To find the most nefarious examples of mind control in the world, look no further than sci-fi. Instead, head to a tropical country such as Brazil and make your way deep into the jungle. Find a leaf hanging nearly exactly 25cm from the forest floor, nothing more, nothing less. If you are lucky, you may spot an ant hanging on the center of the leafs veins due to cordyceps infection, its jaws clenched tightly for dear life. But that ants life is over now.
And his body belongs to the fungus Ophiocordyceps unilateralis, a zombie-ant after the cordyceps infection. When this fungus infects an carpenter ant, it grows inside that insects body, depleting its nutrients and stealing its consciousness. Over a period of one week, it coaxes the ant out of its nests security and up to the nearest plants stalk. It stops the ant at 25 centimeters, a height that provides exactly the right temperature and humidity for the mushroom to thrive. It forces the ant to lock its mandibles around a leaf forever.
The Cordyceps Infection
Eventually, it shoots a long stalk into the ants head, growing into a bulbous capsule filled with spores. And since an ant usually scales the leaves overhanging the feeding path of his colony, fungal spores fall to his sisters beneath, zombie-ing them in turn. The fungals ability to colonize the ants is exceeded only by its ability to colonize pop culture.
It is the organism behind the monsters in video game The Last of Us, and the zombies in book The Girl With All the Gifts. It is also an obsession of David Hughes, a Pennsylvania State University entomologist who has been studying it for years. He wants to find out exactly how this puppetmaster controls his puppets, and his latest experiments show that he is more monstrous than it initially seems.
Using a special microscope to cut julienned ants into slices that were only 50 nanometers thick, a thousandth the width of a human hair. Each slice was scanned, composited the images into a 3-D model, and meticulously marked which bits were ants and which were fungus. It took three months to mark up a single muscle. To accelerate the process, scientists worked with computer scientists, who trained artificial intelligence to tell the ant anotomy apart from a mushroom.
When a fungus first finds its host, it exists as individual cells floating in an ants bloodstream, sprouting new copies of itself. But at some point, the images suggest, those individual cells begin to cooperate.
They link up with one another, building little tubes, the sort of thing you would only seen previously with the kind of fungi that plague plants. By connecting, they are able to communicate and share nutrients. They may even begin to intrude on an ants muscles, either through penetrating into the muscle cells themselves, or growing in the spaces between them.
The result is what you see in this video: A red muscle fibre, enclosed and draining of a web of yellow, interconnected fungal cells. This is what is so distinctive about Ophiocordyceps.
Scientists found another parasitic fungus, one that kills ants but does not control their minds, that spreads through muscles too, but it does not form tubes between individual cells or link up into larger networks. Whenever anybody discusses fungi in zombie-ants, they always talk about it as one single entity corrupting and subverting a host. But one can also consider the fungus to be a colony, just as with the ants it targets.
Individual microscopic cells start out living on their own, but they eventually get together, merging into one superorganism. Together, these brainless cells are capable of commandeering the brains of a much larger organism. But astonishingly, they can do so without ever physically touching the brain itself.
Scientists found fungal cells had penetrated an ants whole body, including his head, yet left his brain intact. There are other parasites that manipulate their hosts without devastating their brains. For instance, a flatworm forms a rug-like layer on top of a California killerfishs brain, leaving the brain untouched but forcing the fish to act bizarrely and attract the attention of birds, the flatworms next hosts. But the manipulation of the ants by Ophiocordyceps is so exquisitely precise, that perhaps it is surprising the fungus did not intrude on its hosts brains.
In hindsight, it makes a lot of sense. If these parasites were simply invading and destroying neural tissue, I do not think the altered behaviors that we observed would have been nearly as convincing as they were. There has to be something far more complex going on. He noted the mushroom releases a vast array of chemicals, which can affect the brain at great distances.
So we have got here an enemy takeover of an exceptionally malignant sort. Enemy forces have infiltrated a hosts body, and they are using the body as a kind of intercom, communicating with one another, influencing brains from afar.
Scientists believe the fungus may even exercise more direct control over ants muscles, controlling them literally like a puppeteer controlling a marionette doll. Once an infection is under way, she says, neurons inside the ants body, the ones that give their brains control of their muscles, start to die. Scientists suspects the fungus has taken control.
It actually cuts off an ants limb from his brain and sticks itself in there, secreting chemicals that cause muscles to contract in place. If this is correct, the ant ends up living a life of imprisonment inside its own body. Its brain is still in the drivers seat, but the fungus has the wheels.