You can tell a lot about people from their ability to hold a semi-serious conversation about the zombie apocalypse. Humor, intelligence, ethics, and most importantly, whether or not they would be someone that could help you survive all can all be derived from these exchanges. Weighing your post Z-Day choices against survival and personal morality is amusing (and important!!), but it’s aged, and now taken to an art form through series like The Walking Dead and other such zombie-fare. The new zombie topic that you can use to filter through your friends? Try discussing the plausible implications that could cause a zombie apocalypse. To give you a leg up on this new undead theme and in homage to October and the upcoming slew of zombie culture we all soon be exposed to, I’m going to discuss my semi-learned opinion on a few events that could lead to a apocalypse of the living dead. Enjoy.
First off, my knowledge mostly pertains to multicellular parasites that cause behavioral changes in their hosts. The most famous of these include the hairworm parasite that causes its insect hosts to commit suicide by jumping into water; the fungus that completely takes over the body of its ant hosts in the Thai rainforest, which has been highlighted on Planet Earth; and the parasite Toxoplasma gondii, that cause rats to seek out felines, their natural predators, as well as cause more aggressive behavior in humans, which is attributed to possibly causing an increased contact with bigger felines like tigers and lions. Because of this, my main discussion will focus on if a multicellular parasite could cause human zombie-like symptoms, which would be most relatable to the zombies seen in Resident Evil 4.
The most important idea about this theory is that complex behavioral manipulative relationships such as these show a long line of coevolution. There are few parasites that manipulate human behavior, and few parasites that humans cannot already avoid, so my discussion is going to focus on a novel parasite that would affect humans.
Currently, research is being done on fungi that infect and kill nearby insects, some of these manipulate the behaviors of the insects, and others simply cause fatal diseases. These fungi could possibly lead to future biological insecticides, safer and “greener” than the chemical alternatives used today. Let us presume that in the near future, scientists find a novel fungus that not only kills insect pests but also degrades insect organic matter, which in turn creates more fertile soil for crops. This fungus is implemented at agricultural sites worldwide, and for a while everything is great.
It is currently unknown whether plants and fungi such as these have a symbiotic relationship where plants provide benefits for the fungus and the fungus act as bodyguards for the plants, but it IS being looked into. Let us once again presume that the fungi and plants share a close relationship that involves bidirectional communication and benefits on both sides. After years of humans harvesting crops—thereby terminating the plants’ lives early and destroying the relationship between fungi and plant—the two flora decide to fight back. Slowly, but increasing in intensity, this once harmless fungus begins infecting humans. The infectious systems begin as just a disease, much like the common cold. As the fungus continues to fight the human immune system, it comes into increased contact with the central nervous system due to the close connection of the two systems; exactly what happens in parasites that currently manipulate their host’s behavior. This new infectious fungus develops ways to bypass our immune system, and in doing so, beomes closely associated with the biochemicals that control our every action: dopamine, serotonin, adrenalin, etc. It then secretes its own chemicals that skew these biochemicals, most likely cause a rise in adrenalin and more aggressive behavior. The fungus could then learn that this increased aggressive behavior leads to higher human violence, and consequently higher transmission. It adapts, and a zombie apocalypse ensures.
There. One proposed zombie theory; the perfect conversation starter.
The biggest flaw in this theory is, of course, that biological processes and adaptations like the ones I proposed take thousands to millions of years to evolve. To bypass that, I’m going to pull up the pop-culture comic book cop out, and say that the fungus was exposed to chemicals, steroids, and possibly even radiation that enhanced its speed of growth, and inevitably its rate of adaption. Whatever. All theories have gaps, especially those concerning the zombie apocalypse.
There is strong biological evidence that parasites have evolved to ‘zombify’ their hosts from initial interactions with the host’s immune system and the subsequent bypassing of it. There is also evidence that these parasites secrete special chemicals that cause the hosts themselves to alter their levels of biochemcials, which ironically leads to their untimely and grotesque demise. Also, it is supported that stress hormones, such as adrenaline, can increase or decrease a person’s aggressive behavior, as well as their innate ‘fight-or-flight’ behavior.
Diseases such as malaria have shown that they can induce behaviors in their infected hosts that are self-beneficial. Even viruses, which are not technically ‘living’ things, have shown that they can alter behavior to increase their transmission rate (rabies anyone?) That being said, my knowledge on viruses and developing diseases is very limited. For brilliant information to supplement those types of arguments I recommend reading into the attempts to weaponize the rabies virus that occurred in The Soviet Union during the Cold War.
Maybe my friends and I are the only ones that spend countless hours preparing for and proposing the zombie apocalypse. If not, though, I hope this helps you boggle your friends’ minds during your next zombie discussion. Maybe some strain of information here will even help you when that eventful day comes: when the dead start walking among the living.