Nathaniel Comfort, “Genes Are Overrated”:
Mukherjee gives us a Whig history of the gene, told with verve and color, if not scrupulous accuracy. The gene, he tells us, was first described by the Augustinian friar Gregor Mendel, in the mid-19th century. Tragically, no one noticed—not even the great Charles Darwin. “If Darwin had actually read” the reference to Mendel in a volume on Darwin’s own shelves, Mukherjee writes, it “might have provided the final critical insight to understand his own theory of evolution.” The “missing link” in Darwin’s day, he continues, was “information,” by which he means genetic or hereditary information.…
The antidote to [this] Whig history is a Darwinian approach. Darwin’s great insight was that while species do change, they do not progress toward a predetermined goal: Organisms adapt to local conditions, using the tools available at the time. So too with science. What counts as an interesting or soluble scientific problem varies with time and place; today’s truth is tomorrow’s null hypothesis—and next year’s error.…
The Whig interpretation of genetics is not merely ahistorical, it’s anti-scientific. If Copernicus displaced the Earth from the center of the universe and Darwin displaced humanity from the pinnacle of the organic world, a Whig history of the gene puts a kind of god back into our explanation of nature. It turns the gene into an eternal, essential thing awaiting elucidation by humans, instead of a living idea with ancestors, a development and maturation—and perhaps ultimately a death.
Mukherjee is far from the only one to have fallen into this trap. Which brings me to what I think is the most interesting question here: why does this particular type of epigenetic inheritance involving an obscure biochemical process have such strong appeal? I think there are several things going on.
First, the idea of a “histone code” that supersedes the information in DNA exists (at least for now) in a kind of limbo: enough biochemical specificity to give it credibility and a ubiquity that makes is seem important, but sufficient mystery about what it actually is and how it might work that people can imbue it with whatever properties they want. And scientists and non-scientists alike have leapt into this molecular biological sweet spot, using this manifestation of the idea of epigenetics as a generic explanation for things they can’t understand, a reason to hope that things they want to be true might really be, and as a difficult to refute, almost quasi-religious, argument for the plausibility of almost any idea linked to heredity.
But there is also something more specifically appealing about this particular idea. I think it stems from the fact that epigenetics in general, and the idea of a “histone code” in particular, provide a strong counterforce to the rampant genetic determinism that has dominated the genomic age. People don’t like to think that everything about the way they are and will be is determined by their DNA, and the idea that there is some magic wrapper around DNA that can be shaped by experience to override what is written in the primary code is quite alluring.
Of course DNA is not destiny, and we don’t need to evoke etchings on DNA to get out of it. But I have a feeling it will take more than a few arch retorts from transcription factor extremists to erase epigenetics from the zeitgeist.