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Note: This post is essentially “what we talk about when we talk about genetics.” If you want a more straightforward scientific rebuttal of the recent Bioscience Resource Project essay arguing that genes have little to no effect on who we are, go here, or, better yet, herehere, hereherehere, or here (last link in Italian).

Michael Pollan, the well-known writer on food and agriculture, is a smart guy. His arguments tend to be nuanced and grounded in common sense. I like his basic maxim on nutrition – “Eat food. Not too much. Mostly plants” – so much that I recently promoted it in a Newsweek cover story. He’s the last person I’d suspect of reactionary thinking, which is why I wish I didn’t have to say this: Michael Pollan has made a deeply unfortunate mistake.

A few days ago, speaking to his 43,000 followers on Twitter, Pollan linked to an essay written by an environmental advocacy group that spends much of its time fighting the depradations of Big Agriculture. Curiously, the essay wasn’t about ecological destruction or even about agriculture. It was about human genetics. It argued that since genetics currently can’t explain everything about inheritance, genes must not influence the development of disease, and thus the causes of illness must be overwhelmingly environmental (meaning “uninherited” as opposed to “caused by pollution,” though the latter category of factors is part of the former one). This was a little like arguing that your engine doesn’t power your car because sometimes it breaks down in a way that confuses your mechanic — and concluding that gasoline alone is sufficient to make a car with no engine run. But Pollan took the argument at face value. He said it showed “how the gene-disease paradigm appears to be collapsing.” He was troubled that its contentions apparently had gone unnoticed: “Why aren’t we hearing about this?!”

Perhaps unknown to Pollan, the human genetics community – or at least the small, vocal part of it that is on Twitter – had in fact heard about this. It set about dismantling and dismissing the essay’s chief conclusions, which were at best overstated and at worst flatly wrong. A number of people outside the genetics community also must have seen the essay. Maybe some of them read it and thought, “huh. My kid looks just like me, but these people are saying genotype has little to no effect on phenotype. Do they really think my kid has my distinctive Roman nose because he grew up in my house?” Maybe some of them wisely thought, “hmm, I was taught that nature and nurture both mattered, this can’t be right” — i.e., don’t you need the engine and the gasoline? — and moved on.

But Pollan’s tweet lent the essay prominence and credibility. Since then, the Huffington Post has jumped on the meme, declaring with typical flair that genomics may just be “one part boondoggle, one part conspiracy by the military-industrial establishment.” The very respectable Marion Nestle has also joined in, tweeting enthusiastically about the “study,” which is no such thing. (It’s an opinion piece on a website, just like this blog post.) Who knows how many people have now seen the essay and been misled into thinking that science has shown the “environment must be the entire cause of ill health?” Who knows how many people far too savvy to subscribe to genetic determinism are now espousing “environmental determinism?”

It’s been more than a week since Pollan’s tweet – which, in Internet time, is an epoch – and he’s said nothing else about the topic. The essay is probably fading away. But I fear the thinking behind it isn’t going anywhere. This looks to me like the first (or maybe the second) flare-up in what may be a new iteration of the nature-nurture debate, which scientists abandoned decades ago as a false dichotomy but which apparently has never disappeared from popular imagination. It’s an iteration in which both sides will speak the language of science but only one will hew to its principles – a debate that could quickly come to resemble the “controversies” over autism/MMR and intelligent design. It will probably center on the issue of missing heritability, which is complicated and messy and lends itself to abuse. And if it does come to pass – if this essay is not an anomaly but a harbinger – it’s going to involve a whole lot of woo.

Well-crafted woo, at that. The argument in the essay – which boils down to “genetics is a work in progress, therefore genes don’t matter” – appeals to many people’s desire to focus on what can be changed (environmental factors) as opposed to what can’t (one’s genetic sequence). It slyly paints geneticists — and indeed, “medical researchers” in toto — as determinists, despite the fact that it’s practically impossible to be a determinist if you work on complex-trait inheritance, as Dan MacArthur has observed. It’s aimed at well-educated people who are naturally suspicious of the “military-industrial complex,” and people who have never had any particular reason to learn how heritability is calculated because they’re busy doing other important things. And it’s counterintuitive and anti-authoritarian in an extremist but oddly appealing way, one that sounds so populist as to resemble the rhetoric of both the Huffington Post and the Tea Party (“all those big-deal geneticists are WRONG!”).

This type of argument could present an enormous challenge for human geneticists, putting them on the defensive for research that should not need defending — and doing so in a way that’s very hard to counter without coming across badly. Sneering at denialists doesn’t work. It only feeds their momentum (“all those big-deal geneticists are SNOBS!”). Calmly explaining the facts doesn’t always work, either, as vaccination advocates and evolutionary biologists have learned over the years.

Last Thursday, I tried to put together a rebuttal of the essay as part of a 15-minute crash course in the basics of human genetics and genomics. After I gave the talk, I put it on the web. (I’m not sure it worked and would appreciate feedback. Also, it cuts off abruptly at the end because I forgot to ask people if it was OK to include the Q&A period and because YouTube doesn’t like videos longer than 15 minutes.) The presentation discusses GWAS design and heritability, present and missing. It touches very briefly on some directions for future genetic research: rare/less-common variants, copy number variants, gene-gene interaction, gene-environment interaction, etc. It considers how much the “missing heritability” debate will matter in the long run. And it does a wee bit of fact-checking the essay, albeit mostly by citing other people’s arguments.

But I don’t expect all that many laypeople, save my captive audience from last Thursday, to pay attention to the point-by-point part of the rebuttal. Who outside the field has the time or will to burrow so deeply into statistical genetics methodology when there are jobs to be done, kids to be raised, lives to be lived?

What I do want people to see is the 10:55 mark, where I try to engage with the essay on a level that doesn’t require any understanding of genomics — because I think this may be a way of explaining what’s wrong with it that speaks to a wider readership. Aside from its factual misinterpretations, the essay makes two logical errors that anyone can see if he looks hard enough:

1. It assumes that absence of evidence is evidence of absence, concluding that because common diseases aren’t caused by a handful of genes with strong effects, they aren’t influenced by genes at all. This is clearly a silly position, but it’s a handy one if you are, say, a group that wants to raise the profile of biomedical research into non-genetic factors such as pollution, and if you’re concerned about money being poured into genetic research at your expense. (For the record, I agree that research into environmental factors is important. Maybe the essay’s authors and geneticists should be lobbying together against pending cuts to the NIH? To borrow a malapropism from someone with whom I disagree on almost every other point: shouldn’t we make the pie higher?)

2. It mistakenly portrays science as a monologue, and a dull one at that. First, it lists some of the potential hiding places for heritability that remain in the genome. Then it notes that a few scientists think some of them are less likely candidates than others and that there’s no consensus that one of them will explain everything. This is presented as evidence that almost all of human genetics is in crisis. But the data has just begun to be generated, and of course it’s unlikely that one type of factor will explain everything. Life, in biology as elsewhere, is complicated. (As geneticists freely point out: take it from David Altshuler, Leonid Kruglyak, and a bunch of other people who would know.) We’ve seen this line of “minor disagreement = major crisis” argument before, from creationists who conscripted Stephen Jay Gould and punctuated equilibrium as “evidence” that natural selection wasn’t a widely accepted principle. It was just as absurd — and effective — a rhetorical tactic then as it is now.

Why do I think these parts of the rebuttal are the most important ones? Because if this essay is indeed the first volley from a new, “environmental determinist” movement, the technical flaws it contains are not going to matter in terms of public opinion. Laypeople aren’t going to have the time to learn the nitty-gritty details of how genomic research is done, and they will react poorly to anything they perceive as condescension from geneticists. As they should: Condescension is bad.

But ultimately, the essay itself — really, the entire “genes don’t matter” argument — is what’s condescending. It starts from a couple of philosophically flawed premises, papers over the holes with something that looks and sounds like science, and assumes that its readers, lacking technical expertise, are unable to see that the conclusions are not reality-based.

Call me an optimist, but I think many readers are smarter than that. And if I were a typical reader — if I weren’t closely acquainted with the scientific literature — I’d be angry to find that people purporting to enlighten me were in fact trying to snow me. (“Hey, this environmental-determinist advocacy group is WRONG!”) Or at least I’d want someone I respected — someone with, say, 43,000 followers on Twitter — to set things right.

Here’s a suggestion for how to do that in fewer than 140 characters: “Genes matter. Not too much. So does the environment.” Over to you, Mr. Pollan.

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21 thoughts on “DNA, Denial, and the Rise of “Environmental Determinism”

  1. Pingback: DNA Deniers | The OpenHelix Blog

  2. Sure! The questions were great, as you’d expect from science journalists, who were the audience. They fell into three basic categories:

    1. Technical stuff. For instance, how likely is it that rare variants will turn out to underlie a lot of common diseases? This is a fascinating question, but it was hard to answer given that (a) no one knows yet and (b) I first had to go back and explain why GWAS doesn’t find them (I had tried as hard as I could to avoid using the term “SNP” but it was ultimately unavoidable) and why sequencing can.

    2. How credible is the essay? Specifically, “how the heck did this get through peer review?” This was enlightening for me — it hadn’t even occurred to me that people would think it *was* peer-reviewed. That’s why I explicitly make the point here about it not being a “study.” Also, “who are the authors of the essay and what’s their background?” I mentioned that they have training in biology and plant genetics, which led to a third strain of discussion:

    3. If the authors of the essay believe that genes don’t influence common diseases, do they also believe that genes don’t influence other complex traits — and that everything is therefore either monogenic or purely environmental? If they do believe genes influence some complex traits (as they’ve suggested in the comments on your blog, I believe), how and why do they draw the line between a “trait” and a “disease?” I honestly couldn’t think of a logical answer to this one, and I didn’t want to put words into the BRP’s mouth. But it’s a key question, and if the authors would like to answer it, I’d be curious to hear their thoughts.

    • Yeah–on the credibility thing. I almost give Pollan a pass on being able to evaluate the details because he doesn’t have the science background for it. But I was very distressed to see Marion Nestle go there. She has no excuse. Her background should be sufficient.

      I also find it interesting that the same authors are around the web claiming all sorts of environmental havoc from a small gene or a small antisense fragment in a plant. They are definitely trying to have it both ways.

      It would have been nice to be able to discuss it on their site, but there’s no mechanism for that.

      Great information. Thanks!

  3. Pingback: Heritability and genes as causes | Gene Expression | Discover Magazine

    • Actually, Michael Pollan is not as smart as he’s cracked up to be. I learned that reading his book, Botany of Desire. As entertaining as it is, with some beautiful writing about plants and gardening, its basic premise – that in the evolutionary process domesticated plants like apples and potatoes have manipulated humans as much as humans have manipulated them, using characteristics like delicious flavor and nutritiousness to beguile humans into nurturing them in gardens – is false. Pollan was not smart enough to notice the obvious flaw, that while we do indeed nurture plants, we have also altered them greatly through breeding. Is he saying plants in their turn have bred us for their own benefit?? In many cases, plant varieties that have been developed for modern agribusiness lack the flexibility of their wild ancestors, being susceptible to diseases, insect plagues, and the like. Human selection has not benefited them as previously natural selection did. Pollan’s intelligence is of the New Yorker variety, distinctly middle brow. So I was not surprised to see him climb on the DNA denier bandwagon – or at least give it a push on its way.

      What I write above is my take on Pollan’s book. If I’ve misinterpreted it, I’d like to know.

  4. Good post and nice video! Thanks for citing my italian article and for stressing the fact that life is complicated: if you choose to keep extreme positions (determinism, both kinds) then you’ll be always wrong. Because cells don’t work that way.

  5. I guess my next question is, “What’s the philosophical/ideological basis going on here?”

    Most of the woo health I’ve encountered (especially the stuff Huff Po champions) seems to start with trying to make biology fit an ideology of some sort, whether it be religious, political, or whatever. I’m curious what’s at play in the background of this one.

    • @Maggie: I’ll take a stab at that, since I found the HuffPo quote and some other tidbits around the web from Latham in my searching for my blog post on it. I’ve also talked to a plant scientist whose gone ’round with him before, on a slightly different topic, but similar strategy: take some actual publication, but misuse the content entirely.

      He’s in league with Jeffrey Smith (frequently appearing at HuffPo), see this article on plums: http://www.newswithviews.com/Smith/jeffrey13.htm For those of you unfamiliar with Smith, you might also want to see Pam Ronald’s recent attempt to educate the public on the Dr. Oz show. She was edited and cut out on the science, while the fear and woo flowed freely otherwise. http://scienceblogs.com/tomorrowstable/2010/12/dr_oz_prescribes_non-gmo_diets.php

      I believe they want to blame environmental features (including but not limited to GMOs and the current agricultural system) for all health woes to support their case.

  6. I’ve just finished reading Steven Pinker’s book The Blank Slate: The Modern Denial of Human Nature. In this brilliant book I learned of a vast ideological schism that I believe underlies this very controversy. There seems to be a sizable and “scientifically literate” community ideologically driven to down play the impact of heritability in favor of environmental determinism. This ideology has deeply political and emotional roots! The downstream consequences of eugenics, I believe are at the core of this. The fear of “guilt by association” is such a powerful force that it compels denial. I had no idea that accepting the evidence of the affect of heredity would put me at odds with liberals forces. It’s truly sad in a way. Evidence must ultimately be the driving force – not ideology, even when it is compelled by legitimate fear.

  7. Pingback: Heritability and genes as causes | Biology News by Biologged

  8. All silliness stems from (conscious or unconscious) political agenda and Leftism is on par with Fundamentalism on this.
    The echo chamber of the Internet risks burying all reason an turn ANY question to political haggling and PR talk.
    This doesn’t bode too well for actual science.

  9. You’re the condescending arrogant one (owner of this blog, whoever you are), you’re the one quick to use the emotive term ‘denier’ when in fact the original article in question does not at all ‘deny’ the entire thing. It agrees with breast cancer genes, rare genetic disorders for instance, doesn’t ‘deny’ them at all.

    As for complex disease. No one in the public is ‘obliged’ to give a crap what you people think until you can actually test THEIR genes and prove they personally WILL get a disease, and then when they do, people will believe in this.

    At the moment, the market is flooded with pseduoscientific tests sold on websites purporting to test people for every disease under the sun.

    I love how you basically acknowledge your fear that scientists cannot sell their science without being condescending, because you know most of them are arrogant bastards.

    You’re just jealous you don’t have 44 000 twitter followers.

    Pollan can tweet whatever he likes, he doesn’t have some responsibility to fall in line with an industry of fraudulent vested interests, like you appear to.

    What idiots who have spent their years with their heads buried in journals lose is common sense. The common man knows gulping down fat causes artery plaque and heart attacks. He knows breathing smoke, from traffic or tobacco will mess you up and cause disease. The far more interesting story is how to get a healthy and clean environment, and not what some fools are trying to pull on us with statistics.

  10. How funny I see here a comment I made on TGGP

    Turning on the comments RSS was not a good idea.
    Wordpress sucks anyway and “geeky” hacks are brittle but as “Transparent Society booster” you should be happy. :-D

  11. Pingback: Nature Versus Nurture: Really? « How Do You Think?

  12. We would propose there is nothing more threatening, to pretty much every belief system out there, than the reality that our conscious minds (and their supernatural constructs) – and therefore the “environment” we wish to control — is not under our immediate conscious perception and control.

    It is a Copernican shift where our conscious “self” is not really at the center of much of anything – personally or socially. We really have very few, if any “choices.”

    “Genetic determinism” becomes the foundation of our fates and profoundly threatening – in milliseconds. It certainly offers the most prosaic model. In contrast, and the default mode of 99.9% of the world — if it’s a political “cause” (environmental) or nurture – we can DO something about it.

    Of course, we really can’t do much about anything especially our illnesses and behaviors.

    There is also increasing pushback to complexity. (Oh my aching head.) All systems are turning out to be waaay more complex than our (very limited) primate brain can perceive, let alone understand, model. Fix (!?).

    But we pay the media time and attention to support out myths – NEVER to challenge them.

    Denialism is best addressed as a symptom of, frankly, limited brain power to process (increasingly) complex experiences. Ideology and identity frames are what we look at in these matters. It is not a matter of IQ or more details/complexity/explanations.

    Genetics, unfortunately, reaches deeply very quickly to trigger identity threats involving oneself, family, food, etc. Very tough territory to navigate. But brain science and social sciences are up to the challenge.

    Let’s be realistic as well — pretty much no one really believes the earth is not the center of the multiverses. lol

  13. Pingback: Otto West: Apes don’t read [genomics] | The OpenHelix Blog

  14. Sorry, but Pollan’s overhyped statement, “Eat food, mostly plants, not too much” is a banality masquerading as a profundity.

    I took over a class that had his book “In Defense of Food” on the reading list and was appalled to find it to be a confused anti-science screed, so that’s what I drew students’ attention to. He is neither nuanced nor grounded in common sense. He is a crank.

    • The banality is actually what I like — if nothing else, it’s a lot more sensible than all the other ridiculous diet advice out there. (I’d rather someone ate a plant-heavy, moderate diet than attempted to subsist on nothing but lemon juice and cayenne pepper, for instance.) But I’d believe that there’s some anti-science sentiment there, too; I don’t know how else to explain Pollan’s embrace of this “study.” Makes me sad.

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