From my perspective as a trained scientist, skeptic and observer of political debates, there are four scientific issues that have wandered into the realm of political debate: evolution, climate change, vaccines and genetically modified organisms (GMOs) generally with regards to food and agriculture.
Evolution and human caused climate change (or sometimes called anthropogenic global warming, AGW) are scientific facts supported by literally mountains of data. The arguments presented by evolution deniers is easily refuted. And the myths pushed by global warming deniers are also quickly debunked. Both of these have become a part of the political conversation, with the evolution and climate change deniers being almost exclusively made up of conservative political groups, including Republicans in the USA. There is no debate about these two facts from a scientific point of view, unless someone cherry picks scientifically weak papers published in bad journals to confirm a bias against these scientific facts.
Vaccines aren't really a scientific principle per se, but the support for the safety and effectiveness of vaccines is pretty much settled by the vast majority of scientists who actually have experience, research and education in the key fields of science related to vaccines, such as epidemiology, immunology, microbiology, virology, etc. etc. The fact that about 95% of children in developed countries(including the USA and most of Europe) indicates that there isn't even a "political debate" except some blathering and noise from a tiny lunatic fringe. And the 5% of children who aren't vaccinated don't exclusively represent active vaccine deniers–most of these unvaccinated children either cannot be immunized for some health reason, have procrastinating parents, or have parents who may be too poor to get their children vaccinated, even if it's free to most people in developed countries. The only reason most of us get worked up about the approximately 1-2% of parents who actively resist vaccines is because we think all children should be protected from vaccine-preventable diseases.
On the other hand, GMOs, at some levels, should have some level of public discourse and debate. For example, glyphosate (Monsanto's RoundUp) resistant crops have raised public concerns, and despite some awful scientific evidence that has been solidly ridiculed in the scientific community, along with solid scientific studies that show no correlation (let alone causation) between human health and glyphosate exposure (see this, this, and this), excessive use of pesticides frighten people.
Personally, I can buy into certain arguments against GMOs. For example, I think that monoculture agriculture is extremely susceptible to an introduced or novel pest, which could be devastating to our food supply. I am also concerned about certain unintended consequences such as evolved pest resistance (but then again this has been a war since the first day genetic modification occurred 10,000 years ago), lower crop productivity, or other issues. So far, science hasn't uncovered any problems so far, so there's that.
If the anti-GMO environmentalist community wants to engage in a reasoned conversation about GMOs with those of us who have scientific evidence supporting our discussion points, then they have to quit using five bad arguments, which they seem to pull out of the manual of science deniers everywhere. Because anti-GMO arguments use the same ridiculous "debate" strategies as those who deny vaccines, evolution and climate change. As I've joked more times than I care to remember, I feel as all the science deniers attend the same convention to discuss tactics and strategies. It seems ironic to me that those who are anti-GMO make the same exact points as the climate change deniers, yet those two groups have nothing in common except they are both humans.
So what are these five bad arguments? Glad you asked, so here we go.
1. GMOs are dangerous to eat.
This is a seriously defective argument by the GMO deniers. Let's start with plausibility–is there any plausible and scientifically supported physiological pathway that would lead any reasonable person to believe that somehow GMO foods have an effect on humans or other animals? Any DNA from the food will be broken down into constituent nucleic acids, and there are only 4 from DNA, which are then absorbed through the digestive system. There are no differences between nucleic acids for any organism on this planet (and one of the fundamental arguments supporting evolution, but that's another story).
The argument that GMOs are dangerous cannot be based on some magical belief or special pleading. It must be based on a well known and understood scientific physiological process, even if it takes some stretch of the imagination, before we accept that there's some possibility above 0%. If the argument includes a nonsense claim, like some genetically modified protein is going to be absorbed, when proteins just aren't absorbed.
The DNA from GMO foods simply cannot be incorporated into human, pig, cow or insect genomes. If it were that easy, we'd have turned into mastodons 15,000 years ago from eating that meat. But less ridiculously, gene therapy has been found to be extraordinarily difficult because we have not been able to perfect gene transfer.
A recent study, which literally looked at trillions of data points, found no effect of GMO foods on livestock after switching from non-GMO to GMO feeds. This study followed 100 billion animals over many years–no ill effects, attributable to GMO foods, were found. The evidence for safety is simply overwhelming.
The rules should be that if one is going to argue a point, like GMOs are dangerous to eat, then there should be significant and well accepted scientific evidence. And right now there is simply no such evidence. And the positive evidence, that GMOs are safe, borders on a scientific slam-dunk.
2. Labelling is necessary
Given that there is no evidence that GMOs are dangerous, it's not a very good argument to say that we need labelled products. That being said, food labelling is relatively detailed today, and many people read them carefully. Diabetics need to know how many carbohydrates and sugars are in a food. Those with allergies need to know ingredients. Those who are trying to limit fats need to know the content. I need to know that my milk is pasteurized. I want to buy coffee from sustainable agriculture.
In a sense, labelling a product as GMO or GMO-free may not be that important, except for one major issue–cost of foods. Unbiased research has shown that GMO labelling could add up to $500 a year (pdf) to the food bills of the poorest people in the USA, even for foods that are not GMO-free. Why? The cost of labeling itself. Compliance to the "non-GMO" standard, whatever that may be, and which will vary from state to state, will add substantial cost. Manufacturers will have to create whole new lines of food processing to be GMO-free, which will be shared across foods.
Finally, a regulatory system will have to be established, the cost of which is usually borne by either the taxpayers (so an indirect cost to all citizens) or by the food processors which is then passed to the consumer.
Those who are wealthy will be able to afford the cost increases. But those who might not care, usually those who are poor and on some sort of government assistance, may have to purchase fewer calories because of the increased costs.
As someone with progressive political leanings, I am flabbergasted that anti-GMO environmentalists, who are generally socially progressive like me, completely ignore or dispute this issue. Even though I agree that GMO labelling is appropriate and not a problem, I cannot in good conscience ignore the cost issue.
3. Only Big Agriculture benefits from GMOs
This is a patently ridiculous argument. There's golden rice that will add vitamin A to the diet of millions of children, preventing blindness and death in millions of children every year, where the vitamin is deficient in the diet. This one food alone refutes the bogus argument that only huge food companies will benefit.
But I can give many other examples. Human insulin andvaccines can be grown in plants, making them cheaper and better for humans. There's a genetically modified mosquito (leaving the world of food crops) that might end dengue fever. There's a cow that is resistant to the sleeping sickness parasite–the cow is affected by the parasite, but passes it to humans, so it breaks the chain that leads to that infection of humans.
Of course, this argument is related to:
4. GMO supporters are shills for Monsanto
Although I once lived in the city where Monsanto is headquartered and had many friends who were in executive management and R&D at the company (talk about full disclosure), I actually don't have any interest in the company in any form. All I care about is scientific evidence, and Monsanto is irrelevant to that discussion. At a more basic level, making an accusation that anyone is a "Monsanto shill" is a logical fallacy–because the accuser lacks any evidence for their claims about GMOs, they resort to a kind of name calling to taint the reputation of the GMO supporters with a corporation that has had a modestly bad reputation in the past.
Worse yet, this bad argument is used to dispute the validity of any scientific study that has even the taint of corporate support. Personally, I find this insulting on so many levels, including the fact that scientists are willing to sell out for some small amount of money. Maybe the accusers have low moral standards, but there really isn't enough money in the planet to buy many of these scientists. They do their work for noble reasons, and as hard as that may be to accept, I don't think that people who make these kind of "shill" accusations represent the moral high ground.
Bring real scientific evidence, which I do realize is very hard. Getting all that education, then doing years of research, then writing papers, then getting them published–yeah that's exhausting work. But accusing someone who's done that with some unethical financial gains from Monsanto, well that just shows a ridiculously illogical and irrational thinking process.
5. GMOs are unnatural
This is just another logical fallacy, the Appeal to Nature. Basically, it's an argument that "natural" is good, and human-made is bad. Philosophically speaking, nature is neither good nor bad. Nature, as we observe it today, is quite a bit different than it was 10,000 years ago, which is substantially different than it was 10 million years ago. Nature is a product of evolution, which is essentially a random process of genetic change in response to environmental pressure.
Nature gives us beautiful flowers. But it also gives us viruses, bacterial and parasites that kill. It gives us cuddly cats and predatory mountain lions that eat humans. Nature is amoral, it is not guided by any particular objective, and has no magical powers. Moreover, arguing from a purely philosophical point of view, humans are a product of "nature," and our activities could be considered "natural."
Thefirst domestication of plants and animals occurred about 10,000 years ago, soon after the end of the last glacial maximum. This domestication process included an artificial selection for traits that provided humans better and more nutritious crops and livestock. In essence, artificial selection "waits" for certain beneficial mutations to occur in target species (say corn), then we choose to breed individuals that have these beneficial characteristics in the hope that they make it to the next generation.
These mutations may appear to be "natural," but they happen because of random cosmic rays hitting the corn plant, some mutagenic compound is in the soil, or because the plant incorporates a gene from a bacteria or virus. In other words, there's no magic here, these are random events. Maybe some cosmic ray hits the corn genome, creating a change that makes the plant grow larger corn kernels. Or it could change a gene that makes the corn resistant to some fungus or insect. The problem with this process is that you have to wait for "nature" to dump that cosmic ray onto the corn genome to cause a favorable mutation. And there are lots of deleterious and neutral mutations that aren't going to help.
What genetic modification does is speed up the process. Instead of waiting for an advantageous mutation to show up in one seed of corn, we place a useful gene in that corn seed–we get artificial selection in one generation, instead of waiting hundreds of generations. Since the gene can't harm humans (sorry, but it is so implausible to think that a modified gene can harm someone, unless it's intentionally made to do so, that it's laughable), all we've done is speeded up evolution. Again, evolution is not guided by anything, unless you're a creationist and believe that some magical being created all of life, and it has no goals. So speeding it up is simply logical, not dangerous.
TL;DR
There might be some good reasons to have public discourse about GMOs. But if the "debate" includes logical fallacies and unscientific beliefs, the discussion ends. The pro-GMO side then gets to legitimately declare the discussion over and moves on. Right now the scientific evidence overwhelmingly supports the safety and usefulness of GMO technology–if there's going to be a scientific "debate" then real evidence has to be presented sans logical fallacies (like one study is better because the other study is supported by paid shill of the Monsanto/Big Agra evil empire).
Now time for me to check out how well that Frankensquito environmental study is going.
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