Entangled Life: How Fungi Make Our Worlds, Change Our Minds & Shape Our Futures

by Merlin Sheldrake

Plants only made it out of the water around five hundred million years ago because of their collaboration with fungi, which served as their root systems for tens of million years until plants could evolve their own.

A mycelial network is a map of a fungus’s recent history and is a helpful reminder that all life-forms are in fact processes not things.

“We commonly think of animals and plants as matter, but they are really systems through which matter is continually passing.”

Humans, like most animals, use brains to integrate sensory data and decide on the best course of action. Accordingly, we tend to look for particular places where integration might take place. We like a where, but with plants and fungi, asking “where” only gets us so far. There are different parts of a mycelial network or a plant, but they aren’t unique. There are many of everything. How, then, do sensory data streams come together within a mycelial network? How do brainless organisms link perception with action?

Are network-based life-forms like fungi or slime molds capable of a form of cognition? Can we think of their behavior as intelligent? If other organisms’ intelligence didn’t look like ours, then how might it appear? Would we even notice it?

within the body of brain-dependent animals, the flexible networks that underpin complex behaviors need not be limited to a small region inside the head. There are other examples. Most nerves in octopuses are not found in the brain, for instance, but are distributed throughout their bodies. A large number are found in the tentacles, which can explore and taste their surroundings without involving the brain. Even when amputated, tentacles are able to reach and grasp.

Remarkably unchanged, mycelium has persisted for more than half of the four billion years of life’s history, through countless cataclysms and catastrophic global transformations.

Lichens have evolved independently between nine and twelve times since. Today, one in five of all known fungal species form lichens, or “lichenize.” Some fungi (such as Penicillium molds) used to lichenize but don’t anymore; they have de-lichenized. Some fungi have switched to different types of photosynthetic partner—or re-lichenized—over the course of their evolutionary histories. For some fungi, lichenization remains a lifestyle choice; they can live as lichens or not depending on their circumstances.

Not just any fungus could partner with any alga, however. One critical condition had to be fulfilled for a symbiotic relationship to arise: Each partner had to be able to do something that the other couldn’t achieve on its own.

Mycorrhizal fungi are so prolific that their mycelium makes up between a third and a half of the living mass of soils. The numbers are astronomical. Globally, the total length of mycorrhizal hyphae in the top ten centimeters of soil is around half the width of our galaxy (4.5 × 1017 kilometers of hyphae, versus 9.5 × 1017 kilometers of space).

Mycorrhizal hyphae die back and regrow so rapidly—between ten and sixty times per year—that over a million years their cumulative length would exceed the diameter of the known universe (4.8 × 1010 light years of hyphae, versus 9.1 × 109 light years in the known universe).

When Mills added mycorrhizal fungi to the model using Field’s measurements, he found that it was possible to change the entire global climate simply by turning the symbiotic efficiency up or down.