I thought that we’d do a quick, just-for-fun post today. ABOUT ZOMBIES. Now, I like me some zombie movies. Sometimes their plots even have cool disease ecology components, like competition between the “zombie virus” and other host pathogens. On the other hand, there are many, many biological inaccuracies involved in the popular zombie idea, as Neil deGrasse Tyson explains.
But if you’ve been following this blog or popular science for any length of time, you know that in a way, Neil deGrasse Tyson is wrong in saying that if zombies exist, they only exist on other planets. There are “zombies” on Earth: parasite zombies! That is, some parasites can dramatically alter their host’s behavior, so that the host is effectively just a vehicle for the parasite. The point of this manipulation is to get the host to behave in such a way as to increase the parasite’s probability of transmission to the next host. Usually, this involves the host getting eaten by the next host, like when infected ants hang out at the top of blades of grass, where they are likely to be eaten by cows or sheep. But that’s not always the case. For instance, with rabies – the pathogen most similar to the classic idea of a zombie virus – the virus makes (some) animals behave aggressively, and this increases the probability that the virus will be transmitted to new hosts via bites.
Now, thankfully, there aren’t any parasites that re-animate dead corpses…yet. But there are parasites that use corpses as points of transmission. For instance, Cordyceps fungus makes ants leave their normal routines to go bite onto leaves above major areas of ant traffic. Then the fungus sprouts a fruiting body out of the ant’s corpse and rains spores of death down on the ant’s extended family.
Don’t you think that a Coryceps fungus apocalypse would be a cool video game plot? Well, actually, it already is a cool video game plot! The Last of Us has been out for a while on PS3, and a remastered version was just released on PS4. From Wiki:
“In 2013, Joel (Troy Baker) is a single father living near Austin, Texas with his twelve-year-old daughter Sarah (Hana Hayes). One night, an outbreak of a mutant Cordyceps fungus ravages the United States, which transforms its human hosts into cannibalistic monsters…”
Now, real Cordyceps doesn’t turn insects into cannibals, but I’m willing to overlook this error in biology because – WAIT FOR IT – they’re going to make The Last of Us into a movie, too! That’s right. Cordyceps is coming to the big screen. Awwyisss.