Some dangers inherent in the production of genetically modified organisms...

In 1999, Cornell entomologist John Losey reported that the pollen of corn plants, which had been genetically engineered to produce an insecticidal toxin, was harmful towards monarch butterfly larvae1. While any but the most benign reading Losey’s article would have revealed a highly suspect scientific method- it is quite possible that the caterpillars in the study died at a higher rate because they ate less, and ate less because they recognized their only food source as toxic- the article’s headline confidently declared that “Transgenic pollen harms monarch larvae” and that was the conclusion internalized by an already suspicious public, triggering a condemnatory backlash by scientists with a vested interest in promoting their research and portraying the organisms that they engineer as safe2. This was unfortunate, because there are a number of valid potential dangers inherent in GMOs, which deserve extensive consideration before policy decisions concerning research regulations, FDA approval protocols, and food labelling are made.

Losey’s study focused on the risk of bioaccumulation. Much as the pesticide DDT makes its way from the leaves of plants into the shells of predatory birds, he proposed that the genetic material of the bacterium Bacillus thuringiensis could make its way from the corn genome into corn pollen, from there on the wind onto milkweed leaves, and into caterpillars. This is not as convoluted a path as it sounds. In fact, the corn toxin has been found to persist in other aspects of its ecosystem, and may be able to pass through corn roots and into the soil3. Agriculturists need to acknowledge that there is no inherent benefit in engineering plants to produce their own insecticides, as opposed to spraying artificial chemicals. Both are foreign introductions into an ecosystem (or a farm’s pale simulacrum thereof), and should at least have their biochemical properties, such as rates of decomposition in soil and water, and poisonous effect on target and non-target organisms, thoroughly understood before their commercial release.

Another relevant property of any GMO plant or animal is its capacity for survival outside of cultivation. Much of our previous manipulation of species has consisted of domestication, creating artificial selection pressures to drive species towards producing more of their respective product via an allocation of resources that neglected resource collection or defense. As a result we created crops and animals that were less hardy than their ancestors, and stood close to no chance of establishing wild populations because they needed humans to proving limiting resources or protection. While not productive per se, the mass-produced immunologically nude mice manufactured for research use today are an extreme example of this trend.

On the other hand, current genetic modification often focuses not on yield but instead on crop hardiness, inserting genes to confer specific immunities and defenses, so as to maximize agricultural profits by minimizing the cost chemical protective measures. The organisms so produced have an advantage over the predators and competitors that they confront, having evolved adaptations on an accelerated laboratory timescale, instead of through the steady arms race of co-evolution, within which organisms in an ecosystem remain equally matched in their offensive and defensive capacities. And these organisms do not only stand a chance of escaping cultivation themselves. Agricultural crops, genetically modified or not, have the capability to disperse their pollen, which in the case of hybridization with related species, followed by an unpredictable but historically common polyploidy event, can produce fertile offspring. Unfortunately agribusiness seems unlikely to protect uncultivated habitats from such an invasion, as an adequate strategy would involve strictly quarantining GMOs and their places of production.

GMOs call for detailed scientific research into both their properties and the composition and interaction of the ecosystems adjoining their places of cultivation, to enable scientists to model their potential effects. Even more important, though, is an acknowledgement that some effects are unpredictable, and any GMO whose use we adopt will always pose a potential danger. The commercial popularity of these organisms is evidence that policy makers care more about agricultural profitability than about preserving ecosystems, and there is no reason for those in power to even feign interest.

1Losey, J.E., L.S. Rayor, and M.E. Carter. 1999. Transgenic pollen harms monarch larvae. Nature 399: 214
2Shelton, A.M. and R. Roush. 1999. False reports and the ears of men. Nature Biotechnology 17: 832
3Wolfenbarger, L.L. and P.R. Phifer. 2000. The ecological risks and benefits of genetically engineered organisms. Science 290: 2088-2093.