Zombies: Science Fiction vs. Fact
Well in the spirit of Halloween I thought I would make a nice little zombie post. Zombies, those brain loving little guys, [and girls] are everywhere. From shows like The Walking Dead — a zombie show where they call them anything but zombies– to video games, music videos, and weird romance stuff. Even the zombie itself takes on a different life depending on the person and film.
For example we are all familiar [if we are horror fans, or at least not living on an Amish compound] with the classic slow moving zombie, World War Z [which shared merely a title with the book] introduced a fast, almost fluid type of zombie, and even nature has its own special types of zombies! Things like the Ophiocordyceps unilateralis, a fungus that takes control of ants, once this happens it will climb down from its habitat, or after falling to the forest floor will climb underneath a leaf, clamp down with its mandibles to secure itself to the leaf vein. This will be where the ant dies, in this “death grip”; from here, the fungus pops out of the ants head and spreads its spores.
That is not even the scariest of zombies, Gordian worms [also known as horsehair worms] can live in crickets for long periods, and then it will cause changes in protein expressions in the brain that make the cricket extremely thirsty. The cricket, possessed, heads to a pool of water where it drowns itself, but the worm exits to mate with other members of its species [that live in the water].
Rats also exhibit self-destructive behaviors when invaded by parasites. Toxoplasma makes rats lose their fear of cats, or more specifically, it causes the rat to be attracted to cat urine, so they may not run away when a cat tries to eat them. That is what the parasite wants: for the cat to eat the rat so that Toxoplasma can pass into the cat, too. The cat passes it by its feces and the cycle continues.
Even snails get in on it, Leucochloridium paradoxum [a mouthful I know], causes the snail to develop eyes that look like caterpillars. Snails, which prefer the dark, head out in daylight while infected, which causes them to be seen then consequently get eaten by birds and the life cycle continues.
That is not even all of them [well the ones we know about], so with all these zombies in nature the real question is, what about humans?
What if some mind controlling parasite started turning us into brain eating zombies?
Well interestingly enough, some [highly controversial] research points to toxoplasma actually subtly affecting human behavior. It should not be a surprise that something [possibly soon] could hijack a human brain if it has not already happened. Just because human physiology is complex [along with our immune system] does not mean we are invincible. Think of all the nasty things that we have going around already, HIV/AIDs loves to hijack the immune system, very different from zombie I know.
So what could come our way? Well things like that are tough to predict, it’s hard because when we talk about mutations in existing virus we have trouble guessing what would happen. That is why I wrote this post on the genetically created flu virus. Of course, there is the alternative, a genetically modified human-created virus that would do the job, perhaps something like in Extinction: The GMO Chronicles [which I thought was a pretty good low budget flick]. The movie revolves around a type of virus [they have one subtle hint it is actually a plasmid, those creepy, creepy things!] that cross breeds genes from plants, animals and even humans. However, that kind of future would still be a ways off, if it were even remotely possible to do.
Loony hint: You can read about Plasmids here
That is because genetic engineering is super complex, it would be like me randomly replacing a word in, say the bible [which would be easier to do mind you, because it is vastly shorter than you’re DNA]. Here is an example, say I hated that Jesus was crucified, so I wanted to replace one instance of a sentence talking about when he was crucified. Therefore, we replace the word crucified with the phrase Jesus farted. Much friendlier, yes? It would be extremely difficult to find the right sentence that these words would make sense. If, for example I “accidentally” replaced it when people were shouting crucify him, it would make absolutely no sense.
[Loony Hint: For anyone not familiar with it sorry for the bible reference, it was just the biggest book I could think of off the top of my head, for anyone interested, I was raised in a very catholic household. I am very much an atheist, but that is just my preference]
This is unfortunately how genes work, most of the time if we edit something it will not do much [and that is a good case], most of the time it will cause cell death, or other really screwy things. So needless to say, we are dealing with very complex machinery. Personally I think a gene swapping, zombie creating virus would be a pretty cool feat, but alas not likely to happen.
Zombies in the undead sense would not happen either, but humans with an insatiable appetite for human flesh or even brains, which would not be too hard to manage with genetic modifying techniques eventually. There already is a condition similar to what we would be talking about called, Prader-Willi syndrome, a condition where you would not only have an incredible hunger, you would not be able to tell when you are full. It would be very easy to turn violent when dealing with such a person, because having a constant hunger can in fact make people violent.
The bottom line is that while we should not worry about zombies anytime soon, it is fun to talk about all the weird ways things like this could happen.
On a side, note I want to point out that the term genetically modified [or GMO] is one of those terms that does not really mean anything. Everything is genetically modified from when it was first created, me, you, your mother, that “all-natural” and organic steak you ate. All genetically modified, it is like saying organic, I would love to see some non-carbon based food [which is what the term organic means after all], because if it is not organic you probably should not be eating it. Furthermore, whether it is modified in the lab, or by nature, it is all the same Lego set, so to speak.
Just a little rant from yours truly. In any case, Zombies or not, have a happy Halloween
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Vyas A, Kim SK, Giacomini N, Boothroyd JC, & Sapolsky RM (2007). Behavioral changes induced by Toxoplasma infection of rodents are highly specific to aversion of cat odors. Proceedings of the National Academy of Sciences of the United States of America, 104 (15), 6442-7 PMID: 17404235
Passamonti L, Crockett MJ, Apergis-Schoute AM, Clark L, Rowe JB, Calder AJ, & Robbins TW (2012). Effects of acute tryptophan depletion on prefrontal-amygdala connectivity while viewing facial signals of aggression. Biological psychiatry, 71 (1), 36-43 PMID: 21920502
Thomas, F., Schmidt-Rhaesa, A., Martin, G., Manu, C., Durand, P., & Renaud, F. (2002). Do hairworms (Nematomorpha) manipulate the water seeking behaviour of their terrestrial hosts? Journal of Evolutionary Biology, 15 (3), 356-361 DOI: 10.1046/j.1420-9101.2002.00410.x
W. Wesołowska T. Wesołowski (2014). Do Leucochloridium sporocysts manipulate the behaviour of their snail hosts? Journal of Zoology , 292 (3), 151-155 : 10.1111/jzo.12094