Category: Science

No GMO = Me Not A Customer

Letter written to Freedom Foods, reproduced below:

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Just thought I’d mention: I ran into your products in a store. Nutritionally they were exactly what I was looking for, except.

Except they contain no genetically-modified organisms. This is exactly saying “These products destroy the environment.” Non-GMO crops offer no nutritional or health advantage, but need more cropland to grow the same amount. By excluding GMO crops you are quite literally helping to destroy the wild and uncultivated lands, while forcing the use of more pesticides and fertilizers.

So I can’t, in good conscience, buy your products.

Please do the right thing and use GMO crops.

Thank you.

 

Note to other food sellers: this is a policy. I can’t help you destroy the world by promoting pointlessly inefficient agriculture.

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Cloned crayfish swarm conquers Europe

… and moves on to the rest of the world!

OK, this is seriously weirder than the mad science plot. Science Magazine reports that a hybridization event among slough crayfish (native to North America) resulted in a triploid strain appearing, all female and reproducing by self-cloning.

Triploid! You all have two copies of every gene, one inherited from your mother and one from your father. There are exceptions, e.g. people with Down syndrome have three copies of all or part of one chromosome. The marbled crayfish is the super-powered version: it has three copies of its entire genome, two near-identical copies (presumably from one ancestral clone-parent) and one of another proto-parental genome.

It’s the only known decapod crustacean to reproduce asexually. It does it fast, it’s displacing other organisms all over the place.

It may not be obvious to a non-biologist how deeply weird this is. Polyploidy (having more than two copies of each gene) is common in higher plants, but it’s very, very rare in animals, and this speciation event happened in the 1980s, so very recently.

The Science article is very readable, and if you’re interested I recommend it.

(Image courtesy Wikimedia Commons user Selso)

Feeling articulate

So, I’m currently reading Dry Store Room #1, a book about the experience of working at the Natural History Museum in London.

It’s a great book by an author who is both a Fellow of the Royal Society (Britain’s pre-eminent scientific body) and the Royal Academy of Literature (same for writing). Highly recommended.

So naturally, I’m thinking in terms of museum preparation when I come across this comic:

And my immediate reaction: this is a museum diorama and not a good one. Real skeletons in the real environment do not look like that. The bones separate and are strewn about, they don’t look like an anatomy-teaching specimen you might find in a medical school–those are wired together to show the normal relationship of the bones. Also, in a real desert everything from ants up to condors would be ripping the corpse apart and taking away useful bits for their own (digestive) purposes, scattering the bones further. The only way real bones stay close together is by getting suddenly buried, for instance by volcanic ash.

No, it isn’t important. No, I’m not criticizing Dave Blazek. Yes, I think my own idiosyncratic reaction was weird enough to be worth posting.

This is a very rare double-post (the only one) between this and my other blog at Nitpicking.com.

10% of your brain: can we please put this one to bed?

I’ve been hearing for decades about how we only use 10% of our brains. It’s silly as soon as you think about it: why would we evolve such huge brains for our body size then not use them?

I believed it as a kid, mind you, before being trained in biology

Now Monty (a decades-old newspaper comic, formerly called Robotman), demolishes that whole urban legend in four panels.

Meddick is right. Can we (as a culture) please stop making idiot movies based on this myth?

Gluten sensitivity: is it a thing?

First off, there is most certainly a real medical condition called celiac disease. It involves a measurable immune reaction to foods that contain gluten. Gluten is a protein-starch complex (but often described in non-technical and medical writing as just protein) found in some grass seeds, such as wheat, rye, and barley, but not others like rice and corn. It is not found in any foods other than those made from these specific grains.

Celiac is apparently found in about 1% of the population.

Some medical authorities and lay people also assert the existence of “Non-Celiac Gluten Sensitivity” (NGCS). As you might expect, this describes people who are sensitive to gluten in some way, but not through the (partially) known mechanism of celiac disease. To quote a BBC article by “Doctor Chris” van Tulleken, “Although many people who do not have coeliac disease claim to suffer gut symptoms like bloating and nausea when they eat gluten – and even other things like “brain fog” and tiredness – these have not been linked to any physiological changes that can be measured and hence used to make a clinical description and diagnosis.”

Someone with my background wonders if a claimed syndrome that has such a wide variety of symptoms which correlate to nothing measurable might be a result of pareidolia, the tendency of the human brain to find patterns in noisy data, even when no such pattern is real. Examples of what I have just named “pareidolic diseases” include Morgellon’s Syndrome, chronic Lyme disease, and Candidiasis/Yeast Allergy. They share having relatively common, non-specific symptoms (e. g. fatigue, stomach upset) and not being detectable by any lab tests, even when (as with Lyme disease) there is a well-known, effective test available.

Dr. van Tulleken’s “Trust Me, I’m a Doctor” team conducted a study to test the reality of NCGS. The found 60 people, some of whom claimed to experience NGCS, and put them on a gluten-free diet including (experimenter-supplied) gluten-free pasta, but for two weeks (randomly selected?) of the study period, each was given pasta containing gluten instead. The team then analyzed the subjects’ reported symptoms, and also performed lab tests to show inflammation and IgE (antibody) levels. The study was double-blinded, in that neither researchers nor subjects knew in which two week period the subjects were eating gluten until after the study concluded. The subjects acted as their own controls by experiencing both with- and without-gluten diets.

The results: subjects did in fact report feeling fewer gut-related symptoms like bloating during the gluten-free weeks. Variation in other symptoms (e.g. tiredness) was not statistically significant. There was also no significant correlation between gluten-free diet and the lab values being measured.

Dr. van Tulleken does state in the linked BBC article that it’s likely at least some subjects knew which weeks they were eating gluten-containing pasta. And as he concedes, this can easily explain the slight variation in the digestive symptoms.

A weakness he apparently did not realize in his analysis: the two pastas are very clearly made with different recipes. It’s perfectly possible that the gluten-containing pasta that was used has some other difference from the gluten-free one that explains the gut symptomology, perhaps an herb or a preservative that some people are really slightly sensitive to. It’s  possible that the gluten-containing pasta just has less fiber (for one possible example), and that the additional fiber in the gluten-free food aided the subjects’ digestion. Dr. van Tulleken doesn’t provide the recipes/brands for the two foods, making it hard to speculate beyond that guess.

Also, the subjects were eating food they selected and purchased themselves, aside from the pasta. Since as far as one can tell from the BBC article they weren’t asked to record their consumption, it wouldn’t be difficult for this dietary variation to randomly cause one group to score higher on some symptoms.

I’m surprised that Dr. van Tulleken did not report whether the self-diagnosed NGCS sufferers showed greater incidence of gut symptoms than the non-diagnosed. If NGCS is real (and not universal in the population) then a difference between NGCS patients and the rest of the subjects would certainly exist.

It is not stated in the article, but I suspect Dr. van Tulleken’s group does not plan to publish these results in a peer-reviewed journal, which seems to me to be disappointing. I’d love to read in more detail about the protocol and results.

As published, the results seem completely compatible with NGCS being a pareidolic disease. They are also consistent with NGCS being a real syndrome, but with only a small effect (at least in the experimental circumstances). Note that with its weak protocol and small sample size (n=60) it isn’t strong evidence for anything.

I suggest that Dr. van Tulleken’s group or someone else repeat the experiment but with the subjects eating identical diets (entirely supplied by the experimenters, ideally, not just gluten-free with the subjects buying their own food). However, each subject would be required to swallow 10 identical capsules per day. For the “control” period the capsules would contain a non-gluten protein. For the “experimental” period, the capsules would contain gluten proteins. That would make it impossible for the subjects to detect which weeks include gluten from the flavor/texture of their food, and also eliminate the possible effect of other ingredients in the two different pasta recipes.

Seeing is, um, inventing?

It’s a truism in cognitive psychology and neurobiology that “seeing” is not what happens in the eyes, but what is perceived by the “higher” brain centers. Our perceptual process largely consists of various brain centers removing information from the stream and pre-digesting it so that the decision-making and analysis parts of the brain are not overwhelmed by too much information. For instance, your visual cortex auto-corrects for lighting changes (like a good digital camera, only better) so you don’t even perceive the dramatic color shifting that “really” happens when the sun comes out from behind a cloud. That explains the famous white-and-gold dress that was really black-and-blue … or vice versa? The brain constantly corrects color perception for what it “thinks” (it isn’t really thought) the lighting is, and in this case can be fooled.

I just experienced a higher-brain-level version of this illusion. Not as dramatic or reproducible, but interesting.

I was looking at the front page of Wikipedia (for today as I write, April 14). The explanation of the featured image refers to scientist and philosopher Charles Sanders Peirce.

Quick: did you read his last name as “Pierce”? Dr. Peirce’s name was not spelled in the far more common way (as the standard spelling of a word meaning “puncture with a sharp object”). However, practiced readers of English will tend to read it as the standard spelling because we don’t consciously take the time to analyze the spelling of familiar words. We “sight read” by recognizing the overall pattern at a lower (subconscious) level and our consciousness receives only the meaning (and/or sound) of the word. That’s a perceptual illusion, like the dress illusion but from a different brain area. (Meaning-perception takes place chronologically after color-perception.)

I had a two-stage experience. I had actually heard of Peirce before, and recognized the name. I also misperceived it as “Pierce”. So my thought process was, “Hey, Wikipedia misspelled his name. I’d better correct it.” At that point, I looked back at it, with my perceptions tuned to perceive spelling instead of meaning, and immediately saw that it was correct in the first place. That brought my normal ability to ignore the shapes and order of the letters when reading to conscious attention, so I blogged about it.

I’ve always been fascinated by illusions, but this is one time I was blindsided by one I hadn’t thought about before.