Epigengle all the way...

Santa on a horse

It’s Santa on a… I’m going to guess horse?

Most people these days are familiar with the idea of DNA – our genetic code. The big list inside us that enumerates – to a greater or lesser extent – everything about us. Eye colour. Height. Diseases or conditions we might fall foul of. How many limbs we have. Where our organs go. Naughty or nice. It’s what separates us from bananas, or monkeys, or trees. We pass this DNA down the generations, and this list is not something we can do anything about. The slow march of evolution takes hundreds of generations to make a change. I am stuck with my DNA, and so are you.

Except, what if we could just… ignore parts of this list? Just turn off this bit of DNA, or that bit? And then pass it on to our kids, a change in one generation…

Well, turns out that we can.

It’s called epigenetics. You can imagine it as being a set of rules that sit on top of your genetic code, telling certain bits to switch on or off, be stronger or weaker. We are discovering that your epigenetics can change based on your environment. And your epigenetics can be passed on to your kids too. One study of a particular Swedish town, which happened to have population data going back generations, showed that if your father suffered through a famine year, you were less likely to die of a heart attack or have diabetes – and you’d live up to 30 years longer on average – than somebody whose father didn’t starve. Even if it was your grandfather who starved, you got a similar health boost – that hardiness could be passed down two generations. This segment of Radiolab has a characteristically good report of the Swedish data.

The environmental change of famine didn’t change your grandfather’s actual DNA sequence or ‘genetic code’ – it takes a long time for those changes to work their way through populations. No, it changed the epigenetics, perhaps by tagging parts of the DNA with particular molecules, or by subtly altering the way that DNA is packaged in cells. And these changes can get passed on too, although they’re not permanent and can, over a generation or two, fade away. It’s a temporary change to how our DNA acts, but it doesn’t change the underlying list. Evolution is the only thing that can do that. This article from Time goes into it all in a lot more detail, and is well worth reading if this has piqued your interest.

So while normal reindeer’s epigenetics has switched off the part of their DNA that allows them to fly, Santa’s reindeer don’t have such a problem. The environmental pressure of having to deliver presents has caused a change in their epigenetics that allows that part of their DNA to switch on. But all those reindeer have been killed! Luckily our heroes know just what to do

Share this on...

Add your thoughts

Your email address will not be published. Required fields are marked *