I just got a notice of an Epigenetics Conference in Portland, Oregon. It made me cringe. It’s infuriating because epigenetics is actually a very important concept in development, but there’s this terrible misperception among the public that it’s a magical shortcut for evolution. I was also a bit primed for it by the mention of epigenetics on Larry Moran’s blog.
The Humanists of Greater Portland™ is supporting the 2014 Epigenetics Conference being held on Saturday 5 April 2014. Epigenetics is a relatively new field of science that looks at how the environment affects one’s genetic make up. In former times, it was thought that it took generations to change one’s genetic make up but studies now suggest it can happen over a matter of weeks or months. What one eats, their environment, their activities etc. all can alter ones genetic make up and this can greatly affect one’s health. Even the environment of the mother can affect the genetic make up of the baby in the womb.
No, it’s not new. Conrad Waddington coined the term “epigenetics” in the early 1940s. He was explaining how development is modulated by gene regulation, and that there is a multigenerational pattern of restriction of cell fates within a lineage…and that’s a concept that’s at least as old as Wilhelm Roux.
It’s broader than just environmental effects. We can talk about epigenetic modification within an embryo, as a consequence of a clocklike sequence of switches, for instance. It really is a well-known, long studied developmental process.
It does not change the “genetic makeup”. Epigenetics affects the expression of genes without modifying any sequence information. Thinking that it represents rapid evolutionary change is the major misconception that leads people to think the timing is somehow radical. It isn’t. A mutation changes the “genetic makeup” of a cell — for realz — in a fraction of a second. Get up and run a lap around the room, and you’ll get a rapid change in your physiological state in a fraction of a minute. Move from your flatland home to Denver (or vice versa) and you’ll get long term changes to the constitution of your blood in a matter of weeks. None of these represent a revolution in how we think about evolution.
You want to greatly affect your health, quickly? Don’t drink any water for a day. Or drink a couple of Big Gulps worth of sugar water. That’ll have about the same effect on evolution as epigenetic modulation.
Fortunately, it’s just the general blurb for the conference that set my teeth on edge. The descriptions of the presentations sound much more focused and of reasonable and appropriate scope. It should be informative. But please, pop culture summaries of epigenetics make PZ cry.
Some people are thinking I’m denying any role for epigenetics in evolution. No — it’s just not the role some less informed people think it is. What epigenetic modification does is broaden the range of phenotypes produced by a given genotype, allowing more genetic variation to persist in the population. That surely does have some effect on evolution, but it’s somewhat more indirect than the Lamarckian mode pop culture assigns to it.
It’s one thing that allows genetic assimilation to occur, for instance. But if you think people misunderstand epigenetics, just wait until you hear what they say about genetic assimilation.