GMOs and the skeptic movement

Genetically Modified Organisms, or GMOs, are a hot topic of controversy in the public arena, just like vaccines, or climate change. Public defenders of science, what are often referred to as “skeptics” (among whom I count myself), have taken sides on all these issues, trying to do their best to bring some sanity and evidence-based clarity to bear upon them. The problem is that while it is beyond doubt that vaccines do not, in fact, cause autism; and it is also pretty darn clear that human beings do, at the least in part, cause global warming; the thing about GMOs is slightly more complex. Make that a lot more complex.

The New York Times gets into the fray

The latest round got started with an in-depth article published by the New York Times and penned by Danny Hakim. It begins by acknowledging that to date there is no evidence at all that GMO technology is directly dangerous to human health, contra the standard — entirely unsubstantiated — position of many environmentalists. What, then, is the problem? Hakim suggests that there is another, hitherto largely ignored, issue: contra to industry hype, the use of genetically modified organisms has brought neither a substantial increase in yield, nor a significant reduction in the use of pesticides.

Well, that ought to be a matter pretty easy to settle empirically, yes? Not exactly. It is difficult to make sensible comparisons, because there haven’t been large scale controlled experiments set up to do so (other than the small trials conducted by the industry itself). So Hakim hit on an interesting idea: noting that the US and Canada opted for GMO technology while Europe rejected it, and noting also that the two blocks are both large, Western, advanced technological societies, why not compare them in terms of GMO and non-GMO yield and pesticide use? While far from perfect (again, it’s not a controlled experiment, more like a “natural” one, made possible by circumstances, not planning), such a comparison could prove informative.

The New York Times piece presents the results separately for the two issues: yield and pesticide use. Beginning then with the former, three graphs published in the article summarize the findings for rapeseed, corn, and sugar beet. In both the cases of rapeseed and corn, the lines plotting increased yield in North America vs Western Europe are exactly parallel, with no inflection upwards of the North American data after the introduction of GMOs, as it would be expected. For sugar beet, European (non-GMO) yield has actually grown faster than its North American counterpart.

Hakim also mentions independent reports bearing on the same issue: “[a] National Academy of Sciences report found that ‘there was little evidence’ that the introduction of genetically modified crops in the United States had led to yield gains.”

What about pesticides? Here the NYT article compares the US with France, the latter being Europe’s largest producer. France’s use of pesticides has fallen significantly in all categories, while the situation in the US is, again, more complicated: according to data from the US Geological Survey, the use of chemicals aimed at fungi and insects has fallen (like in France), but that of herbicides has increased by about 21% (unlike what happened in France).

Why is this a problem? Well, because pesticides enter our food chain, and are known to be highly deleterious to human health. The NYT piece reports a comment by David Bellinger, a professor at the Harvard University School of Public Health, “whose research has attributed the loss of nearly 17 million I.Q. points among American children 5 years old and under to one class of insecticides.” (I’m not sure it makes a lot of sense to cumulate I.Q. points within a population, but the figure would be troublesome even if more properly expressed as average loss per child.)

Hakim — who did get an entirely perfunctory and obviously unconvincing response from Monsanto — went on to point out a possible nefarious background: “The industry is winning on both ends — because the same companies make and sell both the genetically modified plants and the poisons. Driven by these sales, the combined market capitalizations of Monsanto, the largest seed company, and Syngenta, the Swiss pesticide giant, have grown more than sixfold in the last decade and a half. The two companies are separately involved in merger agreements that would lift their new combined values to more than $100 billion each.” (Bear this detail in mind, it will be challenged below.)

The NYT is careful to remind its readers that Monsanto did, in fact, promise a reduction in herbicides as a result of adopting its technology, back in 1994, as reported then by the Los Angeles Times. What happened instead was predictable, says the article: “The whole point of engineering bug-resistant plants ‘was to reduce insecticide use, and it did,’ said Joseph Kovach, a retired Ohio State University researcher who studied the environmental risks of pesticides. But the goal of herbicide-resistant seeds was to ‘sell more product,’ he said — more herbicide.”

Another predictable outcome — from a straightforward evolutionary biological perspective — is that weeds are becoming resistant to Roundup, the main herbicide liberally sprinkled on GMO crops that can withstand the poison. Monsanto is developing an alternative, which hasn’t been approved for commercial use yet, though that hasn’t stopped the company from beginning to sell to farmers seeds that are resistant to it.

Hakim continues his article by directly comparing the case stories of two farmers, Bo Stone in North Carolina, and Arnaud Rousseau in France. The first one uses GMOs, the second one doesn’t. The two plant identically looking corn seeds, but Stone spends $153 per 50,000-seed bag, while Rousseau spends only $85. Why does Stone continue to use GMO seeds, then? Because once you bought into the system it isn’t  easy to do without, as genetic modifications cannot be purchased a la carte, but only in whatever combination the biotech companies sell them. Interestingly, Rousseau would like to have access to the same technology that Stone can use, because he has the feeling that his work would be easier (both farmers have seen increases in their yield over the years).

The issue of yield, however, does not concern just the profits of individuals farmers. As the NYT says: “With the world’s population expected to reach nearly 10 billion by 2050, Monsanto has long held out its products as a way ‘to help meet the food demands of these added billions,’ as it said in a 1995 statement. That remains an industry mantra.” (This is a second point to keep in mind before we turn to the critical analysis.) Indeed, the NYT comparison of US regional data with those from seven European nations (including the two largest producers, France and Germany) shows no broad yield advantage of GMO crops. Jack Heinemann, from the University of Canterbury in New Zealand, who has used UN data to make the comparison, is quoted as saying “Western Europe hasn’t been penalized in any way for not making genetic engineering one of its biotechnology choices.”

Steve Novella responds

My friend and fellow skeptic Steve Novella immediately published a response to the New York Time article, blasting it as “a hack piece with a biased narrative.” I knew that Steve had written before in defense of GMO technology, though I thought his defense was aimed at the sort of unfounded fears about food safety that the NYT begins its article dismissing. I also know Steve as a highly informed, seasoned skeptic, who is not prone to outbursts, so I was curious to dig more deeply into his unusually worded response. In this case, and with all due respect to Steve (I do respect him, a lot), I was disappointed.

The very first sentence of Steve’s piece is a handbook example of poisoning the well (a logical fallacy): “It is unfortunate that so many journalists begin with a narrative and then back fill the facts and points necessary to tell their narrative.” I wonder how he knows this, since he presumably does not have access to Hakim’s mind and intentions, nor does the NYT have a history of anti-GMO crusading.

Steve’s first actual target is Hakim’s claim that GMO technology has failed to deliver on two of its crucial promises: increased yield and lower use of herbicides. “Wrong. This is a very common anti-GMO trope. Genetic modification is a tool, and is not inherently tied in any way to the two currently most common applications, herbicide resistance and pest resistance.” This makes little sense in light of the fact — as clearly substantiated in the NYT article — that GMO companies made precisely those promises, very clearly, and very early on, presumably in order to gain both public support and regulatory approval. It is therefore perfectly legitimate to ask where we stand on both counts about twenty years after the introduction of such technologies.

Steve continues: “The promise of genetic modification, rather, is that it provides a tool for agricultural scientists to make more rapid and more specific changes to crop cultivars. The technology has completely fulfilled that promise. The technology works, it is safe with no demonstrable inherent risks.” Again, this is a rather strange way to put it. No, the promise of GMOs is not just to provide agricultural scientists with faster ways to change crops, it is to make life better for the farmers and the public at large. And yes, the technology works when “works” is narrowly defined, but whether it has delivered on its broader, and most important, promises, is very much at issue. (Keep in mind once again, that we are not talking about food safety here, since Hakim, Novella and I all agree that, so far, there is no issue there.)

Steve’s criticism gains more traction a bit later on, when he mentions that the NYT has used UN data (and other sources, actually, including the US Geological Survey) to make its own comparisons. The NYT article, Steve correctly says, is not a peer reviewed piece. Well, yes, but investigative journalism means just that: to gather evidence and analyze it critically. One can quibble with the specific methods used, but it is a questionable move to reject some conclusions on the only  ground that a newspaper article is not a peer reviewed technical paper.

At any rate, Steve immediately provides his readers with two actual peer reviewed papers to counter the NYT claims. The first one, a meta-analysis of a large number of studies, published in PLOS One, found that “on average, GM technology adoption has reduced chemical pesticide use by 37%, increased crop yields by 22%, and increased farmer profits by 68%. Yield gains and pesticide reductions are larger for insect-resistant crops than for herbicide-tolerant crops. Yield and profit gains are higher in developing countries than in developed countries.” These conclusions do seem in direct contradiction of the NYT ones, but of course we need to remember that they are actually about different things, since the NYT comparison was only for the semi-controlled “experiment” provided by North America and Western Europe, while the PLOS One paper mixes developed and developing countries.

[As a side note, even the paper cited by Steve agrees that yield gains have been far lower for developed countries. This may mean, for instance, that it makes more sense for developing rather than for developed countries to switch to GMOs, given the other environmental and labor practice issues involved. But this sort of middle-of-the-road approach wouldn’t satisfy either supporters or critics of the technology, of course.]

Moreover, a superficial analysis of the PLOS One paper reveals a few problems of its own. (I told you: it’s complicated!) If you read the Materials and Methods section, you discover that the majority of the sources on which the meta-analysis was carried out are not peer reviewed. This is a big problem by Steve’s own standards, and indeed a rather unusual modus operandi on the part of the authors. Their justification for this unorthodox move isn’t particularly convincing: they claim that, first, it is actually difficult to separate peer reviewed papers from much of the “grey” literature, like non-peer reviewed contributions to conferences, governmental and non-governmental reports, and the like. Second, they say that “studies without peer review also influence the public and policy debate on GM crops; ignoring them completely would be short-sighted.”

The first reason is news to me. It is actually very clear what the difference is between peer and non-peer reviewed publications, it just takes a bit more effort to double check individual entries. But it is the second purported reason that is truly astonishing: sure, non-peer reviewed sources probably do have more sway on public opinion than technical papers, but the goal of the meta-review was not to assess influences on public opinion, it was to uncover empirical data concerning research questions. None of the above invalidates the PLOS One study, but it does mean that one ought to proceed with caution.

The second peer reviewed article cited by Steve appeared in GM Crops & Food, and concludes that there have been significant gains for farmers in the adoption of GMOs, mostly as a result of increased yield. Again, though, this isn’t really comparable to the NYT data, because of the issue mentioned above: the latter is a somewhat controlled comparison of similar economies that have and have not adopted GMOs, while the former is based on data from a mix of countries with very different economic and political situations.

Moreover, a bit of digging around reveals a few potential anomalies in this second paper as well. First off, the journal itself publishes a mix of research and policy papers, which is somewhat odd for a scientific publication. It looks more like an advocacy journal than a standard academic one. Second, the specific paper cited by Steve was funded by, you guessed it!, Monsanto. This in and of itself doesn’t disqualify it as a source, of course, but it is a pretty well established fact that industry-funded studies (for instance, in the pharmaceutical field) tend to find about one third more results positive for the industry that shelled the money, when compared to government-funded studies. Given the huge public controversy, and the large profits, involved in the GMO debate, one might, once more, want to be cautious.

Next, somewhat puzzlingly, Steve claims that “Hakim reproduces a common anti-GMO trope to combine Bt crops with herbicide resistant crops — two completely different applications.” But in fact Hakim does no such thing. The NYT article very clearly distinguishes the two, acknowledges that the use of insecticides has gone down in post-GMO USA, and then focuses on herbicides.

About the latter, Steve writes: “Hakim fails to point out that while glyphosate use has increased, it has replaced applications of much more toxic herbicides. If you measure only tons of herbicide you miss the point that overall herbicide toxicity has dramatically decreased, because glyphosate (despite claims of anti-GMO activists) is a very benign chemical.” Well, again, not exactly. The NYT article actually presents a very clear graph where the different kinds of herbicides are distinguished. Moreover, glyphosate may very well be “very benign,” but it is also by far the smallest contributor to the total in the graph.

Steve goes on accusing Hakim of a rather important imprecision: “Monsanto” is actually two companies, he says, one dealing with the chemicals, the other with the seeds, thus implying that the conflict of interest highlighted by Hakim is unfounded. But if you go on Monsanto’s own web site you will find a different, and more complicated (once more!) story, distinguishing between an “original” and a “new” Monsanto. The original Monsanto merged with Pharmacia back in 2000, and in the same year the new Monsanto was incorporated as a stand-alone company, which, however, is actually a subsidiary of the chemical one. So, it doesn’t look to me like the two Monsantos are really that distinct from each other, the maneuver probably having been carried out for tax benefits, shareholders short term profits, or both, as it is standard (and legal) for multinational corporations.

The last part of Steve’s critique of Hakim’s article begins thus: “I also reject the entire deeper premise of the article, that we should judge a technology by its current and early applications.” Well, much depends, of course, on what “early” means. Is twenty years not enough, especially when many billions of dollars and people’s livelihood are at stake?

Steve uses a couple of analogies to make his point, both flawed, I think. The first one concerns the human genome project, which he points out hasn’t cured any major human disease, contra to the hype that helped promote the original effort. Right, but the human genome project was largely an exercise in basic science, and it was funded as such, not because it promised to cure cancer (the National Science Foundation, for instance, clearly separates the actual immediate scientific merits that justify funding a given project from the possible “broader impact” of the same project). Similarly, Steve is right when he says that GMO technology per se has been successful as basic science, i.e., as a technique for experimental use. But that’s not what the controversy is about. The discussion concerns the use that the industry has made of that technology, therefore judgment very much needs to include a consideration of whether what the industry promised has been delivered or not.

The second example brought up by Steve is that of personal computers: “One might have argued (and many people did) even into the 1990s that computers did not improve productivity. They did not reduce use of paper (remember that one – the paperless office).” No, they didn’t, but I adopted personal computers at around the time Steve did, and they delivered immediately exactly what they promised: they helped me run some nice statistical analyses for my thesis, to produce graphics to accompany the same thesis, and to write the thesis to begin with. Oh, and video games, lots of video games. Even allowing for the failure of the paperless office, it is a stretch to argue that we had to wait more than two decades for personal computing to deliver. But that’s the relevant timeframe for GMOs.

The broader point made by Steve is that “How we implement [GMO] technology is an entirely separate question [from whether it allows us to develop new cultivars quickly and precisely], as separate as hardware and software.” No, it isn’t. Again, the promise of the technology lies in the broad scale human applications, not just in making scientists’ job easier. Let us not pretend otherwise.

So, what do I think of the entire controversy? I don’t know. I spent hours researching this single blog post, and the more one digs into the literature the more confusing things become. And I’m a professional biologist. Who worked on plants. For a couple of years I even worked on agricultural species, and for much of my career on invasive weeds, so I know first hand about herbicides, pesticides and all the rest. One thing, however, I am fairly confident of: the NYT article was not a “hack piece with a biased narrative.” If it needs to be criticized, by all means let’s do it, but we need to have good arguments and carefully laid out evidence, and Steve’s piece simply does not provide enough of either.


P.S.: There were several other rebuttals to Hakim’s piece, perhaps the most prominent of which was published by Andrew Kniss on his blog. I read that too, as well as a technical paper by the same author that is linked there. Kniss is a legitimate researcher in the field, and his arguments are complex and well worth considering. However, the technical paper he refers to is actually non-peer reviewed, and his own sources of funding (which are not reported on the paper itself, but are found under the “additional information” section of the web site) include the following: Bayer CropScience, Dow AgroSciences, DuPont, Monsanto, and Syngenta. That is, a who’s who of the GMO industry. Please realize that to note this isn’t an example of the genetic fallacy, it is a simple cautionary application of common sense. I noticed before that skeptics’ quick reach for the list of so called informal fallacies to throw at their critics is misguided and intellectually lazy; such “fallacies” often turn out to be reasonable heuristics to arrive at a first assessment of a complex situation. (See this paper that I co-authored with Maarten Boudry and Fabio Paglieri.)


55 thoughts on “GMOs and the skeptic movement

  1. Let’s examine the mention in the NYT article of the reduction of children’s IQ. That’s a rather emotive topic, and the quoting of the big scary numbers (17 million IQ points, wow, that’s a lot!) adds to it. [Though only 0.7 points per kid, and I seriously doubt that any such effect at that level can be evaluated.] And that comes after the rather emotive mention of Sarin and the gratuitous Godwinning!

    So, the relevance of this. Well, anyone reading that article not paying close attention to the differences between “pesticide”, “herbicide” and “insecticide” would well get the impression that that’s the sort of thing that has increased owing to GMOs.

    But it hasn’t, it’s dropped; that argument is, however, that it has dropped even more in France, where there are no GMOs. [Why only France by the way, why not compare to Europe as elsewhere? Did they have data only for France, not Europe, or do the data for Europe show something different, so they cherry-picked France?]

    But then — in order to assess the relevance to GMOs — one really needs to know why it has dropped in France, and why the same hasn’t been done also in the Americas. Yet the article tells us nothing at all about that. So we don’t really know why it has declined in France, and without that we really can’t tell what effect GMOs are or are not having on the use of those organophosphate insecticides. So all that scary and emotive stuff is pretty irrelevant to any actual substance on the article. Hmmmm.


  2. “Interesting, so you doubt my good faith that that was a typo?” Not what I said at all, but thanks for the demonstration of your verbal slight-of-hand. I said it was not obvious, which is what you subsequently claimed. But your deflection is well crafted, I’ll grant you that.

    I’m sure you’ll continue to muse on why I disagree with you. Since I’m not paid to do so you’ll have to work harder than just claiming shilling. I’m looking forward to that.

    I have seen contracts for land grant positions. Industry is a specified stakeholder.

    And this is hilariously false @michaelfugate: “She actually took to twitter over my sarcastic response to her gushing encomium of Kniss’ work – and guess what Kniss replied!” Kniss laughed at you is what happened. I didn’t mention you at all, as much as I’m sure you wish to be the center of attention.

    This whole piece and Massimo’s choir is really a fascinating look into denial, though. It’s handy to have an example of it in the skeptic arena. It’s the best example since the Bill Nye stuff.


  3. Hi Massimo,

    Yes, I noted that strange effect of the non-peer sources. But, again, why include, them, regardless of the direction of bias?

    It seems peculiar to complain that they include the non-peer-reviewed sources given that they give you the information both with and without, so one can pick.

    Why use it? Well, maybe they have evaluated it and consider it worth using. I’ve done that. For example I’ve used data by amateur astronomers which, by its nature, is not refereed. One then makes an evaluation as to its quality. Peer review isn’t magic, and not-peer-reviewed does not mean low quality, as I’m sure you realise. As I said, I think the difference can be over-played.


  4. Coel,

    You are correct about glyphosate, though it still remains only one fraction of all chemicals used.

    Your comments about the IQ issue seem at the least premature. That bit comes from a quote by an author who has actually studied the issue. Did you have time to look at the original papers? I didn’t. As for something being “emotional,” well yes, one gets worried about children’s and one’s own health. No reason to dismiss it as “emotional.”


    “Massimo’s choir”? I guess you’ve skipped all of Coel’s comments. One of the things I like about this forum is precisely that it isn’t at all “Massimo’s choir.” And your contributions, you might have noticed, are not being censored.

    As for my alleged slight of hand, what, exactly, was your point in making the comment you made about my typo, if my interpretation is incorrect?


  5. HI Massimo,

    Your comments about the IQ issue seem at the least premature. That bit comes from a quote by an author who has actually studied the issue. Did you have time to look at the original papers?

    I had a look, partly because I was interested in how they would do it (and what the sample size was, to find out what the 17 million meant).

    Anyhow, I am not at all saying anything against that paper, which seems sound, just against the use made of it in the NYT article. Again, unless we’re told much more about why the usage of organophosphates is declining in various countries, the relevance of it to an article on GMOs is pretty tangential.

    Re: Mem, I think he’s saying that he accepts your statement that it was a typo, but not the suggestion that it was “clearly” a typo.


  6. Wow, you are twisty. I never said you were censoring (I didn’t even bring up the fact that one of my comments is in moderation because of links) or that Coel didn’t exist–but you have a choir here that’s merely fluffing your statements.

    This is what you said:
    “The herbicides/pesticides thing was so obviously a typo….It was so transparently not a “conflation” of anything, but simply a typo. But it does say a lot about your and Coel’s attitude toward reading the post.”

    It was not transparent and not obvious. Because it is exactly like other discussions in skeptic arenas on this topic. Which is what I said in a subsequent comment because there’s no “reply” to yours possible.

    Then you wrote this: “Interesting, so you doubt my good faith that that was a typo? Why, I wonder? Just because I happen to disagree with your specific take on this?”

    I never said that I doubted your good faith–you made that up out of whole cloth. I said it wasn’t obvious. I know you are better at language than that–so it appears you are conflating two different things again, why, I wonder?

    Maybe it’s just possible that you are wrong on both, and that’s why I disagree with you. It’s really just that simple.


  7. Hi mem_somerville,

    but you have a choir here that’s merely fluffing your statements.

    Who exactly is this “choir”? And what exactly do you mean “fluffing” his statements? Can you give an example?

    Do you just mean that some people agree with Massimo on some subjects? In that case everybody has a “choir”.

    Liked by 2 people

  8. Mary, why are you avoiding my question? Will you be struck deaf or dumb if you admit that planting GM crops doesn’t automatically lead to an edenic world? It is telling that commenters here are able to see both sides – GM crops don’t directly affect human health (one of the tropes of anti-GM), GM crops have the ability to reduce pesticides, GM crops have allowed for no-till cropping which reduce erosion and fossil fuel use, need I go on. Yet you are still drinking the glyphosphate.

    Liked by 1 person

  9. Too bad WordPress doesn’t have a “block” feature. And, Mary, I may be the most congenial commenter here to Massimo overall, but I’ve disagreed with him on plenty.

    I never said that I doubted your good faith–you made that up out of whole cloth.

    No, but actions speak louder than words. Framing does too.

    Go away, if that’s all you have to offer. Please.

    Michael, I’ll have a tall glyphosphate, shaken, not stirred, with a DDT chaser, please. One for Mary with a double twist of arsenic and old lace on the side.


  10. While GMOs are a hot topic, I’m surprised at the level of anger and assumption of wrong doing in thread commentary.

    To re-clarify my position on GMOs, I have nothing against them in general. It always comes down to specific benefits/costs. I thought the original article was interesting in showing that current use of GMOs may not be providing the benefits promised. I think Massimo’s take on this has been largely correct, even if I agree with Coel that the first graph could be misleading (though not intentionally so, and not that important given the main focus of the article) as well as the whole loss of IQ points study being vague and a strange way to treat IQ (not sure what Massimo sees in it).

    The meta-analysis used as evidence by Novella that GMOs are having some great effect is (as Massimo argues) sketchy. Part of their conclusion should give pause to anyone who is strict about data use…

    “One limitation is that not all of the original studies included in this meta-analysis reported sample sizes and measures of variance. This is not untypical for analyses in the social sciences, especially when studies from the grey literature are also included.” (seriously Coel, tell me that doesn’t sound a bit problematic to you)

    …I would point out that the increases they do report with GMOs are well under the increases claimed to be seen by Coel in the first graph of the original article. Indeed, as I (rightly) cautioned Coel in the last thread, you shouldn’t use the whole period in the graph. That led to his claiming an 80% increase, when it was only (if taken from intro of GMOs) ~25% which is in line with the increases in the meta-analysis. And as I also argued, drawing conclusions from the comparison between Canada and EU was problematic anyway due to confounding factors, something the authors mention (way too) briefly in the conclusion…

    “Impacts vary especially by modified crop trait and geographic region. ”

    … Given the large time period looked at that could also include changes/variability in climate as well as other farming related factors not investigated. I think the biggest take home message from all of this was provided by the authors of the meta-analysis when they said…

    “Future impact studies with primary data should follow more standardized reporting procedures.”

    This is perhaps the biggest scandal to me. Everyone knew this question was going to be of interest. Why were standardized protocols and controlled experiments not set up from the beginning? Especially for Novella to defend GMOs as being beneficial to science (which I agree), this lack of standardization and controls has undercut science on the benefits (or lack thereof) from use of GMOs.

    I’m not saying the lack of good, coordinated studies was a conspiracy. But it does seem negligent and a shame.

    Liked by 2 people

  11. Hi Socratic,

    Coel, WHAT “Godwinning?

    This Godwinning:

    “Pesticides are toxic by design — weaponized versions, like sarin, were developed in Nazi Germany — and have been linked to developmental delays and cancer.”

    A nice rhetorical “Monsanto are like the Nazis” touch! 🙂


  12. Hi dbholmes,

    (seriously Coel, tell me that doesn’t sound a bit problematic to you)

    I don’t have a problem with authors fully realising and reporting the limitations of the data and making appropriate judgements about it in their conclusions. That’s what they should be doing. (There is no bad data, only badly-used data 🙂 ) Again, they do report what happens if one uses the refereed-journal data only.

    are well under the increases claimed to be seen by Coel in the first graph of the original article.

    Well, once again, my comments about the presentation of that graph really are narrowly about the presentation of that graph. The link between that and the effect of GMOs is, as you say, more complicated and involves a lot more issues (e.g. what is causing the changes in yield in Europe, etc). I don’t think I’m disagreeing on anything you’ve said on that.


  13. Hi Coel,

    “I don’t have a problem with authors fully realising and reporting the limitations of the data and making appropriate judgements about it in their conclusions. ”

    Of course, and that was good of those authors. I was more just thinking that having mentioned those specific limitations I quoted, you would be less confident in the results of the meta-analysis. Clearly they were caveating that it was (at best) rigorous along the lines of loose social science studies, not biological sciences (which is obviously what it should have been). This is why I agree with Massimo’s criticism of using that specific meta-analysis. From a biologist’s standpoint (or at least Massimo and my own) that looks shaky as hell.

    “Well, once again, my comments about the presentation of that graph really are narrowly about the presentation of that graph.”

    Right, I understand that and we are pretty much in agreement on the flaws of the graph. It is just that after my reply to you in the previous thread, I saw you continue to claim the graph showed an 80% increase which I mentioned was not a valid take away conclusion. The real increase (taking the graph at face value) was ~25%, which is all that the meta-analysis (which you support) argued for. Sorry for using you as my major example, but I thought this showed how people can take away different (even conflicting) messages from graphs/data.

    You were right in spotting it’s flaws, but maybe should be sympathetic that the authors were not intentionally mis-representing anything, or cherry-picking (as I assume you were not). To me the data in the graph (while to the eye a bit misleading) could have been chosen due to misunderstanding or unintentional confirmation bias, but in any case if read properly is not wildly different from the data seen in the meta-analysis and when combined with the latter graphs, make their point well enough. And their overall conclusion, if placed within all of the caveats the meta-analysis gives, does not seem out of line.

    Perhaps the generic question people should stop trying to pose/answer is “Do GMOs increase yields, or otherwise help farmers?”, instead going for the more particular, pragmatic “Under what conditions and in what ways can these (specified) GMOs help?” The answer for any particular GMO could be “none”, and another in a specific context “majorly”.

    The treatment of GMOs as monolithic is a problem.

    “The link between that and the effect of GMOs is, as you say, more complicated and involves a lot more issues (e.g. what is causing the changes in yield in Europe, etc). I don’t think I’m disagreeing on anything you’ve said on that.”

    Right, don’t worry I understand. My questions/comments to you were more focused.


  14. Hi dbholmes,

    The treatment of GMOs as monolithic is a problem.

    Agreed entirely. The whole debate should stop asking whether GMOs are good or bad. We should accept that GM is a valid tool, and move the debate on to: “Is this particular implementation of GM a good one or a bad one?”.

    Liked by 2 people

  15. Meta-analyses should try whenever possible to include “grey literature” studies to avoid problems due to publication bias (“file drawer effect”). In most bodies of literature, smaller (“non-significant”) effects are less likely to be published, so restricting analysis to those studies sent for peer-review leads to an overestimate of effect size. One does need to weight the contributions of these studies by quality.

    Though the main interest in IQ is the effects of organophosphate insecticides, there is also suggestion that some fungicides may be neurotoxic.

    In the National Academy of Sciences report, they looked for a change in annual yield increase in the US before and after widespread GMO use – no obvious change. In many less developed countries the insect resistance or herbicide resistance was often introduced in strains that had conventionally bred advantages over existing plants. Regarding gene flow to other plants, and selection of resistant weeds, although these problems are occurring, the committee were fairly sanguine that this could be dealt with by appropriate management approaches. They commented that only a few current GMOs offers an increase in potential yield (ie maximal yield given optimal conditions and pest control) as opposed to actual yield (under a given intensity of a particular pest).


  16. Per the pingback, and Massimo reposting, it’s fun to see Novella and his readers at least halfway confirm what Massimo said. I’ll note:
    1. He rejects all, not just some, but all, accusations of groupthink/tribalism.
    2. While not explicitly calling Hakim a “hack writer,” does accuse him of “rookie mistakes.”

    I disagree on both counts. Hakim accepted a framing of the GMO issue that was crafted by the anti-GMO movement, namely treating GMOs as one thing. They are not one thing technologically, and the organisms themselves have to be evaluated individually. He then chose to evaluate GMOs based on two biased criteria, yield and overall pesticide use. He also chose to use cherry picked data for his analysis.

    I agree in that I don’t really know if Hakim is biased or a hack, but he is some combination of the two in this article. My sense is that he is coming to this party late, is not up to speed, bought into narratives that are biased at the outset, and so his entire endeavor was doomed from the beginning.

    Tries to separate the seed industry from the farming industry. This is as laughable as the oil industry trying to claim fracking doesn’t cause earthquakes because it’s the wastewater from fracking that’s reinjected, not the fracking operation itself, that causes the quakes.

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  17. First of all, good on Massimo for reading the Weed Contrl Freaks blog post. It was the main link I intended to suggest. There are a few other good ones but Kniss’s blog post is the best.

    It should be noted that not only are there problems with making whole country comparisons over time there can be problems even when making herbicide use per unit area of arable land within the same country over time because the allocation of land to different crops can and does change (thus if more relative acreage becomes allocated to crops using more herbicide —soybean acreage might be a good example— there will be more herbicide use per area of arable land independently of other effects).

    Massimo writes:

    Your comments about the IQ issue seem at the least premature.

    Pot, meet kettle. The inclusion of the IQ comments (and the gratuitous Godwin like insertion of organophosphates into the discussion) in the NYT article is not even premature, it’s of dubious relevance (if anything, current GE traits can reduce the use of these scary chemicals). The comments regarding Sarin & Dr. Bellinger’s research accomplish nothing except maybe poisoning the well and do not in any way contribute to understanding in this discussion about GE crops.

    That bit comes from a quote by an author who has actually studied the issue. Did you have time to look at the original papers? I didn’t. As for something being “emotional,” well yes, one gets worried about children’s and one’s own health. No reason to dismiss it as “emotional.”

    All we need to know is that Dr. Bellinger is looking at the organophosphate class of chemicals which are minimally relevant to the discussion in developed countries and which are not ever specifically discussed in the article (the paper is linked in the NYT article —the other chemicals of interest are methylmercury and lead which do not even have agricultural applications, as far as I know). If anything, organophosphates are used as insecticides and everyone cited in the article acknowledges that insect resistance traits reduce insecticide application (though the impact of this is going to be much larger in developing countries and less significant in developed countries —because other insecticide classes are used less in the former and predominantly in the latter).

    And yet, the naïve reader might conclude from this article that chemicals that are much like sarin are likely to be used increasingly in agriculture due to the adoption of GE crops. I wouldn’t even rule out that Hakim may be confused as I have seen some anti-GMO activist sources classify glyphosate as an organophosphate (it is not) [Insert Hanlon’s Razor here] so it is possible that he is introducing this reference to organophosphates in good faith.


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