Zombies have become iconic figures in popular culture, with the zombie apocalypse appearing in several books, films, and television shows. Is there, however, any evidence of zombiism in nature? Find out in this special feature.
Zombie. The walking dead. Reanimated corpses. The undead.
Whatever you call them, these undead corpses who rise from the grave to terrorize — and occasionally infect — the world’s inhabitants are one of popular culture’s most terrifying monsters.
When poet Robert Southey highlighted it in his History of Brazil in the 1800s, the word zombie — originally written zombi — entered the English language.
The phrase derives from the Louisiana Creole or Haitian Creole word zonbi, and it is similar to the Kimbundu term nzmbe, which signifies ghost, according to Merriam-Webster.
The term originally referred to entities from Haitian folklore that were similar to ghosts from Western culture.
However, the term gradually came to apply to a person who is rendered senseless by a witch doctor and then enters a death-like state while still alive, thereby becoming the witch doctor’s slave.
People nowadays use the term “zombie” to describe someone who appears apathetic, walks slowly, and shows little awareness of their surroundings.
But, if zombies or zombie-like creatures really exist in nature, what are they and how did they come to be in this state of “undeath?” Is it possible for people to become zombie-like?
This Special Feature looks into it.
1. Zombie ants
Ophiocordyceps is a fungus genus with around 200 species and counting, according to mycologists. Many fungi can be deadly, often because they are toxic to mammals, but Ophiocordyceps is particularly terrifying for one reason in particular.
These fungus species use their spores to infect and kill a variety of insects. The parasitic fungus takes control of the insect’s mind after infection, modifying its behavior to facilitate the spread of fungal spores.
Ophiocordyceps “feed” on the insects to which they attach themselves, growing into and out of their bodies until they die.
Carpenter ants (Camponotus castaneus) native to North America are infected, controlled, and killed by one species, Ophiocordyceps unilateralis sensu lato.
Carpenter ants become zombies when Ophiocordyceps unilateralis infects them. The ants are forced to ascend to the tops of tall vegetation, where they become attached and eventually perish. Because of the high elevation, the fungus can thrive and distribute its spores far and wide.
Researchers from Pennsylvania State (Penn State) University found that O. unilateralis take complete control of the ants’ muscle fibers, forcing them to move as it “wants” them to.
“We found that a high percentage of the cells in a host were fungal cells,” notes David Hughes, who is associate professor of entomology and biology at Penn State.
2. Zombie spiders
In the Ecuadorian Amazon, zoologist Philippe Fernandez-Fournier and colleagues from the University of British Columbia in Vancouver, Canada, made a startling discovery.
They discovered that a previously unknown species of Zatypota wasp can manage spiders from the Anelosimus eximius species in ways that researchers have never seen before in nature.
A. eximius spiders are sociable creatures which like to stay in groups and never leave their colonies.
Members of this species infected with Zatypota larva, on the other hand, exhibited strange behavior, abandoning their colony to weave tightly woven, cocoon-like webs in faraway regions, according to Fernandez-Fournier and colleagues.
The researchers discovered Zatypota larvae thriving within these artificial “cocoons” when they opened them.
Further investigation revealed a terrible sequence of events. Zatypota wasps deposit eggs on A. eximius spiders’ abdomens. When the wasp larva hatches from the egg, it begins to feed on the spider and takes over its body.
When the larva gains complete control of its host, it transforms it into a zombie-like organism that is forced to flee its mates and spin the cocoon-like nest that will allow the larva to mature into an adult wasp.
The wasp larva, however, must first complete its “job” by devouring its host before entering its new “cocoon.”
“Wasps manipulating the behavior of spiders has been observed before, but not at a level as complex as this,” says Fernandez-Fournier.
“[T]his behavior modification is so hardcore. The wasp completely hijacks the spider’s behavior and brain and makes it do something it would never do, like leave its nest and spin a completely different structure. That’s very dangerous for these tiny spiders.”
3. The reanimated virus
Reanimating humans, or at least human-like monsters, as in Mary Shelley’s Frankenstein or H. P. Lovecraft’s “Herbert West: Reanimator,” has long tickled the attention of writers, filmmakers, and, of course, scientists.
While recovering dead humans is unlikely for our species at this time, reviving other organisms conceivable. This is especially concerning when we believe the creatures are viruses.
Researchers from the Centre National de la Recherche Scientifique at Aix–Marseille Université in France discovered an intriguing creature in the Siberian permafrost in 2014: Pithovirus sibericum, a 30,000-year-old gigantic virus.
The moniker “giant virus” comes from the fact that, despite their small size, they are plainly visible under a microscope. But there’s something else about P. sibericum that sets it different. It’s a DNA virus with a big number of genes – as many as 500 to be exact.
Other DNA viruses, such as the human immunodeficiency virus (HIV), have just roughly 12 genes in total.
According to the researchers who discovered P. sibericum, the size of huge viruses, as well as the fact that they carry such a vast quantity of DNA, can make them particularly deadly because they can survive for an extraordinarily long time.
“Among known viruses, the large viruses tend to be extraordinarily difficult, virtually impossible to break apart,” Jean-Michel Claverie and Chantal Abergel, two of the virus’s discoverers, explain in a National Geographic interview.
“Because they are cold, anoxic [oxygen-free], and […] dark,” they write, “special settings like deep ocean sediments and permafrost are particularly good preservers of microorganisms [and viruses].”
P. sibericum only infected amoebas – primitive unicellular organisms — when it was “reanimated,” but not humans or other animals. Claverie and Abergel caution, however, that comparable enormous viruses could be buried in the permafrost and pose a threat to people.
Despite the fact that they have remained safely isolated thus far, climate change and human action may force them to resurface and spring to life, posing unknown health risks.
“Mining and drilling mean […] digging through these ancient layers for the first time in millions of years. If ‘viable’ [viruses] are still there, this is a good recipe for disaster.”
Jean-Michel Claverie and Chantal Abergel
4. Zombie plants
Researchers at the John Innes Centre in Norwich, United Kingdom, discovered in 2014 that particular bacteria known as “phytoplasma” can turn some plants into “zombies.”
Insects spread the bacteria, which infects plants like goldenrods, which have yellow blossoms. Instead of blossoms, the goldenrods produce leaf-like extensions as a result of the infection.
More insects are attracted to the leaf-like growths, allowing the bacteria to “travel” and infect more plants.
While the plant does not die as a result of the change, scientists are intrigued by how phytoplasma may manipulate the host’s “will” to make it develop the ingredients they need to expand and prosper.
Prof. Günter Theißen of Friedrich Schiller University Jena in Germany, one of the researchers who has closely researched the activities of phytoplasma, says, “The insects transfer bacteria, so-called phytoplasmas, which damage the life cycle of the plants.”
“These plants become the living dead. Eventually, they only serve the spread of the bacteria.”
Prof. Günter Theißen
5. Human zombies?
Can people, on the other hand, turn become zombies? Dr. Chavannes Douyon and Prof. Roland Littlewood conducted research in the 1990s to see if Haitian zombies – reanimated but mindless individuals — were a serious threat.
In 1997, the two co-authored a study paper in The Lancet in which they examined the instances of three Haitians who had been labeled as zombies by their communities.
One of them was a 30-year-old woman who died shortly after becoming ill. Three years later, her family noticed her going about like a “zombie.” Another was a young guy who “died” at the age of 18 and reappeared at a cockfight after another 18 years.
The third case study involved another woman who “died” at the age of 18 but reappeared as a zombie 13 years later.
Dr. Douyon and Prof. Littlewood investigated these three “zombies” and discovered that they were not the victims of an evil spell. Rather, medical issues could be to blame for their zombification.
The first “zombie” suffered from catatonic schizophrenia, a rare disorder that causes a person to stroll around in a daze. The second had epilepsy and had suffered brain damage, while the third appeared to have a learning problem.
“People with a severe mental disease, brain damage, or learning disability are not often seen roaming in Haiti,” the researchers write, “and they would be more likely to be classified as lacking volition and memory, which are hallmarks of a zombi.”
However, there is a psychiatric disease known as Cotard’s syndrome that can make people act like zombies. A person with this disease believes they are dead or rotting.
It’s unclear how common this illness is, but evidence suggests it’s uncommon. Nonetheless, documented occurrences of people with Cotard’s condition are alarming.
A 53-year-old lady “was claiming that she was dead, smelled like rotten flesh, and wanted to be transferred to a morgue so that she could be with dead people,” according to one case study.
According to another account, a 65-year-old man claimed that his organs, including his brain, had stopped working and that his house was slowly but steadily crumbling.
The man attempted to commit suicide at one point. “His suicide note revealed that he wanted to kill himself because he feared transmitting a dangerous sickness to the villagers, who would thereafter [get] cancer,” researchers write.
Do such occurrences indicate that zombies are real in some manner, or do they simply represent our uneasy relationship with death, as our infatuation with the idea of the zombie in folklore and popular culture does?
We’ll leave it up to you to make your decision.