Friday, November 04, 2005

Nurture That Genome

One of the great debates of the last century was whether genetic inheritance or environment were more important. Also known as the nature v. nurture debate.
So the discovery that environment and experience can change genes is one of those scientific discoveries that turns the world upside down.

This is the claim of the new science of epigenetics. Until last night's excellent Horizon (BBC2) programme I had never heard of it. If and when the programme's repeated, I strongly recommend it.
Don't be put off by the disgraceful review in today's Guardian. The author claims he didn't understand a word of it. I can't decide whether he said this only for comic effect. If he genuinely didn't understand it then he shouldn't be allowed out on his own, still less to review serious television progrrammes. I'm neither a scientist nor an intellectual but I found that it explained the subject in a clear and accessible way and without some of the patronising gimmickry that Horizon is sometimes guilty of.

The theory is that genes have 'memory'.
But a word of warning. Those inverted commas are there for a purpose. Be wary of simple, popular versions of this theory.
What it does not say is that if your mother was frightened by a cow you will have a pathological fear of cows.
But the lifestyle and experiences of your parents, grandparents, etc, can affect your genetic inheritance and your life expectancy.
Genes can be switched 'on' or 'off'. If an experience of a parent or ancestor switches a gene off, it will be transmitted to you in that 'switched-off' state.

This too, of necessity, is a partial and simplified account of a theory for which much compelling evidence has now been accumulated.
One implication is that, just as we hold Planet Earth in trust for succeeding generations, so our genes, previously thought to be 'fixed', must be nurtured and protected for our biological descendents.
One of the scientists involved was deeply moved by this revelation and the fact that 'I'm only harming myself/shortening my own life' was no longer true.

Well, up to a point. As someone who is never going to have children, I felt even more liberated than I previously did from the awesome responsibility that entails. I'm free to lead a life that buggers up my genes, flicking their switches on and off like a drunk in a power station, without affecting anyone else.
These genes are going nowhere. They're all washed up in a solipsistic cul-de-sac, poor bastards, like the being of which they're the puppet master. Whether that's just as well or a sad loss to posterity is not for me to say.
I'll just light another fag and sing that great disco song 'I'm Free To Do What I Want To Do' (Within the Constraints of My Genetic Inheritance).


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