By ROB DUNN - SCIENTIFIC AMERICAN
Added: Tue, 21 Feb 2012 19:22:56 UTC

This article is the fifth (see the first,  second, third and fourth articles here)  in a miniseries of six articles  that will be posted over six days about civilization, fungus, and alcohol.

They found themselves, like any first creatures, lost. Without means, they were unable to survive by anything other than what was in the immediate surroundings.  They ate what grew. They planted nothing. They never left home. There were many dire moments, until they found the animals. The first time would have been accidental. A young one caught an animal and rode it out somewhere, the way a storybook character might ride a boat down the river and out to sea.

With time though, they learned more tricks. They waited where the animals came to feed. They found them where they slept. Soon they were riding them all the time, clinging to their dark bodies as they darted here and there into the unknown.  Good luck took them to more food. Bad luck killed them. Time, birth and death made good luck more common.

Over years, they reined their new beasts in until, as is the case today, the steeds go out and gather food and bring it back. The fungi grow and wait. They have become fat kings whose success can be measured by the number of their beasts. And they are not few. These protagonists, each one a fungal herders, have evolved multiple times. They are exotic, and yet in some contexts, far closer to home than you might believe.

1-The Tree Eaters—We can start with the tree eaters. The problem facing tree-eating fungi, like any gatherers, is not the amount of food. The problem is finding the food, being where it is at the right moment.  This problem is made worse by the absence of legs. A fungus can grow toward food, of course, or toss its spores up into the wind. But one can grow only so fast and the wind is fickle and mean-spirited. The trick, if you want to know, is to find an animal that will carry you to the next dead thing. It needs to be quick and it is best if it is going where you would like to go. As a fungus, you want to arrive before the godforsaken bacteria can begin to divide. Bacteria can turn a good piece of wood terrible faster than you would imagine, at least from the perspective of fungus.

TAGGED: BIOLOGY