Jun 02 2015

PBS GMO Debate

PBS has put up an interactive resource on the GMO (genetically modified organisms) debate. You vote for which side you are on, and then the site feeds you arguments against your position. I like this idea, as it is always helpful to challenge yourself by confronting differing opinions. This is a sort of antiechochamber approach.

Since I accept the strong scientific consensus that GMOs are generally safe (each genetic modification needs to be evaluated on its own, but so far existing GMOs have been found safe, and there are no established specific issues with the technology itself), and are a potentially useful technology, I took the pro side, which means PBS fed me all their anti-GMO arguments. I was struck by how consistently terrible their anti-GMO arguments were. It seems that PBS was trying to be fair and thorough, which implies that there are only terrible anti-GMO arguments, so they had no choice.

I am still honestly trying to find a non-terrible anti-GMO argument, because I agree with seeking out the best arguments on all sides of an issue, and being charitable to those arguments. PBS did not fulfill my quest. To be fair to PBS, they are reflecting the talking points of GMO critics, and that is what they say. They are not endorsing these positions. Here are their anti-GMO points:

What if you knew that detractors fear that GM foods might pose health risks for certain people?

They convey two points here – that new GMO varieties may introduce new allergens into the food stream, and that GM technology potentially introduces antibiotic resistance to our gut bacteria.

The allergen concern is not a valid concern. So far there hasn’t been a single case of allergy to a GMO. Further, GMOs are screened for new proteins that are potential allergens. Protein allergens have amino acid sequences in common, for example ones that allow the protein to survive stomach acid sufficiently intact that it is still an allergen. Most (if not all) potential new allergens are therefore avoided.

This also contrasts favorably to other breeding methods, such as hybrids and mutation breeding, which introduce many more new proteins than GM, and undergo no screening for new allergens. This fear of new allergens is therefore being targeted at the breeding methods that is perhaps the least likely to introduce a new allergen.

What about antibiotic resistance? It is true that scientists will sometimes use a gene conveying antibiotic resistance as a marker to indicate that the desired genetic trait was successfully inserted into the target plant. The concern is that these genes will find their way into the bacteria in the human GI system. There is no evidence that this has actually occurred. Further, a thorough scientific review of the potential for this to happen has revealed that it is highly unlikely:

We conclude that, although fragments of DNA large enough to contain an antibiotic-resistance gene may survive in the environment, the barriers to transfer, incorporation, and transmission are so substantial that any contribution to antibiotic resistance made by GM plants must be overwhelmed by the contribution made by antibiotic prescription in clinical practice.

As an even extra layer of protection, however, resistance to ampicillin and kanamycin are typically used specifically because resistance to these antibiotics are already widespread within pathogenic bacteria. Therefore, even in an unlikely worst-case scenario, the impact would be negligible and would not affect medical treatment. Resistance to antibiotics that are currently used in medical treatment because resistance is not widespread are specifically avoided by GM techniques.

What if you knew that many feel GM crop technology will hurt small farmers?

They begin:

Critics of GM agriculture insist that patenting genetically altered crops, as agribusiness is rushing to do, will make small farmers indentured to big firms. Monsanto, one of the biggest players in the field, is currently suing dozens of North American farmers whom it claims have raised its patented GM crops without paying for the privilege. (Farmers have responded that pollen from Monsanto crops blew in from neighboring fields.)

I understand they are trying to represent the anti-GMO side, but relating factually incorrect statements is not the way to do it.

First, like many of the anti-GMO talking points, they have nothing to do with GM technology or specific GMOs themselves. The fact that big agribusiness provides many of the seeds that farmers use is an issue of how the industry is organized, with or without GMO.

In fact, if this were really the issue protesters should have more of a problem with hybrid seeds. Hybrid seeds cannot be saved and replanted because the hybrid traits do not breed true to the next generation, so you have to purchase new seeds every year. (Something which farmers don’t seem to mind – it might actually make economical sense for them.) Right now more than 90% of vegetable crops are grown from hybrid seeds.

The claim that Monsanto sues farmers for seeds blown into their fields by wind is a myth. They sue farmers who have tried to argue “patent exhaustion” or who have deliberately violated their patents, not for accidental contamination. This is really just a propaganda lie from the anti-GMO activists.

PBS goes on to repeat the claim that expensive GMO seed could be bad for poor third world farmers. In fact, the introduction of Bt cotton in India has increased yield, especially among poor farmers, and increased their profits and disposable incomes. When farmers in poor countries have problems it is because of poor support for farmers and bad regulations and lending practices – having nothing at all to do with GMO or even big Ag.

Their next point is just odd, and I think shows the desperation of the anti-GMO movement. They claim that GM varieties might allow competitors to compete with existing farmers. A GM variety of quinoa that can grow in North America might hurt Bolivian quinoa farmers. This, of course, can be an argument against any advancement in technology. By definition, any meaningful progress will displace some product in the market. This is a weak argument for the status quo.

Their final argument is equally weak, that GMOs support monoculture. I agree that excessive dependence on monoculture is a problem for modern farming. There is a certain efficiency to monoculture that is allowing us to feed over 7 billion people, but it comes at the cost of biodiversity, which is a good hedge against blight and other disasters. Modern agriculture needs a balance.

The problems with monoculture, however, predate GMOs and there is no evidence that the introduction of GMOs has increased dependence on monoculture, or that it contributes more to monoculture than hybrid seeds or other cultivation technology.

In fact, many experts believe that GM technology has the potential to reduce reliance on monoculture, as favorable genes can be inserted potentially into many different local varieties. Further, opposition to GM technology has lead to onerous regulations that ensure that only big companies can afford to bring GMOs to market, which is worsening the problem of monoculture by limiting  the number of varieties on the market.

What if you knew that opponents fear that GM crops could harm the environment?

Their overall point here is the precautionary principle – we can’t predict what possible harms GMOs might cause when unleashed into the environment. This is, however, an abuse of the precautionary principle. There is no particular reason to suspect that GMOs pose any special risk to the environment.

Many of the introduced genes are harmless, or are already out there in the environment. They raise the specter of “superweeds” or “superbugs.” These are misleading terms, designed to stoke fears. There is nothing “super” about these weeds or insects, except that they have gained resistance to a particular herbicide or insecticide respectively. A weed that is resistant to Roundup, for example, is only a problem if you want to use Roundup to control weeds – it does not present any other problem for farmers or the environment.

This is exactly like saying antibiotics are bad for the environment because they can result in “superbugs” resistant to antibiotics.

The real problem here, yet again, has nothing to do with GMOs or GM technology but with massive farming that relies on the use of pesticides. GMOs can actually be a very useful tool in what is called “integrated pest management” which is a series of practices that seeks to limit resistance developing from the need to control crop pests.

Farming practice is the issue here, not GMOs. GMOs have actually been helpful, but of course they can be abused and use improperly like any technology.

PBS also brings up the monarch butterfly issue, referring to one study that shows that GM corn pollen on milkweed reduced monarch survival. They then acknowledge that the study was flawed and later research refuted its conclusions, but amazingly still think it’s a useful argument.

It is true that Monarch butterfly populations have been declining for decades. This is largely due to loss of habitat and declining milkweed populations (they are dependent on milkweed). Milkweed is declining due to farming, whether or not GM technology is involved. There is no evidence that GM crops are directly linked to the decline in milkweed, but it is possible that the increased use of Roundup has contributed to the decline in milkweed.

Again, however, this is a matter of farming practice. Farmers fight weeds, which reduce yield, and this includes the milkweed. The solution is to change farming practice to accommodate the butterflies, having safety zones for milkweed, for example.

What if you knew that many people feel genetically modifying organisms goes against Nature?

Really? They actually write:

Nature also does not mix apples and oranges, much less flounder and strawberries. (Scientists placed an antifreeze gene from the fish into the fruit in a failed attempt to help strawberries withstand frost.) In short, do we have the wisdom to substitute human for natural selection? To play God?

And quote:

“If Nature has spent millions of years building a structure with natural boundaries, it must be there for a purpose. It is there to guide the evolution of life and to maintain its integrity. Using genetic engineering in agriculture is like trying to fix something that has nothing wrong with it in the first place.”
–Dr. Michael Antoniou, Senior Lecturer in Molecular Genetics, GKT Medical School, Guy’s Hospital, London, U.K. [19]

This is literally the “Frankenfood” argument. There are problems with this argument on many levels. First, it’s the naturalistic fallacy – nature is always better, and technology is bad. But it is a particularly unscientific version of this fallacy.

As has been pointed out endlessly, pretty much all the food we eat has been significantly altered by human intervention. Particularly for the vegetables you eat, their “natural” forms would be unrecognizable and  barely edible. GM technology is an insignificant tweak compared to the massive transformations that breeding and cultivation have wrought.

But wait, say GM opponents, these changes took thousands of years instead of tens of years. So what? Hybrids and mutations farming take only tens or maybe score of years. GM technology is faster, but this is not a dramatic difference (especially compared to the “millions” of years they cite for “natural” evolution.)

But wait, say GM opponents, GM technology allow for transgenes from distant species. Again I say, so what? First, it is demonstrably not true that transgenes do not occur in nature, as the recent example of the bacterial gene found in the sweet potato attests.

Second – there is nothing inherently scary about a fish gene. I understand that fish contain 100% fish genes, and people eat them all the time. Also, what makes a fish gene a fish gene? Fish and vegetables share about 60% or so of their genes.

The source of the gene ultimately does not matter, only the protein that it codes for and its overall effect on the genome. As long as this is adequately tested, the source of the gene is scientifically irrelevant. It is only useful to provoke a disgust response in the scientifically illiterate.

Their last two arguments I will deal with together:

What if you knew that many critics inveigh against biotech companies for being profit-driven, with little concern for potential risks to people or nature?

What if you knew that many critics assert that GM foods suffer from dangerously poor oversight and regulation?

My stars – companies are driven by profit? A bombshell like this might give one the vapors. Alert the media while I lie down and recover.

I assume that all industries are driven by profit. Some companies are good corporate citizens, and some aren’t. Some are better to their employees than others.

I firmly believe that industries need to be thoughtfully regulated, to prevent the abuse that will naturally flow from the profit motive and human nature. I think history bears this out. The more critical and the greater the potential for harm and abuse, the more carefully we need to regulate industries. (I say carefully and thoughtfully because careless regulations can stifle industry and have negative unintended consequences.)

So sure – regulate the seed industry to protect the environment, prevent abuse, make sure that other sectors of the industry, like farmers, are protected and have their fair say. In fact, GM technology is highly regulated. It is the most regulated seed technology we have. I don’t know enough to say whether or not our current regulations are optimal, and I would be open to any reasonable argument that they should be adjusted.

However, that large corporations are profit driven is not an argument against GM technology any more than it is an argument again any technology. We could make the same exact claim about organic farming, the supplement industry, or even the kitty litter industry.


The PBS article is representative of the quality of anti-GMO arguments. They tend to be either factually wrong or based on invalid logic. They are often emotional and display a shocking degree of scientific illiteracy.

Many of the arguments conflates the ordinary issues with all large corporations, or issues with large farming as if they were directly related to GMOs when they are not. At best GM technology is incidental to the issues raised, and often may be a potential solution. These arguments therefore miss the point by focusing on the wrong thing, and lead to opposition against a technology that may help the very problems they are raising.

34 responses so far