It was exactly one year ago today that I first uttered the phrase, “paleo is a logical framework applied to modern humans, not a historical reenactment.” That idea seemed pretty straightforward to me, and it was well-received to the point of being quoted in a real life book (you should buy it, but not just for that reason). And sure, Robb and Andy misattributed it to somebody else in a podcast in the distant past, but I already forgave them for that. So here I am, still beating the drum of the paleo framework despite internal and external attempts to refute it, supersede it, minimize it, water it down, or exact (Exacto?) its death by a thousand cuts. Well folks, it still works. But really, this should come as no surprise…

“This guy is irritatingly correct, time and time again, even when he has limited evidence.” – E. O. Wilson on Charles Darwin

Maybe the blogs I read and the people I talk and listen to aren’t representative of the paleo community, and maybe I’m just imagining things, but the paleo zeitgeist has seemed rather buddy buddy with the white devils of late. Of course, I refer here to rice and the [non-sweet] potato. Support seems to come along the lines of, “potatoes/rice are starches. starch is good for you. therefore potatoes/rice are good for you”; “sure, raw potatoes/rice might have saponins or glycoalkaloids or lectins or phytates, but those compounds aren’t always bad, and they’re destroyed by cooking anyway”‘; “sure, rice is a grain, but what about population X and population Y who eat rice and don’t drop dead from these supposedly ‘toxic’ substances”; and commonly included with one of the first two, “I love potatoes/rice” or “potatoes/rice are good”. Even setting aside the restless and ubiquitous specter of The Self-Justification Diet, there are significant problems with these arguments. I’m not going to deconstruct them at length here, but suffice it to say that they’re all logical fallacies of one stripe or another.

Even if I convince you that the individual arguments are flawed, the endeavor still wouldn’t tell you the paleo framework was correct or useful. So rather than that, I’ll introduce recent research that those looking at things from a microscopic perspective have been missing all along. Not surprisingly, the research demonstrates proximate effects that were effectively predictable with the paleo framework.

The two relevant components of the basic paleo framework are:

1. Humans are probabilistically less likely to be adapted to foods introduced more recently into the human diet. This applies to the potato, which is indigenous to South America, and was not available to humans in Africa, Asia, Europe, Australia, or myriad island populations, until the Spanish brought them back to Europe in the late 16th century. All of those populations have been consuming potatoes for only 300-400 (I’m being generous with that second number) years.
2. Because they can’t run away or fight back like animals, many plants have evolved chemical defense mechanisms. Because the ultimate goal of evolution is reproduction, and not survival, we can predict that chemical defense mechanisms are likely to be concentrated in the reproductive parts of plants. In many cases, this is the seed. Rice is a seed of a plant, and is therefore probabilistically likely to have chemical defense mechanisms.

The Meat

Why miRNAs are important

As a wise man once said, “Reprogram your genes for effortless weight loss, vibrant health, and boundless energy.” Without delving into genetics, let’s just agree that gene expression is a proven concept. Roughly, your genome consists of a lot of conditional statements that result in the production of proteins which have wildly varied effects. Our genetic code is shaped by the environment in which we evolved. By matching the inputs of our environment to the conditions ‘expected’ by our genes, we may optimize the expression of our genes. Please know that this is a vast oversimplification, but is useful for thinking about our individual health and well-being.

For now, let’s just say that RNA relates to gene expression, and miRNA is short for “micro RNA”, which is just a subset of RNA.

“…the rapidly developing new field of miRNA, which plays an important role in modulating virtually all biological processes (e.g., cell proliferation, development, differentiation, adhesion, migration, interaction, and apoptosis) through its fine tuning of gene regulation.” (Sun, et al. 2010)

“miRNAs have been widely shown to modulate various critical biological processes, including differentiation, apoptosis, proliferation, the immune response, and the maintenance of cell and tissue identity. Dysregulation of miRNAs has been linked to cancer and other diseases.” (Zhang, et al. 2011)

 The study

This study was recently published in the journal Nature (September 2011). It contains novel findings that miRNA from plants remains stable after cooking and digestion by humans. This plant miRNA has been found in significant quantities in human blood and tissue. Further, it has been demonstrated to interfere with human miRNA by mimicking it and binding to the receptors, then influencing gene expression in ways different from the miRNA produced naturally by our bodies.

Unless otherwise noted, all following quotations refer to Zhang, et al. 2011. Emphasis has been added by me.

 Abstract
Our previous studies have demonstrated that stable microRNAs (miRNAs) in mammalian serum and plasma are actively secreted from tissues and cells and can serve as a novel class of biomarkers for diseases, and act as signaling molecules in intercellular communication. Here, we report the surprising finding that exogenous plant miRNAs are present in the sera and tissues of various animals and that these exogenous plant miRNAs are primarily acquired orally, through food intake. MIR168a is abundant in rice and is one of the most highly enriched exogenous plant miRNAs in the sera of Chinese subjects. Functional studies in vitro and in vivo demonstrated that MIR168a could bind to the human/mouse low-density lipoprotein receptor adapter protein 1 (LDLRAP1) mRNA, inhibit LDLRAP1 expression in liver, and consequently decrease LDL removal from mouse plasma. These findings demonstrate that exogenous plant miRNAs in food can regulate the expression of target genes in mammals.

This wasn’t a gender thing:

” Upon investigation of the global miRNA expression profile in human serum, we found that exogenous plant miRNAs were consistently present in the serum of healthy… men and women.”

This effect was not tiny. Significant amounts of plant miRNA were found in humans:

“the tested plant miRNAs were clearly present in sera from humans, mice, and calves… when compared to the endogenous mammalian miRNAs known to be stably present in animal serum, these plant miRNAs were relatively lower, but in a similar concentration range.”

The following quote demonstrates that not all plant miRNA is digested. Some is digested more than others, and some is not digested at all:

“the levels of MIR168a and MIR156a, the two plant miRNAs with the highest levels in the sera of [human] subjects, and MIR166a, a plant miRNA with modest level, were assessed… MIR161, whose expression level was undetectable, served as a negative control.”

The three plant miRNAs found were present in different levels in different plants. Note that cooking influenced the miRNA content differently by specific miRNA and by plant. While levels in rice decreased dramatically with cooking, levels in wheat increased with cooking. After cooking, all MIR156a levels remained significantly high.

It is worth noting that these three plant miRNAs, MIR168a, MIR156a, and MIR166a, were detected in [rice and] other foods, including Chinese cabbage (Brassica rapa pekinensis), wheat (Triticum aestivum), and potato (Solanum tuberosum).

“Interestingly, plant miRNAs were stable in cooked foods.”

It is important to note the following context. Much of the study was centered around MIR168a in rice. This was not because rice or MIR168a have better or worse effects in humans, but because the effect of each miRNA across each gene locus is unknown at this time. The effects of MIR156a are unknown, so we cannot draw the same conclusions about wheat or potatoes as we can about rice. It is known that plant miRNAs have a tendency to interfere with gene expression, but that precise expression remains a question as large as the numbers of gene expressions that can be interfered with against the number or miRNAs we might ingest from all over the plant kingdom.

“most plant miRNAs can act like RNA interference… [W]e performed bioinformatic analysis to identify any sequences in the human, mouse, or rat genome with perfect or near-perfect match to MIR168a. Approximately 50 putative target genes were identified as the target genes of MIR168a”

This known mechanism is why this study focused on MIR168a and rice:

“LDL is the major cholesterol-carrying lipoprotein of human plasma and plays an essential role in the pathogenesis of atherosclerosis. Downregulation of LDLRAP1 in the liver causes decreased endocytosis of LDL by liver cells and impairs the removal of LDL from plasma… Concomitant with a significant elevation in MIR168a levels in the livers of mice after 1 day of fresh rice feeding , LDLRAP1 expression dramatically decreased in the group of fresh rice-fed mice. In these experiments… LDL levels in mouse plasma were significantly elevated on days 3 and 7 after fresh rice feeding… the level of liver LDLRAP1 was not related to the levels of plasma cholesterol or triglycerides… the elevation of fresh rice-derived MIR168a… specifically decreased liver LDLRAP1 expression and thus caused an elevated LDL level in… plasma.”

Plant miRNAs mimic endogenous mammalian miRNA, bind to their receptors, and inhibit protein expression:

“Plant miRNAs execute their function in mammalian cells… in a fashion of mammalian miRNA…the results that MIR168a was also able to target the artificially expressed LDLRAP1 protein in 293T cells (Figure 3I-3K) strongly demonstrate that plant MIR168a could bind to its binding site located in exon 4 of mammalian LDLRAP1 gene, and then inhibit LDLRAP1 protein expression.”

Why the focus on disruptive plant foods, and not animal foods?

This was one of the biggest questions I had before and after reading the study. Unless I missed it, no specific mention is made of what happens when humans or other mammals ingest mammalian miRNA. This leaves the question open as to the scope of miRNA influence we may obtain through food. Upon closer examination, I did find one point of entry into further inquiry on this question. It seems that there is a difference across the board between mammalian miRNA and plant miRNA. This does not mean that all plants are bad to eat or that all mammals are good to eat. Nor does it mean that all plants are good to eat or that all mammals are bad to eat. It’s likely still true that there is no such thing as food and that everything we might ingest simply exists on a multi-dimensional spectrum of healthful to toxic.

“Plant miRNAs are 2′-O-methyl modified on their terminal nucleotide, which renders them resistant to periodate. In contrast, mammalian miRNAs with free 2′ and 3′ hydroxyls are sensitive to periodate… Indeed, as shown in Figure 1E, most mammalian miRNAs in human serum, such as miR-423-5p, miR-320a, miR-483-5p, miR-16, and miR-221, had an unmodified 2′, 3′ hydroxyls and were therefore oxidized… In contrast, MIR156a, MIR168a, and MIR166a in human serum remained unchanged…”

Whether mammalian miRNAs found in human serum were exogenous or endogenous is not specified. If we knew that they were exogenous, and they were oxidized, we would have a significant difference in mechanism between plant and mammal miRNA. If we assume that the mammalian miRNAs mentioned are all endogenous, we can still see a significant difference, but the question remains open as to whether ingested mammalian miRNAs remain stable after ingestion, are oxidized in the digestion process, or are metabolized via another mechanism.

Still a lot of unknowns

At this point, we can’t definitively say a lot about the effects of plant miRNAs (or mammalian for that matter). Is it possible that the cooking-stable, digestion-stable MIR168a found in rice is the only plant miRNA that interferes with human gene expression? Sure. But is that probable? Nope.

Is it possible that there is an unknown benefit to gene expressions altered by miRNA? Sure. From an evolutionary standpoint, it’s possible that humans have adapted to use plant miRNAs as a cellular signaling mechanism to activate conditional clauses wherein different genes are expressed in order to optimize phenotypic adaptation to a plant-rich environment. What is the probability of this? It is not improbable that an organism would adapt to such a signaling mechanism given sufficient evolutionary pressure, genetic variance, and time. However, there are issues with this line of reasoning. First, in non-agricultural phases of human evolution, the plants would be engaged in an evolutionary arms race to continue to evolve their chemical defense mechanisms as humans adapted to them. Second, it currently appears that this effect does not exert acute deleterious effects on individual humans that would effect survival and reproduction enough to provide significantly strong selection pressure. Third, while time is less important than selection pressure in evolution, it remains true that a few hundred years is indeed very short in evolutionary time, and this period of time is not unknown to history. Had this sort of selection taken place, we wouldn’t have stories of the Irish potato famine (too few calories), we’d have stories of the Irish potato poisoning, in which thousands upon thousands would have died from eating potatoes (too many toxins).

There are many other unknowns. Perhaps you’ll share some in the comments.

Commonly questioned practices this study got right

There are often complaints that studies on mice cannot be extrapolated to humans. This can be a fair criticism, but is not likely to be used to mount a successful challenge to this study. Wherever ethically acceptable, humans were tested.

In particular, actual human blood and tissue samples were taken. These samples convincingly demonstrated the presence of plant miRNA in human blood and tissue in levels relatively equal to miRNA produced naturally by humans.

Further, these levels were compared against mice and calves. An example of the data is shown to the left. Note that the mice tended to demonstrate the lowest relative levels of miRNA. Humans represent the highest levels for the most relevant miRNA. Therefore, it is more reasonable to expect the effects measured in mice would be more pronounced in humans if we could control humans’ diets enough to conduct this experiment.

What conventional medicine should be saying about this study

It seems pretty simple: Rice elevates MIR168a in humans. Elevated MIR168a impairs the liver’s removal of LDL, or “bad cholesterol”. Increased LDL cholesterol causes atherosclerosis which leads to cardiovascular disease. Rice increases LDL cholesterol, and therefore, eating rice causes cardiovascular disease.
Now, I don’t completely buy into this narrative — particularly because there’s no mention of LDL particle size in this study. However, this article was published in Nature, one of the most prestigious journals on the planet, and there’s no uproar. If this study had concluded that eating red meat interferes with the liver in a way that raises “bad cholesterol”, would it not be the cover story everywhere?

How this study might fit with a paleo diet framework.

It’s hard to say anything definitive about this study beyond the convincing proof that rice miRNAs interfere with human gene expression. That said, we can use the paleo framework to make some predictions. We can predict that miRNAs that are evolutionarily novel are more likely to be deleterious to human health than beneficial. We can also suppose that even if the bulk of miRNAs are deleterious to humans, there may be a minority that are beneficial to most humans, and a few might be beneficial to humans with particular alleles.

The view that known individual components are not always harmful, and therefore shouldn’t be totally avoided, still leaves big gaps in our knowledge, and makes our daily decisions about what to eat susceptible to the undiscovered.
Paleo is bigger than lectins and phytates and saponins.

We’ve been presented with many past arguments about rice and potatoes being fine, but too high in carbohydrates to recommend for everyone.
The paleo framework is bigger than metabolic syndrome.

The more we learn about wheat, the more nefarious compounds we find.
Paleo is bigger than gluten free.

Although I personally think bok choy sucks based on taste, I never had a health reason for disliking it…
Paleo doesn’t know everything.

Potatoes and rice, still not paleo.

What I’m doing differently in light of this study

• Less likely to deviate from sashimi at sushi restaurants.
• Downgrading potatoes and rice from “neutral nutrient-poor waste of time” to “sneaky untrustworthy bastards”.
• Downgrading wheat from “probably a bad idea for everyone” to “all the shitty stuff about wheat plus the shitty stuff about soy”.
• Downgrading bok choy from “Hey, I’m not going to eat this, would you like it?” to “I’m not making out with you if you eat that”.

What I’m doing the same in light of this study

• Preferentially consuming animal foods.
• Scaling carbohydrate/starches daily in relation to activity levels
• Eating carrots and sweet potatoes when I want to ingest subterranean plant storage organs (because orange is sexier than white).
• Remaining skeptical of the applicability of populations isolated by geography like islands (Kitavans) and other extremes (Inuit) to humans in general.
• Aping Darwin while recognizing that Science provides us with limited evidence for us to use in our everyday lives, yet trying to be irritatingly correct anyway.

<sarcasm>Eat your vegetables folks, particularly if you want your gene expression impaired by the plant kingdom.</sarcasm>
Final thought: Think like a geek. Eat like a hunter. Train like a fighter. Look like a model. (Play and live like you don’t live in a zoo is always implied)

References
Sun, W., Julie Li, Y.-S., Huang, H.-D., Shyy, J. Y.-J., & Chien, S. (2010). microRNA: A Master Regulator of Cellular Processes for Bioengineering Systems. Annual review of biomedical engineering, 12, 1-27. [full-text PDF]

Zhang, L., Hou, D., Chen, X., Li, D., Zhu, L., Zhang, Y., Li, J., et al. (2011). Exogenous plant MIR168a specifically targets mammalian LDLRAP1: evidence of cross-kingdom regulation by microRNA. Cell Research, 1-20

Mat Lalonde is to message dissemination as the average paleo blogger is to chemistry.

At the beginning of his talk at the Ancestral Health Symposium, Dr. Lalonde showed a picture of the CCB building that houses the Pfizer Lecture Hall at Harvard. He then contextualized the talk as: what he’d say if he were presenting to his peers in this building. While such an exercise has merit, the larger context of the talk seemed odd.

Most Readers of Paleo Blogs Are Chemists?

The implication in Mat’s talk is that those disseminating information based on evolutionary frameworks can’t really say many of the things they say and have them pass muster with chemists. I’m not sure how many chemists frequent various paleo blogs, but I’d guesstimate it’s roughly in the range of “not even close enough to think for a fraction of a second to attempt writing at a PhD. in chemistry level.” This might not be an issue if writing to a general audience and writing to trained scientists wasn’t, in many ways, mutually exclusive.

“so as a chemist i read [a] blog and the immediate thing that comes to mind is that this person is an idiot and i will never come to this blog again. you’ve lost all credibility. this is why chemistry is important folks” -Mat Lalonde

I find this insinuation – that chemists (or any other scientists) are unable to distinguish between a blogger who’s writing for an unscientific public and one who’s writing with the intent of scientific accuracy – to be rather thin. A chemist incapable of recognizing the difference, or unwilling to understand the value of targeting messages accordingly, has just lost all credibility in message dissemination. This is why marketing is important folks.

*I grant that I have taken the above quote somewhat out of context. However, its original use was intended to illustrate the point that being scientifically inaccurate makes one an idiot in the eyes of a scientist, not strictly a commentary on the blog in question.

The stated theme of the talk was “teaching” members of the paleo community how to build and maintaining credibility. Again, such an exercise is commendable, but I find significant oddity in choosing to direct paleo civilians’ (bloggers, et cetera) credibility efforts at the world’s foremost “core” scientists. Credibility efforts will have more effect if focused on credibility relative to the public at large. To my mind, a talk about building credibility in the context of moving paleo forward would have been more effectively delivered by someone who’s spent significantly more time on the other side of the Charles River, at Harvard Business School. A “How to forward the message of paleo” talk would have more impact presented by Don Draper than Mr. Spock.

“[in a talk to core scientists] there are no shenanigans to be made. you can’t make any exaggerations… People who overstate their claims… are treated to a question and answer period that makes a CIA interrogation look like a teenybopper interview.” -Mat Lalonde, PhD.

Statements of this nature are perfectly logical, philosophically correct, scientifically accurate, and maybe even economically optimal – when interacting with Homo economicus. Unfortunately, Homo economicus is a myth. Actual humans in the wild seldom respond optimally to messages crafted for stringent accuracy and epistemological certitude. Individuals among Homo sapiens love shenanigans and exaggerations and overstated claims. Had Mat’s talk been delivered to my peers (from the marketing world), he would have been exposed to a Q&A trainwreck akin to Dr. Sheldon Cooper giving unsolicited improv tips to the cast of SNL. Dr. Lalonde is as far out of his depth when it comes to spreading messages to the public as the paleosphere’s practitioners and propagandists are when it comes to organic chemistry. And that’s all fine, but I think Mat’s message needs to be tempered, and his talk recontextualized.

Optimizing Focus

Developing a level of education necessary for optimal credibility is a worthwhile endeavor. Unfortunately, investment in education significantly suffers from the law of diminishing marginal utility. For advocates of any position, the optimal point on the education curve will be somewhere above the bulk of those they wish to spread their message to, and below that of the foremost experts in the field. Indeed, those with a general audience will attain an optimal level of education/understanding somewhere just above that of their desired demographic, and likely well below that of doctoral level experts. Writing and conversation should be directed to this audience for optimal effect. Education and writing above this level is non-optimal, and potentially detrimental to your message.

For the vast majority of paleo bloggers, practitioners, and adherents, discussions of paleo are intended to help regular people. Regular people aren’t scientists. Talking science to non-scientists may increase perceived authority, but it will also tend to alienate and confuse people.

I highly recommend watching Mat’s talk. It’s valuable from multiple angles of consideration, but there are two I’d like you to keep in mind as you watch: 1) Where does the bar of scientific rigor need to be to engage in credible conversations with people you’d like to converse with or persuade? 2) How much does the scientific minutiae detract from the message for you, and potentially those you’d like to engage with in turn?

[vimeo http://vimeo.com/27570335 w=640&h=360]

Having said all of the above, I conceptually agree with Mat in (at least) one regard. It is important for some members of the paleo community to raise the bar. In terms of demographics, there is room for a subset of thinkers to advance scientific hypotheses and engage with the scientific community.

Specific Comments on the Evolutionary Framework

Dr. Lalonde accurately provides examples of invalid applications of an evolutionary biology framework in the talk. With so many voices, we have no practical way to empirically evaluate how often these statements are presented in an invalid way. Let’s just assume that it’s frequent enough to warrant some attention. Consider the following example Mat provides:

“we evolved over millions of years without consuming the foods that became readily available only after the advent of agriculture, hence we are not adapted to them.”

Indeed, this syllogism is incomplete to the point of being invalid. However, I can also imagine many conversations in which its brevity would deliver more impact than an a sentence sanctioned by Science. Here’s the above statement unpacked into a little more scientifically correct construction:

Dietary constituents may exert selection pressure which, when significant, will subject advantageous traits to positive selection, and negative traits to negative selection, and may result in adaptation. Foods that did not become readily available for human consumption until the advent of cooking and/or agriculture have had relatively little evolutionary time to exert selective pressure on humans, and may not have exerted strong enough selection pressure to drive adaptation, and/or the requisite adaptations may not have arisen to be selected for, or may not have been selected for because of chance. Further, more recently introduced foods may have provided the paradoxical benefit of providing an important boost in calories that  increased the length of survival and overall reproduction rates in-turn, while simultaneously decreasing the objective health of individuals. Hence we are less likely to be adapted to such foods than foods consumed in greater quantities for longer periods of time across the span of hominin evolution.

The example Mat provides is invalid, but it’s a lot easier to fit on a T-shirt than my, somewhat more scientifically accurate, reconstruction.

I also find Dr. Lalonde’s dismissal of the evolutionary biology framework to be rather misleading. Consider the following:

“just because your hypothesis relies on “evolution” doesn’t make you any more right than anyone else”

This is statement is literally correct, but obfuscates the usefulness of the evolutionary framework in a way that inaccurately discounts its importance. In biological organisms which are subject to Darwinian evolution (all of them on planet earth), the probability of an evolutionary hypothesis being correct will increase relative to the known ecological constituents relevant to the species in question. The probability of a hypothesis being correct increases relative to the increase in knowledge from phylogeny, phylogenetics, biology, archaeology, ethology, biochemistry, ecology, et cetera, et cetera, et cetera. While all strictly untested hypotheses may be philosophically equal, they are not necessarily equal in their probability of being “right.”

Mat makes another statement that is true while counterproductively discounting the evolutionary framework. In reference to applying the term anti-nutrient to all species equally with respect to individual substances:

“whether or not a substance is an anti-nutrient depends on the species ingesting the substance, because it depends on their digestion process.”

Absolutely true. However, in analyzing an organisms evolutionary pressures, we can begin to make probabilistic predictions as to their strategy as defense mechanisms. Organisms with predators of a certain type are more likely to have engaged in an evolutionary arms race to develop defense mechanisms targeted at said predators. Knowing something about the predators allows us to formulate hypotheses via probabilistic reasoning that are significantly more likely to be correct than chance. Phylogenic relatedness has direct bearing on our ability to predict the accuracy of such hypotheses. Indeed, this is implied in the above quote, but becomes lost when attempts are made to discount the value of evolutionary logic.

Rather than prove his point, Dr. Lalonde here demonstrates exactly what you lose when you discount the value of the evolutionary framework:

“if you look at things that athletes would be eating on a quote unquote paleo diet, you’ve got things like yams and cassava. and if you look at the antinutrient content, it’s the same order of magnitude… so if you’re going to tell someone, ‘hey, you should not eat grains and legumes because they contain anti-nutrients’ a biologist – a plant biologist – is just going to look at you and say, ‘wow, this guy’s a moron.’ this stuff is really important, and you’re going to loose credibility immediately if you make statements like that. so it’s not the way to sell it. you have to evaluate these things on a one on one basis.”

Yes, ignoring the evolutionary framework and focusing on the proximal anti-nutrient content will tend to lead you astray. However, applying the evolutionary framework to things like yams versus things like grains allows you to quickly make decisions that are more likely to be good decisions.

Takeaways

1. Take Mat Lalonde’s advice if you’re trying to “sell” an idea to a scientist in a relevant field.
2. If you’re trying to “sell” an idea to the vast majority of people, simple heuristics are what humans are adapted to. Strict logical validity bordering on scientism is an anti-nutrient that will prevent your message from being digested.
3. Mat Lalonde is a tremendously valuable asset to the scientific understanding of nutrition and to the paleo community (even if he doesn’t consider himself part of it), and I love learning from him in his areas of expertise.
4. The science needed to positively adjudicate every question on nutrition is simply not available. When confronted with the absence of data, the evolutionary framework of paleo has an above average probability of quickly approximating optimality.
5. Scientists who discount that hypotheses are bolstered by evolutionary logic do so to their own disadvantage.

Addendum: A Less Right Hypothesis

“if your movement is going to move forward it will have to be taken seriously by core scientists, and if it is to be taken seriously by core scientists, then you should present it in these terms. the reason why this is also useful is that scientist love to be handed projects on a silver platter.”

The first premise is simply false. The “movement” can go a long way without being taken seriously by core scientists. It would probably be helpful if more core scientists were on-board. Adoption might happen faster if core scientists were on-board. Counterpoint: The issue of climate change is a great example of how leading with mountains of science and scientists doesn’t necessarily translate to moving forward.

Henceforth, I trust I shall hear nary a word of such contrivances of abominable nonsense. No dear sirs and madams, not so much as a peep.

This article isn’t about a full analysis of the philosophy of the naturalistic fallacy, the nuances that distinguish it from Hume’s “is-ought” problem, or Hume’s extensive, reasoned, and persuasive arguments on the topic. This is a precursor for my upcoming writings that will leave naive regurgitators of Hume behind. I’m not going to [intentionally] violate Hume’s arguments, but people who invoke the is-ought problem too often don’t understand him. This article, and its references, are where I will direct the unsophisticated who attempt to speak Hume’s name in vain in attempts to dismiss my endeavor out of hand by rhetorical slight of hand.

And no, the irony of quoting others arguments to make my argument in light of the first paragraph is not lost on me. However, be advised that I have read these papers and generally understand the arguments within.

The Naturalistic Fallacy

In a nutshell, the fallacy is typically reduced to “ought cannot be derived from is”. Things that evolved through Darwinian selection are natural, or what “is”, but that doesn’t mean we can justify them by then saying that they “ought” to be simply because they’re evolved characteristics.

*King James, a Scotsman, really should have gotten this right the first time.

To take one of the most emotionally charged examples to illustrate the legitimate concerns… Some have argued for rape as an evolved strategy for increasing reproductive success in humans and other animals. The emotional nature of that question tends to preclude rational discussion, but it hasn’t been definitively answered one way or another. However, it becomes a political discussion when some assume that an ought can be derived from an is. The scenario as it stands would be invalid even if factually true (a premise that’s factuality is debatable).

Invalid structure:

Sexual rape of another person to increase reproductive success is an evolved behavior (factual premise).
Sexual rape of another person is right (ethical conclusion).

Hume would regard the following argument as deductively invalid:

Torturing people for fun causes great suffering (factual premise).
Torturing people for fun is wrong (ethical conclusion). (Wilson et al. 2003)

The problem is that Hume’s name and the naturalistic fallacy are often invoked any time something “is” or is natural is being discussed – as an implied refutation or an attempt to silence discussion. That’s not a problem in the two previous scenarios, but Hume explicitly outlined a path to making the connection. And… it’s not a complicated path so it’s easy to misapply the fallacy when its use is attempted without understanding it. Simply: one additional clause is required. Unfortunately, the argument is often dropped from the sky whenever an argument begins with a natural “is” and ends with an “ought” without respect to one, two, or a zillion additional clauses between them. This is a fundamental flaw in argumentation that can be (and regularly is) exploited for emotional and political purposes, then spread through the minds of those naive to what Hume actually said.

Various arguments obscured by the term “naturalistic fallacy”

*Section quoted from (Curry & Oliver 2006) but arranged in normal style for formatting and readability

“The first thing that anyone wishing to investigate the naturalistic fallacy discovers is that there is not one but many arguments that go by this name. A survey of the literature reveals not one but (at least) eight alleged mistakes that carry the label “the naturalistic fallacy”:

1. Moving from is to ought (Hume’s fallacy).
2. Moving from facts to values.
3. Identifying good with its object (Moore’s fallacy).
4. Claiming that good is a natural property.
5. Going ‘in the direction of evolution’.
6. Assuming that what is natural is good.
7. Assuming that what currently exists ought to exist. 8. Substituting explanation for justification.
8. Substituting explanation for justification.

Hume already resolved the “problem”

As I said earlier, Hume’s only requirement to proceed from “is” to “ought” was than an additional clause must be added to the equation.

More generally, a factual statement must be combined with an ethical statement to derive an ethical conclusion . Hence, ought cannot be described exclusively from is. The word “exclusively” is a crucial part of the naturalistic fallacy. If we remove it, the statement “ought cannot be derived from is” implies that the facts of the world have no relevance to ethical conclusions. (Wilson et al. 2003) [emphasis mine]

To resolve the invalid inductive example a few paragraphs back:

if we supply an additional premise, the argument can be made deductively valid:

Torturing people for fun causes great suffering (factual premise).
It is wrong to cause great suffering (ethical premise).
Torturing people for fun is wrong (ethical conclusion).

The addition of the ethical premise takes this from fallacy to logically stable footing. It certainly leaves open challenges to the premises, but not in terms of Hume’s critique.

My use of “is-ought”

I’m going to outline the general structure of my premises and conclusions, but be aware that this structure is not in itself necessarily complete. It can’t always be used alone to derive an ought from an is. Further, it appears problematic in that the grammatical construction appears somewhat circular. However, Darwinian evolution is a feedback mechanism. Thus, the circularity is not without merit.

Human nature is shaped by evolution (factual premise).
Judgments of right and wrong are made based on evolved biases and influences (ethical premise).
Examining human nature can lead us to insight on right and wrong (ethical conclusion).

In other words, if we’re using brains that have evolved ethical cues, all ethical premises are influenced by evolution. Thus, knowing about our evolved biases can help us answer questions in this realm. Further, this can help to spot sociocultural mismatches and assist in reconciling them with human nature apart from power structures.

A less nebulous example:

People evolved psychologically under politically egalitarian hunter-gatherer arrangements (factual premise).
Authoritarian structures are wrong because they limit freedom (ethical premise).
Imposing authoritarian structures on people is wrong (ethical conclusion).

Plainly, my conclusion that authoritarian structures are ethically wrong is subject to the factual premise and the ethical premise. As such, my conclusion are open to falsifiability in the face of sufficient damage to the premises. However, dismissal by illusory chants of “naturalistic fallacy” and clinging to the scraps from Hume’s table are not enough to lodge a successful complaint. At least… not according to Hume. Perhaps your intellect surpasses his, but I’m happy to bet against that occurrence.

Looking at this example more deeply reveals that I am merely adding a factual premise to a commonly asserted ethical premise. Paradoxically, this both bolsters the ethical premise while opening the endeavor to scrutiny by misapplication of Hume’s observations. This trick opens the door to questioning the ethical conclusion by the mere addition of the “is” to the equation. Beware incantations along any of these critical lines; cries of naturalistic fallacy violation may the be simple cries of ignorance.

My goal in future work is to continue to add and refine factual premises to bolster other commonly held ethical premises. Some will take Hume’s name in vain, but do not be distracted by the decontextualization of the is-ought problem and Hume’s own resolution.

Epilogue

Yes, that heading is a bit dramatic. I just wanted to point out that the two references not specifically invoked above have specific bearing on the application of evolutionary psychology in the way I’m using it. There is no doubt that the nurture Nazis will complain that evolutionary psychology is a hoax bla bla bla. If that’s your position, you’re wrong (Teehan et al. 2004; Walter 2006). But more on that later.

References
Curry, Oliver. “Who’s Afraid of the Naturalistic Fallacy?” Evolutionary Psychology (2006): 234-247. [pdf]

Teehan, John, and Roosevelt Hall. “On the Naturalistic Fallacy : A Conceptual Basis for Evolutionary Ethics.” Evolutionary Psychology (2004): 32-46. [pdf]

Walter, Alex. “The Anti-naturalistic Fallacy : Evolutionary Moral Psychology and the Insistence of Brute Facts.” Evolutionary Psychology, no. 1999 (2006): 33-48. [pdf]

Wilson, D.S., Eric Dietrich, and A.B. Clark. “On the inappropriate use of the naturalistic fallacy in evolutionary psychology.” Biology and Philosophy 18, no. 5 (2003): 669–681. [pdf]

Failing that, you could *cough* pay for a journal subscription or actually enroll in an institute of higher learning. The latter is probably a good idea because it gives you a better chance at actually comprehending what’s going on in a journal article. But hey, sometimes it’s more fun to annoy the hell out of trained scientists by reading the conclusion to every study you can feast your eyeballs on and make stuff up about your wariness of the methodology of everyone whose opinion you don’t agree with. You know, just squint and say… “I don’t know, that seems rather methodologically unsound and the sample size is too small to draw any real conclusions.” If you fancy yourself as more of a DIY scientist than an officially sanctioned liberal elite, here are three pointers for scoring free papers without schmoozing friends and acquaintances and flirting with the cute and surly girls with Lisa Loeb glasses…

1. Google Scholar

PubMed, SchmubMed. Sure, PubMed is officially curated by Sir Isaac Newton, Louis Pasteur, and Monsanto® and is thus the search engine of choice for all officially sanctioned science. Unfortunately, 9 out of 9 searches on PubMed lead you to nothing but “Abstracts” and screens asking for your credit card. Get to know and love Google Scholar. Unlike the easy to remember URL for PubMed ( http://www.ncbi.nlm.nih.gov/pubmed, duh!), Google Scholar is located at http://scholar.google.com.

Oh, another cool thing about Scholar vs. PubMed is that you actually get search results without having to know how to construct a “query” with symbols. Type in an author’s name or title or keyword or whatever and you’ll get some stuff. Also, there’s a great “Advanced Scholar Search” option. I like that it’s phrased in such a way that I can interpret it as “Advanced Scholar” who happens to be doing a search. I mean… if Google says so?

It isn’t that complicated. It’s like Google Search but filters out spam results and only spits out stuff for nerds. Another cool bonus is that it indexes Google Books too, which is nice if you’re looking for authors who would be in both categories. There are a couple tricks…

The most important bit is the “All ____ versions” link. For example, if you’d clicked on the “Mate choice turns cognitive” result, it leads you to a paywall. However, clicking the “All 16 versions” link leads you to a page including links to 5 PDF sources. And… PDF is the currency of the academic paper. The one below it that’s listed as “[DOC] from unm.edu” is probably a draft copy on the author’s site. Since we know Geoffrey F. Miller also happens to be a professor at UNM, it’s almost certain. And here again, clicking the “All 4 version” leads to a PDF copy as well.

The other “trick” is the “Cited by _____” link. This is a good indicator of how many other studies reference this particular study. Think of it as a Facebook ‘like’ but you like it so much you spent ten years studying something and wrote 50 pages about it. If that number is 1, it’s probably not very authoritative. The obvious exception is that if it’s a new-ish paper. Another cool thing is that you can instantly get to all the papers in the database that link to the study by clicking through. This is awesome for finding more recent studies or for finding criticisms that came out after it was published.

2. Google (Plebian Edition)

Most of the papers indexed on Google Scholar are hosted on servers at colleges or other semi-reputable sites. However, it’s often the case that you won’t find a PDF version of the exact study you’re looking for via Scholar. In that happens, head on over to regular ol’ Google. There, the magic word is “filetype:pdf”. Here’s an example search for one of the same papers above…

That result happens to be available through Scholar also, but the results will often be different. Also — and this is key — often results will have a weird title in the search result, but still be the correct paper when you click through. Google sometimes indexes the actual filename or a few words from the PDF if it’s not tagged properly.

3. Self-Aggrandizing Scientists

I kid Geoffrey Miller by the title of this subheading. He made a crack about navel-gazing bloggers in his book Spent: Sex, Evolution, and Consumer Behavior. He’ll be fine.

The important thing here is that authors sometimes have rights to host personal copies on their websites. Geoffrey Miller’s page has links to 20+ PDFs of various papers. Academics who are proud of their work aren’t shy about showing it off when they can, and that’s awesome. I’ve time and again found papers not available anywhere else right there on the author’s page. So… just go back to the vanilla version of Google and find their home page (usually a .edu).

*Quintuple your chances of success. Many studies are written by 2-10 authors. That’s right, any of their sites may have a copy.

This method also sometimes turns up entire chapters from books. Many scholarly books are compiled by editors who solicit work from various scientists to each write a chapter of the volume. If you search for the chapter author, you might find they have their contribution on their personal site as well.

Other

Once you’ve amassed a gazillion PDF files you’ll probably go crazy trying to keep them all sorted. For that, I use a cool (free) new-ish service called Mendeley. It allows you to organize, tag, and share PDFs via web or a downloadable interface. I’ve been using it for something like 9 months and I love it. To sign up and for links to “my” Paleolithic Diet Research group and others, you can click over to my profile there.

So there you have it… You’re three steps closer to becoming a liberal elite. And… you didn’t even have to buy a Volvo.

*Skip to below the videos if you don’t care about an aside about doctors.

I almost feel bad focusing this piece on one article in particular. I’ve been squinting skeptically at the talk surrounding epigenetics for months now. Because of that, much of what follows is directed at pop science journalism as much as anything.

I can’t bring myself to actually feel all that bad because Dr. Hyman is a doctor. Not only is he a doctor, but he brings up his doctoryness pretty much everywhere. And that’s fine, but training to be a medical doctor doesn’t necessarily provide special training in nutrition, exercise physiology, et cetera. It’s a problem because people respect doctors. It seems to me that people also tend to respect medical doctors (Dr. Hyman’s flavor) more than PhDs. Unfortunately for reality, the converse should often be true. The brief training medical doctors get in nutrition and exercise physiology has a higher probability of being dated (however slightly) when it comes in the form of chapters of generalized books and/or when it is taught by non-specialists. It’s certainly true that some medical doctors have stepped up their game and are exempt from this criticism, and that isn’t the point. It’s a problem of automatically granted authority where none should be granted. A recent exchange between Deepak Chopra (and M.D.) and Sam Harris (Ph.D. in neuroscience) illustrates this somewhat.

Scientific claims by Deepak Chopra

Response by Sam Harris (rewind to beginning for a funny moment: Michael Shermer calls Deepak “woo woo”)

Hilarious: Leanord Mlodinow (theoretical physicist, co-authored 2 books with Stephen Hawking) pwns Deepak

The Meat of It

“Science is now proving what we all knew intuitively—that how we live, the quality of our relationships, the food we eat, how we use our bodies, and the environment that washes over us and determines much more than our genes ever will.”

Propaganda 101: The False Dichotomy

The above (and below) quote is from a blog post, ‘Secrets to Health are in Diet and Lifestyle Not Human Genome: The Failure of Decoding the Human Genome and the Future of Medicine‘ [it actually starts with “Secretes”, but I assume that’s a typo], by Dr. Mark Hyman. There is some value here, but when I’m being offered “secrets to health” and instead given fluffy science, appeals to intuitive folk psychology, and hyperbole, I have a hard time recommending you endeavor to dig for nuggets of truth. The way the article is framed is misleading, and… well… wrong. It’s not wrong to say that epigenomics is real and important, but it is wrong to dismiss genetics in favor of epigenomics. That approach is not only a logical fallacy, but an advertising/propaganda tactic. Claims along these lines are madness when we consider that all epigenomics can ever do – by its own definition – is influence the expression of genes. Knowing this simple fact refutes the sensationalist claim that, “Science is now proving [that] the environment… determines much more than our genes ever will.” [emphasis mine]

So at first I was put off by the article. But that was before I remembered that I’ve recently been working on a theory proposing that, while beneficial to plants via chlorophyll, our yellow sun presents a contra-optimal environmental input to epidermal vitamin D synthesis. If we were able to find suitable habitat on a planet orbiting a red sun, the spectrum phase-shift would cause a hormone balance reconstituentialization switching the protein cascade of certain genes to unlock the potential for conscious human negation of both gravity and friction. Failing that, I have high hopes for the venom of radioactive spiders.

Now… if I actually believed in the Superman or Spiderman hypotheses, statements similar to those made by Dr. Hyman would enable their theoretic viability.

The Epigenome: Bypassing Darwin and Evolution

More important than our collection of genes, it now appears, is how those genes are controlled by both internal and external factors—our thoughts, stress, social connections, what we eat, our level of physical and mental activity, and our exposure to microbes and environmental toxins. These factors are switches that turn genes on and off and determine which proteins are expressed. The expressed proteins, in turn, trigger signals of disease or health.

In the context of this article, the claim that epigenomics bypasses Darwin and evolution seems to be more of a political hope than a scientifically defensible position. Now everybody, in your best Beach Boys harmony:

Wouldn’t it be nice if genes were over
‘Cause selling magic-bullets never would be wrong
And wouldn’t it be nice to live forever
In worlds where supra-malleable human beings belong

No, I am not saying Dr. Hyman made this argument explicitly. Yes, I am saying the implication of the argument unlocks false hope in a world in which epigenomic influences wield supreme power. Invoking the concept of control by external factors is problematic. It implies that, if only we can find the right environmental factor(s), we can positively or negatively bend genetic expression to overcome any malady or limitation. If genes and/or evolution don’t matter, nothing can stop us, comrades!

Yes folks, I regret to inform you that it’s the “nurture trumps nature” argument all over again. Not only is the mind a blank slate (as others claim) in this warm and fuzzy world,  but now the body is as well. Bla bla fracking bla.

It could be rightly said that I’m attributing more weight to Dr. Hyman’s mention of epigenomics than is appropriate. However, the other factors he discusses (exposomics, nutrigenomics and microbiomics, and toxigenomics) fall under my same criticism asserting an interactionist framework. In fact, while trumpeting the “failure” of genomics, he simultaneously admits “the dynamic interplay of the environment” and genes. Nutrients, microbes, toxins, and (catch-all term) exposomes all collide with the human genotype and phenotype in ways that can’t accurately be cast in a binary light in which genomics has been deemed a failure. And despite the equivocations and qualifications invoked to temper his message to be mostly accurate-ish, there’s no hope of escaping Darwin and evolution in Dr. Hyman’s position.

Three neo-Darwinist points about epigenetic switches

*Note the switch from “epigenomics” to “epigenetics”. For our purposes, epigenomics can sufficiently be thought of as a macro view of epigenetics.

As is always the case in the “nature vs. nurture debate”, there is no “nature vs. nurture debate”. The false dichotomy only exists in the polemical propaganda of the nurture Nazis (think Seinfeld’s “Soup Nazi”, not reductio ad Hitlerum). No, there is no versus, there is only synthesis amidst a continuum. The 3 points below are from Oana Carja‘s excellent answer to the question, “Is it time to revise evolutionary biology textbooks to reconcile Darwin with Lamarck?” They have been edited, but the two quoted paragraphs that follow appear in their original form:

1. A property of the DNA sequence itself is the ability to switch epigenetic state, and is therefore subject to natural selection on conventional mutations.

2. Natural selection will  eliminate switches with maladaptive effects but perpetuate, and refine, those with adaptive effects.

3. The additional ‘information’ represented by a  DNA sequence’s particular epigenetic state is repeatedly being reset.

Thus, epigenetic switches do not involve cumulative, open-ended evolutionary change. Switches are wonderful tools that increase the options available to  DNA sequences but, in themselves, should not challenge the beliefs of a neo-Darwinist. The high rate of epigenetic change is also important because the level of achievable adaptive precision is limited by the  fidelity of replication. Adaptation is constantly being degraded by copying  errors and the higher the rate of errors, the larger the selective advantage that is required to maintain previous adaptation. Thus, small selective advantages are  unable to be maintained in the presence of low-fidelity replication.

Therefore,  significant adaptations are expected to be encoded genetically rather than  epigenetically. Modern neo-Darwinists do not deny that epigenetic mechanisms play an important role during development nor do they deny that these mechanisms  enable a variety of adaptive responses to the environment. Recurrent,  predictable changes of epigenetic state provide a useful set of switches that allow genetically identical cells to acquire differentiated functions and allow facultative responses of a genotype to environmental changes (provided that  ‘similar’ changes have occurred repeatedly in the past). However, most neo-Darwinists would claim that the ability to adaptively switch epigenetic state is a property of the DNA sequence (in the sense that alternative  sequences would show different switching behavior) and that any increase of adaptedness in the system has come about by a process of natural selection.

In other words, epigenetic switches themselves are subject to evolution. Thus, I must sincerely apologize for my current inability to christen epigenetics as the long-awaited mechanism to bring the DC vs. Marvel debate into the scientific realm.

The astute among us may have realized by now that my criticism of Dr. Hyman’s article relies almost entirely on just four of his words. If “failure” wasn’t in the title, and “control” wasn’t used in reference to extra-genomic influence, and “bypassed” didn’t precede Darwin and evolution,  and “determines” wasn’t attributed to epigenetic influence, I may not have been forced to write this. In actuality, those four little words poison an otherwise interesting article in a way that misleads casual readers. I’ll just put aside the problems with the use of “much more” in the lead quote unless someone raises further concern in the comments.

Epigenetics is interesting. Epigenetics is useful. However, epigenetic influence remains confined by genetic potential and Darwinian selection. Let us not make it out to be the panacea it is not. Beyond that, I believe we’re at, or even beyond, the point at which there needs to be some push-back on pop science framings of epigenetics as something that somehow undermines neo-Darwinian evolution. From a strategic perspective, misconstrued epigenetics can be taken out of context far too conveniently by the Creationist and/or Intelligent Design programs.

Oh, and for those of the paleo persuasion… Dr. Hyman’s prescription for gut health? “Eat whole unprocessed foods with plenty of fiber… beans… and whole grains.” Beans and whole grains for gut health!? I don’t feel bad about picking on this article for four words after all. Please don’t take that as ad hominem; it supports the thoughts in the preface.