Young Australian Skeptics

Recently, upon listening to episode twelve of The Pseudo Scientists, I was so astonished by what I heard from the crazy lady interviewed in our On The Street segment that I just had to make a post about GM food.

It’s often said that GM food is “manmade”, “artificial” or “not natural”.

To get an idea about the significance of these concepts of “natural” versus “artificial” varieties of organisms in the context of agriculture and food, let’s consider… a well made banana.

Now if you study a well-​​made banana, you’ll find, on the far side, there are 3 ridges. On the close side, two ridges. If you get your hand ready to grip a banana, you’ll find on the far side there are three grooves, on the close side, two grooves. The banana and the hand are perfectly made, one for the other.
You’ll find the architect of the banana has made it with a non-​​slip surface.

It has outward indicators of inward contents — green, too early — yellow, just right — black, too late. Now if you go to the top of the banana, you’ll find, as with the soda can makers have placed a tab at the top, so the architects of the banana have placed a “tab” at the top. When you pull the tab, the contents don’t squirt in your face. You’ll find a wrapper which is biodegradable, has perforations. Notice how gracefully it sits over the human hand. Notice it has a point at the top for ease of entry. It’s just the right shape for the human mouth. It’s chewy, easy to digest and its even curved toward the face to make the whole process so much easier.

Of course, I’ve never seen a fruit which is slippery and doesn’t have a “non-​​slip surface”, and the fact that its skin is “biodegradable” doesn’t count for much either, since all fruit are. But a desert banana is certainly nice and convenient to eat.

It is obvious that the banana, specifically a Cavendish banana or some other variety of cultivar which is grown agriculturally, has been engineered by an intelligent agent to make it good for people to eat, and it hasn’t just arisen through natural evolution. If you look at a wild-​​type banana on the other hand, it has a thick skin which is harder to peel, is smaller, does not nicely fit in the human hand, and is filled with large seeds — clearly it has not been engineered to be good for people to eat.

The “unnatural” nature of a Cavendish banana or other desert banana cultivar is especially clear when you consider the fact that such a banana is seedless. A seedless fruit is good to eat, but it is particularly unnatural, since a seedless banana could not exist in nature, since it cannot reproduce.

It is only possible for a seedless banana to exist where people cultivate the plants by taking cuttings from the roots of the tree and transplanting them to make new trees.

The point here is that essentially all plants and animals that are cultivated and farmed, everywhere, have always been very “unnatural”. These plants and animals are quite different from similar organisms found in nature, and have been engineered — “intelligently designed”, if you wish — by people (not any invisible friend) over many generations in order to create better varieties of plants and animals for us to use as food (or as fibre, or whatever.)

The genetic modification of the plant and animal varieties that are created in nature by means of evolution due to natural selection to give rise to the unnatural varieties of plants and animals that are the basis of agriculture is done in one of three ways:

i) Artificial selection

We’re surrounded by farm and domestic animals, and countless cultivars of fruits and vegetables, which do not exist in the fossil record. These plants and animals were not once free-​​living in the wild and then domesticated; the present forms of most of these organisms have been engineered by people. They are, almost all of them, made by us.

Humans encourage the reproduction of some varieties, and discourage the reproduction of others. The variety selected for eventually becomes abundant. The variety selected against becomes rare, maybe extinct.

This is the process of artificial selection, and has existed for thousands of years as the basis of essentially all agriculture, even before the science of genetics was established and formalised by scientists such as Mendel, and is responsible for the creation of the countless familiar varieties of plants and animals that are all around us; including but not limited to the well-​​made banana.

ii) Mutation breeding

Mutation breeding is a technique which is essentially a modern modification to the process of traditional selective breeding or artificial selection, which has been widely used in agriculture for many decades.

In mutation breeding, plant material is exposed to a mutagenic agent, for example a chemical mutagen such as ethyl-​​N-​​nitrosourea or ethyl methanesulfonate, or to gamma radiation, thermal neutrons or some other form of ionising radiation. These agents introduce random genetic mutations in dividing cells at a significantly greater rate than mutations occur naturally, and therefore, when combined with an artificial selection pressure as with normal selective breeding, this means that the rate of artificial evolution of new plant varieties with desirable characteristics is accelerated.

For example, in the mid 1960s, buds from a “Ruby Red” cultivar grapefruit tree located on the Texas A&I University Citrus Center were collected and sent to what is now the Brookhaven National Laboratory in New York, where the grapefruit buds were irradiated with thermal neutrons from a nuclear reactor, and then shipped back to Texas for propagation. By the early 1970s, the trees were beginning to produce fruit. The fruit was two times more red both in exterior as well as interior color as the original Ruby Red. In 1976, a single limb on one of the test trees was observed to have much more red colored fruit than fruit on the rest of the tree. Buds were taken from this branch and propagated. By the early 1980s, the trees were producing fruit and the fruit was, in fact, very high colored both inside and out, approaching five times more red as the original Ruby Red. In 1984, a naming contest was held by TexaSweet Advertising and the name “Rio Red” was chosen, and this red grapefruit cultivar remains very popular. [from: here]

More information on mutation breeding can be found at these sites:
http://​www​.nytimes​.com/​2​0​0​7​/​0​8​/​2​8​/​s​c​i​e​n​c​e​/​2​8​c​r​o​p​.​h​t​m​l​?​_​r​=​2​&​a​m​p​;​p​a​g​e​w​a​n​t​e​d​=​p​r​i​n​t​&​a​m​p​;​o​r​e​f​=​s​l​ogin
http://​www​.bnl​.gov/​b​n​l​w​e​b​/​h​i​s​t​o​r​y​/​f​r​u​i​t​s​.asp
http://​www​.cls​.casa​.colostate​.edu/​T​r​a​n​s​g​e​n​i​c​C​r​o​p​s​/​h​i​s​t​o​r​y​.​html

Mutation breeding certainly sounds like “scary” science; the “unnatural” makings of “Frankenstein food”.
But it is a routine part of agriculture, all over the world, and it has been for many decades. And for some bizzare reason, unbenownst to me, you never hear any complaints or protests about it.

iii) Recombinant DNA technology (Genetic engineering)

Finally, after addressing selective breeding and mutation breeding, we finally come to actual genetic engineering, the artificial engineering of the genetic traits of organisms at their molecular basis, and the seat of all this controversy.

Why is there so much darned controversy about genetic engineering of crops, anyway? What are the arguments presented by the opponents of such technology?

Well, the first argument is usually the “it’s not natural” argument; and given what I’ve posted above, I really think that’s a non-​​argument.

Oh noes, it’s the Big Farmer!

Next, we come to the Monsanto, or “Big Farma”, gambit.
That is, you know, Monsanto is a big corporation, and they are guilty of unethical corporate practices, and they’re a big mean capitalist corporation, and they can’t be trusted, and blah blah blah.

Well, maybe that’s true. But the thing is, none of this has anything to do with a discussion of whether or not genetically modified crops are safe and useful and beneficial on a scientific level. It’s kind of like bringing up that Microsoft is a big mean corporation in a discussion of whether quicksort is better performing than merge sort.

It’s just like the whole “Big Pharma” nonsense — it’s just an attempt to divert attention away from a discussion of the actual science and the actual safety of the products on the biological level. It’s sort of kind of analogous to an ad hominem argument; but that’s not a very good way to describe it and I can’t think of a better way.

It’s very important to separate out the big-​​unethical-​​corporation argument from an actual discussion of the science, and look at actual scientific arguments for or against the actual use of genetically modified organisms themselves. I’m not saying there isn’t a legitimate issue there, worthy of serious discussion, but it is separate from the science issue.

Really, genetically modified crops don’t seem to be a big deal at all. Where is the serious evidence that they’re actually, somehow, dangerous?

Genetically modified canola, mostly glyphosate-​​resistant “Roundup Ready” canola, was first introduced to Canada in 1995. Today 80% of acres sown to canola in Canada are sown with genetically modified canola.

These genetically modified varieties are already in widespread use. So, where’s the harm?

In 2003, the Office of the Gene Technology Regulator in Australia approved the release of GE herbicide resistant canola. It has been used in Australia ever since.

I have heard pseudoscientific and poorly backed up claims from GM opponents, for example, that there are “GM crops which only survive if you put another of the same company’s products on them or feed animals grain containing the “right” protein, also sold by the company.”

But does that make sense, scientifically? You’d have to genetically “knock out” some kind of biosynthesis pathway for an essential compound, making a particular compound an essential nutrient in the organism’s diet where it normally is not. Ostensibly, that sounds like it could be plausible.

It’s like the (fictional) plot device in Jurassic Park where they’ve rendered the dinosaurs deficient in lysine, so they need to be fed lysine in their diets or else they die. Of course, that’s complete nonsense because lysine is an essential amino acid, it can’t be synthesised in the organism, and you have to have it in the diet anyway. But suppose you knock out a non-​​essential amino acid, say, aspartic acid, in an organism such as a pig. Then you would have to include the aspartic acid in the pig’s diet, or it would die. But aspartic acid, and any other biochemical that could fill this role, are simple, well-​​known compounds that could be easily synthesised, and manufactured cheaply and generically by anybody; and not patented or expensively marketed by some corporation. That’s just not plausible, and anyway, this is bringing us back to the derailment of the argument into the big-​​corporations issue.

Another key anti-​​GM argument is the safety argument — something like this: “There is no way we can know what the long turn affects will be. I think scientists are being way overconfident if they can claim it is totally safe.”

Of course, we already have thorough testing and regulation of genetically modified organisms before they’re allowed to be released into the environment, to make sure there’s no way they could be dangerous. That’s why we have government agencies such as the Office of the Gene Technology Regulator. There is already plenty of testing and safety assessment.

Opponents of gene technologies, and so-​​called “environmentalists”, often say there isn’t enough testing, we need more testing, more testing and more testing to be really, really, really sure that there’s no risk.

This is the not uncommon abuse of the precautionary principle: “you can’t prove that it has absolutely zero risk, therefore we shouldn’t do it, no matter what the advantages are”.

However, personally, I think that’s kind of a little bit like saying we should spend millions of dollars running sets of repeated scientific, double-​​blind, randomized placebo-​​controlled clinical trials to investigate if homeopathy works or not.

No, I don’t think we need to bother. The reason for this is quite simple. There is absolutely no possible mechanism that exists, that is even remotely plausible, by which homeopathy could possibly work at all. With that in mind, it’s obvious that there’s no point wasting money on the trial. How could it possibly work!?

A well-​​known and controversial example of an agricultural gene technology was developed in 1991, when researchers developed an experimental genetically engineered variety of tomato that expressed a gene identified in an Arctic flounder. The flounder gene encoded a protein which acts like an antifreeze, preventing the crystallisation of ice within cells, which confers cold resistance to the fish.

The goal was to develop tomato plants that express the “antifreeze” protein in their tissues, and could withstand frost in the field and resist cold damage in storage. This particular experiment, however, was a failure and did not produce frost resistant plants. The half-​​fish-​​half-​​strawberry on the supermarket shelves lives on, however, as a persistent urban legend amongst anti-​​GM activists.

But if such a tomato or a strawberry containing this fish gene was released on the market, would we need to spend huge amounts of money and many years testing it to make sure that it wouldn’t be dangerous?

How could it possibly be dangerous? What possible mechanism of harm, no matter how remotely plausible, could there be? If you eat a fish, you’re eating the fish’s antifreeze protein, and it doesn’t cause any harm. The fish isn’t poisonous, or anything. It’s just an ordinary edible fish.

So, when you eat a strawberry containing the gene that expresses the fish’s antifreeze protein, clearly it won’t cause any harm either. Because there is absolutely no possibly plausible mechanism for harm, why should huge amounts of testing be needed, just so that it can be used as a regulatory impediment by opponents of the technology.

There’s only one small exception to the above argument, however.
Suppose that a person has a very severe allergy to fish, resulting in anaphylaxis if they consume that particular fish. It’s just barely possible that that particular “antifreeze” protein will be the antigen responsible for introducing that allergic response, and therefore, that person could very likely be allergic to these GM fruits, as well. There should be definitely be testing to detect that possibility, to see if a protein like that, if it is present, can introduce an allergic response in people who are allergic to fish, or whatever it is, and if that protein can cause a problem, then the fruit should absolutely be labeled accordingly.

But if you have a very severe allergic reaction to any common food product, then you’ve always got to be careful with any kind of food you eat, and you need to be aware about exactly what is in it, and read the label. It’s just like, for example, wine. It is possible that wine can contain traces of a fish protein in it, in the form of isinglass finings, and it is a legal requirement that that be specified on the label if it is used. It’s the same with a hypothetical GM “anti-​​frost” fruit of this type — it should absolutely be labelled, but not banned.

Another common argument from anti-​​GM activists is that it’s all some kind of big sinister conspiracy by the corporations (again, back to the same thing) to somehow make users of their crop varieties dependent on buying more expensive agrochemicals which that particular company has monopolised control over.

Here are some quotes, which I took verbatim from an internet forum, representing these kinds of anti-​​GM ideas.

“What happens when farmer A starts planting a GM crop which requires herbicide X to be used or it dies, and the crop pollinates farmer B’s crop? Farmer B will be forced to buy herbicide X.”

“Genetically modified crops tend to have other sinister undertones anyway — often they’re pushed just so the company that makes the fertilisers and pesticides (you see that wheat that you could use your locally sourced and biodegradable chemicals on? Well, now that we’re forcing you to buy our wheat, guess what? Only our chemicals will work on it. Sorry they cost 5 times as much and we haven’t really tested out the side effects, and I know they won’t break down in your water supplies, but isn’t it great that you can now farm your crops three times a year, instead of once? Yeah, I know, your soil will lose all its nutrients and be completely unable to support anything but weeds as a result, but shhhh — if you don’t tell anybody we won’t.“

What nonsense. There’s no such thing as a genetically engineered plant that only certain fertilisers work on; all fertilisers are the same.

Pesticides don’t act on a plant, they act on the pests; so again, genetic engineering of a plant has got absolutely nothing to do with pesticides working differently in any way.

Now, a very common well known subset of GM crops being grown today are what is known as “Roundup Ready” varieties, especially of canola plants, which have been developed and marketed by Monsanto.

Glyphosate (“Roundup”, as the brand which is marketed by Monsanto) is a broad-​​spectrum herbicide, meaning that it kills all plants, both weeds and the desirable crop plants. There are also more complex compounds called selective herbicides, which target specific biochemical mechanisms which are different in different species, meaning that only certain species of plants are affected by a particular chemical.

This means that you can use a selective herbicide, and spray it on your field, including both weeds and crop plants, and the weeds die but the crops don’t. Needless to say, selective herbicides such as 2,4-D are very, very useful and widely used in agriculture today.

With the genetically engineered “Roundup Ready” crop varieties, the plant is resistant to glyphosate, since it incorporates a version of a particular enzyme from a bacterium which does the same job as the plant’s natural version of that enzyme, but isn’t inhibited by the glyphosate. What this means is that farmers can just spray the entire field with glyphosate, instead of using a selective herbicide.

Now, glyphosate was originally invented by Monsanto, patented, and sold under their famous brand name, Roundup. However, the Monsanto patent on glyphosate expired nearly 10 years ago, and today, the compound is inexpensively available in generic brands from countless suppliers. Therefore, it’s obvious that the engineered glyphosate resistance in ‘Roundup Ready’ crops clearly can’t be just some kind of money making unethical enterprise for Monsanto, that’s nonsense.

Furthermore, glyphosate is less toxic, and less potentially dangerous in the environment than some commonly used selective herbicides such as atrazine. Increased use of “Roundup Ready” varieties actually leads to decreased use of those herbicides, and increased use of the cheaper, less toxic, and less potentially environmentally problematic glyphosate.

Other than that, all the same herbicides that you normally use on the weeds work in exactly the same way, and you can use plenty of other standard herbicides if you want to kill the crop plant for some reason.

Tags: agriculture, Biology, GM, Monsanto, Science

This entry was posted on Wednesday, June 17th, 2009 at 1:10 pm and is filed under Skeptic. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.