We don't need to fear a fungi-fueled apocalypse

After the release of new HBO series The Last of Us, a spate of articles emerged from various media organizations allaying the fears of viewers of the show that no, the entomopathogen (insect-infecting) Ophiocordyceps has not and—at this point in our evolutionary history—will not infect humans. It’s spread through spores (not bites) and research shows it doesn’t begin in the brain. Whew.

For all the fuss, the fungal takeover in the show only takes the spotlight in the first two episodes—with the bulk of the show focusing on Joel and Ellie’s journey west and its accompanying emotional drama (or trauma). But the story of The Last of Us is a great catalyst for contemplating the complexity of a still-relatively-unknown and underappreciated kingdom of life and examining the stories we tell ourselves about fungi.

I eat mushrooms, drink the occasional beer and bake sourdough bread. I am grateful for the banana-flavored penicillin I took as a kid to treat persistent strep infections. More recently, I observed fungal conks growing on trees in an aspen forest my family traipsed through in the summer. But the fact that I can thank lichen, a pairing of fungi and algae or bacteria, for laying the foundations for my eventual existence five million years ago is one I have yet to process.

My ignorance is part of a larger pattern.

Of the estimated three million species of fungi, only around 150,000 species are known. The first State of the World’s Fungi report, published in 2018, found that only three percent of papers published by top conservation journals discussed fungi. The studies that did focused on negative effects to wildlife, sending the message that only animals and plants are worthy of conservation. In 2018 only 56 species of fungi had had their conservation status evaluated by the International Union for the Conservation of Nature, a number that jumped to 285 in 2020 , an improvement but still a fraction compared to animals and plants.

“The first perception I encounter in my work is ignorance,” said mycologist Giuliana Furci, executive director of Chile-based Fungi Foundation and one of the authors of the 2018 Fungi report. “People’s perception of fungi in general is based on an oversimplified notion of a whole kingdom of life.”

But recognition is happening. In 2012, the Chilean government passed a motion, proposed by Furci and other environmental organizations, to include fungi in environmental impact assessments for new development, the first country ever to do so. In 2021 Re:wild and the IUCN became the first global organizations to commit to including “funga,” a term proposed in a 2018 paper co-written by Furci, in their conservation communication and strategies.

“We can't rewild a place with plants without rewilding the fungi,” said Furci. “Fungi are the firmament of terrestrial life. As symbionts and decomposers … they're the base of the equation of how we know life on earth.”

On the surface, then, the villainizing of Cordyceps in The Last of Us stands in stark contrast to this current wave of affirmation. However, having worked for years to destigmatize fungi through education, research and advocacy, Furci isn’t bothered by the show’s narrative use of the fungus.

“It’s great fiction,” she said.

What does bother her is perpetuating the idea that pathogenic or parasitic behaviors are exclusive to fungi. The taking over of one organism by another (parasitism), something done by animals (thrush, head lice, mites, ticks, nits) and evident in diseases like leishmaniasis (spread by flies in the tropics) is, in her words, “a characteristic of nature.”

“Every organism wants to live, thrive and reproduce, so you do that with what's available,” she says. “[The show] is a gateway to talk about the complexities of nature, which include pathogens, and negative things, just like any other kingdom with humans in the center.”

Our view of how Cordyceps overtakes its victims in The Last of Us is laden with feelings of horror, disbelief and fear around what happens when parasitism, which is as old as evolution in the animal, plant and fungal worlds, turns on us. From this new, albeit-imagined, perspective as the preyed-upon species, we experience the vulnerability of other species in the real world, today.

In another universe’s rendering of The Last of Us, Joel and Ellie could have been harlequin toads, hopping their way through the tropics from Bolivia to Ecuador, in search of a watery home free from Batrachochytrium dendrobatidis (Bd), a fungus that causes chytridiomycosis.

Causing an infectious skin disease that results in something akin to a heart attack in amphibians, Bd has been recognized as a primary threat to the majority of the 99 species of harlequin toads and has brought four species (possibly more) to extinction, according to a 2021 report by the Atelopus Survival Initiative.

“As of 2021, approximately 40 percent of harlequin toad species have disappeared from their known localities and have not been seen since the early 2000s despite efforts to find them,” said Lina Valencia, who co-authored the report and is a biological anthropologist and the Andean countries coordinator for Re:wild.

Although Valencia states that more monitoring of harlequin toad populations is needed to assess exactly how Bd contributes to species decline, the reason isn’t, simply, a vindictive fungus. The spread of Bd from Asia to the Americas in the 1980s most likely occurred due to human travel and trade. Compounding its effects are other human-fueled impacts like habitat degradation, forest loss, and of course, climate change.

A warming climate is invoked as the reason for the spread of Cordyceps in The Last of Us, an idea not wholly without merit. In October 2020, the World Health Organization published its first list of health-threatening fungi to humans, stating that “incidence and geographic range of fungal diseases are both expanding worldwide due to global warming and the increase of international travel and trade.”

In a more balanced world, with less human disruption, would fungal pathogens continue to be a threat to harlequin toads?
 
“It is hard to know,” wrote Valencia.

Capturing the wonder of fungi, its omnipresence on this planet and its bewildering behaviors is a prohibitive task, but biologist Merlin Sheldrake does an admirable job in his 2020 book Entangled Life. Among other feats, he describes the cunning work of smelly truffles to lure foraging animals; mycelium and hyphae as Earth’s connective tissue; the mind-altering behaviors of psilocybin mushrooms; and the work of citizen, radical mycologists hell-bent on studying fungi to capitalize on some species’ abilities to both mycoremediate (break down toxic substances) and mycofabricate (build sustainable materials).

With myriad capabilities, there’s little wonder that fungi provide excellent fodder for the stories we tell ourselves. But what’s crucial is remembering that along the journey of scientific discovery, those stories evolve.

Sheldrake pokes holes in the now-popular idea of “the wood wide web,” a term used for stretches of fungal mycelium underneath forests that act as networks between trees and plants. Touted in recent years as a communication tool for trees to transfer resources, Sheldrake is upfront about the metaphor’s problems. It  turns out the symbiotic relationship between mycorrhizal fungi and plants functions on a “mutualism-to-parasitism continuum” where “give and take is fluid.” It’s more complex.

With fungi, and its mycorrhizal networks, “narratives are richer,” Sheldrake writes. “We have to shift perspectives and find comfort in—or just endure—uncertainty.”

Shifting perspectives is something The Last of Us does in spades throughout its first season. It’s easy to draw analogous lines between the show and concepts like symbiosis (Joel and Ellie’s reliance on each other), competition and the fight for resources (FEDRA and Fireflies in the QZs) and cooperation (Jackson’s democratic commune). It’s one hot symbiotic mess, all springing from an imaginative take on a fascinating fungus.

Both The Last of Us and the exciting, unfolding story of fungi allow us to examine the species we privilege, the uncertainty inherent in survival, and the stories we tell in a human-centered world.