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

by Merlin Sheldrake

According to some estimates, if one teased apart the mycelium found in a gram of soil—about a teaspoon—and laid it end to end, it could stretch anywhere from a hundred meters to ten kilometers.

The fungus grew out from the original block in the direction of the newly discovered block. The mycelium appeared to possess a directional memory, although the basis of this memory remains unclear.

She arranged soil into the shape of the British landmass and marked cities using blocks of wood colonized with a fungus (the sulfur tuft, or Hypholoma fasciculare). The size of the wood blocks was proportional to the population of the cities they represented. “The fungi grew out from the ‘cities’ and made the motorway network,” Boddy recounted. “You could see the M5, M4, M1, M6. I thought it was quite fun.”

Researchers at the Unconventional Computing Laboratory at the University of the West of England have used slime molds to calculate efficient fire evacuation routes from buildings. Some are applying the strategies that fungi and slime molds use to navigate labyrinths to solve mathematical problems or to program robots.

After several days—about two minutes of video—there is a sudden shift. In one of the cultures, a wave of bioluminescence passes over the network from one edge to the other. A day later, a similar wave passes over the second culture. On mycelial timescales, it is high drama. In a matter of—mycelial—moments, each network flips into a different physiological state.

In a popular fungal guidebook published in the 1860s, Mordecai Cooke reported that “some years ago the [English] town of Basingstoke was paved; and not many months afterward the pavement was observed to exhibit an unevenness which could not readily be accounted for. In a short time after, the mystery was explained, for some of the heaviest stones were completely lifted out of their beds by the growth of large toadstools beneath

them. One of the stones measured twenty-two inches by twenty-one, and weighed eighty-three pounds.”

Objects within a few millimeters cause the fruiting body of Phycomyces to bend away without ever making contact. Regardless of the object—opaque or transparent, smooth or rough—Phycomyces starts to bend away after about two minutes. Electrostatic fields, humidity, mechanical cues, and temperature have all been ruled out. Some hypothesize that Phycomyces uses a volatile chemical signal that deflects around the obstacle with tiny air currents, but this is far from proven.

Within lichens, branches of the tree of life that had been diverging for hundreds of millions of years were doing something entirely unexpected: converging.

When lichens die and decompose, they give rise to the first soils in new ecosystems.

Lichen samples exposed to six kilograys of gamma irradiation—six times the standard dose for food sterilization in the United States and twelve thousand times the lethal dose for humans—were entirely untroubled. When the dose was doubled to twelve kilograys—two and a half times the lethal dose for tardigrades—the lichens’ ability to reproduce was impaired, although they survived and continued to photosynthesize with no apparent problems.

The record-holding lichen lives in Swedish Lapland and is more than nine thousand years old.

It turns out that fungi and algae come together at the slightest provocation. Grow many types of free-living fungus and algae together, and they’ll develop into a mutually beneficial symbiosis in a matter of days. Different species of fungus, different species of algae—it doesn’t seem to matter.

Zombie fungi control the behavior of their insect hosts with exquisite precision. Ophiocordyceps compels ants to perform the death grip in a zone with just the right temperature and humidity to allow the fungus to fruit: a height of twenty-five centimeters above the forest floor. The fungus orients ants according to the direction of the sun, and infected ants bite in synchrony, at noon. They don’t bite any old spot on the leaf’s underside. Ninety-eight percent of the time, the ants clamp onto a major vein.

Plants pack up light and carbon dioxide into sugars and lipids. Mycorrhizal fungi unpack nutrients bound up in rock and decomposing material. These are fungi with a dual niche: Part of their life happens within the plant, part in the soil. They are stationed at the entry point of carbon into terrestrial life cycles and stitch the atmosphere into relation with the ground. To this day, mycorrhizal fungi help plants cope with drought, heat, and the many other stresses life on land has presented from the very beginning, as do the symbiotic fungi that crowd into plant leaves and stems. What we call “plants” are in fact fungi that have evolved to farm algae, and algae that have evolved to farm fungi.

Agriculture causes widespread environmental destruction and is responsible for a quarter of global greenhouse gas emissions.

Besides the hundreds or thousands of meters of fungal mycelium in a teaspoon of healthy soil, there are more bacteria, protists, insects, and arthropods than the number of humans who have ever lived on Earth.

Then where does Monotropa’s carbon come from? Mycorrhizal fungi obtain all their carbon from green plants. This means that the carbon that powers the life of Monotropa—the bulk of the stuff from which they are made—must ultimately come from other plants via a shared mycorrhizal network: If carbon didn’t flow from a green plant to Monotropa through shared fungal connections, Monotropa couldn’t survive.

What’s more, when fir seedlings were shaded—which limited photosynthesis and deprived them of their supply of carbon—they received more carbon from their birch donors than when they were unshaded. Carbon seemed to flow “downhill” between plants, from plenty to scarcity.

Today, fungal decomposition—much of it of woody plant matter—is one of the largest sources of carbon emissions, emitting about eighty-five gigatons of carbon to the atmosphere every year. In 2018, the combustion of fossil fuels by humans emitted around ten gigatons.

So what happened to the vast areas of forest that didn’t decompose? It’s an inconceivably large amount of matter to pile up, kilometers deep. The answer is coal. Human industrialization has been powered on these seams of un-rotted plant matter, somehow kept out of fungal reach. (If given the chance, many types of fungi readily decompose coal, and a species known as the “kerosene fungus” thrives in the fuel tanks of aircraft.) Coal

Fungi have persisted through Earth’s five major extinction events, each of which eliminated between seventy-five and ninety-five percent of species on the planet.

I harvested Newton’s apples by night with a friend and large camping backpacks. We left some apples on the tree for the sake of the myth, but I’m sorry to say we made off with most of them.