The Wood Wide Web

People thought Avatar was just sci-fi, not realising that there was a global brain right under our feet...

In Oregon USA there exists the largest living organism on the planet.

2,400 years old and spanning 3.5 square miles: The Humongous Fungus.

The Humongous Fungus Areas with Honey Mushroom (Armillaria ostoyae)

Both a blessing and a curse, it plays a vital role in the forest ecosystem. Breaking down dead or dying organic matter for other species to consume, while also parasitic in nature: killing live trees and other plants. While this tends to be great for the ecosystem’s natural cycle, in human-managed environments, such as commercial forests or orchards, it is quite the blow to get infected.

Like around 92% of known fungi, the Humongous Fungus has two parts: the underground network, called mycelium, made of thread-like filaments - and the fruiting body, the mushroom we see above ground. In this case, it blooms into the Honey Mushroom - golden-brown, slender, and growing in tight clusters on decaying wood. It’s a stark contrast to the white button mushroom, the most commonly eaten mushroom in the world, which is small, smooth, and carefully cultivated in soil.

The mycelium is a communication network that can be likened to a human brain, only it sends chemical signals rather than electrical ones. Forests rely on this underground network to share resources and warn of threats, giving plants time to release their defense systems. Because of this, the mycelium is constantly adapting, learning how best to thrive.

It’s estimated that 90% of land plants depend on fungal partnerships for survival. Plants give carbohydrates to the mycelium, while the mycelium helps the plants suck up water and nutrients. Adult trees have also been found to send nutrients through mycelium to younger trees to help their progress.

But mycelium don’t just communicate with trees. A fungus from the Lepiotaceae family has a mutualistic relationship with Attine - leaf-cutter - ants. In exchange for an environment to thrive, leaves to feed on and having debris or pests cleared away, the ants cultivate the mycelium into their food source.

From the Humongous Fungus, the largest organism on the planet, to the humble white button mushroom - only two species and yet so distinctly different in size, texture and use. Only two out of 150,000 known fungal species. That’s not even the final figure: scientists estimate that up to 5 million exist.

White Button Mushroom

Where are all the Fungi?

Fungi don’t just grow on decaying wood, they can grow on anything. Frozen Antarctic soil, skin, hair, metal and oil. They’ve been described as “space-ready” due to some species surviving in a vacuum, being dried out, or living in radiation environments, even using the radiation to feed.

One of the main ways fungi spread is through spores. The cap of the mushroom is the spor factory, each cap producing billions of spors in its lifetime.

And spores are everywhere. A single gram of soil can contain up to a million fungal spores. These spores are in your body, on your clothes, in your food.

So why isn’t fungi growing everywhere?

Animals and plants have adapted to have defense mechanisms to stop the fungi from hijacking them, and unless the ideal conditions are reached: above room temperature, away from sunlight, enough organic material to decay and a wet environment, they are a lot less likely to grow.

But just as fungi have spread into every corner of the physical world, so too are they extending into more abstract human systems.

The Biofabrication Wave

Since the mid-2010s fungi have been becoming more mainstream though they have not yet hit individual consumers. In the medical world, fungi are being explored for antiviral potential and cancer treatments and across industries of clothing, packaging and building materials, mycelium are being applied.

In 2011, a team of Yale students found some strains of fungi could degrade plastic within a few months and since this breakthrough, companies and research labs have been recycling this into biofuels and chemical feedstock.

2016 saw the rise of bio-inspired computing, with studies showing that mycelium can efficiently solve problems, such as finding the shortest path between two points to better transfer nutrients, minimise energy use and avoid obstacles, much like a living algorithm. Now with the epoch of AI, this unconventional mycelial decision making has been researched for optimising systems.

For all the good they’re doing, let’s dive into something a little horrific…

The Zombie Ant

One fungus that hangs out in warm temperature places like Japan, Australia, Brazil and Thailand is called Ophiocordyceps unilateralis and it turns carpenter ants into zombies.

It all begins with sticky spores on the ground that latch onto a passing ant. The parasitic fungus spreads its thread-like tendrils through the ant’s exoskeleton, into the body and starts to digest the insides of the ant - and that’s not even the worst part: it’s how it interacts with the ant’s brain, manipulating its behaviour.

Through the release of chemical compounds the cordycep will induce the ant to leave the colony and climb to moist vegetation above the ground, often 25cm up to have a good vantage point. Some studies have shown that the ant’s muscles are being puppeteered by the fungus. The ant is compelled to bite down on a leaf to grip it into place. After which it will die, alone in that spot as the fruiting mushroom sprouts out of its head. Within a couple weeks, the fungal stalk will burst with millions of spores in the hope of landing on the colony below - and the cycle repeats.

Ophiocordyceps Unilateralis

Carpenter ants in these areas have evolved to limit their exposure to the parasite, often living in trees to avoid the ground and the sticky spores in it. They also practice social grooming to remove spores before they can take control and if an ant is found to be infected, the other ants in the colony will carry it away from the nest and their trails to an area they can avoid: the graveyard of infected dead ants.

Those parasitic fungus are usually thin elongated fruiting bodies - menacing; yet they appear quite similar in shape to the most common mushrooms.

Not all mushrooms look so related.

The Mushroom Misfits

90% of known fungi do not look anything like the typical supermarket mushroom. Most fit better into these categories of appearance: wiggly, coral-like, puffed, tentacled and blobby - pretty alien-looking. Across the globe you’ll find them in rainforests, damp woodlands and undisturbed ecosystems, here are some weird ones:

Giant puffballs - they will release around 7 trillion spores and are found in Europe and North America.

The Blue Pinkgill (Werewere-kokako) - it’s said that the blue wattlebird, native to New Zealand, brushed its cheek against the mushroom and in doing so, gave the bird it’s blue color.

The Witch’s Butter (Tremella mesenterica) - slimy and edible, can be found all around the world.

The Black Witch’s Butter (Exidia glandulosa) - a wood-rotting species, it can be found in Europe.

Clavaria Zollingeri - looking like coral and a vivid violet, found all around the world.

The Wrinkled Peach (Rhodotus palmatus) - they have a jelly-like texture and are found in North America, Europe, North Africa and Asia.

The Devil’s Fingers (Clathrus archeri) - they’re stinky and found in Australia and New Zealand.

The Veiled Lady (Phallus indusiatus) - also stinky and found in tropical areas around the world.

Out of all extant known mushrooms, none beat the top spot: the extinct and tallest mushroom ever to be on the Earth!

Mushrooms Taller than Trees

Prototaxites reigned in the Late Silurian and Devonian Period, around 430 million years ago and existed for just over 50 million years. This was a time when the first insects and millipede-like creatures were emerging. At the start of this era, the tallest trees were only a few feet in height, allowing the Prototaxites to tower above all. These mushrooms would have been 8m tall and 1m wide, a lonely skyscraper in a field of moss.

By the end of the Devonian era there was likely a mass extinction of Prototaxites, although we don’t technically know if any descendant survived, nor what they might be today. Back then with the changing climate, more trees growing and fungi-eating organisms appearing, the Prototaxites lost their dominance.

As time went on, the mushrooms you see today would not have appeared for a while, fungi spent a lot of time diversifying and adapting, growing below the surface.

Originally, it was thought that modern-style mushrooms (with gills in cap) made their appearance 90 million years ago; that was until a fossil discovery in 2017 Brazil found that they would have existed 115 million years ago. They were lying in the undergrowth on the same world that the dinosaurs ruled.

Gondwanagaricites magnificus

Those “magic” mushrooms

The first evidence of the emergence of humanoids was 6 million years ago, and it’s very likely that they used mushrooms for spiritual rituals. Although the first consumption of psilocybin - magic - mushrooms may have been 2 million years ago, shrooms have existed for roughly 67 million years, so it seems likely early humans would have stumbled across them before that.

It has been speculated that early humans consumed mushrooms and received enhanced cognitive function, since 2 million years ago was the same time the brain tripled in size (the speculative Stoned Ape Theory). It begs the question: did they make humans conscious?

Evidence of shroom usage remains around the world: 9,000 BCE cave paintings in Spain and North Africa, small sculptures from 500 BC and 900 AD in Mexico and Guatemala. Uses would have always involved a spiritual aspect: initiation rites in Central Africa, Aztecs and Mazatec conducting healing and religious rituals, and in Siberia the Saami and Evenki would have used it for spirit communication. Globally, despite no official records due to a lot of knowledge being oral, there has been folklore that strongly hints that everyone was taking shrooms. Through mushrooms or not, getting high by consuming psychoactive substances has been a human constant.

A shroom trip would usually last 4-6 hours and include a ramp up of physical sensations and changes of perception. As the trip goes on and reaches its peak, people have felt the death of ego (a person’s sense of importance) hence the '“oneness with everything”. In the come down, users have reported a sense of well-being and clarity of thought. If you want to know more, here is a couple retellings of trips: the experience of simulation, chef in past life and this is what a bad trip looks like.

Its a shortcut to the altered state that monks, through practice of meditation have been achieving for centuries. Indian and Tibetan monks achieving dissolution of ego. The Taoist monks in China transcending ordinary perception. Christian monks in Medieval Europe achieving a union with God. Buddhist monks inducing a timelessness and also a dissolution of ego.

Conspiracy theories about fungi stretch wide - are they sentient? A world wide web, subtly influencing actions, spreading everywhere, a planetary brain. Or are they alien? Put here on earth to accelerate our path to consciousness. Anyone who’s eaten a magic one will tell you they are.

Across history, mushrooms have appeared in the diets, medicines, and mythologies of cultures all over the world - they are interwoven into our entire existence. And how could they not be? Closer to animals than plants, some species differ more than mammals differ from fish, and produce thousands of unique and useful chemicals:

• Antibiotics (penicillin)

• Psychoactives (psilocybin, LSD precursors)

• Toxins (aflatoxins, ergot)

• Fermentation agents (for alcohol, bread, cheese)

• Bioluminescent compounds (luciferin, luciferase)

And that’s only from the 150,000 known ones - there’s still 4,850,000 species to discover.

Fungi, the Brain and the Universe

There are 3 structures I want to draw your attention to: mycelium of fungi, the neural network of the brain and finally the cosmic web of the universe.

If I hadn’t labelled them, could you tell the difference?

All three systems have web-like structures.

All three are a fully decentralised space - no node knows everything.

All three systems demonstrate emergent behaviour - simple interactions from nodes leading to complex behaviour.

They can all be described as a fractal structure. A mathematical term for a never-ending pattern. Zoom in close and it’ll look the same as from afar.

Fractals are efficient and scalable systems, which is why much of nature tends to recurse into fractal geometry.

The decomposers of nature, instrumental to our Earth’s natural cycle, spreading its threads into our medicine, altering our states of mind, the very idea of consciousness and our food.

I think it’s safe to say - we don’t know all of fungi’s secrets just yet.