Since the recent publications of books like The Zombie Survival Guide and World War Z, zombies (and zombie trivia) have certainly been in vogue. In 2010 Seattle hosted a Zombie-con, which included everything from guest appearances by Bruce Campbell to a vintage zombie prom. Zombie films have exploded in popularity, and these days zombies come in all forms: some are altered by nuclear radiation, others are the classic risen from the grave type, and still others are monsters effected by poisons, evil spirits, what have you. It’s able to be fun because it’s not really possible…right? What if zombies could be a real threat, what if there really were a mind controlling parasite or virus that would manipulate its host’s behavior to its own ends? What if science suddenly becomes a lot more like science fiction?
WARNING: The rest of this post may blow your mind (provided you don’t already have a parasite living in it.)
Turns out scientists are discovering an ever growing number of parasitic organisms who take up residence in the human brain. Recently, in Washington D.C., flies started exhibiting exceedingly strange behavior: they would perch on the edge of a high point like the end of a blade or grass and then essentially…explode. From their poor little brains would emerge fungal spores which would then be carried on the wind and would infect other flies. The fungus only needed to occupy the brain of the fly in order to reproduce. When it fully infected the fly, it released chemicals which caused the fly to place itself where it would be most advantageous for the parasite’s reproduction: a high point from which it would be carried by a gentle breeze.
Other suicidal insects include grasshoppers and crickets: the nematomorph hairworm reproduces in freshwater, but live much of their lives in these poor insects. Once mature the hairworm is over four times as long as its host when fully extended. It gets a little cramped in there, so the worm releases similar chemicals to that of the fly fungus. Instead of causing the grasshopper’s brain to explode, however, they direct the grasshopper to find the nearest body of freshwater and dive right in. Once submerged, the worm emerges from the backside of the grasshopper, leaving it drowned or drowning in the water. Basically the worm eats the grasshopper from the inside until it’s no longer convenient, at which point it manipulates the grasshopper into seeking its own watery end. Nice.
But the cream of the parasitic crop, the potential mother of all mind trips (and mind residents), is known as Toxoplasma gondii. Now generally, rodents fear cats. If cat urine is sprayed in a corner, a rat will avoid that corner. Unless, or course, they have a healthy dose of T. gondii. Because T. gondii can only reproduce in the intestines of cats, the parasite causes the rats to not only cease to avoid cats, but to actively seek them out. The most recent research has shown that the virus causes them to essentially fall in love with cats. Unfortunately for them, the cats don’t seem to return the affection. Because these rats are invariably eaten the T. gondii is able to return to the cat and reproduce. Strangely, the rats are still afraid of other predators. Apparently, this self destructive infatuation only applies to cats because they’re the only creature the parasite needs.
The scariest part? Toxoplasma gondii is found in human brains. For quite a while, it was thought to be completely without symptoms. But recent studies are finding a highly suggestive correlation between presence of T. gondii and rates mental illnesses characterized by imbalances in dopamine levels. Simply put, T. gondii is consistently more present in people with paranoid-schizophrenia and bi-polar disorder. Similarly, when examinations have been done upon the brains of aggressive drivers similar correlations are found. Could this perhaps mean that the same parasite driving rats insane has the same effect upon humans, making them more restless and self-destructive? The coincidences are unsettling.
Is it a far cry from this to an actual mind-controlling parasite? Or is this perhaps an evolutionary stepping stone toward the next great extinction, the first in which the species will not be destroyed but will rather be driven to destroy itself? Either way, bet you’ll never look at cats the same way again…