Earlier this month the discovery of genetically modified (GM) wheat that was not supposed to be in an Oregon wheat grower’s field ignited an international uproar that threatens US wheat exports to other nations. The Oregonian provided especially good coverage, even including other examples in Oregon where GM crops were found outside the areas where they were expected, at potential or real economic detriment to other growers or organic growers of the same crops. Then, Grist reported that although Monsanto had discontinued field trials of GM wheat in Oregon in 2005, the company was still testing GM wheat in Hawaii and North Dakota.

US wheat growers worry that Japan and other countries, including those in the European Union, where GM foods are poorly received, will halt US exports, at least until further field testing resolves the purity of US wheat. The uproar also gives US growers an economic incentive to support GM food labeling, which could allow US crops easier access to international markets.

The Oregonian explained the scientific details, but here’s a summary: Monsanto modified the DNA of wheat to make it resistant to the company’s Roundup-brand weed killer, glyphosate. In theory, growers could plant the GM wheat, spray with Roundup to reduce weeds, and the glyphosate-resistant crops could grow to harvest season, even with repeated Roundup spraying. But to paraphrase a defender of Darwin, “Ugly facts can destroy a beautiful theory.” The catch is that the GM crops are Roundup-resistant, but not Roundup immune. For Monsanto’s approach to work, growers have to use a “Goldilocks” approach to herbicides: too

Chemical structure for Glyphosate; source, Wikipedia Commons  (For the OH groups connected to Phosphorus, the solid line represents a three-dimensional projection toward the viewer, and the dotted line a projection away from the viewer.)

Chemical structure for Glyphosate; source, Wikipedia Commons (For the OH groups connected to Phosphorus, the solid line represents a three-dimensional projection toward the viewer, and the dotted line a projection away.)

little Roundup will allow weeds to grow, but too much will prevent the crop from growing to maturity.

Moreover, as the scientific community is aware, pests can multiply more rapidly than the agribusiness industry can come up with new chemicals to kill them. But the results, including glyphosate-resistant weeds, are consistent with Darwin’s concept of “selective pressure”: propagation of the members of a species that can best survive current conditions and who will pass on the genes that allow their offspring to multiply. (A familiar example of selective pressure is the case of black moths in England. When “London fog” was coal-dust black, darker moths were better camouflaged from birds and other predators. As a result black moths had higher survival rates than white moths, and their offspring multiplied. When Londoners reduced coal burning, the relative population of white moths increased.)

In a similar manner, target pests, such as insects or weeds, can become resistant to chemicals that are supposed to eliminate them: After the first spraying of Chemical X, the least-susceptible individuals may survive to reproduce; and their progeny similarly will be resistant to the Chemical X. Spraying in higher concentrations increases the “selective pressure,” favoring individuals with the highest resistance capabilities; and over time Chemical A can become ineffective against the target pest. This general phenomenon of pesticide resistance has more recently been demonstrated with weeds resistant to Roundup. The first glyphosate-resistant weeds were reported in Australia in 1996. As of 2010, such “superweeds” were found in nearly 10 million acres across the US.

  • Another concern is the potential spread of GM crops, through weather and human error, to normal crop fields. In that regard, the rogue wheat in Oregon provides one more example that GM crops can show up in fields where they were not expected, and where growers do not want them. In addition, scientific skeptics worry about human health impacts, since there have been no long-term animal feeding tests to determine the potential effects to humans of eating GM foods.

    One potential response to these concerns, consistent with the principle that consumers have a right to know what they eat, would be clear labeling of GM foods. Wary consumers could avoid eating genetically modified foods, leaving the market to those who accept the assurances of companies and the regulatory agencies that approve GM foods. Such an idea has overwhelming support among consumers, but overwhelming opposition from agribusiness interests .

    All of which bears on public policy in the Northwest. So far only one state, Connecticut, has passed a bill that will require GM food labeling, but the Constitution State hedged. Its law only takes effect provided at least four other states pass similar laws. As Grist explains, this “middle-way” approach avoided the massive agribusiness lobbying that turned out against a comparable California initiative to label; but amounts to a “come on in, the water is safe,” approach to other states. In 2013, Washington voters will have the opportunity to cast their votes on a similar measure. Meanwhile, the brouhaha in Oregon may encourage state legislators there to follow suit.


    John Abbotts is a former Sightline research consultant who occasionally submits material that Sightline staff turn into blog posts.