If you’ve been watching HBO’s The Last of Us, you might have some questions about fungus zombies, and maybe fungi in general. In this bonus episode, Sam calls up field mycologist Giuliana Furci for a little fungi 101 and to talk fungi fact vs. fiction in the show. We promise there will be no jump scares!
Transcript of this Episode
Sam Jones: Hi, everyone. Sam here, popping in with a little bonus episode for you this week on top of our regular episode. So if you, like me and millions of other people, have seen The Last of Us, you might have some questions about the possibility of fungus zombies, and maybe fungi in general. And if you're listening to this episode when it drops, what better time to tune in than 48 hours before the finale of The Last of Us season one? So fungi: they are eukaryotic organisms that can be microscopic, like yeasts and molds, but they can also be things like mushrooms. For this bonus episode, we called up Chilean-British-Italian field mycologist Giuliana Furci.
A mycologist is someone who studies fungi, and in Giuliana's case, she's been studying them since 1999. She's the founder and CEO of the Fungi Foundation, the first NGO in the world dedicated to the protection of fungi. Giuliana's also a Harvard University Associate, National Geographic Explorer, and she's written a whole lot about fungi. And the place where I actually first spotted her was a couple weeks ago when I was watching Fantastic Fungi on Netflix. I had a lot of fun chatting with Giuliana about The Last of Us, how much is fact versus fiction, as well as some of the very cool, complex stuff that fungi can do. So, without further delay, let's hop into that conversation.
I would love to start off by hearing a bit about your work. What led you to fungi, and should I call them fun-gee, fung-eye, how do you pronounce it?
Giuliana Furci: So, different people from different parts of English-speaking countries say the word funj-eye, fung-ee, fung-eye. And they're all valid. I switch between them depending on who I'm talking to. Really, what led me to dedicate my life to them, I think, was the sensation of injustice to the fact that nobody else was doing that in Chile or very prominently in the world in terms of conservation. So I was interested in them, took a look around to see what I could find. There was hardly anything out there, and I thought, I have to do something about this. And that was really where it was born.
Sam Jones: And so actually this perfectly segue-ways into my next question, which is fung-ee, fung-eye are not plants, they're not animals, they're not bacteria. They sometimes feel like the forgotten kingdom. So what are they exactly?
Giuliana Furci: Well, they're neither plants nor animals. And the basis for saying that is because they have a totally different cell, and they have a cell wall that's different from the ones that plants have, and they don't have a cell membrane like animals have. And they obtain their energy in a different way. But I don't know if forgotten is the right word. They haven't been recognized or acknowledged as much as they deserve. And we have been speaking with obsolete language for a very long time, so referring to macroscopic life on earth as just plants and animals without mentioning the fungi is a mistake. And so that's why we've been pushing a lot of institutions and countries and people to speak with mycologically inclusive language around the world.
Sam Jones: Yeah. And we're going to talk about some of the importance and very cool things that fungi do, but first I'll ask, how many species of fungi do scientists think exist?
Giuliana Furci: There's consensus among mycologists that we don't know more than five to 10% of fungal diversity out there. The number of species is estimated in different ways by different people, but more or less about 5 million species, I would say, is an average, of which we know maybe 5%, a bit more.
Sam Jones: Wow. And so are there a couple that you particularly like or like working with?
Giuliana Furci: I frequently get asked what my favorite fungus is and my answer's very honest, and it would be whichever one I'm looking at or holding at a given moment. Yeah, there are different cool species. I really like earthstars. I love entomopathogenic fungi like Cordycep species or Ophiocordyceps. And I really love puffballs, giant puffballs.
Sam Jones: What are those?
Giuliana Furci: The giant puffball, it looks like a big football. And they grow on grasslands at different parts of the world. And they're edible when they're young. When they mature, the spores are medicinal. And then when they get old and have sporulated, the sterile base on which they've been held is a tinder fungus. So you have one species that can feed you, heal you, and you can start fire with. And I just find that giant puffballs extraordinary.
Sam Jones: That's so cool. I did not know about those. I need to go look up a picture after this. All right. So now, I want to hop into some questions that are related to The Last of Us, because it seems like people are very, very intrigued, I'm including myself in that, by fungi right now. So a question that I'd really love to ask all mycologists is have you watched The Last of Us or played the game? And if so, what do you generally think? Do you like it? You can't stand it?
Giuliana Furci: So yes, I've seen it. I think it's great fiction. I love that the actor is from Chile. And I mean, I can't stress enough how fictional it is. I mean, there's no chance that that's going to happen. It's never happened before. We never know with nature, but... And also I think that the thing that really triggers me, I keep on thinking about all the animal parasites that we live with and how much more creepy they are.
Sam Jones: Yeah, absolutely. So, I'm going to ask you a few more questions related to some of the things you just said in a second. But let's talk a little bit about the fungus in The Last of Us. So in the series, the fungus that takes over people's bodies is Ophiocordyceps unilateralis, which is also referred to as Cordyceps or zombie ant fungus, because insects like ants, it can infect and take over, changing the insect's behavior, ultimately killing it and growing out of its body. So why do you think that fungus has evolved to do that?
Giuliana Furci: With ants?
Sam Jones: Yeah, with ants. Not with people, with ants.
Giuliana Furci: Well, the fungus has evolved to do it to ensure its survival. The fungus has devised these evolutionary traits to ensure that they can feed and reproduce and keep on living. Fungi have this incredible characteristic that they're very specific to their substrate. And so a fungus that grows on the back legs of a cockroach might not grow on the head of a cockroach. And the fungus that grows on mountain lion scat doesn't grow on chicken scat. And the fungus that grows on the roots of an oak tree doesn't grow on the roots of an orange tree. So in this specificity, your Cordyceps unilateralis has evolved to live on these ants.
And so it's a very specific relationship in which the fungus basically makes the ant do what it needs to be able to reproduce in a more effective way. So it modifies the behavior for the ant to go up a tree or up a plant and then bites into what's called a death grip or a death bite, bites onto that leaf or a twig. And there is where the fungus continues to feed off of the ant and then reproduces sexually by producing these long stroma that come out of the head of the ant, or in a lot of cases, in other parts of the body of an insect. But it's a co-evolution that has evolved to ensure that more fungus can live and reproduce.
Sam Jones: So interesting. So, I have a clarification on Cordyceps, because I feel like Cordyceps I often see listed on a variety of things. Maybe it's an ingredient in some sort of tea or supplement. Is this the same Cordyceps, or is Cordyceps kind of an all-encompassing term that's used?
Giuliana Furci: No, it's hilarious. I'm enjoying watching people freak out about Cordyceps while drink their Cordyceps tea, that was really expensive, probably. So, Cordyceps and Ophiocordyceps are genera, so they're names of a group of entomopathogenic fungi. And names change as well. So many of what we today call Ophiocordyceps were once called Cordycep. And what we're seeing listed in functional mushroom supplements and in coffees and teas and medicine is a species, Cordyceps militaris, which is found in different parts of the world, cultivated, and then made into these supplements.
And this all comes from one of the most important medicinal mushrooms in the world, medicinal fungi in the world, which is called Ophiocordyceps sinensis, which is the Viagra of the Himalaya, they call it. But it's basically a fungus that grows in the plateaus of the Himalaya that infects the larva of a ghost moth. And it's one of the most expensive fungi in the world. It's extremely important in traditional medicine. It has a similar status, and it's very much sought after. So much that there are even assassinations on those plateaus between people trying to get first to those mushrooms. So it's fungi, really mushroom-shaped.
This is an ancient medicine that's being cultivated and commercialized in modern times, and that is a relative of Ophiocordyceps unilateralis. So it's the same group. And the beauty of the discussion that's happening now is that while people are watching and freaking out about a possible inoculation with these, we can finally start talking about the complexities of the fungi organisms that form a kingdom of their own. It's not one thing. They're not one species, they're not one group. And they're complex.
Sam Jones: I feel like this is really opening up the conversation, which for a mycologist like yourself must be kind of fun.
Giuliana Furci: Well, the fungal awakening that's happening has been deliberate from a group of us that have been working for the fungi for over two decades or more. And Fantastic Fungi is just one show where many of us have even a minute in it, whatever, we've been part of it or written chapters in the books. And we've been doing this for a very, very long time. The Last of Us, actually, is welcome in what I mentioned before, in finally, let's talk about the complexities.
Sam Jones: Yeah, absolutely. With this series, there's a lot of conversation of could a fungus actually infect us? What would have to happen with Ophiocordyceps unilateralis for it to actually infect a person?
Giuliana Furci: There's no way Ophiocordyceps unilateralis could infect a person. We live with hundreds of species of fungi on our bodies. There are studies that show that we have up to 200 species on each foot. And I would ask, how many have had a yeast infection? Yeast are fungi. And the answer is probably less people than those who have had head lice. So I think we need to also take the conversation out of the trend of stigmatizing fungi. We have more animal parasites or bacterial parasites than we do fungal parasites. But your Cordyceps unilateralis would have to evolve into different species over millions of years to be able to have a parasitic relationship with a mammal like us.
Sam Jones: All right. So I want to talk a little bit about underground fungus communication. This is a big part of The Last of Us where these fungus zombies are communicating over long distances. Is that a real thing that fungi do?
Giuliana Furci: Some fungi are so large that they cover huge distances. They're mycelia, and so that's one organism, and yes, there's communication. Entomopathogenic fungi, like Ophiocordyceps do not form those networks, and that's totally fictional. They don't do that. Where that's taken from and fictionalized is from the notion of what we were calling the wood wide web, which is this underground network of species that could connect one tree to the other, and basically the notion that these fungi would sustain the plants.
We now know that it's not that simple, that it's a lot more complex, that there are huge communities of organisms involved in that. But what we do know as well is that there are some plants that don't have the ability to photosynthesize and depend 100% on fungi giving nutrients. So there's a lot of complexity, and it's the complexity that comes with such a large group as a kingdom. So we don't ever think about animals reproducing in one way or behaving in one simple way because we appreciate that they're very different. Just so that listeners can have an idea, an oyster mushroom and a morel are as related as an ant and a whale.
Sam Jones: Wow. That's amazing.
Giuliana Furci: Ants and whales are both animals. They're related, they're kingdom mammalia. And oyster mushrooms and morels are both fungi, but they are not closely related within the kingdom. So wrapping your head around that is the first step in acknowledging the complexities and acknowledging what fungi are. There are unicellular fungi like yeast and multicellular fungi like molds. And so it's a lot more complex, and it's so fascinating. I would definitely recommend everybody read Entangled Life by Merlin Sheldrake. He does just a beautiful job of showing us those complexities.
Sam Jones: I'll have to check that out. I think I just have just a couple more questions about The Last of Us. So, in the show, the outbreak is thought to start with fungi contamination in a flour mill. So, if there were an actual fungal outbreak where people were getting sick from a fungus, does flour make sense as a disease vector, or no?
Giuliana Furci: No, it doesn't. But where that comes from is from ergot and from ergotism on rye. There's a fungus from which LSD was synthesized that is a parasite of rye, and of some grains. So this infected grain would be made flour and then bread made from it and entire villages would be poisoned with ergotism. And ergotism was responsible for a lot of upheaval in medieval times and older times with mass hallucinations and mass intoxications. So really, the program is mixing some fungal facts, making them very fictionalized, putting them all together in a mix. But fungal fact is way cooler than fungal fiction. And so I invite people to understand more about fungal fact.
Sam Jones: Yeah, absolutely. So, I guess I'll just close out by asking, is there anything else that you want to say about it? Anything else that as a mycologist, you think this series or this game has done well, or anything that you want to point out that you haven't yet that is just way too far fetched for you?
Giuliana Furci: I just think for mycologists, our responsibility is that the series doesn't transform into what Jaws was for sharks that created mass fear. It's our responsibility as mycologists to talk about The Last of Us in a way in which to educate the public about these organisms and not continue to stigmatize them as they have been unfairly for so long.
Sam Jones: Yeah.
Giuliana Furci: I welcome that this game and series has opened up the conversation about talking mycological language, and I think we all have a responsibility to adopt mycologically inclusive language, to start recognizing that macroscopic life on earth is not just fauna and flora, it's fauna, flora, and funga.
Sam Jones: Thank you, Giuliana. This was great. Like you said, The Last of Us, it's fiction, right? And so they're pulling from some things that are real, but kind of smashing them together in ways that would never happen. And so it's nice to understand what is real, what is not real, and have a cool conversation about fungi.
Thanks so much for tuning into this bonus episode of Tiny Matters, and many thanks to Giuliana Furci for being our guest today. If you have feedback, episode suggestions, other things I'm not thinking of right now, shoot us an email at email@example.com, and we'll see you next time.