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 ES Home > Vol. 4, No. 1 > Art. 12

Copyright © 2000 by The Resilience Alliance

The following is the established format for referencing this article:
Walker, B. and M. Lonsdale. 2000. Genetically modified organisms at the crossroads: Comments on "Genetically Modified Crops: Risks and Promise" by Gordon Conway. Conservation Ecology 4(1): 12. [online] URL: http://www.consecol.org/vol4/iss1/art12/

Commentary, part of Special Feature on Genetically Modified Organisms

Genetically Modified Organisms at the Crossroads: Comments on "Genetically Modified Crops: Risks and Promise" by Gordon Conway

Brian Walker1 and Mark Lonsdale2

1CSIRO Wildlife and Ecology2CSIRO Entomology

KEY WORDS: GMO technology, agriculture, ecosystem effects, genetically modified organisms, indirect effects, introduced species, risk analysis, risk assessment.

Published: March 27, 2000

Life-sciences firms such as Novartis, AstraZeneca, and Monsanto are at a crossroads. Their agribusiness divisions have been hit by a double whammy: already suffering from a slump in commodity prices (e.g., prices for wheat and soybeans have fallen 30% over the last two years), they have now been badly hit by a consumer backlash against genetically modified crops. Although this backlash is most vehement in Europe, it is intensifying in the United States.

It has been argued that the industry made a major strategic mistake in leading the genetically modified organism (GMO) charge with organisms intended primarily to increase the profitability of farming systems rather than those that might, say, improve human health or help solve environmental problems such as waste-site contamination or agricultural soil degradation. Taking the profitability approach has led to public disquiet, because it is perceived that the public will bear all the potential risks of this unknown technology, while farmers in the developed world and multinational companies will enjoy all of the gains. In reality, the introduction of herbicide-resistant or insecticide-producing crops should lead to a reduction in pesticide use overall, and the risks to human health of consuming genetically modified (GM) foods should be negligible, but this strong negative perception is now well entrenched.

Gordon Conway’s address to the Board of Directors of Monsanto is a very good state-of-science account of the secondary or indirect ecological issues associated with the introduction of GMO technology. It is also an attempt to advise a major player in the field how to recover from the bind in which the industry now finds itself. In keeping with the mandate of the Rockefeller Foundation, his advice leans heavily toward recommending initiatives to help Third World peoples. However, his concepts, both technological and philosophical, could also be applied in the developed world.

In addition to his technological ideas, which are appropriate for developed countries like Australia that have extensive land systems, problems with undesirable effects of agriculture such as salinity, and an indigenous population living on the land and facing numerous environmental and health problems, the GMO debate in the developed world would also benefit from his philosophy of a new form of dialogue ("a new way of talking and reaching decisions"). His starting point is "a new kind of honest discussion involving all kinds of stakeholders," rather than a new offensive by a public relations agency. Central to this would be an understanding of all the possible areas of risk and benefit.

Davies (1995) identified what he termed the "four pillars of risk analysis": comparative risk analysis, risk assessment, risk communication, and risk management. All these need to be considered if we are to minimize the risk and maximize the benefit of a new technology. Using this four-pillar model allows us to identify where things have been going wrong for GMOs. Most work with GMOs has focused on risk assessment, but even this has been fairly unquantitative and lacks a probabilistic basis for assessing risk. This is an area to which ecologists can contribute, particularly by designing studies that explore the effects of introduced organisms on ecosystems (Williamson 1996). The literature on higher order interactions and indirect effects of organisms should prove particularly fruitful here.

In terms of GMO risk assessment, the main points of concern identified in Conway’s address, with which we agree, can be summarized as follows:

  • spread of introduced genes to wild relatives, leading to "super weeds";
  • loss of insect resistance in non-target species, e.g., insects might become immune to Bt (a toxin from the bacterium Bacillus thuringiensis that kills the caterpillars that ingest it). This loss of resistance would be a disadvantage to other soil/plant systems;
  • recombination of GM viruses with other viruses to yield new viruses with undesirable traits;
  • ineffectiveness of common antibiotics as a result of resistance developed due to the use of antibiotics to kill non-GM cells (marker gene technology).

It is useful to consider GMOs and ecosystem effects in two dimensions:

  • direct effects vs. indirect effects, and
  • biogeochemical effects vs. trophic web effects.

This yields four categories of potential problems, as follows:










Conway’s examples fall mainly into category 2, with some in 1. All four need to be considered, however, if a GMO is to be introduced into a region. It is also important to consider the issue of scale. Many of the indirect effects will be long term and off site.

It is not our task to present a complete account of all possible ecosystem effects, but rather to suggest that what is needed is a systematic approach to ecosystem risk assessment, and this four-way analysis is one way to approach it. When assessed using the criteria of category 4, for example, earlier suggestions for genetically modifying graminaceous crop plants to fix their own nitrogen were shelved (at least temporarily) on the grounds that excess nitrogen is the cause of major soil acidification problems in countries like Australia. The recent controversy over insecticidal GM pollen from maize affecting monarch butterflies on milkweed is an example of a category 2 risk. A herbicide-resistant crop would have category 1 effects (fewer weeds) and possibly category 2 effects (fewer species of vertebrates and invertebrates associated with the crop because of lower plant biodiversity); it could also lead to effects in categories 3 and 4 if herbicide use and runoff were reduced. Human food risks from GM crops would, of course, be classified in category 1.

Comparative risk analysis, which involves comparing the relative risks of different activities to make rational policy and resource decisions, is also rudimentary for agricultural systems. For example, because of their sheer volume, introductions of non-GMO plants pose a far greater risk to the environment than does the comparative trickle of GMO crops, but the former receive only a fraction of both public attention and risk assessment resources. Take the perceived risk that a GMO may create a new "super weed." For Australia, it is a hard truth that roughly half of all our noxious weeds were introduced intentionally, mostly as ornamentals (Panetta 1993), and none of them had been genetically modified. It could be argued that, if Australia allowed in only GMOs, which are presently being introduced at an extremely low rate due to the expense of developing them and the limited ability of the agricultural industries to use them, the country would be in far better shape than it is now, when it is virtually inundated by several thousand new non-GMO taxa per year.

Incidentally, we part company with Conway when it comes to his belief that Terminator and similar technologies are unequivocally bad. If horticulturalists could be persuaded to release new ornamentals that were incapable of propagating outside the garden, this would be a major advance for vegetation management. This approach is analogous to work already being carried out by agencies such as ours on "sterile ferals," which aims to resolve the problems that arise when introduced species that are commercially valuable escape into the wild and become pests. Australia has numerous examples of species of this type. The concept is that the GM species is identical in every way to the original except that it requires a particular compound (for example, in its diet) to remain fertile. If it escapes into the wild, in the absence of that dietary component it becomes sterile.

Communication of the risks associated with specific GMOs has been poor. This has resulted in a dialogue of the deaf, with scientists and technocrats as proponents pitted against environmentalists who lack hard data but are full of alarmist claims. Despite the fact that it already takes hundreds of millions of dollars to bring a GMO to market, more funding to explore and quantify the risk side might have resulted in a more informed debate and, paradoxically, perhaps a greater degree of public acceptance. It is also worth noting that some GMOs have apparently been withdrawn by their proponents because existing assessment procedures have identified unacceptable levels of risk. In other words, at least some proponents of GMOs are showing greater caution than might be implied by the prominent public pronouncements, and all GMO proponents should be playing this card more strongly. Different strata of society may perceive risks very differently, and the social psychology of GMO risk perception is an area that needs to be researched if public concerns are to be properly addressed. Conway is correct in identifying the need to label GM foods, and it defies imagination that agribusiness would not support this in a world in which the market is supposed to reign supreme.

Returning to our introductory comment on the strategic approach to using GMOs, we suggest that a serious effort by the GMO multinational companies to apply GMO technology to environmental problems would be both timely and wise. It would be timely for three reasons:

  • rising concerns about sustainability and the dawning realization of the enormous costs environmental problems are placing on industry and society are opening major opportunities to do "business" in this area; 
  • GMO technology has reached a stage where it can make a real contribution in the environmental area, in which conventional approaches are proving very difficult; and, 
  • if environmental concerns are not addressed, many agro-ecosystems will be unable to benefit from GMO crops aimed at profitability.
Putting it bluntly, it is in the interests of the GMO agribusiness companies to help ensure that there are healthy agro-ecosystems with farmers who can use their products.

It is also important that the pathway to adoption of GMOs be properly considered before embarking on a potentially ruinous route. The history of intentional introductions is mainly one of a large number of species that disappear without a trace, a substantial minority that are of no use to anyone but cause a lot of harm, and a very small group that are of some value to industry. It would be an important step forward if we could eliminate most of the species in the first two groups. This could be achieved by stepping back and looking more critically and strategically at the proposed GMO and comparing it to more conventional technologies. For example, if the aim is to control an insect pest of a crop, would that aim be better served by developing a GM plant that is resistant to insects, or by using classical biocontrol? The best solution is not always obvious and will depend on lead times and costs, the ecology of the cropping system, and, crucially, the sociology of the farmers.

Gene technology is just one more new technology, neither good nor bad in itself, whose results depend on how people use its products. The risks of GMOs are perhaps no greater or less than those of any other introduced organisms, although perhaps less predictable, and the benefits are potentially far greater, if Conway's ideas for helping Third World peoples are any indication. Ecologists and economists should participate in this debate by helping to characterize and quantify these risks, and conservationists should seek to identify ways in which GMO technology could help conserve biodiversity, e.g., through management of invasives or minimization of the off-site effects of agriculture.


Responses to this article are invited. If accepted for publication, your response will be hyperlinked to the article. To submit a comment, follow this link. To read comments already accepted, follow this link.


Conway, G. 2000. Genetically modified crops: risks and promise. Conservation Ecology 4(1): 2. [online] URL: http:\\www.consecol.org/vol4/iss1/art2

Davies, J. C. 1996. Comparing environmental risks: tools for setting government priorities. Resources for the Future, Washington, D.C., USA.

Panetta, F. D. 1993. A system of assessing proposed plant introductions for weed potential. Plant Protection Quarterly 8(1): 10-14.

Williamson, M. 1996. Biological invasions. Chapman and Hall, London, UK.

Address of Correspondent:
Brian Walker
CSIRO Wildlife and Ecology
P.O. Box 284
Canberra, ACT 2602, Australia
Phone: 61-02-6242-1742
Fax: 61-02-241-2362

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