Chapter 1
The Underground Kingdom That Shapes Our World
Have you ever stopped to consider that beneath your feet lies an entire kingdom of life so vast, so influential, yet so hidden that most of us barely acknowledge its existence? Fungi-neither plant nor animal but something else entirely-form one of life's great kingdoms, yet we've documented less than 10% of an estimated 3.8 million species. In "Entangled Life," biologist Merlin Sheldrake takes us on a mind-bending journey through this hidden world that shapes everything from our soil to our minds. Since its 2020 publication, this book has become something of a scientific sensation, praised by everyone from naturalist David Attenborough to musician Brian Eno. It's not hard to see why-Sheldrake's exploration of fungi reveals them not as mere decomposers but as Earth's great connectors, the living seams that stitch our world into relation. As we face unprecedented environmental challenges, understanding these ancient organisms might just hold the key to our future.
Chapter 2
The Invisible Web That Sustains All Life
Fungi are everywhere yet easy to miss. They sustain all terrestrial life, digesting pollutants, making soil, nourishing plants, and influencing our atmosphere. Though they form one of life's kingdoms alongside plants and animals, over 90% remain undocumented. The more we learn about fungi, the less makes sense without them.
These organisms have shaped Earth's most dramatic events. Plants only left water 500 million years ago through collaboration with fungi that served as their root systems. Today, over 90% of plants depend on mycorrhizal fungi, forming what scientists call the "wood wide web." Four hundred million years ago, enormous fungal structures called Prototaxites dominated landscapes, standing taller than buildings when plants were barely knee-high.
Fungi thrive everywhere from seafloors to deserts, breaking down everything from tough plant lignin to nuclear waste. They disperse billions of spores, influence weather patterns, and form vast mycelial networks that conduct nutrients and even electrical signals. Whether as single-celled yeasts or complex mushrooms, fungi have formed essential relationships with plants and animals throughout evolutionary history.
Humans have deployed fungal solutions since before we were Homo sapiens. Neanderthals used penicillin-producing molds to treat infections 50,000 years ago. The 5,000-year-old Iceman carried tinder fungus for fire-making and birch polypore as medicine. Fleming's 1928 discovery of penicillin revolutionized medicine and helped change the course of World War II.
Beyond medicine, fungi produce 60% of industrial enzymes and 15% of vaccines. The edible mushroom market alone is projected to grow from $42 billion to $69 billion by 2024. Fungi also offer environmental solutions through mycoremediation (breaking down pollutants), mycofiltration (cleaning water), and mycofabrication (creating sustainable materials).
Despite their importance, fungi have received minimal scientific attention compared to plants and animals. This oversight is particularly striking given how fungi challenge our fundamental concepts about life itself. They exist as networks rather than discrete individuals, solve complex problems without brains, and blur the boundaries between organisms. In studying fungi, we're not just exploring an overlooked kingdom-we're reconsidering what it means to be alive.
Chapter 3
The Seductive Power of Fungal Chemistry
Imagine holding two kilograms of white truffles worth $12,000-scruffy, irregular, socketed like skulls. Their value lies not in appearance but in their powerful aroma, a chemical lure that has fascinated humans for millennia. But why would fungi buried underground evolve such potent scents?
The answer lies in their reproductive strategy. Truffles face a fundamental challenge: how to disperse spores when buried beneath soil. Their solution is smell-producing aromas powerful enough to penetrate soil, distinctive enough to stand out in the forest's olfactory landscape, and enticing enough to make animals dig them up and eat them. This evolutionary strategy recruits animals as spore dispersers, carrying fungal spores to new locations in their digestive tracts.
Our human sense of smell is remarkably sophisticated, capable of distinguishing over a trillion different odors and detecting molecules at incredibly low concentrations. When we experience a truffle's aroma, we're briefly participating in the fungus's chemical ecology-a relationship that has evolved over millions of years. Unlike our centralized olfactory system, fungi experience chemicals through their entire bodies, living "bathed in a rich field of chemical information" and using chemicals to communicate with plants, animals, other fungi, and even themselves.
Truffles have long been associated with sex across cultures, with names often translating to terms like "Earth's testicles." Their powerful aromas can trigger "olfactory flashbacks" complete with visual and emotional memories. The value of truffles drives extraordinary behaviors-prayers to saints, theft, fraud, and even violence. As one truffle scientist explains, "Truffles bring out the dark side of people. It's like money lying on the ground, but it's perishable and mercurial."
Beyond truffles, fungi communicate through subtle chemical dialogues. Mycelial networks form through processes of branching and fusion, with hyphae finding each other through "homing"-the fundamental attraction of fungus to itself. Yet fungi must also distinguish self from other, with some species having tens of thousands of mating types. Beyond self-recognition, fungi communicate with plant partners through chemical call-and-response, with both producing volatile compounds that make them attractive to each other.
Some fungal chemical attraction leads to death rather than sex or symbiosis. Nematode-hunting fungi demonstrate remarkable sensory abilities, producing traps only when they detect nearby worms through chemical eavesdropping. Their hunting methods are diverse and gruesome: some create adhesive nets, others mechanical nooses that inflate in a tenth of a second, while some produce toxic droplets that paralyze worms before digestion.
The fungus Arthrobotrys oligospora shows particularly versatile behavior, able to decompose organic material, trap nematodes, parasitize other fungi, or feed on plant roots depending on environmental conditions. Different individuals of the same species can respond idiosyncratically, producing different types of traps or positioning them distinctively. This behavioral flexibility challenges our understanding of fungi as simple, predictable organisms.
How should we talk about fungal communication? Scientific views often reduce fungi to automatic responders without deliberate intentions, yet their mycelium actively senses and responds to surroundings in unpredictable ways. Perhaps we need to expand our concepts of communication beyond requiring mouths, ears, or nervous systems, understanding fungi as articulating themselves through a chemical vocabulary that other organisms can interpret.
Chapter 4
Living Networks: The Intelligence of Mycelium
Fungi challenge our animal imaginations with their remarkable ability to branch and explore multiple paths simultaneously. When faced with a forked path, fungal hyphae don't choose-they take both routes, existing as both singular and plural entities. Mycelium serves as ecological connective tissue, the living seam stitching the world into relation, running through soil, ocean sediments, coral reefs, living and dead organisms, and human-made structures.
Elegant experiments demonstrate mycelium's sophisticated problem-solving abilities. When a wood-rotting fungus encounters a new food source, it completely remodels its network, withdrawing exploratory parts and thickening connections to the new resource. Remarkably, fungi appear to possess directional memory-when separated from a newly discovered food source and placed on fresh medium, they grow toward where the food had been.
Mycelial networks face constant trade-offs-dense networks increase transport capacity but limit exploration, while sparse networks cover more ground but remain vulnerable to damage. The typical growth pattern involves initial exploration in all directions, followed by reinforcement of successful pathways and pruning of unproductive ones-a form of natural selection within the network.
How does a sprawling mycelial network coordinate itself? Experiments with bioluminescent fungi revealed mysterious waves of light passing across entire networks within minutes-far faster than chemical signals could travel through hyphae. When one side of a mycelium was wounded, the entire network lit up within ten minutes, suggesting some rapid internal communication system.
Unlike animals with central control systems, mycelial networks operate with distributed intelligence-no head, no brain, no operational center. A fragment can regenerate an entire network, making a single mycelial individual potentially immortal. Mycelium represents fungi's unique feeding strategy: rather than ingesting food like animals or making their own like plants, fungi digest the world where it is and then absorb it.
Hyphal tips can generate tremendous pressure, up to eighty atmospheres, enough to penetrate tough barriers like Kevlar. Unlike most multicellular organisms that grow by cell division, hyphae grow by extending indefinitely at their tips, with hundreds of bladders filled with cellular building materials fusing with the advancing tip each second.
Mycelial networks function as sophisticated transport systems. Cords and rhizomorphs-large pipes formed from many small tubes-can conduct flow thousands of times faster than individual hyphae. These structures allow networks to move nutrients and water over vast distances. Over short distances, substances travel on microtubule "motors," while longer distances utilize flowing cellular fluid.
Hyphae steer themselves through their environment with remarkable sensitivity. Most fungi can detect and respond to light direction, intensity and color, temperature, moisture, nutrients, toxins, and electrical fields. The bean rust fungus can detect grooves half a micrometer deep, three times shallower than the gap between laser tracks on a CD.
How do brainless fungi integrate sensory information and coordinate behavior across vast networks? Research suggests electrical signaling might be key. When microelectrodes were inserted into hyphal strands, regular impulses were detected firing at about four per second-similar to animal sensory neurons-and traveling ten times faster than fluid flow in hyphae. Most remarkably, when wood blocks were placed on the mycelium, the firing rate doubled instantly.
Are mycelial networks like brains? Some researchers speculate that fungi might achieve "brain-like circuits" through mechanisms like hyphal compartments with regulatable pores that could modulate electrical signals. Others have proposed treating mycelium like living circuit boards in a "fungal computer." While not replacing silicon chips, mycelium could potentially serve as environmental sensors, monitoring soil quality and pollution.
Can network-based organisms like fungi possess cognition? Traditional definitions center on human-like brains and minds, but many biologists find this view too limited. Darwin pragmatically defined intelligence as "how efficient a species becomes at doing the things they need to survive." The brain itself is just one type of dynamic network, and mycelium may represent one of life's earliest network forms, with fossils dating back 2.4 billion years, persisting through countless global transformations.
Chapter 5
The Intimate Dance of Symbiosis
In 1869, Swiss botanist Simon Schwendener proposed the radical "dual hypothesis of lichens"-that lichens weren't single organisms but composed of two different entities: a fungus and an alga living together. This idea was initially met with fierce opposition from lichenologists who found it shocking that two different species could form a single organism with its own identity. Most troubling was that lichens represented evolutionary lineages converging rather than diverging, contradicting the prevailing understanding of Darwin's tree of life.
In 1877, German botanist Albert Frank coined the term "symbiosis" specifically to describe the relationship between fungal and algal partners in lichens. The concept was later expanded to cover the full spectrum of interactions between organisms, from parasitism to mutually beneficial relationships. Lichens became the gateway to understanding symbiosis, challenging the dominant evolutionary narrative of life as a competitive "gladiator's show."
Lichens cover approximately eight percent of Earth's surface-an area larger than tropical rainforests. They appear in diverse forms: some drab, others brightly colored; some like stains, others like shrubs or antlers. They colonize rocks, trees, buildings, and even beetles. As geological forces, lichens physically break up surfaces and deploy acids to dissolve rock in a process called "weathering." When they die and decompose, they create the first soils in new ecosystems, transforming inanimate minerals into components that can enter living systems.
Lichens qualify as "polyextremophiles"-organisms that survive multiple extreme conditions. They thrive in scorching deserts, inside solid rock, and in Antarctica's Mars-like Dry Valleys. They can survive immersion in liquid nitrogen at -195C and live for thousands of years. This resilience makes them particularly interesting to astrobiologists as potential interplanetary travelers. Studies show lichens can withstand the shock pressures of meteorite ejection, though atmospheric reentry presents greater challenges.
The concept of symbiosis transformed our understanding of how complex life evolved. Lynn Margulis's endosymbiotic theory demonstrated that eukaryotic cells arose when single-celled organisms engulfed bacteria that continued living inside them. Mitochondria and chloroplasts are descendants of these engulfed bacteria, making all complex life-humans included-a story of the "intimacy of strangers."
In 2016, lichenologist Toby Spribille upended the traditional dual hypothesis by discovering a third fungal partner (a yeast) in lichens across six continents. Two years later, his team found a fourth fungal partner in wolf lichens. These findings were just the beginning-Spribille found that every lichen group has different combinations of partners. Lichens are now understood as dynamic systems rather than fixed combinations of components-less about the identity of the participants and more about the metabolic "songs" they collectively sing.
Lichens challenge our understanding of biological identity and individuality. Like all organisms, humans can't be defined anatomically (our bodies host more microbial cells than "our own"), developmentally (we depend on symbionts for development), genetically (we inherit microbes alongside our DNA, and viral DNA comprises 8% of our genome), or immunologically (our immune systems manage relationships with resident microbes rather than simply fighting external threats).
Researchers use "holobiont" to describe assemblages of different organisms functioning as units-entities that are more than the sums of their parts. These relationships aren't utopian; collaboration always blends competition and cooperation. As one seminal paper declares: "There have never been individuals. We are all lichens."
Chapter 6
Fungi That Change Our Minds
Psychedelic fungi have profound effects on human consciousness, altering perception, dissolving boundaries of self, and creating mystical experiences that defy quantification. These fungal molecules-including LSD and psilocybin-have become entangled in human culture precisely because they confound our concepts and structures, particularly our sense of self. Their ability to soften rigid mental habits makes them powerful medicines for addiction, depression, and existential distress, while also changing scientific understanding of consciousness itself.
Some fungi manipulate animal behavior with astonishing precision. Ophiocordyceps unilateralis hijacks carpenter ants, making them abandon their nests, climb plants, and clamp onto leaf veins in a "death grip" at precisely the right height and orientation for fungal reproduction. The fungus infiltrates the ant's body, comprising up to 40% of its biomass, but surprisingly avoids the brain. Instead, it likely uses chemical compounds-possibly related to ergot alkaloids (the chemical family of LSD)-to control the ant's movements.
Humans have used mind-altering organisms since before recorded history. Cave paintings in southern Algeria dating from 9000-7000 BCE include figures of deities with mushroom-like forms. While archaeological evidence confirms ancient human use of mushrooms as food and medicine, definitive proof of prehistoric psilocybin use remains elusive.
Parasitic mind-controlling fungi have evolved independently across the fungal kingdom. These fungi employ sophisticated biochemical techniques to control host behavior, including compounds that have found medical applications. Cyclosporine, an immunosuppressant enabling organ transplants, and myriocine (fingolimod), used for multiple sclerosis, were both originally derived from fungi that infect insects.
While parasitic fungi harm their hosts, psilocybin mushrooms have demonstrated remarkable therapeutic benefits for humans. In 2016, research at NYU and Johns Hopkins found that a single dose of psilocybin alongside psychotherapy reduced psychological symptoms in 80% of terminal cancer patients, with effects persisting for at least six months. Participants reported profound experiences of joy, love, and interconnectedness, with most rating their experiences among the five most meaningful of their lives.
Psilocybin is converted to psilocin in the body, which mimics serotonin and infiltrates our nervous system. Contrary to expectations, brain scans reveal psilocybin reduces rather than increases brain activity, particularly in the default mode network (DMN)-the brain's "corporate executive" that maintains order during idle thought and self-reflection. When the DMN is suppressed, cerebral connectivity explodes with new neuronal pathways, and previously distant networks link up.
The therapeutic effects appear to come not from biochemical mechanisms alone but through the mind itself-the mystical experiences psilocybin induces correlate directly with symptom reduction in depression, anxiety, and addiction studies. Unlike conventional drugs that bypass consciousness, psilocybin acts on symptoms via the mind, "dope-slapping people out of their story" and softening rigid mental models, particularly our sense of self.
Could psilocybin mushrooms' effects on human consciousness be considered part of their extended phenotype, similar to how Ophiocordyceps controls ant behavior? This speculation faces challenges under Richard Dawkins' criteria for extended phenotypes. While psilocybin production is certainly inherited and varies between species, it's unclear how fungi producing "better" altered states would gain reproductive advantages. Additionally, psilocybin evolved approximately 75 million years ago, long before humans existed, raising questions about its original purpose.
The outlawing of psilocybin and LSD in the late 1960s marked a new chapter in these fungi's evolutionary history. In 1976, the McKenna brothers published "Psilocybin: Magic Mushroom Grower's Guide," enabling anyone to cultivate these mushrooms at home. This DIY mycology movement exploded, with Paul Stamets further simplifying cultivation techniques. Today, these fungi benefit enormously from human cultivation, with new varieties being bred for specific effects.
Chapter 7
The Ancient Partnership That Made Land Life Possible
Six hundred million years ago, green algae began moving from shallow waters onto land, eventually evolving into plants that now comprise 80% of Earth's biomass. This transition was transformative for our planet, but presented enormous challenges. Before plants, land was harsh and desolate-scorched, dusty, with wildly fluctuating temperatures and no soil.
Academic consensus holds that algae could only make the transition to land by forming relationships with fungi, evolving into what we now call mycorrhizal relationships. Today, over 90% of plant species depend on these fungi-making them more fundamental to planthood than flowers, leaves, or even roots. These intimate partnerships involve cooperation, conflict, and competition, underpinning terrestrial life as we know it.
Mycorrhizal fungi are the true roots of terrestrial life, with the word "mycorrhiza" capturing this reality-roots (rhiza) followed fungi (mykes) into being. These fungal networks are astonishingly prolific, with hyphae fifty times finer than the finest roots and capable of exceeding a plant's root length by a hundredfold. Globally, mycorrhizal hyphae in just the top ten centimeters of soil would stretch half the width of our galaxy, with a surface area that could cover all dry land 2.5 times over.
The term "mycorrhiza" was coined in 1885 by Albert Frank, who had earlier created the term "symbiosis." While studying truffles for the Prussian government, Frank documented the intimate relationship between tree roots and fungal mycelium, suggesting they shared "intimate, reciprocal dependence" rather than a parasitic relationship. Despite fierce criticism from colleagues who viewed all symbiosis as disguised parasitism, Frank conducted experiments showing pine seedlings grown in forest soil with fungal partners developed into larger, healthier saplings than those in sterile conditions.
The Devonian period saw plants establish themselves on land, with atmospheric carbon dioxide dropping dramatically. Researchers have used climate models to measure mycorrhizal fungi's impact on ancient climates. By adding mycorrhizal efficiency data to climate models, they found it was possible to change the entire global climate simply by adjusting symbiotic efficiency.
Mycorrhizal fungi continue to shape life on Earth today. They provide up to eighty percent of a plant's nitrogen and as much as one hundred percent of its phosphorus, along with other crucial nutrients like zinc and copper. Plants, in turn, allocate up to thirty percent of their harvested carbon to these fungal partners. This mycorrhizal way of life has evolved independently over sixty times in different fungal lineages since plants first colonized land, suggesting fungi have discovered a truly winning strategy.
Plants and fungi maintain their "balance of power" through sophisticated trading strategies. Plant roots supply carbon preferentially to fungal strains providing more phosphorus, while fungi receiving more carbon provide more phosphorus in return. Some fungi are more cooperative partners while others "hoard" phosphorus, but behavior remains flexible depending on circumstances. Fungi actively transport phosphorus from areas of abundance (where it fetches a low "price" from plants) to areas of scarcity (where plants pay more carbon for it).
The complexity of mycorrhizal relationships induces a sense of vertigo-from microscopic trading decisions at cellular levels up to planetary impacts involving trillions of trees and quadrillions of miles of fungal networks. This scale presents challenges for researchers, as mycorrhizal relationships occur underground and out of sight.
Albert Howard, a founding figure in organic farming, warned in the 1940s that chemical fertilizers would disrupt mycorrhizal associations upon which "the health and well-being of mankind must depend." Modern industrial agriculture has doubled crop production but at steep environmental costs. Research confirms Howard's concerns: conventional farming practices significantly reduce mycorrhizal fungal abundance. These fungi hold soil together, increase water absorption, store carbon, support soil food webs, and enhance crop resilience.
Chapter 8
The Wood Wide Web: How Forests Think Together
Mycorrhizal networks challenge our understanding of plants as autonomous individuals, creating physical connections that embody ecology's most basic principle: relationships between organisms. These fungal pathways form what scientists now call "the wood wide web."
In the Pacific Northwest, bright white Monotropa uniflora plants (ghost pipes) push through fallen fir needles. These plants have abandoned photosynthesis, leaves, and their green color-a radical departure from fundamental plant nature. Their solution is fungal: unlike normal plants that exchange carbon compounds for minerals with mycorrhizal fungi, Monotropa receive both carbon and nutrients from fungi without apparent reciprocation. This carbon ultimately comes from other plants via shared mycorrhizal networks.
Since the 1980s, scientists have discovered that most plants engage with multiple mycorrhizal partners, and these fungal networks can fuse with each other, creating vast, complex systems of shared mycorrhizal networks. As researcher Toby Kiers puts it, "The fact that it's connected underground wherever we walk is just mind blowing."
In 1984, David Read conclusively demonstrated that carbon could pass between normal green plants through fungal connections. His experiment used radioactive carbon dioxide to visualize the transfer between plants connected by mycorrhizal fungi. In 1997, Suzanne Simard published the first study showing carbon transfer between plants in a natural forest setting, finding that carbon moved from birch trees to fir trees that shared mycorrhizal networks, especially when fir seedlings were shaded. Read coined the phrase "The Wood Wide Web" in his commentary on Simard's groundbreaking paper.
While no one denies shared mycorrhizal networks exist in nature, their ecological significance remains debated. Some studies show substantial carbon transfer between trees through fungal connections, while others find minimal exchange. Ghost plants like Monotropa help settle this debate-their total dependence on shared networks proves these connections can support entire lifeforms. About ten percent of plant species are mycoheterotrophs ("mycohets"), including all 25,000 orchid species at some developmental stage.
Resources in mycorrhizal networks flow "downhill" from areas of abundance (sources) to scarcity (sinks). Larger plants with better access to light typically serve as sources for smaller, shaded plants. In Canadian forests, carbon transfer between birch and Douglas fir switches direction twice yearly: in spring flowing from evergreen fir to leafless birch, in summer from leafy birch to shaded fir, and reversing again in autumn.
Why would plants give resources to fungi that might benefit competitors? Several explanations exist: many plants have surplus carbon that costs nothing to share; benefits may alternate seasonally between species; and kin selection might explain why more carbon transfers between sibling seedlings than unrelated pairs. Most fundamentally, our plant-centric perspective distorts understanding-fungi aren't passive pipelines but living organisms with their own interests.
Every link in a wood wide web is a fungus with its own agenda. A mycorrhizal fungus benefits from keeping its various plant partners alive-a diverse portfolio insures against the death of any single plant. This myco-centric view avoids the problem of altruism and positions fungi as brokers of entanglement mediating plant interactions according to their own needs.
Wood wide webs transport more than just resources. Some plants produce chemicals that stunt or kill nearby competitors, and mycorrhizal networks can provide a "fungal fast lane" for these toxic deterrents. Beyond poisons, growth-regulating hormones can pass through networks, and even genetic material like DNA-containing nuclei, viruses, or RNA might travel between plants via fungal channels.
Plants emit chemicals that communicate their condition. When broad beans are attacked by aphids, they release volatile compounds that attract parasitic wasps. Researchers discovered these "infochemicals" can pass between plants underground via shared fungal networks. Plants connected to aphid-infested plants through fungal networks increased their defense compound production, creating plumes large enough to attract parasitic wasps-even without direct aphid contact.
Without understanding the architecture of these fungal networks, it's difficult to comprehend their functioning. Mapping studies revealed that fungal networks aren't evenly distributed-young trees have few connections while older trees act as highly connected hubs. Through these hubs, any tree can connect to another in just three steps, creating "scale-free" properties similar to the World Wide Web.
Wood wide webs are dynamic "complex adaptive systems"-entities whose behavior can't be predicted from their constituent parts alone and which self-organize into new forms in response to circumstances. Like brains, financial markets, or the internet, these networks feature constant turnover, with fungi forming and reforming connections, redirecting flows, and responding to chemical signals.
Chapter 9
Radical Mycology: Fungi as Environmental Allies
Fungi are veteran survivors of ecological disruption-inventive, flexible, and collaborative through periods of catastrophic change. With much of Earth's life threatened by human activity, radical mycologists are exploring how we might partner with fungi to help us adapt to life on a damaged planet.
During the Carboniferous period (290-360 million years ago), early wood-producing plants spread across tropical swamps with their mycorrhizal partners. As these forests grew and died, they pulled massive amounts of carbon dioxide from the atmosphere. For tens of millions of years, much of this plant matter didn't decompose, creating layers of un-rotted forest that stored so much carbon that atmospheric CO2 levels crashed. This un-rotted plant matter eventually became coal-a negative record of fungal absence that humans now burn, thermally decomposing what fungi couldn't break down enzymatically.
Despite fungi's ecological importance, mycology remains what David Hawksworth called "a neglected megascience." While plants and animals have dedicated university departments, fungi are typically lumped with plant sciences. The 2018 State of the World's Fungi report revealed only 56 fungal species have had their conservation status evaluated, compared to 25,000+ plants and 68,000+ animals.
Peter McCoy, anarchist and self-taught mycologist, founded Radical Mycology to develop fungal solutions to technological and ecological problems. This grassroots movement emerged from the psychedelic mushroom-growing scene of the 1970s pioneered by Terence McKenna and Paul Stamets, evolving alongside hackerspaces and citizen science projects.
At the Radical Mycology Convergence in Oregon, I discovered how fungi transform waste into value. The omnivorous Pleurotus mycelium (oyster mushrooms) can digest used diapers, agricultural waste, and even cigarette butts. McCoy demonstrated how he trained Pleurotus to consume toxic cigarette butts by gradually eliminating alternatives until the fungus "learned"-or rather remembered-how to use them as its sole food source.
Fungi might help save the world through mycoremediation-the use of fungi to restore contaminated ecosystems. Fungi have remarkable appetites for pollutants, including toxic chemicals like VX gas components, pesticides, explosives, crude oil, some plastics, and pharmaceuticals. Mycelium can decompose materials, accumulate heavy metals for safe removal, and even filter polluted water.
In the absence of institutional support, radical mycologists have launched grassroots projects worldwide. CoRenewal studies fungi that can detoxify oil extraction by-products in the Ecuadorian Amazon. California activists have deployed miles of straw tubes filled with Pleurotus mycelium to remediate toxic runoff from wildfire-destroyed homes. Danish harbors use floating mycelium booms to absorb fuel spills.
Beyond breaking things down, fungi can also build things up. Companies like Ecovative Design are pioneering "mycofabrication"-growing building materials from mycelium. Their New York facility produces boards, bricks, acoustic tiles, packaging, leather-like textiles, and foam from fungal mycelium. These materials offer sustainable alternatives to plastics, concrete, and animal leather.
The process is simple yet revolutionary: mycelium weaves itself into a dense fabric as it grows through agricultural waste like sawdust packed into molds. Once dried, it becomes a versatile material that's stronger than concrete when subjected to bending forces, more insulating than polystyrene, fire-retardant, and fully compostable. Major companies like Dell, IKEA and Stella McCartney have adopted these materials, while DARPA has invested $10 million to explore growing self-repairing military barracks from mycelium.
Paul Stamets epitomizes what it means to "go fungal"-living with infectious mycological zeal and an unwavering belief that fungi are eager to partner with humans in novel ways. His latest breakthrough involves using fungal extracts to dramatically reduce bee mortality. Extracts from wood-rotting fungi like amadou and reishi reduced viral infections in bees by extraordinary amounts-up to 45,000-fold for certain viruses.
Like many radical mycological solutions, this approach isn't about inventing something new but remembering ancient relationships-in this case, bees potentially medicating themselves with fungi in nature. Whether these fungal antivirals will save bee populations long-term remains uncertain, but represents another step toward what might become a mutually beneficial symbiosis between humans, fungi, and bees.
Chapter 10
Stories We Tell About Fungi
Yeasts share the most intimate history with humans of all fungi. They live on our skin, in our lungs, and throughout our bodies, while also being some of the most widely used model organisms in cell biology and genetics. Despite their importance-with yeast-related research earning a quarter of Nobel Prizes for Physiology or Medicine since 2010-yeasts were only discovered to be microscopic organisms in the nineteenth century.
Humans have worked with yeasts for millennia, with unambiguous evidence dating back 9,000 years in China. The anthropologist Claude Levi-Strauss argued that yeasts oversaw one of humanity's most dramatic cultural transformations-the transition from hunter-gatherers to agriculturalists. Modern brewing yeast arose around the same time as domesticated animals, suggesting the Neolithic transition 12,000 years ago may have been partly a cultural response to yeast, whether for bread or beer (with the beer-before-bread hypothesis gaining scholarly support).
The transformational power of yeast has been personified as divine energy across cultures. Ancient Sumerians worshipped Ninkasi, goddess of fermentation. Egyptians addressed "givers of bread and beer" in prayers. The Ch'orti' people understood fermentation as "the birth of the good spirit," while Greeks had Dionysus, god of wine and drunkenness.
Unlike microscopic yeasts, mushroom-producing fungi have been understood more directly but still generate polarized responses. While East Asian poets wrote rhapsodic verse about mushrooms, European authors issued stark warnings about their dangers. In 1957, Gordon and Valentina Wasson categorized cultures as either "mycophilic" (fungus-loving) or "mycophobic" (fungus-fearing). Throughout history, fungi have defied classification-Theophrastus could only describe truffles by what they were not, while Linnaeus called fungi "still Chaos, a scandal of art."
Our attempts to make sense of fungi often reveal more about ourselves than the organisms we study. Field guides might describe the same mushroom as "poisonous" or "delicious, when fried," depending on the author's physiological response. This bias becomes particularly apparent in discussions of symbiotic relationships, which have been understood through human metaphors since the concept emerged in the nineteenth century.
For much of the twentieth century, Western biology emphasized competition over cooperation, mirroring industrial capitalism, while Russian thinkers like Peter Kropotkin stressed mutual aid. Today, shared mycorrhizal networks are variously described as socialist redistribution systems, parental care networks, or biological markets-each metaphor carrying political baggage.
When we describe organisms, the direction of our metaphors matters profoundly. Robin Wall Kimmerer notes the Potawotomi word "puhpowee" describes both mushrooms pushing up overnight and certain human anatomical events-but is this anthropomorphizing fungi or mycomorphizing humans? What if we considered fungi, rather than animals or plants, as our template for "typical" life?
Our relationship with fungi extends to our very metabolism. About ten million years ago, our primate ancestors developed a mutation in alcohol dehydrogenase that made it forty times more efficient at detoxifying alcohol. This mutation coincided with our ancestors' adaptation to ground living, allowing them to safely consume overripe, fermented fruit that had fallen from trees-the "drunken monkey hypothesis."
Stories about fungi shape our perceptions in profound ways. At Cambridge Botanical Gardens grows a clone of the supposed apple tree that inspired Newton's theory of gravitation-though the story itself is considered apocryphal. When I asked to pick some apples, I was refused because "the apples have to be seen by the tourists to fall from the tree to add verisimilitude to the myth." The absurdity was striking-respectable people intoxicated by a story, making plants perform in service to human narratives.
I collected a fallen, decomposing apple with its alcoholic smell of fermentation and decided to make cider from Newton's apples. After "scrumping" most of the apples at night and pressing them with a borrowed community apple press, I let the indigenous yeasts on the apple skins ferment the juice naturally. The resulting cider was delicious-floral, delicate and dry with a gentle fizz. I called it "Gravity" and found myself intoxicated not just by yeast's metabolism but by the weight of the story itself.
