Epigenetics

I remember when I first heard about epigenetics–the concept sounded awesome.

Now I cringe at the word.

To over simplify, “epigenetics” refers to biological processes that help turn on and off specific parts of DNA. For example, while every cell in your body (except sperm and eggs and I think blood cells?) have identical DNA, they obviously do different stuff. Eyeball cells and brain cells and muscle cells are all coded from the exact same DNA, but epigenetic factors make sure you don’t end up with muscles wiggling around in your eye sockets–or as an undifferentiated mass of slime.

If external environmental things can have epigenetic effects, I’d expect cancer to be a biggie, due to cell division and differentiation being epigenetic.

What epigenetics probably doesn’t do is everything people want it to do.

There’s a history, here, of people really wanting genetics to do things it doesn’t–to impose free will onto it.* Lamarck can be forgiven–we didn’t know about DNA back then. His theory was that an organism can pass on characteristics that it acquired during its lifetime to its offspring, thus driving evolution. The classic example given is that if a giraffe stretches its neck to reach leaves high up in the trees, its descendants will be born with long necks. It’s not a bad theory for a guy born in the mid 1700s, but science has advanced a bit since then.

The USSR put substantial resources into trying to make environmental effects show up in one’s descendants–including shooting anyone who disagreed.

Trofim Lysenko, a Soviet agronomist, claimed to be able to make wheat that would grow in winter–and pass on the trait to its offspring–by exposing the wheat seeds to cold. Of course, if that actually worked, Europeans would have developed cold-weather wheat thousands of years ago.

Lysenko was essentially the USSR’s version of an Affirmative Action hire:

“By the late 1920s, the Soviet political leaders had given their support to Lysenko. This support was a consequence, in part, of policies put in place by the Communist Party to rapidly promote members of the proletariat into leadership positions in agriculture, science and industry. Party officials were looking for promising candidates with backgrounds similar to Lysenko’s: born of a peasant family, without formal academic training or affiliations to the academic community.” (From the Wikipedia page on Lysenko)

In 1940, Lysenko became director of the USSR’s Academy of Science’s Institute of Genetics–a position he would hold until 1964. In 1948, scientific dissent from Lysenkoism was formally outlawed.

“From 1934 to 1940, under Lysenko’s admonitions and with Stalin’s approval, many geneticists were executed (including Isaak Agol, Solomon Levit, Grigorii Levitskii, Georgii Karpechenko and Georgii Nadson) or sent to labor camps. The famous Soviet geneticist Nikolai Vavilov was arrested in 1940 and died in prison in 1943. Hermann Joseph Muller (and his teachings about genetics) was criticized as a bourgeois, capitalist, imperialist, and promoting fascism so he left the USSR, to return to the USA via Republican Spain.

In 1948, genetics was officially declared “a bourgeois pseudoscience”; all geneticists were fired from their jobs (some were also arrested), and all genetic research was discontinued.”  (From the Wikipedia page on Lysenkoism.)

Alas, the Wikipedia does not tell me if anyone died from Lyskenkoism itself, say, after their crops failed, but I hear the USSR doesn’t have a great agricultural record.

Lysenko got kicked out in the 60s, but his theories have returned in the form of SJW-inspired claims of the magic of epigenetics to explain how any differences in average group performance or behavior is actually the fault of long-dead white people. Eg:

Trauma May be Woven into DNA of Native Americans, by Mary Pember

” The science of epigenetics, literally “above the gene,” proposes that we pass along more than DNA in our genes; it suggests that our genes can carry memories of trauma experienced by our ancestors and can influence how we react to trauma and stress.”

That’s a bold statement. At least Pember is making Walker’s argument for him.

Of course, that’s not actually what epigenetics says, but I’ll get to that in a bit.

“The Academy of Pediatrics reports that the way genes work in our bodies determines neuroendocrine structure and is strongly influenced by experience.”

That’s an interesting source. While I am sure the A of P knows its stuff, their specialty is medical care for small children, not genetics. Why did Pember not use an authority on genetics?

Note: when thinking about whether or not to trust an article’s science claims, consider the sources they use. If they don’t cite a source or cite an unusual, obscure, or less-than-authoritative source, then there’s a good chance they are lying or cherry-picking data to make a claim that is not actually backed up by the bulk of findings in the field. Notice that Pember does not provide a link to the A of P’s report on the subject, nor provide any other information so that an interested reader can go read the full report.

Wikipedia is actually a decent source on most subjects. Not perfect, of course, but it is usually decent. If I were writing science articles for pay, I would have subscriptions to major science journals and devote part of my day to reading them, as that would be my job. Since I’m just a dude with a blog who doesn’t get paid and so can’t afford a lot of journal memberships and has to do a real job for most of the day, I use a lot of Wikipedia. Sorry.

Also, I just want to note that the structure of this sentence is really wonky. “The way genes work in our bodies”? As opposed to how they work outside of our bodies? Do I have a bunch of DNA running around building neurotransmitters in the carpet or something? Written properly, this sentence would read, “According to the A of P, genes determine neuroenodcrine structures, in a process strongly influenced by experience.”

Pember continues:

“Trauma experienced by earlier generations can influence the structure of our genes, making them more likely to “switch on” negative responses to stress and trauma.”

Pember does not clarify whether she is continuing to cite from the A of P, or just giving her own opinions. The structure of the paragraph implies that this statement comes from the A of P, but again, no link to the original source is given, so I am hard pressed to figure out which it is.

At any rate, this doesn’t sound like something the A of P would say, because it is obviously and blatantly incorrect. Trauma *may* affect the structure of one’s epigenetics, but not the structure of one’s genes. The difference is rather large. Viruses and ionizing radiation can change the structure of your DNA, but “trauma” won’t.

” The now famous 1998 ACES study conducted by the Centers for Disease Control (CDC) and Kaiser Permanente showed that such adverse experiences could contribute to mental and physical illness.”

Um, no shit? Is this one of those cases of paying smart people tons of money to tell us grass is green and sky is blue? Also, that’s a really funny definition of “famous.” Looks like the author is trying to claim her sources have more authority than they actually do.

“Folks in Indian country wonder what took science so long to catch up with traditional Native knowledge.”

I’m pretty sure practically everyone already knew this.

“According to Bitsoi, epigenetics is beginning to uncover scientific proof that intergenerational trauma is real. Historical trauma, therefore, can be seen as a contributing cause in the development of illnesses such as PTSD, depression and type 2 diabetes.”

Okay, do you know what epigenetics actually shows?

The experiment Wikipedia cites is of male mice who were trained to fear a certain smell by giving them small electric shocks when they smelled the smell. The children of these mice, conceived after the foot-shocking was finished, startled in response to the smell–they had inherited their father’s epigenetic markers that enhanced their response to that specific smell.

It’s a big jump from “mice startle at smells” to “causes PTSD.” This is a big jump in particular because of two things:

1. Your epigenetics change all the time. It’s like learning. You don’t just learn one thing and then have this one thing you’ve learned stuck in your head for the entire rest of your life, unable to learn anything new. Your epigenetics change in response to life circumstances throughout your entire life.

Eg, (from the Wikipedia):

“One of the first high-throughput studies of epigenetic differences between monozygotic twins focused in comparing global and locus-specific changes in DNA methylation and histone modifications in a sample of 40 monozygotic twin pairs. In this case, only healthy twin pairs were studied, but a wide range of ages was represented, between 3 and 74 years. One of the major conclusions from this study was that there is an age-dependent accumulation of epigenetic differences between the two siblings of twin pairs. This accumulation suggests the existence of epigenetic “drift”.

In other words, when identical twins are babies, they have very similar epigenetics. As they get older, their epigenetics get more and more different because they have had different experiences out in the world, and their experiences have changed their epigenetics. Your epigenetics change as you age.

Which means that the chances of the exact same epigenetics being passed down from father to child over many generations are essentially zilch.

2. Tons of populations have experienced trauma. If you go back far enough in anyone’s family tree, you can probably find someone who has experienced trauma. My grandparents went through trauma during the Great Depression and WWII. My biological parents were both traumatized as children. So have millions, perhaps billions of other people on this earth. If trauma gets encoded in people’s DNA (or their epigenetics,) then it’s encoded in virtually every person on the face of this planet.

Type 2 Diabetes, Depression, and PTSD are not evenly distributed across the planet. Hell, they aren’t even common in all peoples who have had recent, large oppression events. African Americans have low levels of depression and commit suicide at much lower rates than whites–have white Americans suffered more oppression than black Americans? Whites commit suicide at a higher rate than Indians–have the whites suffered more historical trauma? On a global scale, Israel has a relatively low suicide rate–lower than India’s. Did India recently experience some tragedy worse than the Holocaust? (See yesterday’s post for all stats.)

Type 2 Diabetes reaches its global maximum in Saudia Arabia, Oman, and the UAE, which as far as I know have not been particularly traumatized lately, and is much lower among Holocaust descendants in nearby Israel:

From a BBC article on obesity
From a BBC article on obesity

It’s also very low in Sub-Saharan Africa, even though all of the stuff that causes “intergenerational trauma” probably happened there in spades. Have Americans been traumatized more than the Congolese?

This map doesn’t make any sense from the POV of historical trauma. It makes perfect sense if you know who’s eating fatty Waestern diets they aren’t adapted to. Saudia Arabia and the UAE are fucking rich (I bet Oman is, too,) and their population of nomadic goat herders has settled down to eat all the cake they want. The former nomadic lifestyle did not equip them to digest lots of refined grains, which are hard to grow in the desert. Most of Africa (and Yemen) is too poor to gorge on enough food to get Type-2 Diabetes; China and Mongolia have stuck to their traditional diets, to which they are well adapted. Mexicans are probably not adapted to wheat. The former Soviet countries have probably adopted Western diets. Etc., etc.

Why bring up Type-2 Diabetes at all? Well, it appears Indians get Type-2 Diabetes at about the same rate as Mexicans, [Note: PDF] probably for the exact same reasons: their ancestors didn’t eat a lot of wheat, refined sugar, and refined fats, and so they aren’t adapted to the Western diet. (FWIW, White Americans aren’t all that well adapted to the Western Diet, either.)

Everybody who isn’t adapted to the Western Diet gets high rates of diabetes and obesity if they start eating it, whether they had historical trauma or not. We don’t need epigenetic trauma to explain this.

“The researchers found that Native peoples have high rates of ACE’s and health problems such as posttraumatic stress, depression and substance abuse, diabetes all linked with methylation of genes regulating the body’s response to stress. “The persistence of stress associated with discrimination and historical trauma converges to add immeasurably to these challenges,” the researchers wrote.

Since there is a dearth of studies examining these findings, the researchers stated they were unable to conclude a direct cause between epigenetics and high rates of certain diseases among Native Americans.”

There’s a dearth of studies due to it being really immoral to purposefully traumatize humans and then breed them to see if their kids come out fucked up. Luckily for us, (or not luckily, depending on how you look at it,) however, humans have been traumatizing each other for ages, so we can just look at actually traumatized populations. There does seem to be an effect down the road for people whose parents or grandparents went through famines, but, “the effects could last for two generations.”

As horrible as the treatment of the Indians has been, I am pretty sure they didn’t go through a famine two generations ago on the order of what happened when the Nazis occupied the Netherlands and 18-22,000 people starved.

In other words, there’s no evidence of any long-term epigenetic effects large enough to create the effects they’re claiming. As I’ve said, if epigenetics actually acted like that, virtually everyone on earth would show the effects.

The reason they don’t is because epigenetic effects are relatively short-lived. Your epigenetics get re-written throughout your lifetime.

” Researchers such as Shannon Sullivan, professor of philosophy at UNC Charlotte, suggests in her article “Inheriting Racist Disparities in Health: Epigenetics and the Transgenerational Effects of White Racism,” that the science has faint echoes of eugenics, the social movement claiming to improve genetic features of humans through selective breeding and sterilization.”

I’m glad the philosophers are weighing in on science. I am sure philosophers know all about genetics. Hey, remember what I said about citing sources that are actual authorities on the subject at hand? My cousin Bob has all sorts of things to say about epigenetics, but that doesn’t mean his opinions are worth sharing.

The article ends:

“Isolating and nurturing a resilience gene may well be on the horizon.”

How do you nurture a gene?

 

There are things that epigenetics do. Just not the things people want them to do.

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