Environment, Science

Should We Be Worried About GMOs?

After shaping life on earth for billions of years, evolution via natural selection is in decline and being replaced by intelligent design. For the last 12,000 years, the survival of species has been primarily determined by their usefulness, and vulnerability, to human beings. Now, finally, we have found a way to do away with even this vestige of our biological past and to design species from the top down, working out what traits are desirable and undesirable to us and genetically engineering organisms accordingly. How much should this worry us?

For many, the answer is “a lot.” For instance, Nassim Taleb has made dire warnings about the application of GMOs, arguing that they “represent a public risk of global harm” given their potential to produce unrecoverable losses or “ruin.” According to him this justifies a highly precautionary response of “avoid at all costs,” unless and until GMOs have been proven to be safe beyond doubt.

GMOs pose such risks, and justify such a response, because, Taleb argues, their impact cannot be localized or contained. GMOs interact with wider global systems that they could potentially undermine, with terrible consequences. In particular, “the cross-breeding of wild-type plants with genetically modified ones prevents their disentangling, leading to irreversible system-wide effects with unknown downsides,” while “healthwise, the modification of crops impacts everyone.”

Against such claims, supporters of GMO development point out that great care is taken to avoid the escape of GMOs, that the hypothetical risks cited against them seldom have anything like a scientific foundation and that GMOs have many benefits, including their potential to support global environmental and health systems by reducing the demand for agricultural land, the use of pesticides and the prevalence of malnutrition and disease. However, none of these arguments implies that GMOs couldn’t have the kind of systemic impacts that Taleb and others have worried about, so, how can we be so sure that they are safe?

Sometimes, the answer is straightforward. All one has to do is remember that the only reason most traits are selected for in a GMO is that they are in the interest of human beings, not that they benefit the GMO itself.

E. Coli

Consider Escherichia coli, which has been genetically modified for the production of a variety of proteins, including insulin and chymosin (the enzyme responsible for making many kinds of cheese). The ability to produce these proteins is important to humans, and a lot of research has been done to understand the conditions that help produce as much as possible.

However, for the bacteria, the production of these proteins is of no value whatsoever and places a metabolic burden on the cells that substantially decrease their rate of division. Therefore, outside of carefully optimized laboratory conditions, such bacteria will be significantly disadvantaged and unable to compete against their wild cousins. Similarly, many crops have been modified to make their fruits bigger, sweeter, or more nutritious, but usually in ways that reduce the crops’ ability to reproduce naturally, or that even render it sterile.

Hence, despite the fact that genetically modified bacteria are technically compatible with wild-type organisms, the genes that had been inserted into such GMOs would be strongly disfavored by natural selection, and hence disappear from any hybrid population, posing no risk to wild populations or their ecosystems.

Of more concern are organisms whose traits confer adaptive advantages, such as disease or pest resistance. These GMOs have the potential to provide substantial benefits, such as aiding in the preservation of biodiversity, eradicating agricultural diseases, and even contributing to the rescue of keystone species from extinction. However, the problems that these organisms seek to resolve are themselves pervasive, and thus require solutions with an equal potential for widespread, systemic impact. Unfortunately, it is this very quality that could result in a GMO posing a systemic threat. By outperforming non-GMOs, these organisms could overtake or substantially corrupt wild populations. Additionally, the containment of the organism itself may be insufficient to prevent systemic consequences, as the presence of the organism may alter the nature of the threats present in the ecosystem.

For instance, consider Q124, a variety of sugarcane cultivated in Central Queensland with resistance to the fungal disease orange rust. Q124 was initially effective at increasing crop yields and became the dominant agricultural monoculture as a result. However, in the year 2000, an outbreak of an evolved strain of the disease overcame the resistance of Q124 and resulted in a dramatic reduction in the size of the sugarcane harvest that year across Central Queensland and the costliest disaster to hit the industry.

The initial adaptive advantages of Q124 led to a decrease in genetic diversity in the area, as it outperformed other varieties of sugarcane, resulting in 85 percent of the cultivated population in Central Queensland being Q124 and, therefore, vulnerable to the evolved disease. This example demonstrates the potential for adaptive traits to both provide short-term advantages that lead to a widespread monoculture but then ultimately exacerbate long-term threats, with the potential for ruinous systemic impact.

This seems to provide an excellent example of the kind of systemic risk that worries Taleb and others. There is only one problem – Q124 is not a genetically modified organism. Developed as part of the Queensland Bureau of Sugar Experimentation Station’s sugarcane breeding program, its parent varieties were selected to optimize disease resistance and yield, but at no point was genetic engineering involved in conferring these adaptive traits. Taking a precautionary approach to the regulation of GMOs would, therefore, do nothing to prevent bad outcomes such as this.

Aedes aegypti mosquito

Consider another example (not a trick one this time). The bioscience company Oxitec has been developing GM mosquitoes that have the potential to eliminate populations of the Aegypti mosquito that spreads many tropical diseases. These mosquitos, however, have proven highly controversial, with many advocating a precautionary approach to their release. But such concerns almost universally relate to the potential that GM mosquito genes might escape into the wild or even into humans. Such concerns miss the critical fact that the trait these GM mosquitos possess is one that will almost certainly kill them before reaching adulthood, something that is clearly highly disadvantageous to the mosquito and therefore one that will not survive without continuous human support.

Nevertheless, the release of these GM mosquitos will undoubtedly have at least one significant systemic impact; it will remove a species from an ecosystem. Right now, we have little knowledge about what implications that might have, but, strange as it sounds, it is not impossible that mosquitos play an important ecological role. However, such impacts aren’t really anything to do with the use of GMOs per se – humans have been trying to wipe out mosquitos for a very long time. The only thing that the use of GMOs changes is that we are now more likely to succeed.

Taking a precautionary approach to GMOs, therefore, risks going too far while simultaneously not going far enough. Not only does it overlook the potentially important benefits that GMOs can bring and the many ways that the risks they pose can be mitigated, but it also fails to acknowledge the real source of the systemic risks that we should be most concerned to avoid. A regulatory regime that emphasized the potential role that a GMO, or any novel organism, could come to play in wider systems, and reviewed the practices that would be involved in its cultivation, would be far more appropriate. This would allow for the development of safe and beneficial technologies while remaining alive to the risks they pose.


Simon Beard is a postdoctoral researcher at the Centre for the Study of Existential Risk. His research examines the ethical challenges in evaluating existential risks, with a special focus on the risks associated with developing new technologies. 

Rachel Polfer is an undergraduate student in Biochemistry and Philosophy at Mount Holyoke College. She recently completed a summer as a visiting student at Cambridge University’s Centre for the Study of Existential Risk.


  1. pekkanikolaus says

    Interesting insights. Your basic reasoning doesn’t really do much to put my layperson’s doubts to rest, though.

    The fake example tells us that breeding – a manipulation of nature we’ve been practicing for centuries – can already have destructive consequences. That’s true, and not an especially new argument to anyone who’s been paying attention. But isn’t the issue with GM technology – what makes many of us so uneasy about it – that it’s going to increase the speed and scope of these manipulations by orders of magnitude? I.e. if our conventional technology can already have consequences on the ecosystem like this, imagine what widespread genetic manipulation is capable of doing!

  2. Joe Halstead says

    It’s grotesque to me that people who benefit from the eradication of mosquitos are the same people who wring their hands about what might happen to DA PLANETZ!!!!!11!1!!! if we help OTHER people get rid of mosquitos.

    It’s okay of Africans keep dying of preventable diseases, so long as we don’t die along with them, I suppose.

    • $100,000 says

      Not sure tbat ybe mosquito argument is germain. Perhaps a more compelling argument would be based on the advent of virus or fungus attacking 9p% of tbe world soy and corn? Mo oculture has never worked for anyone or tbing besides a few old rich guys. Gamine is a very real possobility with this much of the world forced to use one strain of crops.

  3. World population is expected to reach 9.7 B by 2050 and 11.2 B by 2100. The leading evident risk to biodiversity is the declining stock of undisturbed land. The quantity of arable land consumed to meet demand depends on productivity. This, one must assume, will continue to depend, in turn, upon human ingenuity in manipulating the traits of crops and, thereby, directly or indirectly, their underlying genetic composition.

    One of our most essential hopes must be that human population growth will reverse in order to halt the extinction of species. In the meantime, widespread famines — which, in addition to presenting humanitarian disasters too horrendous to contemplate, might lead to potentially catastrophic consequences for human civilization — must be averted. Much may be riding, in short, on continued success in raising crop yields.

    It’s difficult to think of many issues that are more ethically straightforward than the prima facie case for innovative technologies, including future GMO, in agriculture. Any speculative discussion of their undemonstrated, marginal risks should give earnest acknowledgement to this general context from the outset.

  4. Smegma says

    Most anti-GMO folks don’t even know what GMO means. If you ask them point blank what they think a GMO is they’ll give you a litany of descriptions that doesn’t make it sound any different than the traditional form of genetic modification. What they are really afraid of, and can’t name, is genetic xenotransplantation. That is, genes transplanted from one species to another. This sort of gm activity is extraordinarily rare, and usually undergoes rigorous testing. Most GMO transplants use genes from the same species. Instead of cross breeding over several generations, taking several years to imbue a recipient plant with the trait of the donor plant, it can be done in a single generation. Basically, most GMOs are nothing new; they are just a new way of doing the same thing. Any potential agricultural disaster has more to do with the agricultural industry as a whole and not just one part of it.

    • Rigorous testing? GMOs are classified as foods, not pharmaceuticals or gene therapy. Right now, the pharmacokinetics of a new aspirin product receives much more rigorous human testing than GMOs.

      There have been reports of multiple GMO gene modifiers surviving human digestion and arriving in the human bloodstream – so your claim that gene modification is intra-species may not be true. We simply do not know, because rigorous testing is NOT mandated.

  5. This discussion is an interesting blend of the Butterfly Effect, morality, and anthropology. First, the net result of removing a species (even a mosquito) does impact the future but the question is how much. It isn’t catastrophic unless you throw away the concepts of evolution. Species will adapt the same as they have for millennia.

    The morality aspect is the removal of this species removes a disease transfer vector. I could go into the complete sham science around DDT but I won’t except to say it flows in the same direction as the GM mosquito with, ironically, the same potential outcome. It was banned through flawed research findings and as a result millions have needlessly died. But, is that a good thing or a bad thing?

    As a prior comment pointed out, the human population is exploding. On one hand, some things like DDT/GM Mosquito result in even greater expansion which drives the need for GMO crops to meet the food demands worldwide. Of course, that results in population density problems which history shows leads to wars which contract the population.

  6. augustine says

    Interesting how a topic revolving around mosquitoes and crop plants can elicit such strong views and sentiments. I would submit that the real fear many harbor is the dawn of GMO humans, which is OT in this case.

    The article employs the familiar disarming propaganda about how GMO science is all about helping mankind, especially the poor and weary, across the globe. But is this really true? And is it so helpful to introduce more intensified ways to increase the carrying capacity of the land to support more people who must then face unexpected consequences in social and economic terms? In some areas earlier technologies, ostensibly provided to help alleviate famine, have allowed human populations to grow beyond the traditional capacity of the land; when inevitable droughts hit (e.g., Sahel region) millions suffer on a scale that could not have existed before.

    The worries about “escaped” designer genes and organisms may be eclipsed by other problems. Farmers who partake of this bounty cannot generate the GMO seed they use and so they are beholden to the supplier corporations. This is a radical change from the traditional ways farmers have been able to keep seed stocks and replant independently, especially in the developing countries that we are supposedly so concerned about.

    GMO is a path to centralization and a weakening of the fabric of both crop diversity and their associated human systems. Is the tradeoff worth it and who benefits or suffers most from the uneven, unforeseeable outcome?

    • nicky says

      Lack of crop diversity? Did we not have the potato-blight, causing the Irish famine in the 1840’s, because of a virtual monoculture of a single cultivar, the Irish Lumper?
      There is no intrinsic reason why GMO’s would cause more monoculture than other ways of obtaining useful cultivars. The problem is large monocultures, not selective gene transfer.
      In fact, selective gene transfer might allow for resistant cultivars to be developed much faster than previously.

  7. nicky says

    A relatively effective way to alleviate ‘GMO-phobia’ (and that term is mine, thanks Monty Python), is to explain how new cultivars were made before we had selective gene transfer (GMO).
    Those seeds were irradiated with X-rays (or even Gamma rays), causing multiple mutations, and the surviving mutants with some ‘positive’ traits were selectively bred from there.
    The present GMO way is much more elegant and immeasurably ‘safer’.

    The only argument that could possibly have some validity is that it would make farmers dependent on the big seed companies, but then, weren’t they already?

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