Post by Tamrin on Apr 1, 2013 19:10:28 GMT 10
The Trouble with Epigenetics
Epigenetics is a word that seems to have caught the public imagination. This is especially true among those, both in science and without, who decry what they see as genetic determinism or at least an overly “genocentric” point of view. Our genes are not our fate, because epigenetics! Such-and-such disorder is not really genetic, because epigenetics! Acquired characteristics can be inherited, because epigenetics!
The trouble with epigenetics is that the word means very different things in different contexts. Each of them may be quite valid, but when these meanings are conflated or when the intended meaning is not specified, the word becomes dangerously ambiguous. This is especially evident in the fields of behavioural and psychiatric research where the term is much abused, often, it seems to me, to give an air of mechanistic truthiness to ideas that are in reality both speculative and vague.
The trouble with epigenetics is that the word means very different things in different contexts. Each of them may be quite valid, but when these meanings are conflated or when the intended meaning is not specified, the word becomes dangerously ambiguous. This is especially evident in the fields of behavioural and psychiatric research where the term is much abused, often, it seems to me, to give an air of mechanistic truthiness to ideas that are in reality both speculative and vague.
Based on these kinds of examples, epigenetics has become quite a buzz-word in the fields of psychiatric and behavioural genetics, as if it provides a general molecular mechanism for all the non-genetic factors that influence an individual’s phenotype.
So, while epigenetic mechanisms may indeed play a role in the stable expression of certain behavioural tendencies (at least in rodents), it remains unclear how general this phenomenon is. In any case, there is no reason to think of “epigenetics” as a source or cause of phenotypic variance at the level of the organism. And here is a plea: if you are tempted to use the term epigenetic, make it clear which meaning you intend. If you simply mean non-genetic, there is a more precise term for this: non-genetic.