The Ancestor's Tale: A Pilgrimage to the Dawn of Evolution

by Richard Dawkins

Diverse and important though fungi are, of these three kingdoms they are certainly the most hidden. Of the doubtless millions of species, only 99,000 have been described, substantially less than the tip of an iceberg. Even the familiar species are mostly concealed from us, for mushrooms and toadstools are merely the spore-producing reproductive organs of a vast underground organism. The conspicuous plant-like structures above ground have been pushed into the light by the main body of the fungus: a spreading subterranean network of threads called hyphae. The collection of hyphae belonging to one individual fungus is called the mycelium. The total length of mycelium of an individual fungus may be measured in kilometres, and may spread through a substantial area of soil. A single mushroom is like a flower growing on a tree. But the ‘tree’, instead of being a tall, vertical structure, is spread out like the strings of a giant tennis racket underground, in the surface layers of the soil.