Ophiocordyceps sinensis

I know, you’re tired of hearing me rattle on about how crappy the classical theory is. “Nathan,” you ask, “when are we going to become better people from this blog and learn about the way things really are on this rock we call Earth, instead of living in a fantasy world?” Well, here you go. I don’t theorize. I don’t imagine. What follows is nothing more than cold, hard facts.

The basic idea behind the zombie is that it is still an organism that contains life (whatever “life” is), trying to accomplish a particular objective (classically, eating “brains,” although there is no explanation as to how they would penetrate the skull, and all movies show zombies eating from the abdomen, a good distance from the brain) until it is killed off. It still lives, just without higher brain function. What would be the culprit if the classical theory is not true? Well, you might be surprised.

It’s a fungus. A fungus is what will cause the real zombie apocalypse. It is very bizarre thinking, I know, and it seems farfetched at best, but hear me out, and read what is ahead. The biology may surprise you.

For now, let’s talk about these zombies. There is a fungus in Thailand that is taking over the bodies of ants and wiping out entire populations. Don’t believe me? Maybe you’ll like BBC and Penn State more, then.

http://www.youtube.com/watch?v=XuKjBIBBAL8

http://www.youtube.com/watch?v=2irXpAMBHkE

This fungus, as pointed out in the study above, actually has huge diversity, and it has a wide spread. Essentially, you can find this anywhere you find a jungle (Asia, Africa, South America, etc.) There are thousands of species of this fungus, each with its own victim-species.

In case the video was “too long; didn’t watch,” a basic breakdown is this: An ant will become infected with the fungus, Ophiocordyceps sinensis (the specific binomial nomenclature for the species directed at the carpenter ant), and go to the top of leaves, or to the underside of leaves, and die there (killed by the fungus). The fungus will grow out of the back of its neck, blow up, and its spores will spread to the entire population.

The physical mechanism for control is rather interesting. The fungus essentially hijacks the brain and takes the driver’s seat, as mentioned by Penn State. From there it grows and reaches every part of the body, growing among all muscles. It controls every muscle extension and contraction, and walks just like the ant would up the stem. If it is on the underside of the leaf, it can use the ant’s jaws (mandibles) to grip very tightly onto the central vein, and dangle there. The grip is so strong it can last after death.

http://www.manolith.com/files/2012/05/zombie-ants.png

This is a serious deal! This fungus is wiping out thousands of ants, moths, snails, and other small creatures simply by following this technique. And it is growing every day, finding more and more prey. But more on this in the next section.
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Cordyceps: Attack of the Killer Fungi. Perf. David Attenborough. YouTube. BBC, 03 Nov. 2008. Web. 09 Apr. 2013.

Evans, Harry C., Simon L. Elliot, and David P. Hughes. Hidden Diversity Behind the Zombie-Ant Fungus Ophiocordyceps Unilateralis: Four New Species Described from Carpenter Ants in Minas Gerais, Brazil. Ed. Corrie Moreau. PLoS ONE. N.p., 2 Mar. 2011. Web. 9 Apr. 2013.

Pontoppidan, Maj-Britt, Winanda Himaman, Nigel L. Hywel-Jones, Jacobus J. Boomsma, and David P. Hughes. Graveyards on the Move: The Spatio-Temporal Distribution of Dead Ophiocordyceps-Infected Ants. Ed. Anna Dornhaus. NCBI. PLoS ONE, 12 Mar. 2009. Web. 9 Apr. 2013.

ScienceCast: Zombie Ants. YouTube. Pennsylvania State University, 29 July 2011. Web. 9 Apr. 2013.