The scientist – he knew he had no claim to the title, but could not break the habit of calling himself one – bent down among the standing stones, and stared at the lichens. The last time he had been here, he had not remembered seeing any on these stones. Surely there hadn’t been any. Not enough to get his attention, anyhow. Thirty years these stones had stood, fresh and inviolate. But the lichens were here now, gritty crusts and blobs of black and grey and sickly green, spreading over and dulling what had once been polished stone.
Strange creatures, lichens. Not really creatures at all, but combinations. An alga and a fungus, and the merger looks like neither one. Or maybe two kinds of algae and a fungus. Or three algae. Or two fungi. Each year brought a new scientific paper, or maybe five, each one describing a different combination. And a new consequence. Here’s a lichen, a combination of an alga and a fungus, that is edible, and has supported human and animal life for millennia in places like Scandinavia. Add a yeast to the mix, and it changes color, becomes poisonous. Bad company, if you are the consumer. Good, if you’re the consumed.
And, they’re tough. Able to grow without soil, without nutrients, apparently even without water. Sitting on rock, perhaps helping it to rot, catching airborne dirt underneath. Pioneers building a life for those more effete, higher-maintenance lifeforms to come.
At least, that’s what their press agents said. But press agents often do not know the whole truth, and do not tell all of what they do know.
The scientist thought back to when the stones did not have lichens, and people worried about this. Soot, they said, deprived the algae of the light they needed for the lichen to survive. Acid derived from the soot, they said, was too strong for the fungus to survive. Paths less well traveled became more traveled, and the lichens that survived the soot and the acid fell to the constant abrasions of feet and hands. “The lichens are dying, and so will our world, and us with it, if we don’t stop this acid rain!”
Now, the worry is that the world will soon become too hot to hold us. But the lichens have returned. The soot and the acid that held them back have been taken away, and the heat, and the carbon dioxide greenhouse gas, do not faze them. Indeed, the heat and the carbon dioxide help them to grow. To grow on the standing stones, to rot them, to bury them under the airborne dirt caught underneath them. To break down the stones, erase their inscriptions, so that the reasons for the stone, and too soon the stones themselves, are lost.
As if this wasn’t happening fast enough without the lichens.
The scientist cleared away the leaves and weeds from the standing stones, did the best he could, without water or tools, to remove a few lichens from each, and walked away, wondering how long it would be before he, too, was a forgotten, lichen-covered stone.