Seasons

Not knowing eternity is to do evil things blindly.
—Lao Tzu

To everything there is a season and a time to every purpose under heaven.
—Ecclesiastes 3:1

To understand today’s posting, I’m going to need to teach some biology first.  Specifically, I am going to need to explain a concept that most people even with a background in biology are not always aware of—the concept of epigenetics.  This idea and its field of study explore how environmental impacts on an organism’s genetic code can be passed down through generations independent of the genetic code itself, and it is yet another stake in the heart of what for decades was considered the Central Dogma of genetics:  that a sequence of DNA codes for a specific protein which produces a specific trait.  Turns out, per usual, the truth is more complicated.

What’s more, it can also seem somewhat eerie, especially when we look at an example of epigenetics in action.  Take the common white rat.  This favorite of genetic research everywhere has a gene, called fosB, that directly impacts the nurturing behaviors of female rats with their young.  Normal rat mothers will actively groom their offspring, cuddle with them, and perform other calming, attentive behaviors that significantly support and impact their offspring’s proper development.  However, there is a mutation possible in the fosB gene that can render a rat mother perpetually anxious and inattentive toward her offspring—which if passed down through the germline makes future daughters and granddaughters, etc. anxious and inattentive as well.

So far, seems like classic inheritance, right? Inherit the normal fosB gene, and you’re an attentive, nurturing mama rat; inherit the defective fosB gene, and you’re an anxious and negligent mama rat.  Ah! But it turns out that if you take female baby rats with normal fosB genes and place them with an inattentive, neglectful mother, these rats with normal fosB genes will grow up to be anxious and distracted mothers themselves.  And so do their daughters and granddaughters even as the normal fosB gene is passed on to them!  In fact, it can take up to 8 generations of rats before this normal fosB gene starts working properly again in the mother rats.

What gives? We know that differences in environment can impact whether a specific gene is activated or not, and a classic example is the extra melanin production in human skin in response to strong exposure to UV light radiation.  But when there is less UV light, this melanin production decreases.  Change the environment; change the activation and/or activity of the gene.  With the fosB gene, though, we seem to have a situation where it is as if one time exposure to UV caused my skin to stay perpetually high in melanin and then I passed this trait down to my children, their children, and their children’s children.  Given the power of the genetic code (I look like my father for a reason), how is it possible that a one-time environmental impact can cause the impact itself to be passed on independent of the gene involved?

It turns out that our cells have two processes, methylation and acetylation, that enable them to take certain sections of our DNA and keep those sequences either permanently unavailable for expression (methylation) or always available for expression (acetylation)—basically keeping some genes “off” at all times while others are kept perpetually “on.” Which makes lots of biological sense for a complex organism such as ourselves (and our rat friends) because since we all come from a single fertilized egg, every cell of our bodies possesses every single gene, and I do not want my brain cells, for example, ever activating my digestive enzyme genes. Nor do I want the cells lining my stomach ever activating my neurotransmitter genes.  In a similar fashion, since every cell of my body is a eukaryotic cell that needs to transform energy, manufacture proteins, and other tasks common to all my cells, I want the genes for these general functions always activated.

Certain genes, though, such as the fosB gene in rats, can be either methylated or not and still others, such as the one for cortisol in the human brain, can either be acetylated or not.  Therefore, there are certain genes where their expression, their “on-off” status, is very environmentally dependent, and it turns out that this status can be passed down from one generation to the next without any actual alteration in the genetic code itself.  It is a process that is well documented but not yet fully understood, known as epigenetics, and it has revolutionized our understanding of a whole host of human traits from obesity to mental illness.

What, though, does any of this have to do with the primary focus of this project, namely education?

Well, what triggered this walk down my memory lane was hearing neuroscientist, Bessel van der Kolk, speaking with Krista Tippet and revealing that he was one of the survivors of the Dutch Winter during World War II—an event that we now know to be one of the most significant epigenetic events of the Twentieth Century.  The basics are that during the last winter of the war (1944-45), the famine conditions were so severe in the Netherlands as the retreating Nazi’s stripped the country of every resource available that any fetus conceived in the fall or early winter methylated key genes associated with metabolism to help it survive the starvation.  Any fetus, though, conceived in the late winter/early spring—and therefore benefiting from the famine relief brought by the surging Allied troops—did not. 

How do we know all of this? It turns out that when an explanation was sought by the Dutch medical system for why the children and grandchildren of the winter babies seemed to inherit all of their parents’ tendencies toward obesity, hypertension, and cardiovascular diseases while the children and grandchildren of the spring babies did not—populations that were each basically the exact same generations and so should display similar medical patterns—researchers found that the presence or absence of methylation markers appeared clearly on the DNA samples taken from each of these two groups, separated by a single environmental event.

Again, though, I can hear a reader wondering what any of this has to do with teaching and learning?

It turns out for anyone not familiar with his work that van der Kolk specializes in the impact of trauma on the mind and body, and he was conversing with Tippet about the potential impacts of the pandemic’s trauma on people.  That caused me to have one of those small epiphany moments as all the ideas of trauma, the Dutch Winter, COVID, and epigenetics coalesced into a single thought:  what epigenetic impact will the pandemic have that could potentially impact generations of humans to come?

We know, for example, that trauma of any kind has the potential to cause epigenetic changes, and in fact, part of what makes Post Traumatic Stress Disorder (PTSD) so challenging to treat is the on-going highly elevated levels of cortisol in the brain (acetylation in action!).  Moreover, while the kinds of environmental events that can trigger PTSD in individuals is not likely to cause the PTSD itself to be passed down (since the acetylation isn’t occurring in the gamete cells), the elevated cortisol from any pandemic stress a pregnant mother might be experiencing can enter her blood stream, crossing the umbilical cord to the developing fetus, where it can impact gamete cell development (something similar is what happened in the Dutch Winter).

And since cortisol levels in the brain are critical to the success or failure of the memory process (see Chapter 3), how the regulation of those genes gets passed down to future generations impacts all future teaching and learning.  Any stress induced epigenetic changes the pandemic is having on all our genomes has the potential to impact education’s effectiveness for at least a couple of generations (the great grandchildren of the winter babies displayed healthier phenotypes).  Therefore, whether the pandemic causes the mutism of a young boy challenging his Baltimore City school teacher’s attempts to teach him right now or the pandemic produces inheritable methylation and/or acetylation of key genes governing brain development in the future, the pandemic will very likely be impacting how we teach and learn for decades to come.

What’s more, I haven’t even touched upon what epigenetic changes the pandemic might be causing to genes governing an individual’s physical health and the known impact that can have on learning.  Hence, when the experts keep saying that we have no idea yet of what the long-term impacts of COVID are, we need to recognize that they are not just talking about the direct medical consequences it might have for an individual who contracted the disease.  They are talking about the unknown long term potential impacts on every single one of us for possibly generations.

Which can feel scary and overwhelming and despairing even if you are not a fellow educator facing pandemic children in the classroom right now (and might explain the behaviors of the “roaring 1920s” even if they didn’t know the biology then).  However, I would conclude by offering a note of cautious optimism:  those winter babies? They did, in fact, grow up to help rebuild Europe, and they and their children lived long enough to help form the European Union, and—in a definite piece of irony—their grandchildren lived long enough to produce the healthier great-grandchildren who are presently rioting in the streets of the Netherlands protesting the restrictions of their own “Dutch Winter” that will introduce its own set of epigenetic change. Who said nature doesn’t have a sense of humor?

The simple truth facing us at this time (and always if we have the wisdom to recognize it) is that life’s cycles transcend us, with eternity sweeping us along in its currents, and it is how we navigate this journey that ultimately matters.  Change is the only thing that is changeless, and as the generations before us had to deal with their own “winters” as best as able, so too must we deal as best we can with ours.

Remember, hope is a verb.

References

Bowie, L. (Nov. 14, 2021) “We Didn’t Ask for This.”  The Baltimore Sun.  https://digitaledition.baltimoresun.com/html5/desktop/production/default.aspx?edid=a9897f19-3d9f-4abf-9819-2260fef2a265.

Carey, N. (2012) The Epigenetics Revolution.  New York: Columbia University Press.

Nestler, E. (December, 2011) Hidden Switches in the Mind.  Scientific American.  Pp. 77-83.

Tippett, K. (Nov. 11, 2021) Bessel van der Kolk: Trauma, the Body, and 2021.   On Being. https://onbeing.org/programs/bessel-van-der-kolk-trauma-the-body-and-2021/#transcript.