Grandispora cornuta – a lament

In ‘normal’ conditions, the tiny spore Grandispora cornuta (‘big spore with horns’) has a regular shape and a spiny outer coat. But when its DNA is exposed to UV-B radiation, its coat darkens and its spines become malformed. In such a state, it cannot reproduce. According to Professor John Marshall of the University of Southampton, who has studied its fossils, there are two main candidates for the cause of this exposure, one of which is severe global warming, such as might have happened some 359 million years ago at the end of the Devonian Period*.

I’d hoped to be a big, horned spore
With a regular shape, like those of yore;
But something let more UV-B
(The genome-busting frequency)
Come crashing through the ozone sphere
Round Earth’s sustaining atmosphere.

It might have been a supernova
Which blasted UV-B all over;
Or Earth had warmed too much to bear,
And ions wrecked the ozone layer,
Allowing UV’s hurtful rays
To do their thing in unseen ways.

Then spores formed in these situations,
Like me, got ugly malformations.
We did our best by getting tanned,
But DNA could not withstand
Such fierce UV. All we can do
Is be a warning sign to you…

*The other is a continental-scale lava eruption: a ‘Large Igneous Province’.

Images: John Marshall (with permission)

This entry was posted in GeoVerse and tagged , , . Bookmark the permalink.

Leave a Reply

Your email address will not be published.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