The free will thing has come to the fore of my head again recently because of an offhand ‘no free will’ remark I made, which of course caused some friendly argy-bargy. When the topic comes up I like to throw ‘the lot’ at it, our early neurological wiring, unwiring and rewiring, our hormonal activity, our genetics, our epigenetics, our position in the womb, our early interactions with parents, siblings and others, our culture, our gender, our first language, the time and place of our birth and so on.
Of all these variables, epigenetics is one that’s likely to catch people off guard. If they ask, I’ll say it’s all about gene expression, hoping that will silence them, and even impress them. But if they inquire further, I’d only be able to say something like ‘environmental factors affect how genes are expressed’ – and that would be the limit of my knowledge, even though, some years ago, I read Nessa Carey’s The epigenetics revolution, published in 2011.
So now I’m reading it again, and it seems for the first time. I’m finding it really hard to understand, and I’m sure it isn’t Carey’s fault. I suspect it’s the kind of topic in which you need to be active in the field to fully understand it, and even then….
But, I’ll have a go. Rett syndrome is a rare but devastating neurological disease which occurs almost exclusively in girls. Apparently, if a male child contracts it, it’s more or less immediately fatal. As AI (never lies) puts it:
Infants typically develop normally for 6 to 18 months before experiencing a severe regression in motor skills, speech, and hand use. While there is no cure, symptoms can be managed with targeted therapies and specific medications.
The development of this syndrome happened to coincide with infants receiving the MMR vaccine, which, as we know, caused much controversy some time ago, but the mechanism was worked out in 1999. It mostly has to do with mutations in a gene called MECP2, which severely affects the production of a functional MECP2 protein. Dysfunction/mutation in other genes have caused the syndrome, or something like it, in a minority of cases. The cells are able to methylate their DNA correctly, which is what much of what epigenetics is all about, but they’re unable to read that section of the epigenetic code properly. So Rett syndrome isn’t a mental/psychological disorder at all, it’s purely genetic, and because the dysfunction is on the X chromosome, and because females have two X chromosomes while males have XY, the male karyotype is more vulnerable to the condition.
I choose this extreme condition (suffered by one in 8500 females) as one among many examples of how our genetics can fail us, and there are many others, much more subtle and hard to pin down, both in terms of our genes themselves and how they are expressed. We – I mean the scientists and researchers among us, and those going along for the ride – have learned especially in recent decades just how complex and beyond our control our brains and bodies are, not just in terms of physical make-up, but genetic and cultural inheritance. A regular awareness of this – a mindfulness, if you like – helps me to cope with the people who damage our world – the war-mongers, the bullies, the intolerant and over-confident – as well as to sympathise with the overwhelmed (like myself).
So, again to epigenetics – I’ll keep trying to comprehend at least some of it, as it’s intrinsically interesting when it’s not completely baffling. Meanwhile, I’ve had a book recommended to me, by two humanists and no-free-will proponents, called Being: why it’s harder to be human than a hamster or a herring, by a daughter and father duo, Rachel and Ross Menzies. Sounds like an antidote to all that epiphenomena…
References
Nessa Carey, The Epigenetics Revolution: How modern biology is rewriting our understanding of genetics, disease and inheritance, 2011.