Below the fold is a link to a British documentary about epigenetics. It’s primarily about the discovery of epigenetics in the transmission of disease down generations, but we need always to remember that the medical aspects are just a window on a process that must, by its nature, be primarily physiological and adaptive, and is turning out to be ubiquitous:
You’ll note, when you get round to watching it, the allusions to the disappointments and surprises of the Human Genome Project – a matter which is usually allowed to fly under the popular radar, but which is hugely significant. The implications of epigenetics for heredity – and naturally that includes evolution in the long term – shouldn’t really need spelling out.
Just one example – the film speaks of an identical genetic defect that presents as two entirely different clinical syndromes according to whether it is inherited from the mother or the father – for some reason the gene is marked up differently by the epigenetic system. Now consider that the deliberate and widespread insertion of new genes – whether into crops, pests, pets or people – has so far been done in blithe disregard of the existence of that system, and of how it might respond or fail to respond to entirely alien genes. Ignorance is bliss.
The underlying importance is that epigenetics is hard to account for, outside the perspective of disease, apart from an inherent teleology that is utterly alien to the Neodarwinian paradigm. Organisms choose what genes they will express and which they will suppress, and although experiments may show environmental associations, we cannot account for epigenetics as physiology; what is going on functionally.
It’s no more rational to say epigenetics arose through accepted processes of ateological evolution than it is to say that life did – it lies outside current theory, and therefore undermines it as a complete explanation, and so as an ideological weapon in support of materialistic naturalism.
But I don’t want to go any further down that route here, and instead I simply wish to point to an intriguing example of a possible physiological epigenetic event within my own family. Regular readers will be aware that I’ve had my own informal identical twin study going for the last thirty-something years. Our twins have been stubbornly different on many measures from the very beginning, and one such difference was that one of them learned to get mobile by crawling in the normal way, whereas the other went the route of bottom-shuffling in order to be different. They both started around the same time, were cognitively pretty comparable overall and were treated, within the usual meaning of the Act, identically because we usually couldn’t tell which was which. Our Shuffler took only a little longer to walk, possibly because her chosen intermediate stage was so efficient. It’s just one of those interesting little differences parents of twins see all the time.
Researching this behaviour on the internet, it’s significantly uncommon – the best figure I could come up with was about 5% of babies, only a small minority of which cases are associated with general developmental delay or other health issues. One source said it is genetic, carried on an autosomal dominant, but if that’s ever true it wasn’t in this case – identical sister crawled, and there are no other known bum-shufflers in the family tree. Imitation can clearly be ruled out on the same basis. In fact, the only instance of sibling imitation was the occasion when Shuffler tried to follow Crawler up the stairs. Her method, being unsuitable for this, led to a fall and temporary fears that she’d broken something.
No, one must either attribute it to one of those accidental occurrences – she was one of a minority that just happen to hit on that method rather than the other – or to some cause unknown. Most researchers seem to consider it a rare variant of normal, like those who walk immediately without any earlier stage.
Either way, we must now fast-forward to the present, and both my daughters now have babies of their own. Isn’t the cycle of life wonderful? Crawler’s is only two months old, and so it’s too early to say much about her, apart from that she’s beautiful. But Shuffler’s daughter, just over a year and equally beautiful, is now getting well and truly mobile – via the unusual method of bottom-shuffling.
In fact she took her first tentative
steps bumps whilst she was staying here, and it was a remarkable case of déjà vu, which also served (in terms of the research program) to enable us to confirm that mother wasn’t venting some kind of suppressed frustration on the child and forcing her to shuffle when she wanted to crawl. The only difference was that, a generation on, I was now conditioned to notice a resemblance to attempts at yogic flying – but the new Dalai Lama she is not, thank the Lord.
In terms of crude probability, the chances of idiopathic bottom-shuffling recurring in a second generation are 5% of 5%, or 0.25% – pretty slim odds. It’s more plausible to suggest a genuine link, which can’t be genetic, can’t be imitative and so seems quite likely to be epigenetic. Isn’t that interesting, and so much less disturbing than epigenetic PTSD or diabetes?
It remains to be seen, of course, whether Crawler’s baby girl will, for mysterious reasons, follow her cousin’s suit, or crawl in the usual way – either would be an interesting result, but I’m willing to bet she’ll follow the crowd and crawl. Perhaps some keen epigeneticist will be interested enough to trawl through the literature on bottom-crawling, with twins and epigenetics in view. It seems an ideal subject to study.
Now, I’m inclined to ask, if my epigenetic hypothesis is legitimate, just what genes are being suppressed or activated here, and with what physiological purpose. It’s not likely that there are alternative genes for crawling and bottom shuffling, any more than it’s intrinsically plausible that one of our mere 20K genes codes for rubber fetishism or navel-piercings. But that’s no harder a question than explaining the reason why established epigenetic mechanisms – like the inheritence of anxiety after parental traumatic stress – happen the way they do, if one is looking merely for efficient causes working via natural selection.
The situation alters if one once allows for the possibility that goal-orientated organisms habitually use a multi-level genetic control system as a library for dialling in characters and behaviours to the genome. That possibility is truly a game-changer, because it destroys the machine-metaphor and restores the concept of essential forms at a stroke.
Then one could speculate that, since shuffling worked well for my daughter, her Lamarckian physiological “angels” (the “ghost in your genes” of the documentary) saw to it that it passed to the next generation. It certainly makes heredity a more complicated issue than Mendel and his successors made it.
Here’s a possibility to consider: in a Neo-lamarckian epigenetics, it would behove organisms to have a hard-wired system in which to store adaptive, and quite complex, behaviours and transmit them down the generations. Once our minds are liberated from the reductionist one-gene-one-protein-one-mutation-one-object-for-selection concept of the genome, the multi-level algorithmic structure of the genome would be a good candidate for such a physiological function, seeing that the nervous system itself perishes with each generation. It’s a whole new view of things.
But one thing is sure. Epigenetics is prevalent enough to alter the whole landscape of life, and to make such questions of “purpose” not only relevant again, but unavoidable.