used to 'green light' the cultivation of transgenic maize in Mexico, while putting the burden of controlling it on the backs of indigenous peoples and peasants. The only real way to control contamination is not to plant transgenics. We don't need more studies or education campaigns. We don't want genetically modified seeds; they are here only to increase the profits of transnational companies while putting our maize heritage - the work peasants have done over the last 10,000 years - at risk."

  1. Elizabeth Velasco, "El maíz criollo de Oaxaca, libre de contaminación genética: científicos," La Jornada, Mexico, Aug. 10, 2005.
  2. S. Ortiz García, E. Ezcurra, B. Schoel, F.Acevedo, J. Soberón and A.A. Snow: "Absence of detectable transgenes in local landraces of maize in Oaxaca, Mexico (2003-2004)," Proceedings of the National Academy of Sciences, August 9, 2005.
  3. For more information, see The nine states where GM contamination was found include: Oaxaca, Puebla, Chihuahua, Morelos, Estado de México, San Luis Potosí, Durango, Tlaxcala y Veracruz

The Action Group on Erosion, Technology and Concentration, formerly RAFI, is an international civil society organization headquartered in Canada. The ETC Group is dedicated to the advancement of cultural and ecological diversity and human rights. The ETC Group is also a member of the Community Biodiversity Development and Conservation Programme (CBDC). The CBDC is a collaborative experimental initiative involving civil society organizations and public research institutions in 14 countries. The CBDC is dedicated to the exploration of community-directed programmes to strengthen the conservation and enhancement of agricultural biodiversity. The CBDC website is

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Genetically engineered food is corporate bioterrorism