Three weeks ago John covered the continuing saga of GM corn, and the divide between U.S. and European environmental regulations. This week Nature news picked up the story, and the council for agricultural science and technology (CAST) threw in its two cents with a new study on gene flow and how it thinks GM corn would have minimal harm on the environment.
All of this attention is aimed directly at the EU, who is being pressured by the WTO to end their national moratoriums on GM corn by January 11, 2008. The German agriculture minister Horst Seehofer summed up the issue when he said "The reservations of the public are not being sufficiently considered."
To help gain perspective, this might be the perfect time to look at some of the science of GM corn, and listen to a few dissenting voices that may just be speaking for those who are not being sufficiently considered.Gene flow is the general term used by population biologists to discuss how genes 'migrate' between different distinct populations. The idea is that a population of GM corn might be able to have sex with a population of non-GM corn. Corn sex is an interesting, and in this case, important part of the story. Each corn plant releases anywhere from 4 to 18 million grains of pollen, that is around 20,000 grains for every potential kernel of corn.
The pollen grains travel on the wind, and typically land within a short distance of the plant. It has been found that isolating fields by more than 50 feet will reduce cross-breeding down to about 1%. But, 1% is actually a lot of gene flow. And some pollen grains can travel for miles. So while most of the genes will stay close to the field, there will always be a few cases of interbreeding, no matter what measures you take to protect your fields.
Yet the story gets stranger. It turns out that genes don't just flow from parent to child, or corn stalk to corn stalk but quite readily move from one individual to another- even in another species. Called horizontal gene transfer, this new method of gene flow has been proven in bacteria, and increasing evidence shows gene transfer may be common in higher organisms, like corn or humans. One of the more subtle aspects to consider is how gene transfer from the GM corn into other crops, insects, bacteria, or humans might effect our environment or health.
Dr. Mae-Wan Ho, a critic of genetic engineering writes:
"While horizontal gene transfer is well-known among bacteria, it is only within the past 10 years that its occurrence has become recognized among higher plants and animals. The scope for horizontal gene transfer is essentially the entire biosphere, with bacteria and viruses serving both as intermediaries for gene trafficking and as reservoirs for gene multiplication and recombination (the process of making new combinations of genetic material)."
With such fundamental questions about biology still being discovered it seems a little foolish to rush into pushing GM crops as a solution. Michael Pollan, in an interview with the Sierra Club from 2004 provides a prescient view of GM corn:
"Genetically modified organisms are a tool, and tools help you do what you want to do. So what is it we want to do? We need to stop spraying so much pesticide. Are GMOs the only way to do that? No. There are other ways: We can plant a polyculture instead of a monoculture, for instance. But Monsanto doesn't like that strategy because it wants to sell as much of its product as possible. So far, GMOs have mainly been a way to sell more Roundup herbicide.
The first generation of GMO products offered the consumer nothing. The food was not cheaper, and it was still grown with pesticides--and in some cases required even more pesticides. In the late 1990s, the companies told me about this second generation of products that was going to provide superior nutrition. Where are they?
We still have the same crops that were rolled out in 1996. It suggests that either the capital to do research and development is drying up, or they've found it's harder than they thought to make these more complex products work. Either way, the industry is on the ropes. I don't think in ten years we'll be talking about GMOs. I can easily see the industry withering away."