The scariest shows and movies are often the ones rooted in reality — about psycho serial killers, late-night home invasions, and AI-powered robot dolls. Zombie apocalypses don’t usually count.
But a new show on HBO called The Last ofUs, a compelling case that maybe there is such a thing as a real-life zombie. or realistic-ish. Which is definitely scary.
The premise of the show, which is based on the popular video game of the same name, isn’t much different from the typical post-apocalyptic horror story: US cities are collapsing, there are frenzied humans everywhere, and a virile man has to do to protect a young girl as they travel across the country. .
However, the zombies are really inspiring. More specifically, it is inspired by nature – by the real zombies that live on Earth.
In the show, which premiered last Sunday, it’s not the virus that turns people into brainless robots, but a type of fungus called Cordyceps. The fungus takes over their minds and bodies and makes them want to spread the fungus to the uninfected.
These fungi are real.
In tropical, subtropical, and even temperate forests around the world, there are many species of fungi in the genus Cordyceps and Aviocordyceps (formerly these fungi were called just Cordyceps) that infect insects such as ants and other invertebrates. And they’re basically turning them into zombies. Fungi take over their minds and bodies, causing them to act in such a way as to spread germs to others of their kind.
Fungi was published in 2016 by Presentation Planet Earth, which captured Ophiocordyceps parasitizing a bullet ant. In fact, the clip below – where the fungus causes the ant to climb a branch before killing it and sprouting a spore-producing fungus from the ant’s head – Maybe Game creator, Neil Druckmann.
So, mushrooms are real and can turn insects into zombies. That’s pretty rad. But does it pose a danger to us?
A reassuring fact is that people have been eating Cordyceps for centuries now without getting sick. It is a traditional Chinese medicine used to treat kidney disease and other ailments. Even wellness brands are now marketing it.
But to be sure – because one can never be sure enough, right? — I reached out to Charissa de Bekker, a mycologist who researches Ophiocordyceps. De Becker, a biology professor at Utrecht University in the Netherlands, has not seen the show but is familiar with the game. Our conversation has been edited for length and clarity.
To be clear, fungus is on show The last of us It is real, right?
yes. Cordyceps and Ophiocordyceps fungi are true and infect insects in the wild. There are many different types.
many!? how many?
Researchers have described at least 30 species of Ophiocordyceps that parasitize ants, but we know there are more, because each species of ant that becomes infected has its own species of Ophiocordyceps.
There are also Ophiocordyceps and Cordyceps fungi that infect other insects such as wasps and flies. We also see this going beyond insects to arthropods like spiders. And then a whole other group of fungi, in the order Entomophthorales, are doing the tinkering too—and this one looks nothing like Ophiocordyceps.
Manipulation has evolved many times across the kingdom of fungi. It is likely that the biodiversity of these fungi is really high, and we haven’t discovered all of them yet.
How do these fungi manipulate their hosts in the wild?
What we see, especially with ants, is that they pick up germs [which are kind of like seeds for fungus] when they go out to find food. The spores infect the ants and fungal cells begin to grow inside their bodies.
At first, this ant may behave normally. Eventually, however, it ceases to participate in the colony’s foraging efforts. He doesn’t communicate well with his nest mates anymore.
Then this ant begins to become hyperactive and no longer has the same circadian rhythms as the other ants. Most carpenter ants, for example, feed during the night, but infected ants become active basically all the time.
At some point, the infected ant moves away from the colony to find a place in the forest to climb and bite [down on the twig or vine]. This is where the fungus will quickly begin consuming everything in it, killing the host. The fungus uses this energy to sprout a stock with a fruiting body — the fungus, if you will — which contains spores that fly off and infect more ants.
Climbing higher into the forest, the ant essentially helps the fungus spread its spores. The specific spot you choose to climb may actually help fungus develop.
This whole process can take days, weeks, or even months. What you often see in zombie movies, or the last of us, Things happen faster. In nature, things take time.
Does Ophiocordyceps really control the minds of ants?
We think that these fungi secrete certain chemicals that can bind to or interact with receptors or other types of proteins associated with the nervous system, and they usually lead to different behaviors. For example, these could be receptors that normally bind to dopamine or serotonin, which may then trigger a certain type of behavior. We’re still trying to figure that out a lot.
We definitely think it’s more than just these fungi gnawing at some brain tissue because the behavior is so specific.
Would you call these infected hosts “zombies”? Is this scientifically accurate?
If you compare it to zombies from pop culture, it’s not entirely accurate. These insects are very much alive, while zombies in fantasy movies are mostly alive. These ants infected with Ophiocordyceps do not die and wander.
What makes real-life hosts similar to fictional zombies is that they behave in a way that benefits the parasite, not the host.
Is there any reason to believe that a fungus like this can infect the human body and turn us into zombies?
The short answer is: no.
Everything in the human body is very different from the insects that these fungi usually infect, including our physiology, our nervous tissues, and our body temperature. Even if the fungus is capable of causing a small infection, the mechanism required for the fungus to perform such a delicate manipulation simply does not exist.
These fungi have evolved strategies to deal with specific insect hosts over millions and millions of years. They are not general. Each species only knows how to deal with a specific insect.
We don’t see mycologists jumping from one species to another, much less jumping from one ant species to another insect. Spreading from an ant to a human is just one big leap.
In the show, a fictional epidemiologist suggests that climate change could make harmful fungi more tolerant of warmer temperatures. As a result, they are able to jump more easily to warm-blooded humans. Is this a real concern?
Most fungal infections are skin infections — or if you’re sick, say, and immunocompromised, some normally benign germs may take up residence in your lungs and cause a problem. But most fungi do not grow happily at our body temperature. Most of them actually prefer lower temperatures.
Some experiments show that fungi, perhaps, can adapt to higher temperatures, as they have adapted to a warming world. You can imagine that if the optimal temperature gets close to body temperature, then fungal infection could become a bigger problem.
In the show, the fungus is spread by bites, not spores. That’s not how it would actually work if these fungus-infested zombies were real, right?
If you play the game, you will see that germs play a role in spreading infection. But no, the fungus will not spread by biting. Generally, across the fungal kingdom, transmission from one place to another, or from one host to another, is by means of spores.
I am a big fan of mushrooms. Plants decompose, can be dope. It’s also delicious. Is it unfair that Cordyceps is the villain of the show?
It’s so cool, finally, that fungi are hip and happening. I hope the show sparks some interest in fungi in general, because they are incredibly fascinating organisms. It’s more important than people think.
They’re very much the show’s bad guys, and that’s how we generally see Parasites, because they make us sick. But in nature, they are actually very important and no less important than all other living things.
They keep everything under control. If ants, for example, weren’t bothered by certain parasites—not just Ophiocordyceps but anything else that makes them sick—their numbers could spiral out of control. You may get an overpopulation of certain species. Getting rid of a parasite of such a fungus could be like removing a predator from the ecosystem, and doing so could cause a decline in biodiversity.
I’m kinda afraid to ask, but how common are fungi in general?
Not to scare you, but in every breath of air you take there will be fungal spores. Most of them are harmless to us – most of the germs you inhale now are benign, or fungi that don’t know how to manipulate our bodies, so you’ll never notice them. But they are everywhere.