Fungi have not always gotten the attention they deserve—“they will probably never make the bestseller list,” opens a 1996 New York Times Magazine article titled “The Fungus Among Us.” But just look at them now, taking their place in the spotlight thanks to The Last of Us, the wildly successful video game franchise that’s found a whole new audience as a critically acclaimed television series.
Fantasy and science fiction buffs know that fungi infiltrated literature long before we first met Joel and Ellie. Fungi—those mysterious, confusing, grotesque, and intriguing life forms considered plants until just a few decades ago, which include mushrooms, spores, mycelia, hyphae, moulds, mildew, lichens, and yeasts—are great subjects for speculative and weird fiction for a good reason. What are they? Are they visible, or invisible? Friends or foe? Venerated or despised? Are they poisonous, or can they be used for healing? Familiar, or still mysterious and unknown? Yes and yes, to all of those questions.
Warning: The text contains graphic details about real-life human diseases caused by fungi
Fictional fungi creep across a variety of genres, styles, and epochs. Fungi can be found everywhere from the short horror story “The Voice in the Night” (1907) by William Hope Hodgson, the collection of cosmic horror sonnets “Fungi from Yuggoth” (1943) by H. P. Lovecraft, Ray Bradbury’s classic science fiction short story “Come into My Cellar” (1962), and Jeff VanderMeer’s Ambergris trilogy (2001, 2006, 2009) to children’s stories like Alice’s Adventures in Wonderland (1865) by Lewis Carroll and Eleanor Cameron’s The Wonderful Flight to the Mushroom Planet (1954).
Fungi elude us, never offering easy answers. Through them, we travel into the realm of cosmic horror within the minuscule. Does some kind of mould slowly possess and consume the narrator in Jeff VanderMeer’s Annihilation? Do we truly need to know? Personally, I do not. Perhaps, I don’t even want to know—let me stay in the unknown, when it comes to these fictional mysteries. Real-life fungi can be terrifying enough.
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Emergent Properties
No one explains this better than Paul Stamets, the mycologist and fungi evangelist who inspired the eponymous Lieutenant in the Star Trek franchise. In Mycelium Running (Ten Speed Press, 2005), he describes how fungal spores attach to the surface of their prey and feed to complete their life cycles: “Once inside, the mycelium forks and runs through the internal organs.” Paul Stamets is not trying to scare us, but I challenge you to read these words without experience a sense of unease. He explains how, after boring through the prey’s external layers while secreting dissolving enzymes, the fungus mummifies its host, noting “[o]ther portals of entry include the respiratory tract, anus, and mouth.”
Here, Stamets is describing fungi preying on ants—the same fungi which inspired the story behind The Last of Us. Using some form of mind control, the fungi (both the real-life and the fictional one) compel their prey to behaviours they would not normally do. In ants, that means seeking an elevated, moist place to die; in The Last of Us, this takes the form of hyperaggressive cannibalism. Welcome to the fungal zombie apocalypse.
So let’s get nerdy and take a look at the science! I promise no spoilers and, unless mentioned specifically, when I speak about The Last of Us or “the story,” I refer to both the video game and the TV series. Let’s start with the reassuring side of things first:
What The Last of Us Gets Wrong…
To appreciate the science behind The Last of Us, let’s imagine ourselves in the shell of an ant for a fleeting moment. Once the fungus infects our ant-bodies, we do what the fungus wants us to do. Now, we are hollow ant-vessels: nourishment, transportation, and final home all in one. We are the walking dead, bringing the “zombie-ant fungus” within us inside the colony, effectively acting like a Trojan Horse.
The mycelium feeds inside our ant-bodies, but it does not reach the brain—yet. Instead, with some sort of chemical signalling, the fungus compels us to erratic behaviour: We seek altitude, something which, as ants, we would not normally do. As our ant-bodies wither, we reach our ultimate destination. A twig, or the veins on the underside of a leaf: perfect spots for the fungus to complete its life cycle. The fungus sends a final command to the brain: bite. We tighten our ant-mandibles in a death grip as the fungus reaches the brain and mushrooms burst from the head. Raining spores will infect the whole ant colony.
And now, some reassuring facts:
We are not ants. No mutation can cause a “zombie-ant fungus” to become a “human-ant fungus,” as it is the case in The Last of Us. Our biology is just too different; human bodies are too hot. Such a specific infection is achieved by the very slow process of evolutionary adaptation. Fungi live in the environment and infect mostly plants, insects, amphibians, reptiles. Ants and fungi have co-evolved for millions of years.
Human-to-human transmission of fungal diseases ain’t common. “Bomb. Start bombing. Bomb this city and everyone in it,” advises the desperate scientist in episode two, distraught because no cure for the mutated fungus exists. Well, let’s have a coffee first, shall we? In real life, the fungus needs to complete its cycle and release spores in order to infect us. Oh, but spores are gone from the series, right…
They cut the spores out completely from the TV series, apparently to prevent difficulties in shooting. It makes sense that seeing people passively avoiding inhaling spores is less visceral and exciting than watching people running away from fungus-zombies. Instead, we see this new element of fungi communicating with each other via an underground mycelial connection, certainly inspired by current research on soil fungi.
How would the fungus survive? In the series, the mutant Cordyceps fungus comes from grain food stocks. The biggest danger in that case would be mycotoxins (toxins derived from fungi) rather than living fungi. Even so, then why no one is ever worried about eating food? And: If the Cordyceps fungus can only feed on humans, then what is the survival strategy of the fungus? Do infected live forever? Can infected reproduce?
That. Is. Not. Even. A. Fungus. The slimy, labyrinthine thing shown in the show’s opening titles and winding its way throughout the post-apocalyptic landscape is not even a fungus. It’s a slime mould and it belongs to a different kingdom of life altogether. Slime moulds and fungi might be similar in the way they grow and feed, but that’s pretty much it. Between us and moths or worms or capybaras, we all share more commonalities than those shared between fungi and slime moulds. (Believe it or not, there are more similarities between us and those absolute maniacs who enjoy watching the Eurovision Song Contest than there are between fungi and slime moulds—it’s true!)
It should probably be noted that the actual name of the “zombie-ant fungus” is Ophiocordyceps unilateralis. Cordyceps is a genus name, but is also used as umbrella term for a group of related fungi; in nature, there are hundreds of entomopathogenic (causing disease in insects) fungi using all sorts of weird dispersal mechanisms, and each one is usually specific for one prey species. One fungus (Entomophthora muscae) induces necrophilia in houseflies. Once it kills the female prey, it emits a volatile chemical signal acting as a pheromone for males, inducing them to copulate and get infected. Male flies seem to be more attracted to cadavers into more advanced stages of putrefaction. With such a grotesque reproduction mechanism, reality easily surpasses fiction.
…and what The Last of Us gets right
If The Last of Us is based on a clichéd trope and no one believes in the possibility of fungal apocalypses, then why did the story got so many people excited, including mycologists?
I can speculate: The Last of Us is simply a great story, compellingly told. The predation strategy of real-life “zombie-ant fungus” is a funky and fascinating natural phenomenon. The series does a great job of presenting the narrative in a way that taps into the familiar anxieties of our immediate present, rooting the story in the context of climate change and global pandemics. Most importantly, the story puts fungi front and centre, exposing some unsettling truths.
Global warming is a training ground for fungi. In so many ways, the series has managed to tie its story to our current moment (and very recent past, as in one scene, we watch Ellie hoarding toilet paper and other basics). The opening scene of episode one brilliantly introduces the threat of fungi adapting to rising global temperatures. Our lifestyles and medical predispositions also increase the danger: diabetes and co-infections are risk-factors for certain fungal pathogens.
We don’t have a single vaccine against fungal diseases. Fungi are more similar to animals than to plants in the way they feed (by digestion) and in their cell biology and biochemistry, which make vaccination (as well as drug treatment) challenging. Fungi affect heavily those persons with a compromised immune system, but vaccines work exactly by stimulating the immune system. It’s a poor match.
Fungi are overlooked in healthcare. In our drug cabinet, we have fewer antifungals than antibiotics, and resistance is rising. We use very similar antifungals in medicine and in agriculture, increasing the pool of mutations which could spread from the environment to our bodies, and, at the same time, reducing the efficacy of the drugs to heal us. A patient suspected of an infection is diagnosed and treated for a viral or bacterial infection first, and for a fungal infection only later, if antibiotics do not bring about any results. Diagnostic tools are not well developed nor equally distributed globally. Global epidemiologic data of fungal infections are poorly recorded and maintained.
When it comes to pathogenic fungi, it really is a vicious cycle. Just 1.5 % of the budget for infectious disease research is reserved for fungal pathogens (see the WHO Fungal Pathogens Priority List, released in October 2022). This makes not only treatment but also diagnosis a challenge, but the lack of funding for further research means that opportunities to learn more are continually disregarded or ignored. How can we break this vicious cycle?
For those already affected by fungal pathogens, the question is largely superfluous. And who is ‘us,’ anyways? Just ourselves and the people we start to care for along the way, or should we think bigger?
All of Us
Perspective matters, in both fiction and non-fiction. Paul Stamets’ Mycelium Running is such an influential book for mycologists because it puts fungi centre-stage in a way that has rarely been done. He anthropomorphizes fungi: they “know” and “dance” and “runs.” For him, fungi are a solution—a very powerful one—to human-caused problems. “We seek balance, not extinction,” Stamets cautions, referring on how he used fungi to fight ants gnawing at his house.
Fungi certainly have a tremendous destructive power. For the poorest, the unprivileged, the most vulnerable, those at the margins of society, and those without access to medical care, fungi already pose a dire health threat.
One only has to look at India during the Delta peak of COVID-19. In May 2021, a surge of ‘Black Fungus’ attacked COVID-19 patients before vaccination rolled out globally, but after widespread use of the cheap anti-inflammatory corticosteroid dexamethasone. The drug, which suppresses the immune system, left an opening for spores of ‘Black Fungus’ to enter the lungs and take hold in the patient’s body.
In patients with a suppressed immune system, the ‘Black Fungus’ spreads from lungs and sinuses, eventually reaching the eyes and the brain. The disease shows itself with black patches of necrotic tissue and fungus treads. ‘Rhinocerebral mucormycosis’ is the medical term. After invading the body, the fungus kills up to four in five patients. For many, the price of drug treatment is prohibitive. Often, treatment involve surgical removal of eyes, parts of the jaw, and other facial parts.
It might feel wrong to include such grisly descriptions if solutions were not at hand: more awareness and more funding to prevent fungal diseases. It seems simple enough, to prevent such suffering.
The Last of Us is a story of survival, but perhaps not one of hope—at least from the perspective of our current, reasonably comfortable present. For me, even from the privileged position of knowing that fungal pathogens are not a tangible threat for me and my family and friends, the most unsettling aspect in The Last of Us was the sense of a lurking threat which I felt throughout. The video game evokes this feeling particularly well. As players, we find handwritten notes left behind by survivors documenting the looming catastrophe. People sketching half-baked plans, leaving hasty instructions. We encounter those people some scenes later, as zombies or corpses. Stray dogs howl in the background. A boy writes down in his diary that school is closed now; surely not the worst thing coming out of the pandemic, isn’t? Only… “What to do with all the free time?” asks the boy (and probably his parents too). Then, a few days later, the order to leave home and go to a Quarantine Zone. The dog cannot go, the boy notes in the diary, they must abandon him. He will surely be okay on its own, the father reassures the boy.
Stories like The Last of Us do not transport us to a distant future or to an unrelatable, unrealistic scenario: they catapult us into the midst of a present we do not take seriously enough. The Last of Us hits us like a punch in the face, warning us to pay attention while we can. We need those stories. For many vulnerable people, better funding and research, a better understanding of the realities of fungal pathogens would mean a safer and healthier future. When it comes to fungi, all of us should care.
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Please share your thoughts—on The Last of Us, and on the science and science fiction behind it. For those like me who love learning about fictional fungi: What are your favorite examples of fungal fiction stories? (Bonus point if you can think of examples where fungi have a less stigmatized or stereotypical role!)
Corrado Nai (@jan_corro) is a former fungal researcher who cannot stop thinking (and writing) about fungi. He created the Wikipedia page on Fungi in art, and currently lives in Jakarta with his wife and daughter.
