Hypothetical Hunger

Welcome once again Zombiology Students,

I was contacted by Albert who asked me the following;

“Say there was a zombie apocalypse and all humans were eradicated.  What would the zombies do after they have eaten all the human brains and (as far as I know) depleted their only source of nutrients?  Is there any knowledge regarding this topic?  They wouldn't just starve themselves out, would they?”

But we haven't thought about food security, not one meeting.

Before I can answer it we must first establish some points about Zombieism. Regular visitors will be aware of our Institute’s current Zombieism research and can skip this section, but for those of you not familiar with it, read on. Here at the ZITS we believe that zombie’s will most likely be caused by a new type of prion disease, similar to vCJD AKA human mad cow disease. Unlike movie zombies, sufferers will not eat only human flesh or brains, but any food source they come across. In fact there is presently nothing that can occur in a human to make them only want to eat human flesh or brains. Genuine Zombieism is highly unlikely to make a person become clinically dead, then return to life, referred to in fiction as undead. They would in reality be a human who has contracted an illness with specific symptoms. They would not live indefinitely, but wither and die as the disease progressed. How long that would take very much depends on the causal agent.  Furthermore, prion disease is very rare in humans, to date there have been less than 200 cases of vCJD, so at the moment it is very unlikely we will reach a scenario whereby there were no humans left who were not infected.

Of course there is no guarantee that Zombieism will be the result of a prion disease, it might be a new strain of virus or a previously unseen parasite. So to answer Albert’s question we can widen our net to include these biological agents. The fact that you are alive and reading this means that there has not yet been a disease that has wiped out the human race, or left only infected humans, unless such a disease occurred a very long time ago to a different species of Homo genus.   

The Homo Simponus perhaps ...?

If we look at the most deadly disease pandemics that have occurred we can try and seek a comparison. The Spanish Flu may be the deadliest pandemic in history, with somewhere between 20 – 200 million people dying because of it. Then there is the infamous bubonic plague that throughout its history has claimed the lives of some 200 million victims. Now whilst these diseases have produced a tremendous loss of life it is worth bearing in mind that the human population is presently just over seven billion. So Zombieism would have to be particularly vicious to turn us all.

But let’s think hypothetically, say Zombieism did spread to the entire population of the world, how long would the food supply last? We produce around seven billion tons of food each year. If everyone in the world has succumbed to Zombieism, it is safe to say no one will be producing any more. It is very difficult to get exact figures to work with here. It is hard to know how much food is readily accessible to the zombies. Some may be in cans they cannot open, and as a zombie isn’t exactly a gourmet chef, they’re going to be going for raw food only. Zombies may also consume each other when they get desperate.

'We've had some times zombie-ing together Bill but I can't take your moaning one minute more'.

The average person/zombie needs between 2,000 – 3,000 calories a day. In 2003, the world produced 2,809 calories per person per day, but by the end of 2006 there was only enough of a reserve to last the world 57 days. I haven’t been able to source data more recent than that, but we could assume that we’re running a careful balance these days whereby we only just keep producing enough food to get by, without having large reserves. So by the time we reached a point where there were only zombies, and no one producing more food, these zombies would run out of food in probably a matter of weeks, maybe even days.

How long the zombies will ultimately survive from there depends on how long the disease takes to kill them, assuming they don’t die of starvation, or dehydration, first. With a prion disease we estimate a person surviving three to six months after full onset. A more aggressive biological agent, like a virus, may act even quicker.

So in conclusion, the answer to the question, ‘what would the zombies do after they have depleted their only source of nutrients’ is ... they would die. However it is unlikely we’d reach a scenario where everybody was infected by Zombieism in the first place, and if we do there’s no need to worry, because you’d soon be dead.

As always, if there is anything you want to know about the real science behind zombies, do get in touch. We’ll always do our best to answer your questions, no matter how difficult or strange. You can contact the Institute at info@zombiescience.co.uk.

Best wishes,

Doctor Austin

Doctor Austin ZITS BSz MSz DPep, is a Theoretical Zombiologist and Head of the Zombie Institute for Theoretical Studies at the University of Glasgow, Scotland UK.  

For even more Zombie Science pick up the official Zombie Science book on Amazon now. 

A Tale of Two Zombies

Hello Zombiology Students,

We recently received two interesting questions from you Zombiology fans and decided to share them in today’s ZomBlog.

The first is from Vicki who emailed asking ‘would it be possible for zombies to be made from a natural mutation of a dual-infection? My idea is that the fer-de-lance snake and a vampire bat causing rabies, both in Panama, could both infect someone, possibly mutate and cause a zombie apocalypse.’

The Bothrops atrox aka fer-de-lance, is a venomous snake, ‘regarded as the most dangerous snake in the Panamanian jungles, chiefly because it is the commonest of the vipers’ (Elton 1999). The snake bite releases venom which contains a substance called a haemotoxin.  In the human body this kills red blood cells, stops blood clots forming and can cause tissue damage.    

Fig 47# Fer-de-lance (with snake)

Vampire bats can refer to three species of bat whose diet consists of blood. Contrary to popular belief they do not suck blood through their teeth, but rather create a wound and lap the blood up. As with all bats they have the possibility of transmitting Rabies, however in reality only a small percentage of the population carry it.

Fig 420# The Vampire Bat (aha ha, gosh I pee'd a little there)

Now we know some basics let’s turn to our resident viral expert, Dr. Katie White for more details, ‘the damage caused by fer-de-lance snake bite isn’t caused by an infection.  Infections are caused by the presence or growth of a biological agent (e.g. bacteria, virus) within the host body.  As an infectious agent grows and multiplies within the host body, the host can then pass on the infection to other people/animals.  The snake venom is not an infectious agent, so the host won’t start producing more of the toxin and won’t have enough inside them to pass it on to anyone else. The snake bite won’t pass on any genes to the host, so there is no genetic material to mutate or combine with that of the Rabies virus.  

As it affects the brain, the Rabies virus does cause some zombie like symptoms and yes it could possibly mutate to cause a more zombie like disease.  However, the Rabies virus is only really transferred between animals and people through bites, as infected hosts produce the Rabies virus in their saliva.  A zombie would have to produce a very large amount of saliva to infect a town’s water supply at a high enough level to actually cause disease.  The Rabies virus normally enters the body through the wound caused by the bite and then it travels along the nervous system to the brain.  If it was drunk in water instead, the virus would probably be destroyed in the stomach and would have no way of actually reaching the nervous system and brain.’

We would advise that any zombies found drooling in your local dam be guided away, and of course never share a drink with a zombie.

No matter how tempting it may be...

Our ZITS colleague Dr. Kevin O’Dell, a senior lecturer in Genetics at the University of Glasgow, kindly explained more about virus mutation, ‘any virus can and does mutate. Usually this leads to a mutant virus that doesn't function at all so doesn't infect and doesn't replicate. Very occasionally a mutation makes a virus more virulent (more infective). The snake venom would only make this more likely if it actively damaged virus DNA, but as Katie says, it doesn't.

If the snake bite occurs first and causes tissue damage then you might be able to argue that a subsequent bite by a zombie bat is more likely to happen as (a) the previously damaged host may not be able to run away as fast so is an easier target and/or (b) a zombie bat may be able to actively detect a compromised host (although I’m not 100% that they have that ability).’

Dr. Kevin O'Dell, he puts the 'S' in 'Necrosis'

Of course you’d have to be having a really bad day to be both bitten by a fer-de-lance snake and a vampire bat in short succession. Or for the optimists out there, a really lucky day, as apparently you are more likely to be struck by lightning than bitten by a fer-de-lance.

So to conclude Vicki, it would seem your theory of dual-infection, whilst creative, is thankfully a long way from causing the zombie apocalypse.

Our next question came from Lydia who asked, ‘could you please answer a zombie conundrum me and some zombie enthusiast friends are having over the Walking Dead TV series. In Season One we see the policeman dude and his new pals in the city covering themselves with blood and guts so that the walkers wouldn't sniff them out. And yet, one of my eagle eyed friends noticed they didn't do that when hiding under the cars from the zombie swarm in Season Two - the zombies never got so much as a whiff of them. And yet the redneck dude covered up the other dude who cut his arm in dead bodies so that the walkers wouldn't smell his blood. So what's that all about? Is this a TV continuity error? And could zombies really smell us living folk? Do they smell us if we are cut; like sharks can 'smell' blood? What's going on?’

 I feel I should start by pointing out that the Walking Dead zombie disease is very different from the condition we investigate in our research. Certain aspects, like being ‘undead’ are not possible at present, and having continual decomposition of skin and organs, would be a lot different than they portray. Regular visitors will know that I love the Walking Dead in its many formats but at the end of the day it is fictional, and so shouldn’t be criticised for its scientific inaccuracies.

My ex-wife used to say this all the time

However your smell question is still a good one, and I will endeavour to give you an answer all the same.

Those who have attended my lectures or read my book will know I believe a new type of prion disease, similar to Mad Cow Disease (vCJD), may be responsible for delivering Zombieism in the future. This type of disease occurs when our natural prion protein (PrP) is forced to change shape by a Rogue form, possibly by ingesting the Rogue through an infected food source, as occurred with cow meat and vCJD (note; this is not the only way to get a Prion disease). Scientists are still unclear as to what function the normal PrP has in our bodies. Many studies to determine an answer have involved mice who had this PrP gene removed or ‘knocked out’. Recent work has shown that mice without the gene perform badly in smell tests, failing to find hidden cookies, amongst other things. Therefore it is likely a Prion diseased zombie would have a poor sense of smell.

If we took the Walking Dead zombies as being real (ignoring the obvious inaccuracies) I would say that they would also have a poor sense of smell and restricted sight. If their bodies are decomposing their eyes would too, getting worse over time. The same would apply to their sense of smell. This means that in Season One using camouflage should work, depending on how long the zombies around them have been decomposing. Any recently turned zombie would have better senses compared with a longer term sufferer. In Season Two, what might be happening is an example of the disease giving rise to low zombie intelligence. Some of them may smell blood or humans, but are not smart enough to think to look beneath a car to find one.  

     

With regard to sharks, they smell around 10,000 times better than humans. A zombie, due to being gradually reduced in operating capacity by the disease, is definitely going to have a worse sense of smell than you or I, or a shark.

But if it's a zombie shark... oh dear

Double oh dear if it's a zombie land shark (although I don't know if I believe Google Images on this one...)

Finally, on the question of TV continuity, it is worth noting that Frank Darabont was the showrunner during Season One, and was replaced by Glen Mazzara for Season Two. You can read various reasons for this online, and I daren’t wade into the debate.

   

Ultimately I think we should all take something from Ron Moore’s First Law when creating the show Battlestar Galactica. When describing questions people asked about the real science of its content he advised taking the mantra, ‘it’s just a show, I should really just relax’. 

We do hope you are both satisfied with your answers. If you want to know anything further, or someone else has a question, do get in touch on info@zombiescience.co.uk.

Very best wishes,

Doctor Austin

Doctor Austin ZITS BSz MSz DPep, is a Theoretical Zombiologist and Head of the Zombie Institute for Theoretical Studies at the University of Glasgow, Scotland UK.  

For even more Zombie Science pick up the official Zombie Science book on Amazon now. 

Bibliography 

Elton, N. (1999, September 27). The Venomous Snakes of Panama from http://www.czbrats.com/Facts/snakes.htm