With the news this week that transgenic (GMO) wheat plants made it into a farmer's field in Oregon, the whole debate over transgenic crops has reignited. The lapse in containment of an experimental transgenic plant (no GMO wheat has yet been approved by the US Department of Agriculture beyond experimental trials) is not a trivial issue, but the reaction shows a deep misunderstanding of the dangers and benefits of transgenic organisms.
First off, the transgenic trait inserted into the wheat plant was resistance to Roundup (glyphosate), a commonly-used herbicide; indeed, it was the fact that the plants were not killed by an application of the herbicide that alerted the farmer to the problem. The way a plant like wheat is made resistant to this herbicide is by adding a gene from the soil bacterium Agrobacterium to the wheat. The gene codes for an enzyme (EPSPS) which both the bacterium and the plant have; while the plant version is essentially shut down by Roundup, the bacterial version is not as affected by that herbicide.
Knowing that this was the transgenic trait lets us make some reliable predictions about the dangers of this "rogue" transgenic plant. First off, the advantage it has over conventional wheat is resistance to an artificial pesticide, so it is unlikely to have any effect on the plant's ability to survive outside fields sprayed with Roundup. That could be inconvenient for farmers using the herbicide, but there is no reason to suspect the wheat would spread in a system that did not include Roundup (i.e., natural grasslands, organic farms, etc.).
Second, while Japan and South Korea suspended wheat shipments from the US, there is no reason to suspect any health risk, even if this crop somehow infiltrated the US wheat distribution network. First off, the modification is merely substituting versions of an enzyme the plant already makes; there's no reason (and, indeed, no evidence) that any of the glyphosate-resistant crops already in wide use (such as corn and soybeans) have any health effects different from conventional varieties. In other words, there's no reason to expect any actual damage to anyone in this case (although knee-jerk bans like those of wheat importers could certainly do economic damage to wheat farmers). I will grant that one farmer in Oregon has a minor weed problem.
Yet what is the result? A firestorm of generic anti-GMO protest. Perhaps, as this interesting article points out, it's just mentally easier to assume a big conspiracy (led by the profit-seeking Monsanto) than to evaluate the actual risks of the case in front of us. In other words, most folks (and many countries and the EU) are just anti-GMO, period. But that is as clumsy a position as it is possible to take, since what matters is not the technology used to put a trait in an organism, but what that trait actually is.
Perhaps an analogy will help. I'd assert that being broadly anti-GMO is like being anti-syringe. Just as transgenic technologies make it possible to put a much broader pool of genetic traits in plants, syringes allow us to put a huge variety of substances into our bloodstreams. Think of what you can do with a syringe. You could fill it with air, pump that into a vein, and give yourself a heart attack in seconds. You could inject an overdose of heroin and stop breathing - or inject a dose of morphine that made a traumatic injury much less painful. You can inject insulin to enhance your body's signal to your cells to take up glucose from your blood (thus treating diabetes). You can inject a tiny dose of the tetanus toxin so that your immune system prevents you from dying horribly from a Clostridium tetanum infection. You could use poor hygiene and give yourself a nasty infection while injecting a vitamin, or you could inject sterile saline and have absolutely no effect at all. In other words, while the syringe makes many new medical treatments possible, the syringe itself is just a delivery mechanism. What really affects the outcome is what you put in the syringe. One could, of course, decide that the potential risks were too great and spurn syringes entirely, but I think we can agree that such a policy was premature!
Transgenic techniques (that result in GMOs) are much the same. They make new things possible, but in themselves are just a tool. What we need to examine carefully are the traits being put into organisms with those techniques. There is potential to do all kinds of good (see, for example, the recombinant production of insulin), and there is potential to carelessly do a lot of damage if GMOs escape human control (although we hardly need transgenic technology for that - see cane toads or rabbits in Australia, or the gypsy moth in North America). There is every reason to be wary of a company like Monsanto that would like to sell farmers both an herbicide and a license to grow a crop that resists it, just as we should be wary that Apple sells both the iPhone and the apps that make the device functional. The potential uses of transgenic technologies are so much broader than anything Monsanto has in mind, however, that it would be foolish to dismiss them outright. Imagine how much medicine would be handicapped if the syringe had been abandoned after the wife of its co-inventor overdosed on morphine.