Curse of the undead- the science behind zombies

Movie rentals, remember them? A college friend went on a binge of renting movies with “marine science” themes. The feature presentation one night was 1998’s “The Serpent and The Rainbow”. While I remember it as a decent scary movie, IMDB only gives the movie a 6.5 rating and it scores 65% on the tomato meter. Zombies, suspense, mysticism- all around good horror movie material. I was confused with his “marine bio” tie-in.

Disappointed, my friend told us the movie wasn’t like the book (color me shocked).  The film is based loosely on a non-fiction book by ethnobotinist/anthropologist Wade Davis. In the book, Davis puts forth his hypothesis that tetrododoxin derived from the puffer fish (ah, the marine bio tie-in) is one of several Zombie chemicals.

I was intrigued and immediately set out to find this book for my collection. As a science nerd, the book fascinated me. Davis simultaneously demystifies the zombie legend while romanticizing the zombie culture. While some of his ideas and methods have been disputed by scholars, his notion of a “zombie chemical” touched off a movement.  

nature can be creepy

Mind control over another organism is common in nature. Carpenter ants infected with the zombie ant fungus (Ophiocordyceps unilateralis sensu lato) climb up plant stems, latch onto leaves and stay there until they die. The fungus then pervades the dead ant’s body, grows a stalk from its head, and spews out spores to infect more ants. A Penn State study showed how fungal cells invaded all parts of an ant’s body, except inside the brain. The authors proposed the fungus kept the ant’s brain alive until it could bite onto the leaf. Diabolical, if not gruesome; hopefully ants aren’t sentient.

Sacculina carcini  (there is no common name) is a parasitic barnacle that makes a living infecting crabs, mostly green crabs. The female bores into a crab where she deposits fertilized eggs into the crab’s abdomen. The crabs own gonads are destroyed in the process. The host crab provides all of the care for the larvae. Infected crabs stop growing and their behavior is altered to act as if they are brooding their own egg masses instead of the barnacle parasite- for the rest of their lives.

Organisms evolve and adapt to maximize the odds of survival. Zombifying a keystone species like Homo sapiens would be an effective means of passing on genetic material.

You know, just sayin’.

the zombie drug

The zombie drug addict stories have died down in the media. For a time maybe three years ago there were a lot of news stories about naked erratic people running amok, some of them eating human flesh and possessed of super human strength. The drug α-pyrrolidinopentiophenone hydrochloride (α-PVP) goes by the street name flakka, it’s in the bath salts family. It has been known since 1963 but showed up in the US in 2013 as a “recreational” drug.

What’s more,this drug is so potent ingesting 0.1 gram can lead to an overdose. This dosage can cause the body’s muscle fibers to dissolve leading to uncontrollable movements (zombie-like). The drug alters brain chemistry; people suffer anxiety, delusions, hallucinations, can’t control thoughts or actions and become irrationally violent.

This is a relatively new drug to the streets, limited studies suggest it is as addictive as meth or cocaine, but there little information about the long term mental or physical effects. Flakka has been associated with kidney disease and renal failure. While it has become scarce in the US thanks to government efforts, the drug is showing up in other countries.

Ingesting this drug is a voluntary decision (a really bad one) the responsibility for making you act like a zombie lies with you for taking flakka. Unless the drug was to, say, get dumped into a public water system, there would be no wide spread danger to society, unlike some infectious agents.

prions

My final lecture course in graduate school was environmental microbiology. My focus has always been ecology so I hadn’t been introduced to prions until this class. The prion is a fascinating and frightening molecule.

The term prion is derived from the longer name proteinaceous infectious particle. As the name would suggest, a prion is a protein. It contains no nucleic acid in its structure and hence, no DNA. Prions are mis-folded proteins that can induce healthy proteins to fold in a harmful way leading to diseases. Until they were isolated for what they are, researchers thought diseases caused by prions were actually caused by bacteria or viruses.

Chronic wasting disease and mad cow disease are two of the best known, but the CDC lists eleven that have been isolated in humans and other mammals. Prion diseases are classified as transmissible spongiform encephalopathies, basically diseases of the brain and nervous system.

Johns Hopkins Medicine reports about 300 cases of prion disease a year.

This symptom chart reads rather zombie-like doesn’t it? Prion disease is rare, and always fatal. They can in very rare cases be inherited, but most cases involve exposure; primarily eating infected meat.

a zombie zeitgeist

It’s the possibility of a scientific connection and a logical cause that makes a Zombie cataclysm such a believable concept. Other monster dogma involves some sort of mysticism and a stretch of reality. The “theory” of a virus or pathogen that could infiltrate our brain and turn average people into unwitting catalysts of carnage is plausible…if you’re the imaginative type.

The Resident Evil video game franchise entered our lives in 1996. I was hooked on this game and the idea of a Monsanto-like corporation bio-engineering a virus which could turn living things into undead killing machines. By the time I met the other member of team DLP in, I had obsessed over Resident Evil 1, 2, and Nemesis. It was time for me to sit back and enjoy watching the uninitiated dive into the world of the Zombie apocalypse (my partner had a sheltered childhood).

The world of the undead became a fascination to him. Not only does he have a zombie figure collection (like our little friend above) but an impressive Grim Reaper collection too. 

The fact that a collectible zombie is even a thing seems kind of a creepy sign of our times. The undead have become mainstream. The Walking Dead franchise and Z-nation along with uncountable movies and video games have brought the zombie phenomenon to a place in society where otherwise rational intelligent people believe a virus, bacteria or some other biological agent could send us into a dystopian society where we become the chief prey item for the undead.

The early part of the 21^st century may well become known for our cultural fascination with the zombies.

Every pair of shoes I buy comes with the caveat, “but, can you out run a zombie in those?”

the take home

In the end, what we know as “zombie” the undead minion could actually be a real thing- to a point. The brain and nervous system are susceptible to outside influences be they physical or in the case of humans psychological. Something Wade Davis investigated in the book version of Serpent and the Rainbow, was the psychological effect on the victims. They continued to believe they were undead henchmen.

Could the zombie apocalypse destroy us all? I doubt it. The pathogens, whether they are street drugs, prions, parasites, or toxins, will probably kill of the human race pretty quick before society becomes a collective host of the undead- you know, like the medieval plagues did. This time of year though it‘s fun to scare ourselves with the thought of the zombie horde coming to scarf our brains.

If you’re looking for a good zombie movie this spooky season, Paste magazine posted a list of their 50 best zombie movies of all time. I’ve seen many on the list, sadly though “Zombeavers” didn’t make the cut. My personal viewing choice for this Halloween is “Train to Busan”.