Genetically modified organisms: Where is the science?

What has been of particular interest in this and past debates on the subject is the way in which those who oppose GM crops are painted as being against science (see for instance, the editorial in The Hindu on 21 October, 2009 or Starved for Science by R Paarlberg). There is a blatant attempt by GM promoters to polarise the discussion and manufacture a science-vs.-antiscience debate. All those who oppose GM crops are neither anti-science nor luddites. Indeed, many scientists have been, and still are, critical of GM for a number of good reasons. Scientists and scientific academies, including the National Research Council of the US National Academy of Sciences, have expressed serious concerns regarding the scientific rigour of experiments and the impacts of GM crops, especially on biodiversity.

Those who support GM crops generally believe that science and technology can solve most problems, and see crops as requiring tinkering to improve agriculture. It is such short-term and piecemeal thinking that led to the excesses of the Green Revolution causing damage to soils, depletion of ground water and other harms to ecosystems. There are other supporters of GM who continue to believe that private production of goods and services is inherently superior to public ones, even as governments have been bailing out the private sector in the last year! And then there are those who have financial gains to make if the GM industry prospers.

Let me compare the GM debate with the other major scientific debate - global warming. While scientists who work on climate change and global warming rightly embrace the precautionary principle, many who work in the area of GM plant technologies abandon it altogether. A charitable explanation is that this may have to do with differing perceptions of risk in each case. Perhaps global warming is seen as a serious threat to the entire world, and GM crops may not be understood in the same way. Moreover, some benefits have been attributed to these crops by promoters, making it harder for people to reject them.

But while the naysayers of climate change have now been marginalised through more research and data, those who are concerned about GM crops have been silenced through smear campaigns launched against them. Some of the scientists, like Arpad Pusztai, who raised questions regarding the health effects of GM crops, have had their careers turned upside down. In order to learn about the tentacles and might of agribusiness, one must ask Ignacio Chapela from UC Berkeley about his gut-wrenching tenure battle, which followed his publication in Nature on the contamination of wild strains of Mexican maize by GM maize

The mere use of technology does not make an approach scientific, but this is a common fallacy even among scientists. Good science is characterised by transparency and falsifiability. These do not figure in GM. Instead, faith, the antithesis of science, features in a big way. There are few peer-reviewed journal articles on GM crops. When companies make claims about various positive contributions from their engineered crops, their statements cannot be verified or tested independently. Policymakers and even other scientists who work in the same area have to accept the results on faith.

Earlier this year, an anonymous public statement was signed and submitted to the U.S. Environmental Protection Agency (EPA) by 26 leading scientists, entomologists who work with insects that infect corn. It stated that scientists are unable to conduct independent research on GM crops as patents prevent full access to research materials and the ability to grow and study these plants. As a consequence, the scientists state, the data that the Scientific Advisory Panel of the EPA has available to it is unduly limited. This means the claims of GM proponents cannot be verified independently or indeed be falsified.

There is general agreement among scientists and academics on the adverse effects on biodiversity as a result of cross-pollination from engineered to non-engineered crops. Still, field trials for GM crops in unmarked areas blow caution and engineered pollen to the winds in closely cultivated fields in India.

The potential damage to human health from GM crops has been shown quite clearly in a few animal systems, but perhaps needs further study. There is good peer-reviewed published evidence to show that Bt toxins are both immunogens (a substance that provokes an immune response) and immunoadjuvants (a substance that enhances immune response) for mammals. Moreover, studies have shown that Bt toxins bind to the mammalian small intestine and have effects on its proper functioning. The concerns raised by the use of viral promoters, which are hotspots for genetic recombination, the use of antibiotic resistance genes, and strong gene promoters (sequences that facilitate the transcription of a gene) to ensure that the foreign genes are expressed, have already been highlighted by many scientists.

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