Click here to support the Daily Grail for as little as $US1 per month on Patreon
DNA

Your DNA is the Size of the Solar System

When it comes to humility, science can dish it out with a big spoon: we’ve often heard of the inconsequential nature of human beings compared to the size of the cosmos (and in fiction, Douglas Adams riffed on this idea in coming up with the Total Perspective Vortex in The Hitchhiker’s Guide to the Galaxy).

While there’s plenty of criticism that could be directed at this idea – that physical size is the be-all and end-all of importance (vs intelligence, imagination, purpose etc) – an interesting aside is the fact that, while our bodies seem like specks of dust, they contain systems that are cosmic in size.

One such example is human DNA: our body contains approximately five trillion cells, with ‘long’ strands of DNA immaculately folded into the tiny space within the cell walls. If you were to take all the DNA in just one person, straighten it out and put it end to end, it could stretch from the Sun to beyond the heliosphere (which some use as the demarcation of the ‘edge’ of our Solar System). Or to put it another way, the DNA molecules in your body could be stretched out to cover the distance from the Earth to Jupiter and back, ten times over.

But perhaps an even more amazing aspect is the way in which this massive length of DNA molecules is compacted within our tiny cells – it needs to be folded via biological origami in specific ways, so that our genes can work together in different ways.

If you have a gene it is often controlled – like, turned on or off – by another piece of DNA, that can be located very, very far apart from this gene. The chromosome is folded in such a way that the switch which turns the gene on or off is actually touching the gene. So all the DNA in between is looped.

These amazing aspects of DNA are discussed in the fascinating science short below, presented by the esteemed science writer Carl Zimmer:

You might also like:

Mobile menu - fractal