Epigenetics and the Brain: Woo-free Coolness

switchboardIn my latest column for Discover, I take a look at epigenetics and the brain. Along with the genetic circuitry in the DNA of our brain cells, we also have an additional layer of molecules that can switch genes on and off. A lot of this so-called epigenome gets locked into place when our brains are first developing, but it still remains malleable throughout our lives. Our environment can rework our epigenome, and some studies suggest that this reworking may produce long-term changes in personality. Even mental conditions like depression may be partly epigenetic. And if we can figure out how conditions like depression alter the epigenome, we may be able to re-alter it to counter those disorders.

For some reason, epigenetics is getting burdened with a lot of sensationalist quasi-mysticism these days. Epigenetics does not overturn everything we ever knew about everything. But it’s possible for something to be woo-free and cool at the same time, as I hope my column makes clear. Check it out.

[Image: U.S. Army Center of Military History]

0 thoughts on “Epigenetics and the Brain: Woo-free Coolness

  1. Great article, Carl.

    I think epigenetics is fascinating and I’m always excited to hear about new findings in the field, but I accept it as part and parcel of molecular biology research and I’m always dissapointed with the sensationalist coverage it seems to get.

    The point that’s constantly raised is that physical experiences by a parent or grandparent can result in epigenetic inheritance by offspring. I can understand this happening in terms of something like nutrient stress occurring to a male, but beyond that I can’t see a mechanism, and if I’m missing something it’d be great if someone could let me know.

    Either way, I think the idea of epigenetics arising as some massive obstacle to contemporary ideas of evolution and (as is often mentioned) offering support to Lamarckism is exaggerated to say the least.

    But as I said, it’s fascinating, and I can’t wait to learn more as it’s discovered.

  2. My reading of the “woo” attached to epigenetics is similar to my reading of “woo” often attached to the “environmental” contribution to heredity.

    Our entire cultural discourse is dripping with genetic reductionism, and imbues genetic variation with all sorts of meaning–in the memetic zeitgeist, it mixes with sexism (see Larry Summers), racism (ask James Watson–I’m betting he’s good for a quote in all of these categories, as a matter of fact), classism (the Selfish Gene was Enron’s Jeff Skilling’s favorite book–others may reasonably choose not to read into that, but I think it’s telling). Our culture posits a relationship between DNA and phenotype that is ludicrously deterministic–a relationship so unrealistic that we don’t even need to turn to the lab bench to see its flaws.

    Some people know in their gut that this is a false picture–that too much beautiful complexity is being reductively explained away–that subtlety is being ignored more than explained–and they use what language they have to express this sentiment.

    That doesn’t mean I give them a complete pass–often when science draws back a curtain, there’s a reaction “close it, we prefer the beautiful, mysterious darkness!” which is a) antithetical to my aesthetic as a science-person–I love light & truth as much or more than I love puzzles & mystery–and b) potentially unhealthy for society. But I urge us not to judge the “woo woos” too harshly–they’re just representing the other side of the popular coin.

    Anyhow, this is why I love reading your writing, Carl–I think you do a great job of telling the lay reader what the science is actually asserting, and bringing the beauty of the subtle truths and the tantalizing challenge of the remaining questions to the fore, where they belong–stepping around and pointing out incorrect or unsupported potential interpretations along the way. This kind of thoughtful approach offers the reader a rare chance to get closer to a “real” picture of the glorious overarching patterns & relationships in nature.

    Can’t wait to read the article–thanks for the wonderful work!

  3. “Nothing ruins your day like finding that your brain has turned into a pancreas.”

    Hehe. I love this line. It certainly puts the role of epigenetics in perspective.

    Fabulous piece.

  4. I agree about the rather sad attempts to link epigenetics with “woo”. The silliness never ceases, it just finds new targets…

    I write about epigenetics once in a while myself (see link on my name, for example), although without the luxury of writing for the likes of Discover 🙂

    Luke,

    Take the view for a moment that the ‘founding’ “epigenetic mark” is methylation of DNA bases with the ‘higher levels’ of epigenetic states being derived from this.

    One possible model for (some cases of) “inheriting” an epigenetic state is that after methylation marks are erased in the early embryo (as is the case for most genes in mammals), the developing embryo sets the methylation state of some genes in response to levels of factors received from the mother while still in the uterus. In effect, the parent is an “environmental factor” for the developing embryo. You’ll notice that this isn’t inheritance in the sense of genetic inheritance, but really “environment” effects on (long-term) gene regulation, where the environment in question just happens to be the mother. You’ll also notice this is a maternal effect, not paternal.

  5. There is a strain of thought in woo that believes the ideas are scientific, but are simply beyond the current ability of technology to measure. Of course, like any pseudoscience, they’ll disregard any evidence that would prove their beliefs to be wrong. So you get weirdness like Homeopaths embracing the language of “quantum” and “epigenetic”, while ignoring the widely understood mechanisms of germ theory, placebo and biochemistry that prove the entire concept is flawed.

  6. I imagine the point of view I’m about to express will be considered “woo” here, but i’ll try it anyway.

    I would be that if you had a Carl Zimmer writing 50 years ago even vaguely alluding to the kind of genetic flexibility in the Discover article, the physicalists of the time would be shouting “woo” (or whatever the equivalent was half century ago).

    There is also the opposite problem from the “woo” you describe here. I recall in the 1970s, reading dream researchers who vehemently denied that anything like lucid dreaming could ever take place (one philosopher, my favorite, simply defined it out of existence – if sleep was a state in which there is no consciousness, he “reasoned”, then not only lucid dreams, but dreams simply are impossible, since dreams are a form of consciousness which takes place during sleep. Really this guy was considered a genuine academic philosopher at the time!).

    Well, when you look at research which has been validated, replicated, approved by Nobel prize winners, accepted as a possibility by over 60% of all physicists – I’m talking about parapsychology, which I’ll wager $10,000 that everyone here “knows” is woo and will vilify me and anyone else for daring to assert it’s anything but absolute pseudoscience – what does it mean that everyone here will dismiss it as woo?

    And what happens 50 years from now when telepathy and remote viewing and psychokinesis are considered acceptable by mainstream science?

    What do the scientists of 2072 think of the comments in 2010 that seem so assured of what is “woo” and what is not?

    What then?

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