Genetically modified crops

MIHIR SHAH and DEBASHIS BANERJI

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ENVIRONMENTALISTS have, in recent years, acquired a bad name. They are seen as anti-science, anti-development and even anti-people. From being pioneers of popular causes in the early years, they are now portrayed, especially in countries of the South, as comfortable elites cut off from the livelihood struggles of the vast majority.

To an extent this is because they challenge many vested interests who paint them in dark colours. But it is also a reflection of the way many environmentalists state their case and how they seek to articulate their concerns, often completely ignoring life and death issues of the common man. We have argued, for instance, that while opposing destructive development projects, we must also bear the responsibility of working out concrete alternatives to meet water and energy needs of the rural poor. This is both ethically and strategically important.

In the same spirit, in this article, we want to try and answer the question: how can we make the critique of genetically modified (GM) crops most effective? In response we suggest that:

a) It will not do to merely assert the need to go back to our version of natural or traditional agriculture, as if this were something frozen in time, waiting out there to be recovered by us. Rather, in the spirit of Hans-Georg Gadamer, it is important for us to view tradition in a dynamic manner, as a ‘fusion of horizons’, being continuously redefined. We must remember that any movement towards an alternative has to be mediated through the lived experience of millions of Indian farmers who have their own understanding, right or wrong, of various agro-ecological systems. This is, once again, not merely an ethical but also a strategic imperative.

b) We must not conflate our critique of GM crops with a general critique of the Green Revolution – rather, attention must be paid to the specificity of GM crops and to highlighting that GM technology makes a complete break with technologies of the past – and to show why this difference is crucial and unprecedentedly dangerous.

c) We must engage with the science of genetics on its own terms. Our attitude must not be anti-science. We need to both try and understand the specific science and to ground our critique in its highest principles and achievements. We must make the practitioners of the science of genetics accountable to their own standards. This is not merely a strategic but also an ethical imperative. It is an engagement with the ‘other’ in his own terms – not a mere or total rejection, but an evocation of the terms of the dialogue that must ensue.

d) Our arguments must not be in terms that may be seen as narrowly elitist, such as the extinction of the Monarch butterfly, for example. Rather, even when we speak of the need to preserve biodiversity, we must take care and be able to show the deep links this has with the livelihood concerns of the poorest, indeed with the survival of all living beings on earth.

e) We must build, through concrete action in the field, an organic agriculture for the neglected drylands of India, which provides a living alternative to the paths we seek to question.

 

 

Opposition to GM crops is growing all over the world. In October 2001, the European Union (EU) decided to extend its existing three year moratorium on GMOs. The National Farmers’ Union of Canada and the Canadian Wheat Board have demanded a halt to GM test plantings, fearing GM wheat will damage exports. Argentine growers recently announced a move to implement identity preservation plans to ensure the non-biotech integrity of Flint corn, guaranteeing customers a non-biotech food product.

EU buyers already prefer Argentine Flint corn. Europe, Japan, Taiwan and South Korea now largely buy non-GM corn and soya from Brazil rather than the U.S. Since about 70 per cent of the U.S. soyabean crop is planted with GM soyabeans, Brazil, which bans GM crops, has become the major source of non-biotech soyameal. Japan, which takes 20% of all U.S. food exports worth $11 billion a year, has imposed tough labelling rules on 24 product categories.

Latest reports from Mexico also indicate that the Mexican Congress unanimously demanded that President Vicente Fox ban the import of GM corn, claiming that the new corn could affect the genetic integrity of Mexico’s crops and threaten the country’s food supply. GM corn has been a hot issue in Mexico since genes from U.S. GM corn were found in wild corn in the southern state of Oaxaca last year. The New Zealand government confirmed last year that it would legislate to stop the commercial release of GMOs into the New Zealand environment for two more years. Algeria, a large food importer, says it may completely ban the import, manufacture or sale of GM products. Egypt, which imported 3.5 million tonnes of US wheat in 2000-01, has begun expressing similar concerns.

In the face of this worldwide opposition, even the U.S., the citadel of GM farming, is beginning to get shaky. A recent survey of 14,000 members of the American Corn Growers’ Association suggested that 78% would abandon GM to recover lost export markets. The U.S. Department of Agriculture itself has cancelled the registration of StarLink Bt corn and future planting of stocks of StarLink has been prohibited. It is making aggressive efforts to remove StarLink from the U.S. market, all of which is expected to disappear by the end of 2002.

 

 

Meanwhile, Iowa state farmers and elevators have received a total of $9.2 million in compensation for losses associated with growing and handling StarLink Bt corn which contaminated grain supply. Some estimates place total eventual payments in compensation to farmers and elevators in 17 states at more than $200 million. Elevators are being compensated for the genetically modified corn being mixed with traditional corn. Farmers were paid a premium to keep it off the market by feeding it to livestock. Farmers, whose corn was contaminated through cross-pollination, or those who purchased corn without being told it contained StarLink genetics, are also being compensated.

All these developments find reflection in a striking statistic – the rate of growth of total GM acreage worldwide fell from 152% in 1997-98 to 44% in 1998-99 to only 11% in 1999-2000. Ironically, what all this means for India is only increased intimidation and inducement for the introduction of GM crops. For the transnational corporations that manufacture GM crops are now seeking to primarily target the massive Chinese and Indian markets.

The Indian government is under tremendous pressure to give its nod to GM crops. Surprisingly, some of the pressure is being mounted by a few farmers’ organisations themselves. This is, in part, a reflection of the desperate situation in which Indian farmers find themselves today. It has become clear that increases in productivity in Indian agriculture, over the last three decades, have been restricted to mainly rice and wheat and that too to only the resource-rich regions and farmers. The drylands of India and our poorest farmers have suffered systemic neglect.

FCI godowns are bursting with grain, while the poor without the capacity to buy food, continue to suffer the effects of successive droughts. Suicides by farmers are occurring on a scale unprecedented in independent India. Or else the neglected regions, especially the tribal pockets, are witness to violent protest movements. What is more, in the heartland areas of the Green Revolution (GR) such as Punjab itself, overexploitation of groundwater, excessive irrigation and increased pest resistance (especially in cotton) are creating their own problems, even among the relatively better off farmers.

 

 

Our primary concern is that this desperation of farmers should not end up leading them blindly into the GM fold. For this not to happen the critics of GM must be careful not to merely repeat old environmentalist arguments deployed against the GR technology, which was after all widely embraced by Indian farmers. Of course, the GR technology had serious problems. But the important thing to highlight now is the complete break that GM represents with GR, rather than the obvious continuities.

We believe that once its ramifications are fully comprehended, recombinant DNA (r-DNA) technology (on which GM crops are based) may come to be regarded as one of the most dangerous technological interventions in the history of humankind. To understand the dangers of this technology, it is important to recognise its completely unprecedented character, that it is not a mere carrying forward of the Green Revolution and to see it for what it is – a genuine and truly dangerous paradigm shift in the application of science and technology to life on earth.

 

 

No one should be allowed to get away by saying that r-DNA is a mere carrying forward of nature’s work or even of conventional breeding as practiced thus far. r-DNA is a technology completely different from anything known hitherto. In nature, gene transfer is gradual, holistic and vertical, i.e., from parents to offspring. The same process is somewhat accelerated in conventional (GR) breeding. GR technologies sought to enrich crops in desired traits that could be inherited. This was done by selection breeding or gene transfer via the hybridisation technique. Both these techniques are intra-specific; they operate within varieties of the same species. By contrast, r-DNA involves forced, unidimensional, horizontal gene transfer across species, generic and even phyletic barriers. Transfers across different animals, plants, animals to plants, microbes to higher organisms etc. are attempted. There are examples of pig genes in GE vegetables or arctic fish genes in GE potatoes, tomatoes and strawberries.

In nature, DNA from a species cannot normally enter the cell of another species, survive in the new cell milieu or get incorporated in the latter’s genome. This is due to barriers at the cell surface that preclude entry, as also the existence of degradative restriction enzymes that destroy the alien DNA.

 

 

The exceptions to this rule in nature are the nucleic acids of infective bacteria and viruses that can enter all kinds of cells, survive there by using the cellular machinery and even get integrated into the host DNA. Genetic engineers have utilised precisely this phenomenon to carry out their horizontal gene transfers. They use the DNA of microbial pathogens/parasites as ‘carriers’ to smuggle an alien DNA fragment into plants. These are designed to deliver genes into cells and to overcome cellular mechanisms that destroy or inactivate foreign DNA.

Being particularly good at transferring genes horizontally between unrelated species, they can jump out of the host into other organisms, and will do so whether intended or not. Thus the very mechanism that has to be necessarily deployed to enable horizontal gene transfer becomes a potential source of proliferation of dangerous bacteria and viruses.

We must also recognise that a gene’s expression is predictable, stable and reproducible only in its own evolved genomic environment, as is the case in nature and even conventional breeding of the Green Revolution type. In r-DNA technology, however, the gene insertion is both random and in an alien neighbourhood, which produces a totally unpredictable disturbance in host genetic function as well as in that of the introduced gene.

What is more, in order to mark distinctly the cells where the transgene has been integrated, genetic engineers use ‘markers’. These markers are usually antibiotic resistance genes. This creates the danger of spread of antibiotic resistance in all organisms that come into contact with the transgene. Further to switch on the transgene, genetic engineers use ‘promoters’. These promoters are DNA sequences, often derived from disease-causing viruses.

A common example of this is 35SCaMV (from Cauliflower Mosaic Virus), which resembles the HIV and Hepatitis B viruses. Thus, each element of the r-DNA technology – carriers, markers and promoters – has potentially lethal consequences for the health of all living organisms. These are risks inherent to transgenic technology and are bound to manifest themselves wherever it is used.

Scientific research journals abound with evidence of the risks inherent to transgenic technology, the worst of which was the death of 37 people and permanent disability of 1500 others in the U.S. in 1989, after they consumed genetically engineered Tryptophan, a nutritional supplement.

 

 

The most chilling evidence regarding GM farm trials is provided by the New Zealand Soil and Health Association, which has discovered that the only means apparently available to clean-up after a GM field trail is a highly toxic and antiquated chemical, Chloropicrin. Developed in 1917, the U.S. military have used it in chemical warfare. It could lead to long term, chronic effects on respiratory, eye, skin, heart, gastrointestinal and musculo-skeletal systems. Occupational exposure to this chemical is thought to have caused a potentially fatal condition known as rhabdom-yolosis, which is marked by degeneration of skeletal muscles.

Exposure to chloropicrin has also been linked to recurrent asthma, pulmonary oedema, anaemia and irregular heartbeat. It is highly toxic to the aquatic environment. It kills beneficial insects, earthworms, plants, people, as well as bacteria and fungi and nematodes. Indeed, the vast majority of organisms that it kills are beneficial, not harmful.

 

 

Apart from the risks inherent to all GM products, we must also consider the additional, more specific problems of Bt crops, for whose immediate introduction there is a clamour among some farmers’ organisations in India. Bacillus thuringiensis or Bt is a common soil bacterium. It is a natural resource that has evolved over millennia, whose spray is one of the most important biological pest control techniques in use worldwide. Bt is most effective in managing insects that are very hard to control for farmers producing cotton and corn. This natural Bt is very different from the genetically modified Bt crop that contains the insecticidal gene of Bt, so that the plant itself makes the toxin necessary for protection against pests. The plant itself becomes the pesticide. And this is where the problems begin.

As we all know, the effectiveness of any pesticide depends critically on precision in the quantum and timing of its dosage. And this becomes terribly difficult to control in a plant. In Bt crops, the toxin is produced in nearly all growing tissues, regardless of whether pests have reached ‘threshold levels’ or not. It is like using a pesticide indiscriminately (‘calendar spraying’), which will certainly accelerate the development of resistance.

Further, being a plant, its growth will naturally be affected by various environmental factors. The expression of toxins in Bt-transgenic crops is, therefore, inadequate in harsh conditions, such as drought. This ‘sub-lethal dose’ of the toxin can hasten the development of resistance over time, just as it happens with pathogenic bacteria when we fail to complete the necessary course of antibiotics.

Imagine the scenario in a country like India, with recurrent drought and millions of poor farmers! Bt-transgenic crops are likely to grow unevenly across farms, leading to many cases of sub-lethal doses of the Bt toxin and, therefore, resistance might be engendered at an even faster rate. Estimates of how long resistance can be delayed vary, but the average figure in most research, even in the relatively favourable circumstances of the U.S., is not more than five years.

Unlike risks of conventional pesticides, which are typically limited to specific circumstances of use and location and can conceivably be tackled, risks following Bt-transgenic resistance are essentially irrevocable. Once resistance genes emerge and gain a foothold in populations, they cannot be recalled. And the worst part is that they would also foster resistance against the Bt spray, ultimately destroying the effectiveness of this safer bio-pesticide.

Also, while the natural Bt toxin gets destroyed by ultraviolet rays of the sun, the toxin from decayed leaves of Bt crops persists in the soil, bound to clay and humus particles, and has been found to seriously disturb soil micro-flora. This is, then, the most important difference between GM and the older GR technologies. While the negative effects of the latter, serious as they were, could in principle be reversed, the pollution caused by GM techniques is essentially irreversible. The damage they cause could be beyond human control. It is this difference that must be the constant focus of our critique of GM technology.

 

 

What is truly ironic is that GM crops are based on a technology whose very basis has been undermined by the latest discoveries of the Human Genome Project (HGP), the pinnacle of achievement in the science of genetics. The HGP finally overthrows narrow genetic determinism, the theory that there are simple one-to-one relationships between individual genes and characteristics of human beings.

This has been the presumption underlying the use of r-DNA technology by genetic engineers over the last 20 years. They hunt for genes that cause problems and try to insert new, more desirable genes to engineer ‘better’ organisms. This entire enterprise has been brought into question by the HGP that supports a more complex and nuanced understanding of the way genes work, that was all along being advocated by molecular biologists opposed to genetic engineering.

 

 

Announcing the findings of the HGP, Craig Venter, President Celera Corporation and one of the two most important scientists in the effort to map the human genome, put it bluntly: ‘In everyday language the talk is of a gene for this and a gene for that. We are now finding that that is rarely so. The number of genes that work in that way can almost be counted on your fingers. The notion that one gene equals one disease, or that one gene produces one key protein, is flying out of the window.’

Genetic engineering is based on a number of assumptions, now decisively overthrown by the HGP. It was assumed that each gene codes for a single protein molecule, adding a unique trait to the behaviour of the organism (genes govern events in a cell by creating different proteins). In a closed, one-way, linear causal pathway, proteins are encoded by DNA and, therefore, DNA may be said to encode function. Each gene was seen as an independent unit of information. The environment acted as a trigger to activate preset programmes in DNA. It was also assumed that genes are stable, being passed on unchanged to the next generation.

In fact, for relatively simple diseases, such as muscular dystrophy, the one gene-one disease model appears to work very well. Unfortunately, however, this is true for only two per cent of all known diseases. In all other cases, including cancer, heart disease and manic depression (the most common targets of the genetic engineers), causation is found to be much more complex. Many genes interacting with each other appear to play a role. Also an array of signals, including nutrient supply, hormones and electrical signals from other cells, which form the cellular environment, critically influence the course of these diseases.

 

 

Changes in the cellular environment are sensed or measured by regulatory networks of proteins that function inside each cell. These networks interpret such signals so that the cell can make an appropriate response to these changes. Thus, protein networks feed back information from the outside world to the DNA and change pat-terns of gene expression in a context-dependent manner.

The crucial point is that these dynamic networks have rules not specified by DNA. And this is an information management system we are only now beginning to follow. Research has started to shift in this direction. But it is clear that we simply do not know enough about the response of living cells over time to their manipulation by genetic engineering.

We must also remember that while molecular biology has made great advances in describing the ‘structural’ genes that affect properties of bodily parts, knowledge about the genes that regulate the activity of all the structural genes is still incomplete. We are still unable to ascribe any function to as much as 95 per cent of all DNA. If we really want to understand and predict the effect of the insertion of a foreign gene, we must surely take this 95 per cent into account.

 

 

What is more, since each human being has a unique genetic background, mutations in specific genes that produce disease in one human body, may not do so in another. Also, since many genes appear to be involved in most diseases, the effect of each specific gene is small. Thus, more importance comes to be attached to factors such as the initial conditions surrounding the development history of the individual.

The fallacy of the assumption that each gene just codes for one specific protein has time and again been exposed by unanticipated metabolic changes following single gene transfers. These changes have resulted in the appearance of very sick and monstrous transgenic animals as also unexpected toxins and allergens in transgenic plants. The lower survival capacity of transgenic plants in environments different from those where the plants were originally developed has undermined belief in unidirectional control of gene expression.

This may be the reason why transgenic maize developed in the U.S. failed completely when planted in the Philippines, or why the tomato FlavrSavr, developed in California did not grow well in Florida, and why Monsanto’s Bt-cotton crop did not work properly in Texas because it was hotter or in Australia because it was colder than where it was originally developed. The belief that genomes are stable and unchanging has led to an underestimation of the rapidity with which insects develop resistance against built-in crop pesticides.

An additional problem is that genomes normally do not accept intrusions by foreign genes. This ‘species barrier’ is one of the reasons why most gene insertion attempts fail. It also contributes to the destabilisation of genes that have been successfully inserted. Because of this it has been difficult to create genetically stable transgenic organisms.

The problems of GM crops are, therefore, not merely the empirical negative effects that we may or may not observe in a specified time frame. On the contrary, they are deeply inherent to r-DNA technology itself and are bound to manifest themselves, sooner or later. The absence of evidence at a given point of time cannot be regarded as decisive evidence of the absence of these effects. Rather, it is the opposite presumption that the latest findings of the science of genetics themselves suggest.

 

 

We may end on an empirical note though. Some damaging evidence has come to light in a recent study reported in the journal Nature Genetics, probably the most reputed scientific journal on the subject. A study by Japanese scientists shows that cloned mice exhibit a significantly higher mortality rate than naturally fertilised mice. This, in all probability, is because the important phenomenon of crossing over of chromosomes is missing in genetically engineered mice. This crossing over is what allows for the origin of diversity and reprogramming, both vital for survival. Without this diversity, which cloning deliberately seeks to eliminate, there is much greater vulnerability, leading to quicker mortality. Diversity is the very basis of life and any attempt to destroy it through corporate-controlled monoculture or cloning is bound to threaten life itself. Science must then recognise what it is – a human endeavour – and not pretend, dangerously, to play God.

 

 

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