How often do you see an editor of a scientific journal complain that a field is overhyped? Well, you can see it this week in Current Biology, where Florian Maderspacher, the senior reviews editor, takes out after the current penchant of journalists to see epigenetics as the Great Missing Piece of Biology—a field that will completely revolutionize Darwinism and our view of inheritance. (I take epigenetics to mean “inheritance not based on coding changes in the DNA”.) The title of Maderspacher’s piece pretty much says it all: “Lysenko rising.” (Sadly, it seems to be behind a paywall.)
This isn’t the first time we’ve encountered journalistic hype about epigenetics: last March there was a dire puff-piece in the Guardian asserting that epigenetics was the death knell of Darwinism. I went after it, arguing that while epigenetics was a novel and important new phenomenon in genetics and development, it wasn’t poised to completely revise our view of evolution for three reasons.
First, epigenetically inherited changes in DNA and protein, like methylated bits of DNA, ultimately rest on “normal” mutations in DNA that affect those changes. Things get methylated because the nucleotide bases in DNA code for that methylation. How can “nongenetic” changes in DNA reside in the DNA? Here’s one way. There are genes whose DNA sequence tells them to do this: “put methyl groups on another bit of DNA if you detect that you’re in the body of a male. Don’t do that if you’re in the body of a female.” Males and females would thus have the same DNA code, but it would be used differently depending on the DNA’s “environment”—for example, different hormone titers in males vs. females. The two sexes would then have produce different types of modified DNA even though their primary DNA sequences were identical. These modifications usually last only one generation, and then are reset when the DNA finds itself in a new body that could be of a different sex.
Second, as I just noted, in nearly all cases the epigenetic modifications are not inherited past one or two generations, so they can’t serve as lasting templates for evolutionary change. Insofar as those changes are important in evolution, they must ultimately reside in the primary nucleotide sequence of DNA, the genetic material.
Finally, those who tout the importance of epigenetics in evolution, most notably Eva Jablonka and Marion Lamb, keep trotting out the same handful of tired examples, like changes in toadflax and mouse coat color, that are inherited only temporarily and have nothing to do with evolution.
Maderspacher was cheesed off because the latest issue of his German magazine Der Spiegel devoted ten pages to epigenetics, including a racy cover of a nude nymph whose naughty bits were conveniently occluded by DNA-shaped splashes:
Florian translates this as “THE VICTORY OVER THE GENES. Smarter, healthier, happier: how we can outwit our genome.” And he explains that this is not a one-off bit of hype:
Epigenetics is of course being considered ‘sexy’ in vast circles of the scientific world (and has attracted the funding to go with it), but that Spiegel cover was a different type of ‘sexy’. This kind of public attention seemed unusual: molecular biology rarely makes it to the front page. And what’s more, this wasn’t just some German oddity: Newsweek had last year a similar cover story, touting a revolution in biology in gonzo-journalism style: “Roll over, Mendel. Watson and Crick? They are so your old man’s version of DNA”. Likewise, the New York Times is in tune, as a news piece last year celebrated the role of the ‘epigenome’ in controlling “which genes are on or off”; nor is the hype confined to the popular press, as a recent editorial in Nature also noted that: “genome sequences, within and across species, were too similar to be able to explain the diversity of life. It was instead clear that epigenetics — those changes to gene expression caused by chemical modification of DNA and its associated proteins — could explain much about how these similar genetic codes are expressed uniquely in different cells, in different environmental conditions and at different times”.
And the wonders of epigenetics, at least in this piece, came down to the same tired old data:
The article itself was mainly concerned with listing examples supporting the notion that ‘genes aren’t everything’: on the one hand, cases where genetic predisposition, e.g. for adiposity, does not lead to the development of that phenotype, as well as the much-discussed weaknesses in genome-wide association studies to pick up causative genetic agents for common diseases; on the other hand, examples of how the environment can influence the genome, evident for instance as differences in DNA modifications between monozygotic twins in different environments and lifestyles. The piece culminated in bold statements like: “Epigenetics is the long sought link through which the environment influences the hereditary material [… and it] currently leads to a dramatic new understanding of human biology”.
In other words, neo-Lamarckism: the inheritance of acquired characteristics. Well, in one way that’s true: stuff like methylation is an “acquired” characteristic that can be passed on for one or a few generations. But it’s acquired via genetic instructions in the DNA, and it’s inherited for only a handful of generations. So, while important, it’s not a dramatic new paradigm of genetics. As Maderspacher says,
There is thus no need to construe a dichotomy between the power of the genes and the power of the environment — a molecular version of the ancient nature vs. nurture debate. The environment influences the phenotype through the genes. There is no contrast, no one over whom to achieve ‘victory’.
Indeed. I’m not sure I agree with Maderspacher’s analysis of the reasons why this misconception is so important. He floats the idea that Germans are particularly fond of it “for historic reasons,” that is, because it apparently contradicts the hegemony of genetic determinism that undergirded Nazi racist ideology. But ultimately he lays the hype at the feet of Marxism, which trumpets the malleability of the individual by the environment. (This is where Lysenko comes in—the Russian agronomist whose fraudulent claim that one could permanently modify crops by environmental manipulation so impressed Stalin, and so ruined Russian agriculture.) Maderspacher sees epigenetics as “a kind of lysenkoism for the molecular age.”
Well, maybe the popularity of epigenetics is a vulgarised environmentalist response to the “vulgarised genetic determinism” that so dominates our times. And maybe that’s why journalists love it, though, as Maderspacher notes, they love anything that smacks of an overthrown paradigm—especially Darwinian evolution. Regardless, he sees this kind of buzz-journalism as injurious to the public understanding of science, and I agree 100%:
Therefore, a larger frame has to be invoked, far-fetched as it may be. Building around the story is a legitimate literary technique to some extent, but becomes dangerous when the frame interferes with the presentation and interpretation of empirical data. In effect, it’s not far from what Lysenko did, and makes the whole purpose of science journalism questionable. It won’t cost lives as Lysenko’s mad ideas — after all, it’s only molecular biology — but the public have a right to be informed correctly. First, because they pay for the research. Second, because at the very least they need to know that science, and genetics in particular, cannot give them simple answers about who they are and how they should live, and neither can epigenetics. They’ll have to work that out for themselves and let Lysenko lie.
Well done! But I’d go further and include among the miscreants those scientists—especially those evolutionists—who argue in the face of the data that epigenetics will overthrow conventional ideas about evolution and natural selection. Unlike journalists, they know better.