Could a Zombie Fungus Evolve to Infect Humans? The Last of Us… for Real?

The unique control mechanism of Ophiocordyceps unilateralis sets this fungus apart from other natural organisms since it earned its “zombie-ant fungus” classification. These microscopic intruders penetrate insect hosts where they take control of the brain functions that drive insects to perform a death ritual before the agent activates its spore production cycle. After the host finds an optimal location, it fixes itself in position and waits before the fatal process where fungal spores burst out and initiate an infection of another unfortunate victim.

You would probably see it in a sci-fi horror movie right? (The Last of Us fans, you know where this is going.) The fundamental question remains whether such a fungus could develop traits to dominate human beings. Can our world contain true zombielike organisms which cause their condition by fungal brain manipulation instead of viral infection?

What is the Science Behind Zombie Fungus?

The Cordyceps fungus family consists of parasitic fungi that target insect bodies. Inside the host body the fungus spreads while taking control of the insect nervous system and its muscle functions. The fungus creates neuroactive compounds which interrupt neurotransmission to penetrate the brain of its insect victim in a way similar to digital brain control.

Well, here’s the catch: Ophiocordyceps unilateralis demonstrates strict host-particularity which constitutes the main limitation. Through the process of perfectly developing its ant manipulation skills the fungus has spent millions of years. Warm-blooded mammals combined with other mammals represent an entirely separate biological domain from ants.

Could a Fungal Pandemic Turn Us Into Zombies?

Suppose an extremely versatile Cordyceps-like fungal species develops the ability to infect human bodies. What would it take?

1. Surviving Our Internal Temperature: The temperature of insects remains completely at the mercy of environmental conditions because they possess cold-blooded metabolism. The temperature of human bodies remains constant at 37°C (98.6°F). Cordyceps alongside other fungi demonstrate limited survival ability under such heat levels. Certain fungal species including Candida auris and Histoplasma demonstrate fungi’s capabilities for adapting to human hosts.
2. Crossing the Blood-Brain Barrier: The fungus cannot control human actions unless it manages to reach the brain and compromise the nervous system. The fungal infection Cryptococcus neoformans results in brain swelling along with behavioral modifications. Turning humans into zombies who walk mindlessly and hunt for brains would be the result of such a biological change. That’s another level of bio-horror.
3. Transmission and Spread: Fungal spores infect insects by attaching to their bodies and take control of the organism. Direct bloodstream infection by fungal spores shows more potential for human transmission compared to airborne spores (The Last of Us got that part eerily right). The most direct mode would be through bloodstream infection after exposure to fungal contamination. So, washing your hands and avoiding suspicious mushroom risottos is still a good life strategy. Scientists debate about the possibility of zombified organisms among human society as part of real-life scenarios.

The Real-Life Zombie Risk: Is It Even Possible?

Scientific evidence suggests that a human-infecting form of the Cordyceps fungus will remain implausible throughout our existing evolutionary cycle. Among all Earth’s organisms fungi show themselves as one of the most adaptable life forms. The future mutations from environmental changes or climate shifts toward fungal species remain unknown despite current scientific predictions.

Despite current feasibility concerns, there’s no neet to start prepping your fungal apocalypse survival kit– at least not yet. Even though fungi can cause serious medical conditions, but an infection that turns us to a flesh-eating zombies remains solidly in the realm of fiction.

A More Realistic Scenario: Behavior-Altering Fungal Infections

The future possibility of mental invasion by Cordyceps remains distant but such fungal behavior-altering abilities already exist in nature. Magic mushrooms referred to as Psilocybe cubensis represent an example of fungi that produce psychedelic effects. This type of fungi does not compel its human victims to climb trees until they pass away; instead it intercepts human thinking and mental processes for short periods.

The parasitic fungus Toxoplasma gondii affects rodents by driving them to behave without fear of predators. Research indicates that infections with T. gondii could possibly modify human tendencies to take risks. A hypothetical scenario exists where fungi might develop incremental manipulation abilities instead of traditional brain control like zombie attributes. Maybe. Honestly, I’d be okey with it if a fungus just made me crave salad instead of fast food.

“The only thing we have to fear is… highly adaptive fungi evolving beyond our control.” –  Franklin D. Roosevelt

The Takeaway: Science Fiction or Future Threat?

Nature presents itself with weirdness as well as wildness and sometimes displaying true terror. A fungal pandemic that controls minds and turns us into zombies is the stuff of nightmares which both inspires TV shows and blockbuster games. While it makes an outstanding horror story, the science suggests (probably) there is no significant threat of developing a zombie fungus outbreak.

For now.