May 16, 2019, by Brigitte Nerlich
Epigenetics in popular culture: The case of turkey dinosaurs
This post has been written in collaboration with Aleksandra Stelmach
On the 5th of May Charlotte Church asked a question in the Guardian that probably many parents ask themselves in these epigenetically informed times: “Will the turkey dinosaurs I ate as a kid affect my children’s health?”
On twitter, experts answered that question with a resounding ‘no’ (Kevin Mitchell, John Greally, Adam Rutherford, Simon Fisher). As John Greally said in a tweet: “Yes, this is about multigenerational #epigenetics This area of science is *far* from resolved, @charlottechurch, please don’t feel so guilty.” We’ll get back to the blame and guilt!
But this was not what attracted our initial attention. Instead, we were rather surprised to find a novel metaphor, a metaphor which we had not come across in our research into the metaphorical framing of epigenetics; and that was the metaphor of ‘witness mark’.
In this post we reflect on what Church’s article can tell us about public understanding of epigenetics. It links up with a previous post on epigenetic pancakes that we posted on 1 March, 2019. In a second post we shall go on the trail of the new metaphor, a trail that turned out more interesting than we thought and can’t be mapped in a few sentences. (You can now access it here)
The epigenetic mystique
What was Charlotte Church’s article about? What you see first when looking at the article is the name Charlotte Church in red, the title of the article in black italics, a photo of Charlotte and a picture of junk food (that is, spam, I think, smilie potato faces, fish fingers, turkey dinosaurs, a salt sprinkler, overlaid with the obligatory double helix, but one swollen up in the middle, signalling ‘obesity’).
The article starts with a quote from Church’s grandmother who proclaimed: “You can never be too rich or too thin.” From there we are taken on a journey through Charlotte’s childhood and from there to obesity, class and cheap food, which all makes a lot of sense.
Then we come to what one may call ubiquitous genetic superstitions: “For a long time, I had assumed it was a genetic thing, too, that I was the recipient of a sorry strand of DNA that said: ‘Will struggle with weight.’” That was what many people thought for a time, including for example Roy Hattersley, a decade ago, around the time of the Human Genome Project boom. He was visiting Iceland at the time and then wrote about it in The Times:
“The purpose of my … visit was an investigation of the genetic research centre where, a blood sample having been tested, the secrets of my DNA would be revealed. ‘You have,’ the director told me, ‘the cancer gene, the thrombosis gene and the Alzheimer gene.’ Looking for a silver lining, I added: ‘And the obesity gene?’ Had not my mother told me ‘It’s the way you’re made’? The director did not hesitate. ‘No. You are fat because you choose to be fat.’ Another admirable Icelandic characteristic is a reluctance to mince words.” (The Times, 8 January, 2010)
But things have changed since then and so have expectations around the influence of genes on obesity, as the following sentence from Church’s article shows: “While I’ll keep telling myself that [that genes are what cause weight gain], the fact that my recent predecessors had a nutritionally narrow diet has almost certainly had a physical effect upon me, and indeed my children, through the mysterious phenomenon of epigenetics”. The ‘DNA mystique’ (Nelkin, 1993) has been replaced by the epigenetics mystique!
Epigenetics is in the air and particularly widespread in columns on parenting and nutrition. Charlotte found some information about it from a reputable source referencing an article published in Nature Genetics. So, no pseudo-scientific woo merchants here! From this online source (not referenced in the article), Church extracted a quote by Professor Bill Sullivan who said: “If you consider DNA to be a ‘book of life’, the book handed down to the child is not necessarily a pristine copy – some passages may be highlighted, a page or two may be missing, or notes may be scribbled in the margins.”
Here we have a well-known metaphor for the genome (book of life) and some now well-known, if not altogether accurate, metaphors for epigenetic marks (highlighting, notes in the margins) (see Stelmach and Nerlich, 2015).
Church goes on to say that if you want to have healthy children and grand-children, you should take care of your epigenetics through the food you eat – and here she introduces a metaphor nobody seems to have used before: “We can rewrite our methylation profile (the “witness marks” of our DNA’s epigenetics) through interventions such as exercise, diet and even weight-loss surgery”. (Again this is not an absurd idea, but one many natural and social scientists are talking about, see for example Hannah Landecker, in an article entitled “Food as exposure: Nutritional epigenetics and the new metabolism”).
By witness marks Church means epigenetics marks, marks that are believed to record ‘experiences’ of lives lived, marks that bear witness of lives lived. But what are epigenetic marks really? As Carl Zimmer, a renowned science writer, has recently told his readers:
“Our genes are not just naked stretches of DNA.
They’re coiled into intricate three-dimensional tangles, their lengths decorated with tiny molecular ‘caps.’ These so-called epigenetic marks are crucial to the workings of the genome: They can silence some genes and activate others.
Epigenetic marks are crucial for our development. Among other functions, they direct a single egg to produce the many cell types, including blood and brain cells, in our bodies. But some high-profile studies have recently suggested something more: that the environment can change your epigenetic marks later in life, and that those changes can have long-lasting effects on health. […]
Even more provocative studies suggest that when epigenetic marks change, people can pass them to their children, reprogramming their genes.”
Zimmer rightly points out that such studies are highly contested, especially by scientists such as those mentioned at the beginning of this article. However, while revolutionary seeming studies are reported widely, criticisms of such studies are not (Zimmer’s article in The New York Times being the exception to the rule). This skews public understanding.
Interestingly, Church brings this metaphor of the witness marks in contact with another, well-known, metaphor: the carbon footprint. Both can, it seems, be managed, through better nutrition. You can manage your environmental and your genetic ‘traces’ in one go! That’s really interesting, although managing one’s carbon footprint through a change in diet has actual benefits, while trying to rewrite one’s witness marks is probably not possible.
Now the question we asked ourselves was: Where does this metaphor come from? Did Church create it herself or did somebody else use it before her? We searched on the web; we searched on academic databases; we asked experts. Nobody had come across this metaphor in the context of epigenetic. Cath Ennis pointed us in the direction of engineering when she tweeted: “I found some references to witness marks as an engineering term (marks or scratches on two parts of a machine, to aid with accurate assembly/reassembly), but if that’s the origin then the metaphor doesn’t really work IMO http://www.engineering-dictionary.org/Witness_mark .” And it doesn’t;.
We left a question underneath the article; we asked Charlotte on twitter, but to no avail. In a second blog post, i.e. the sequel to this one, we shall go on the trail of this metaphor. So stay tuned! (The mystery has been solved!)
Public understanding of epigenetics
Why is it important to write about all this? Because Church’s article and its core metaphor resonate with and might even influence popular understanding of epigenetics and they encapsulate some aspects of it really well.
The 757 comments underneath the article would deserve further analysis, but they seem to indicate that quite a lot of people are persuaded by the epigenetic argument put forward here. There are however also some doubts, some criticisms and some discussions. Here is one example:
One commenter says: “The explanation suggested regarding DNA is conflated with that of inherited behaviours. Genes are made of DNA and are inherited. You may, for instance, have inherited genes that result in your tendency to put on weight. Memes, on the other hand, are ideas, behaviours, or styles that spread from person to person within a culture. You may, for instance, have inherited memes from your parents, or others that you’re in close contact with, about the type of food that you eat.
Memes can be regarded as cultural analogues to genes in that they self-replicate, mutate, and respond to selective pressures. So that’s my lecture for today over, and I hope you enjoyed it.”
Another commenter replies: “Both of you go and look up Epigenetic’s for some real nurture effects on animals (inc man) without the long timescale of DNA changes to kick in and allow fat genes to be allowable as an excuse.” A third one says: “You need to go read up on epigenetics. Try not to patronise unless you really know what you’re talking about. https://en.m.wikipedia.org/wiki/Epigenetics?wprov=sfla1”
There are many more struggles over the meaning of epigenetics and its implications for obesity in these comments, worth a more in-depth study.
Blame, guilt and responsible communication
Now it’s time to get back to what John Greally said, namely that Charlotte Church should not blame herself for future generations’ health problems.
The issue of guilt, blame and responsibility has been discussed quite a bit in social science literature responding to early headlines (in science magazines as well as in mainstream newspapers!) such as ‘You are what your grandmother ate’ (and here) and so on. (Fathers and grandfathers rarely figure in these headlines). Sarah S. Richardson in particular has studied this mother blaming in epigenetics and related fields. In 2014 she and others wrote a comment for the journal Nature entitled ‘Don’t blame the mothers’ in which they warn that careless discussion of epigenetic research on how early life affects health across generations could harm women.
In the view of Richardson and her co-authors media reports on research into epigenetics often present exaggerated and over-simplified claims which in effect scapegoat mothers for the ill-health of their children. While such coverage highlights potentially harmful consequences of development in the womb, which in turn increase the risk of obesity and diabetes in later life, it pays much less attention to other factors influencing health outcomes, such as paternal contributions to the health of future children, family life and social environment.
Healthy behaviour in pregnancy is important, but, as Richardson et al. warn, over-simplified public messages about the dire consequences of certain kinds of diet or stress in pregnancy can lead to increased surveillance and regulation of pregnant women. They urge not only reporters and scientists but also press officers and educators to discuss and disseminate research findings in a responsible fashion, as “it will help the field to improve health without constraining women’s freedom” (Richardson et al. 2014: 132).