Apr 28 2009

GM Corn

Dr. Paul Christou and colleagues announced in the latest issue of PNAS that they have created a stable genetically modified (GM) version of South African white corn that has enhanced levels of three vitamins:

The transgenic kernels contained 169-fold the normal amount of β-carotene, 6-fold the normal amount of ascorbate, and double the normal amount of folate. Levels of engineered vitamins remained stable at least through to the T3 homozygous generation.

That’s precursors to vitamins A and C, and vitamin B9 respectively.  This is the first time a GM crop has been enhanced with more than one vitamin. The GM corn needs to go through the testing process, however, including animal testing for safety. It will likely be years before this corn is growing in the fields of sub-Saharan Africa – it’s intended target.

Of course – we’re talking about GM food, so there is going to be controversy. I will state my bias up front (i.e. what follows is purely my opinion) – I think genetic modification of crops is a perfectly reasonable technology. It is potentially a powerful tool, and like all the powerful tools science has placed in our hands, it needs to be used with caution. Of course there are risks – just as there are risks with piping explosive gas into our homes, operating nuclear power plants that can melt down, and speeding along highways at 60 mph where one mistake can mean death.

Also – like all such issues, there is hysteria and pseudoscience on both sides. Corporations likely have their eyes more on the potential profits than the potential risk and will tend to oversell claims. While the anti-GM food groups exaggerate risks and downplay benefits.  Somewhere in the middle there is a balance where GM foods can be beneficial, if used with caution. GM opponents serve a useful purpose in forcing governments and corporations to ask the tough questions and raise the bar on safety. But beyond a certain point they become obstructionist, needlessly hampering a useful new technology.


Genetically modifying food involves inserting genes into a plant or animal, typically to give them a trait they currently lack. This type of modification has been done to make crops droubt resistant or pest resistant, and has also been used to increase the nutritional content of food. There are also efforts underway to create a peanut that does not cause allergies. Here is a list of currently available GM crops.

Defenders of GM technology point out that modifying plants and animals by humans has been going on for thousands of years. Just about all the plants we grow and consume have been radically altered from their naturally evolved states. Plants in particular are amenable to hybridization, where genes from one related species can be combined with another.

The analogy is limited, however, because with modern GM technology genes can be taken from a bacteria and inserted into a grain crop.  This type of transfer is actually possible in nature – for example by viral vectors. But with GM technology gene transfer can be immediate and targeted.

Dr. Christou argues that his new GM corn is geared toward the malnourished in poor countries, where many people cannot afford a varied diet. In many parts of the third world people live on a limited number of staple grains, and lack variety in their diets. They are therefore susceptible to vitamin deficiencies. Therefore, enhancing the nutritional value of a staple crop could alleviate much malnutrition.

In Asia, for example, blindness from vitamin A deficiency is common. This has led to the development of so-called golden rice, which has enhanced levels of beta-carotene. Rice can already produce beta-carotene, but only in the husk, not in the consumed part of the rice. By inserting three genes into white rice scientists have turned on the beta-carotene production in the rice grain istelf, giving the rice a golden color.

GM Critics

In the BBC article discussing this new corn, Clare Oxborrow from Friend of the Earth is quoted as the GM skeptic.  It’s important to note that such articles rarely do justice to a person’s complex position, but with that caveat she does raise the typical concerns over GM crops.

Ms Oxborrow said it was “virtually impossible” to contain GM crops and to be sure that all the people eating them were getting the correct dose of what they had been modified to make.

The primary argument of opponents to GM crops is that they are too risky becauses it is impossible to contain them. The new genes they contain may contaminate other crops or wild plants, with unintended consequences. This is a legitimate concern, although it is not clear how much of a risk this really poses. For genes that confer resistance to pests or herbicides I can see why this would be a real concern – we do not want to create super weeds. But for genes that enhance nutritional content it seems that the risk would be quite low. What is the risk from nutritionally-enahanced weeds?

Theoretical risks revolve around unintended consequences, such as creating a crop that has more potential to induce allergies, or affecting the natural food chain. What will the effect be on the animals who eat the weeds that are now modified by GM genes? I think these are good questions, but to me they equal proceeding with caution, not abandoning GM technology.

Oxborrow also plays down the potential benefits of GM crops:

Rather than opt for “expensive, untested and potentially risky GM technofixes”, she said “research efforts would be better placed ensuring that people are able to grow, or otherwise have access to, a diverse range of foods that will give many other health benefits.”

Ms Oxborrow said golden rice, fortified with vitamin A, had been available for many years but was still not widely used or commercialised.

This is a good example of the perfect being the enemy of the good. Sure, wouldn’t it be great if the entire world had access to the variety of food we enjoy in the US and other industrialized nations.  And of course there should be efforts to improve food availability in the third world. But let’s be realistic – there are real-world economical, political, and logistical reasons why there are still billions of people with inadequate access to nutrition in the world, and no one is going to solve these complex problems anytime soon. Nutritionally enhanced staple crops is a partial fix only, but it can significantly improve the situation and reduce diseases of nutritional deficiency that place an even further burden on poor countries.

There are also obstacles to implementing the use of GM crops, such as golden rice. I am actually not sure why it has not been more widely adopted. Perhaps it is resistance to GM foods or the slowness of regulatory agencies. GM critics argue it is simply the greed of corporations, who create GM foods primarily to maintain their monopoly. There is probably some truth to all of these claims, but I have not found a convincingly definitive answer (and would welcome any informative links).

Of note, the Golden Rice Humanitarian Board claims that:

Those who need the product of this new technology most are those who can least afford buying a mixed diet, rich in essential nutrients. This has been taken into consideration by the creators of Golden Rice technology, Professors Peter Beyer and Ingo Portrykus, and the crop protection company Syngenta, who have donated it for humanitarian use in developing countries, free of charge.

Also, Dr. Christou claims:

Dr Christou told BBC News: “Our research is humanitarian in nature and targets impoverished people in developing countries. This specific project is targeted towards sub-Saharan Africa.”

He added: “Our funding is exclusively from public sources so we are not encumbered by any commercial constraints.”

A cynic could argue that this is PR by an industry with a troubled reputation.  Perhaps, but human behavior is rarely one-dimensional. Most corporations engage in charity for the PR benefit, but the people in those corporations also probably have charities they really care about and want to think of themselves as good people and good corporate citizens.

So let the GM food industry engage in a little humanitarian aid, putting their technology primarily to the purpose of enhancing the nutrition of the poor.


The GM controversy is one of those heated topics that I find very challenging to completely wrap my head around. Like recycling, organic farming, and even global warming – the science is complex, the claims made on both sides are complex, and the vast majority of information available to a non-expert like myself seems tainted by bias. I find it hard to get to the bottom.

In the case of GM food I think part of the reason for this is that there really are legitimate points on both side of the issue. Perhaps the risk/benefit is close to the line. Perhaps the technology has not yet advanced enough for the benefits to clearly outweigh the risks or expense.

But I find the concept of GM food to be reasonable, and many of the products that are already on the market seem to have clear advantages and to be commercially viable. This technology has great potential.  I also find that many of the arguments against GM food are ultimately rooted in a visceral reaction against anything artificial or corporate. I find their arguments less compelling and logical. For example, arguing that a more nutritious variety of corn is not a good thing, as Ms. Oxborrow did, seems like ideological advocacy to me and not a reasoned position.

But I acknowledge that my current position on this topic is tentative pending further exploration of the issue.

33 responses so far

33 thoughts on “GM Corn”

  1. medmonkey says:

    I certainly agree that there are potential pitfalls for GM technology, but I fall in the pro-GM camp with less reservation. While those on the anti-GM side tend to provide their guesses at the risks, I’ve always found their claims to be overblown and irrespective of the clear benefits. I found some good science on the topic (DOI link is at the bottom) by the European Food Safety Authority. Their report addresses some of the concerns listed in the blog post such as increased allergenic responses with listed references.

    The authors make a conclusion about post-market monitoring that seems very relevant to this debate.

    “Post-market monitoring (PMM) is not an activity intrinsic to the risk assessment, but could in certain circumstances be considered a part of the subsequent risk management process.”

    Some of the concerns held by anti-GMers, such as creation of the superweed, seem to be relevant to post-market management rather than pre-market risk assessment. The debate should be over how rigorous the regulations should be for pre-market risk assessment for a GM food.

    From the report:
    “PMM does not substitute for a thorough pre-marketing safety testing programme but complements it in order to confirm the pre-market risk assessment. It may increase the probability of detecting rare unintended effects.”

    This comment is in regards to rare effects in humans, but could be applied to consider adverse agricultural effects as well. This debate seems to be similar to anti-vaccinationists who claim that vaccines will inadvertantly create the super-bug that is resistant to everything we can throw at it and will kill us all! Overblown, speculative and with no real way of falsifying.


    Abstract: http://www.ncbi.nlm.nih.gov/pubmed/18328408?log$=activity

  2. This piece brings to mind one of my scientific ‘heroes’, Norman Borlaug. Those unfamiliar with him can fix that here:


  3. HHC says:

    Genetically modified corn is useful. But mold effects corn and can be deadly to inhabitants. Ohio State University has studied some of the deadlier molds on corn and identified them. Safety is a factor in corn production and consumption .

  4. Fred Cunningham says:

    I think that GM has the potential of having one of the most profound benefits to man. Neurotoxin free grass peas (lathyrus sativus) that more closely resemble native varieties would be great in impoverished drought areas. In addition to better food crops, it is possible to develop plants that remove and sequester undesirable chemicals from soil making food crops on such soil possible. An dual benefit example is a tomato that extracts salt and can make the soil usable for other crops. Current research hardly scratches the surface of what will be possible. Maybe veggies that all kids will like.

  5. synapse says:

    Do people in sub-Saharan Africa eat corn? In many parts of the world, corn is grown as animal feed, not for human consumption.

    OK, hmm. The article mentions that in South Africa, white corn, which is beta-carotene-deficient, is eaten by people, while relatively beta-carotene-enriched yellow corn is given to animals. Will the target consumers accept eating yellow (actually, almost orange) corn? I recall that this was one of the issues with the golden rice as well- rice is not “supposed” to be yellow, so consumers were wary of eating it.

  6. Smed says:

    I too have little knowledge of genetically modifying crops, but I recently read an essay by Barbara Kingsolver (http://www.organicconsumers.org/gefood/SmallWonders.cfm) and I am curious about her claims.

    Her primary concern is that genetic engineering would remove genetic diversity from crops, which is what she claims was the cause of the 1970 corn disease disaster.

    The part I have a hard time believing is how GM would prevent genetic diversity (aside from the few genes being inserted). Aren’t the crops still being grown by pollinating seeds which would allow for genetic drift?

    If anyone has time to read the essay, I would appreciate an insightful response.


  7. triptik says:

    It’s been a few years since I followed up on this topic, but when I was in university I did quite a bit of research on GM crops (and genetic engineering in general) for an ethics class. This must have been 2002/2003ish.

    My impression was, at the time, that most of the resistance was political. “Activists” burning test fields in Europe, Greenpeace and company spreading panic over the dangers of “Frankenfoods”, and general suspicion in poor nations that The West was trying to pull one over on them. The scientists were mostly saying, “We can’t prove there is no risk, but we aren’t seeing much risk,” which just doesn’t have the punch that “omg GM crops cause cancer well all die” carries.

    There had been a recent controversy over disease-resistant grain, grown in the US, that had been shipped to someplace in Africa or Asia as part of an aid program. The grain was left sitting (undistributed), and then was eventually refused, because of suspicion by the local government that the GM grain was sent because it was dangerous and the Americans didn’t want to eat it. I don’t have the exact reference now, but this may be what I am remembering: http://www.un.org/ecosocdev/geninfo/afrec/vol16no4/164food2.htm

    I have heard of similar controversies over getting drought-resistant seed into the hands of local farmers. Governments were suspicious that the corporations just wanted to use them as labs. With the track record of some of these companies, I can sympathize, but that doesn’t invalidate the technology.

    Monsanto and its competitors weren’t helping things, either. One particularly poor mistake was when the GM grain from some test fields was harvested and processed along with grain from normal production fields. All the grain from one processing facility had to be destroyed so that it wouldn’t enter the US food supply. Mistakes like that just make people more wary.

    We’ve also been in a period of up and down anti-American sentiment in many parts of the world. For better or worse, the biggest name in GM is Monsanto, the very image of an American corporation (pushy, greedy).

    Until something shakes loose, politically, it will remain a very difficult thing to get GM seeds into the hands of people who can truly benefit from them.

    Still, I’m glad there are companies working on it. The more data, the more years of experience, the more we know about the risks, and the better decision we can make.

  8. Ian Willmore says:

    Another interesting and lucid post. I essentially agree with your analysis. I would add two points:

  9. Ian Willmore says:

    Another interesting and lucid post. I essentially agree with your analysis, but would add two observations.

    1. The first GM crops intended for introduction into the UK market were intended to be pesticide resistant, e.g. to Monsanto’s Round-Up pesticide. Monsanto and other firms marketed their product and lobbied for Government support in a remarkably arrogant and stupid way and were duly trounced by a rather effective campaign by green groups.

    2. There were – and may still be, although I am now out of touch with the issue to some degree – reasonable concerns about what the early GM crops would do to farming practice, i.e. increase intensity and damage biodiversity. They certainly appeared to represent a move away from green policy in relation to agriculture, which is a strong reason why green groups campaigned against them.

    My qualifications for writing this post are: scientific – nil; political and environmental – I was the head of media for Friends of the Earth in the UK during the height of our anti-GM campaign and so do know something about its motivations, tactics and impact.

    Perhaps this post is either the arrogance of ignorance, or an appeal to authority. You choose!

  10. Karl Withakay says:

    Ian Willmore,
    A minor correction, Round-Up is an herbicide, not an pesticide.

    It is specifically a broad spectrum, glyphosphate based herbicide. Monsanto Round-Up ready GM corn is glyphosphate herbicide resistant.

  11. Ian Willmore says:

    Quite right, shows that it’s a while since I worked on this issue, sorry. Of course herbicide resistant crops raised biodiversity concerns. Obviously arrogance of ignorance …

  12. Regarding biodiversity – the concern is that everyone will start using a high-yield or otherwise desirable GM crop and give up their local variety, thereby decreasing biodiversity. This is a legit claim, IMHO.

    I think the answer is that we need to GM smart – add the gene to a hundred local varieties of tomatoes, not just one. Of course, this is more work and investment.

  13. Ian Willmore says:

    That’s certainly one concern, one other in respect of early GM crops was more intensive use of herbicides, leading to monocultural fields, leading in turn to loss of species diversity. I think there was at least some evidence of this from early Government-backed trials.

  14. TheBlackCat says:

    @ triptik: I am in the same boat as you. I, too, did a research project on GM crops for a science ethics class in university and arrived at very similar conclusions to you. There are, of course, dangers if you behave stupidly, but as Steve said there are such dangers with everything. Many of the opposition claims are misleading or grossly overblown and some border on hysteria. In the end the claims seem to boil down to “we don’t know everything, therefore we should do nothing”.

    One classic example is the claim that pollen from GM crops in field caused a small increase in deaths of monarch butterfly caterpillars on milkweed plants along the edge of the field. The claim is highly suspect itself. But even if it is true, if the growers weren’t using GM crops they would be spraying insecticide, which would have killed all the caterpillars and additionally would have killed many more insects much farther away. So they paint it as though the GM crops are bad, when in reality they were much, much better than the alternative. That is a claim I consider highly misleading, but the anti-GM crop groups were promoting it heavily.

    I also find their claims about the lack of successful experiments with GM crops, particular in Europe, highly misleading considering they have a habit of burning experimental GM fields whenever the experiments seem to be going well.

    And I do not agree the biodiversity issue is legitimate. Our modern agricultural system is already based on a very small number of breeds of each crop developed over the last century through traditional selective breeding enhanced through knowledge of Mendelian inheritance. This was the so-called “green revolution”. So the whole argument is based on a false premise: that there is much biodiversity in non-GM crops to begin with. That is one of the reasons for these seed banks, even without GM crops the small number of selectively bred crops have rapidly displaced the much wider variety of local breeds and those local breeds are rapidly disappearing.

    As for yellow rice, I remember reading about that a while back. The scientist who developed it did so thinking he was using entirely free techniques, trying hard to avoid any patented processes or genes, specifically so he could give it away. He screwed up, missed a patent, but he was able to negotiate with the company owning the patent to allow him to give it away in developing countries in return for, if I recall correctly, exclusive rights in developed countries. The claim that it is just PR is totally bogus. I remember reading about yellow rice when it was first being developed, before the patent issues came to light. That was his stated goal at the time, not something they tacked on retroactively.

  15. BlackCat – you are correct that the lack of biodiversity is a generic problem with modern agriculture not specific to GM. If a crop developed with old-school cultivation is cost effective enough it too will displace local varieties. I did not mean to suggest this was a GM problem, but successful GM crops may exacerbate it.

    But lack of biodiversity is a real problem, in my opinion. Look at the banana – we have already lost one crop (Gro Michele) about 80 years ago to a fungal blight, and now the current banana variety (cavendish) is threatened by the same fungus and will likely be wiped out (not extinct, just no longer viable as a commercial crop).

    It does not make sense to have all our agricultural eggs in a few baskets – that’s a ticking time bomb. We should, in my opinion, use GM technology and cultivation to increase biodiversity, by giving favorable traits to many local varieties so that super crops won’t displace them. The seed bank is also a good idea, but it takes time to develop a new crop for massive planting.

  16. weing says:

    You can still get Big Mike bananas in Jamaica, I’m told. That’s going to be my next vacation.

  17. TheBlackCat says:

    @ Steve: I agree completely. The loss of crop biodiversity is a serious problem.

    My issue is with people who present this is a problem specific to GM crops when it is a problem throughout our agricultural system. It is another one of the misleading anti-GM arguments you see, where they criticize GM crops but conveniently leave out the fact that the alternatives are just as bad if not worse.

  18. Quokka says:

    I think some may be overstating the biodiversity problem. As an example; canola was first grown in Western Australia in the 1980’s, and we had access to one or two varieties. several years of good production followed before the blackleg virus spread which pretty much saw canola disappear from the region. It wasn’t until the 1990’s that blackleg resistant varieties started to be developed, along with many other agronomic features that have greatly increased diversity in what we can now plant. We now have over 25 different oilseed varieties being grown, some of these differ greatly from each other.

    This year Roundup Ready canola is being grown for the first time in Western Australia; if it proves to be as successful as some research predicts, it will most likely be the dominant variety grown and nearly all of the other varieties will become redundant. So (like Canada and the U.S.) we are likely to see a reduction in canola biodiversity; but this will hopefully be followed by breeding programs that will give us as much choice or more than we have now. It will be even quicker once some of Monsanto’s and other’s patents start to expire.

    A great trait of GM crops is that we can insert favourable genes into the large range of diversity that we already have.

  19. relativitydrive says:

    I like Steve’s conclusions but feel that the population control approach to economic and social issues was missed completely as it’s an important part of a discussion such as this.


  20. kwakley says:

    A problem that’s often forgotten with regards to GM in developing countries is that the poorest farmers in these countries are subsistence farmers.

    They grow their crop, sell some, eat some, and keep a certain amount of the seed to plant the following year.

    As I understand it the seeds produced in a GM harvest are infertile, to ensure that seed sales continue year on year (where else are the developers of the seeds to get an income?). Can a subsistence farmer afford to buy seed each year?

    This will effect those people said to be those with most to gain from GM.

  21. Karl Withakay says:

    I can’t speak about all GM crops, but that is not true of Monsanto GM corn. Monsanto has filed numerous lawsuits against farmers who violate their contracts and “save seed” for replanting.

    Monsanto requires any purchasers/end users of their GM crop seeds to sign a contract stipulating that they will not save any seed from their GM crop for replanting. That is how they sustain their GM seed income year to year.

    I can only guess that it would be difficult to produce fertile GM seeds that did not produce fertile seeds themselves, not to mention it would likely not be economically viable to do so. Monsanto does not “manufacture” each seed they sell. They engineered the crop variety but produce the seeds conventionally, on a farm through harvesting GM crops for seed.

  22. TheBlackCat says:

    @ kwakley: I agree with you on that. That, as far as I see it, is the main legitimate problem with GM crops (assuming people don’t act stupidly with GM technology).

    I see three ways to overcome this:

    1. Do what yellow rice did and convince the company to let you give it to the poor for free.What

    2. Develop a single, effective GM technique that is fully free of patents and patents every step the process, then sign the patents over to a humanitarian organization to that can use them to provide free GM crops to the poor and charge wealthier countries to keep itself self-sufficient. If any fundamental steps are patented, either acquire the patents or get the company to join your group and sign a contract not to sue the group or anyone working under it.

    3. Do what Linux did with the patent commons project (http://www.patent-commons.org/), where they basically acquired some key, absolutely essential patents that they promise to use only to defend open-source software against other patent attacks. Basically the idea is that you acquire some patents that all GM crops absolutely require, and if anyone tries to stop you from infringing in their patents you sue them into oblivion for infringing on yours. Otherwise you just do whatever you want and ignore everyone else.

  23. sonic says:

    We know that the GM genes will show up in plants miles from the original planting.

    Two problems-
    1- If the GM gene turns out to have bad effects, how do you do a clean-up? (Understand some people still believe there is ‘junk’ DNA- to give you some idea of the ignorance in the field)

    2- If the gene shows up on my property Monsanto can charge me a fee for using their plant. Eventually everyone with a plant on their property will owe a fee to the seed company.

    So the real question is this, do you but the stock of a company like that?

    (An interesting side note- there is one place you can buy food that is for certain non-GMO. It’s the Monsanto cafeteria!)

  24. Sonic,

    Regarding #1 – that junk DNA exists is still the dominant opinion supported by the evidence. Some junk DNA has been found to have a function – but only a tiny minority. Since the ID folks have been bringing this up, I will probably do a full post on it soon, but meanwhile here is Moran’s take: http://sandwalk.blogspot.com/2009/03/casey-luskin-on-junk-dna-and-junk-rna.html

    Regarding #2 – This is a legal issue with legal solutions. New technology often challenges existing regulations. Corporations are likely to push their rights, but farmers, consumers, and countries can push theirs. Regulations will catch up.

    For example – pass laws that state that if a GM gene finds its way into your crops, you are free to use it. Or – it the company wants you do stop using their gene, they have to buy you the seed in exchange for the ones with their gene.

    Someone else brought up the issue of farmers having to buy seed each year. Well, if the government wants farmers to use more expensive GM crops to improve nutrition – then subsidize the purchase of the seed.

    Also, patents on GM crops are limited, so eventually they will be public domain.

    I just don’t buy – evil corporations have all the power – arguments.

  25. daedalus2u says:

    I think the case that Sonic is refering to is the case in Canada where a farmer claimed that the Round-up resistent canola in his fields was due to exposure to pollon from fields that were miles away. Monsanto sued him and won. It was very convincingly demonstrated in court that the canola he had could not have been derived solely from pollon contamination of a non-resistant population. The crops he was growing were almost pure homozygous resistant. By hybridizing resistant and non-resistant populations (as by pollon transfer) you first get heterozygous plants and then a fixed percentage (25%) of homozygous plants in their descendents. This is not what was observed. The farmer was lying about what happened. Anti-GM activists preferred to believe his obvious lies because of their beliefs.

    If you find resistant plants on your farm, if you call Monsanto they will come and remove them.

  26. obxneil says:

    A terrific story about historical and current international efforts at establishing a global seed bank coupled with a history of the rise of monoculture in our food supply, by John Seabrook, “Sowing for Apocalypse,” originally appeared in The New Yorker, but can be found in The Best American Science Writing 2008, edited by Sylvia Nasar.
    I did a paper on GM foods for Biology this past year, much to the chagrin of my professor (I got a 100 on it, however, and she loved it: she was delighted I wasn’t a rabid, crunchy enviromentalist, just a sensible one.)
    My conclusions were that the most touted genetic fears are the result of a dismal illiteracy regarding biology (big surprise, eh?), and the real concerns I have hardly ever hear mentioned.
    I’m most concerned that plants bred for resistance to herb- and pesticides allow the drastic over-application of them, and even in the most developed countries agricultural water-management of runoff is dismal. GM foods like those mentioned exacerbate already irresponsible, and very consequential behavior.
    As for loss of biodiversity, if you set aside a patch of your backyard to grow food, you’ve just reduced biodiversity in that patch. It’s the inevitable tradeoff when we feed ourselves, and I’ll always err on the side of keeping people alive, and free from misery.
    That said, even with the worrying increase in monoculture, the green revolution has allowed us to feed far more people with relatively little increase in arable land, so it potentially allows the conservation of native ecosystems. Now, what a country does with that potential is an issue of policy, and while we all have opinions about what other countries should do, I’d advise we each cast an eye towards our own countries, and notice how much, or little, our own houses are in order.
    I failed to find any evidence that engineering food crops in any way increases the potential for a dangerous mutation (though it does increase the ignorance of what kind of mutation could occur: add brand new genes and you have a whole new, astronomical realm of combinations to consider.) Your traditionally hybridized beefsteak tomato could start producing many times more carcinogenic compunds tomorrow, or evolve to host a lethal virus, or evolve herbicide restitance all on its own. It’s a crap shoot whether the genes it’s working with are all its own, or it has a few new ones from somewhere else.
    As for superweeds, if you can engineer a resistance to an herbicide, you can certainly engineer a susceptibility to another one. It would be nice to see policy in place requiring such a foresightful trade-off.
    Lastly, my biggest concern is the lack of any real international policy, or body with oversight over GM foods. We currently possess an ad hoc of varying regulations from country to country. This leads me to a two-fold concern:
    1) That just in case the worst-case scenario happens, there’s no entity to monitor, identify, and coordinate efforts to stop, and amend the scenario (I leave it to you to dream up your own nightmare. Those with some scientific background or education can usually far outstrip the illiterate in dreaming up horror. Whatever evolves, I propose it immediately be named the Triffid Scenario.)
    2) That same nonexistent body could also be used to use the power of science to combat threats from the natural world. Uganada-99 is still spreading, yet no GM crop has arisen to replace the wheat susceptible to, and devestated by the blight 10 years later. An international body might have the leverage to encourage swift investment into research to support a more humanitarian effort, instead of a purely commercial one. I nominate myself for president.

  27. Ian Willmore says:

    I went back and checked the early UK Government research reports on GM crops, which do bear out my suggestion that there were concerns about some early herbicide resistant GM crops and their effects on biodiversity, but also show that these concerns arise because of changes in argicultural practice, rather than from the character of the crops themselves. Therefore, I suggest the research would tend to bear out Dr Novella’s argument that risks and benefits need to be assessed on a case by case basis, rather than adopting an ideological position opposing (or promoting) GM crops on principle.

    “Managing GM crops with herbicides: Effects on farmland wildlife”

    “In the largest ever field trials of GM crops in the world, the researchers compared GM and conventional varieties of four crops. The crops were winter-sown oilseed rape, spring-sown oilseed rape, beet and maize. The GM crops had been genetically modified to make them resistant to specific
    herbicides; they are called herbicide-tolerant (GMHT).

    In 2003, the team reported that there were differences in the abundance of wildlife between GMHT and conventional spring rape, beet and maize. New results show that there were also differences for winter rape, and these are broadly consistent with those for spring rape and beet.

    Growing conventional beet and spring rape was better for many groups of wildlife than growing GMHT beet and spring rape. There were more insects, such as butterflies and bees, in and around the conventional crops because there were more weeds to provide food and shelter. There were also more weed seeds in conventional beet and spring rape crops than in
    their GM counterparts. Weed seeds are important in the diets of some animals, particularly farmland birds.

    In contrast, growing GMHT maize was better for many groups of wildlife than conventional maize. There were more weeds in and around the GMHT crops, more butterflies and bees around at certain times of the year, and more weed seeds.

    Growing GMHT winter rape resulted in the same number of weeds as in the conventional crops. However, in the GM crops, there were fewer broad-leaved, flowering weeds that are especially beneficial for wildlife, and there were more grass weeds. There were also fewer bees and butterflies. But there were no marked differences in overall numbers of
    other insects, slugs and spiders.

    The researchers stress that the differences they found do not arise because the crops have been genetically modified. They arise because these GM crops give farmers new options for weed control. That is, they use different herbicides and apply them differently.

    The results of this study suggest that growing such GM crops could have implications for wider farmland biodiversity.”

  28. obxneil says:

    Terrific response, Ian. Highlights the need for thoughtful policy, and tremendous investment in research and education needed to both fully exploit the benefits of GM crops, and minimize any risks or damaging effects, or practices.

    This post got me thinking in a more science-fictional vein about the potentials inherent in modifying organisms, and the incalculable, hence profitless, benefits that we could accrue from applying principles we routinely use almost exclusively for food and decorative plants.

    Say, engineering trees that more efficiently capture CO2, and at increased volumes in the species we use for lumber and paper farms. Wouldn’t be a bad idea to do that with Christmas tree species either.

    I wonder what could be done to help out with endangered species. Perhaps increasing the birth rate, or engineering adaptations to a changing environment.

    Bacteria to break down poisonous heavy metals (which already exist in the wild) could be engineered to be inserted into non-native environments, say…landfills.

    Any thoughts?

  29. mindme says:

    Sonic, regarding junk DNA there’s a thing called The Onion Test. An onion has a larger genome than the human being. If you think your “all junk dna is functional” hypothesis can explain why an onion needs such a large genome, well, have at it.


  30. daedalus2u says:

    Onions are autotrophs. All they need to survive is light, water, CO2, O2 and minerals. Everything else they can synthesize. The metabolism to synthesize all of those compounds that heterotrophs derive by consuming other organisms requires a higher overhead of enzymes which must be coded for by DNA.

    A lot of what is called “junk” DNA is highly conserved, from fish to mammals. No one is quite sure what it is doing, but for it to be conserved for so long it is very likely doing something.

  31. TheBlackCat says:

    I wouldn’t suggest using GM for anything intended to be released into the wild except for very rate situations (primarily organisms for cleaning up dangerous chemicals like oil spills or superfund sites). I think genetically modifying endangered species is extremely dangerous.

  32. s says:

    There are several animal studies indicating potential GM maize toxicity on liver, kidney, pancreas, gut etc. Thus raising concerns about human safety.

    A number of these are reviewed in “Risk assessment of genetically modified crops for nutrition and health”(Nutrition Reviews 67(1):1-16, 2009, http://www3.interscience.wiley.com/cgi-bin/fulltext/121580373/HTMLSTART)

    To exemplify some quotes from various research follows:

    “We observed that after the consumption of MON863, rats showed slight but dose-related significant variations in growth for both sexes, resulting in 3.3% decrease in weight for males and 3.7% increase for females. Chemistry measurements reveal signs of hepatorenal toxicity, marked also by differential sensitivities in males and females. Triglycerides increased by 24–40% in females (either at week 14, dose 11% or at week 5, dose 33%, respectively)…” (New Analysis of a Rat Feeding Study with a Genetically Modified Maize Reveals Signs of Hepatorenal Toxicity,


    “The GM, but not the non-GM, diet induced zymogen-granule depletion after 15 days feeding, returning to normal levels after 30 days (P

  33. s says:

    Missed the less tha sign that cuts the text. Here follows the rest of my post.


    “The GM, but not the non-GM, diet induced zymogen-granule depletion after 15 days feeding, returning to normal levels after 30 days (P [less than sign] 0.05). Acinar disorganization started as early as 5 days after initiation of the GM diet and it recovered after 30 days. Levels of PAP mRNA significantly increased in the GM diet between day 1 and day 3 and decreased to the basal level by day 15. Trypsinogen mRNA peaked at two different times; at day 1 and at day 15, decreasing to basal levels after 30 days. Plasma amylase levels remained unchanged at all times. This indicates that GM soy protein intake affected pancreas function,..” (Pancreatic response of rats fed genetically modified soybean, http://www3.interscience.wiley.com/journal/117352162/abstract)

    Then there is the question of business practices: http://www.dailymail.co.uk/news/worldnews/article-1082559/The-GM-genocide-Thousands-Indian-farmers-committing-suicide-using-genetically-modified-crops.html

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