With the return of the hit TV series The Walking Dead, and with Halloween season upon us, it's time to address some burning questions about zombies. Obviously, the genre requires a certain suspension of disbelief, but because most zombie fiction adheres to a strict set of rules (e.g., they only die if you shoot them in the brain, a bite from one will turn you into a zombie as well, etc.), I can't help but wonder about the "reality" of zombies – that is, the biological (im)plausibilities of the living dead. This list is decidedly tongue in cheek, but I hope it provides some food for thought.
- Why can't a zombie starve to death? The whole point of zombies is that they are ravenous for human flesh. They're desperate to eat 24/7, which suggests that if they don't eat, something bad will happen to them. After all, the body needs fuel to keep moving, and food is that fuel. So if an unlucky zombie doesn't eat for a few weeks, how on earth can it still move around? Even though its heart has stopped (and I'm not touching that biological conundrum with a ten foot pole), its shifting, shuffling body still burns calories. An unfed zombie's muscles would surely atrophy after a while. But in movies and TV, they just keep on going.
- Do zombies pee and poop? You have to figure that after a zombie gorges on a human body, there will be some waste, even if what they're eating is mostly raw protein that gets put to use. An undead human body would still have to excrete waste – it's not like turning zombie makes it instantly 100% efficient.
- Can a zombie get full? Just as most people can't eat more than a couple pounds of food at one sitting, I imagine a zombie feasting on an entire 150-pound human could only devour so much before saying, "UGH, ENOUGH." At which point, would they wander off, bored, waiting until they get hungry again? Or would the instinct be to hang around their most recent meal, as if to say, "BEST STAY HERE AND EAT MORE THIS GUY LATER, INSTEAD OF LOOK FOR NEW VICTIM." (I don't know why I envision zombies speaking like Tonto and typing in all caps.)
- Are zombies better biters than eaters? The #1 zombie rule is that if you get bitten by one, you become one. The corollary is that if they eat you entirely, you don't get turned at all, because there's nothing left of you. So how come zombie movies and TV shows seem to suggest that at least 90% of the people on Earth have been turned? I mean really, do that many folks escape a zombie attack with just a few bites, and then become zombies on their own while no other zombie is around to gobble them up completely? In most cases, a zombie close enough to give you a bite would also be close enough to kill you and eat you. So it should be really hard to propagate the zombie species, since the vast majority of human victims would either get away bite-free (after all, zombies are traditionally easy to outsmart and outrun) or be totally consumed.
- Why don't their bodies break down from lack of proper nutrition? I realize that zombies look pretty bad as it is, but still. Humans are omnivores. We depend on plants for fibers, sugars, vitamins, and other things that animal protein just can't give us. But in most movies and TV shows, zombies are 100% carnivorous. How well can an undead human body possibly function? Here's just one example: without vitamin C, scurvy would eventually set in. This would be devastating for a zombie because its teeth and fingernails would eventually fall out, rendering it fairly harmless. And that's just the tip of the iceberg. Also, I presume that zombies obtain all their water from human flesh, but one would have to eat a lot of people to get the recommended daily amount of water. In other words, even a reasonably well-fed zombie would be severely dehydrated, malnourished, and weakened. Which leads me to the next question...
- How do zombies get to be so strong? Your average human being isn't that physically powerful. I mean, could you tear another person to pieces with only your bare hands and teeth? It would take a ton of work, even if you were a psychopathic cannibal and could handle the gruesomeness. Considering that an undead human body would naturally be much weaker and more uncoordinated than a living one – and factoring in that scurvy thing – it doesn't add up that a zombie's jaw would have sharklike strength, or that its brittle fingers and mangled fingernails could rip a grown man limb from limb. Although I will say that this weakened state at least provides a reason why so many people could get bitten by a zombie then run away before being killed and eaten: because it would take most zombies quite a while to chew through your skin and cause enough blood loss for you to pass out and become more docile prey. But what are you doing in the meantime? Obviously not just standing there, letting it happen.
- How exactly can the dead rise from their graves? The answer seems simple: they crawl their way through coffin lids and tons of dirt, using their now inexplicably powerful limbs. But even if you buy that, here's the under-discussed problem: most Americans are autopsied after they die. During a routine autopsy, the brain is often removed, examined, then replaced into the skull before the body is buried. In other words, the brain becomes disconnected from the nervous system. So in movies where zombie epidemics cause the dead to rise from their graves (as in Night of the Living Dead), we're asked to believe that the only way to kill a "ghoul" is to shoot it in the brain – yet the brain had likely already been severed from the rest of the system much earlier, by a coroner. So I guess the only dead to rise from the grave are those who were lucky enough to have intact brains? For long-buried corpses that didn't routinely get autopsied, the worms would have eaten the brains anyway. I call foul.
- Wouldn't most zombies be blind? Let's face it: When you're dead, the eyeballs are the first to go. (I'm not even going to go into the gory details of what morticians do to eyes to keep them from sinking into the sockets.) So whether you've been buried for a little while or even left out in the sun, it doesn't matter what the rest of your body looks like – you probably have no eyes. Thus, most zombies would have no eyes. Which also makes me wonder: for those zombies that still have their eyes, do they blink? Or do they just let the eyeballs gather dust and dirt? Would crows swoop down and peck them out? If not, then why not? I think zombie movies should have comical scenes where the undead are constantly trying to shoo away crows from their faces. That would be pretty funny.
- Why don't zombies eat each other? Zombie fiction defenders have a ton of answers for why zombies don't cannibalize other zombies. Something to do with an appetite for living flesh and thus a revulsion for necrotic flesh. But let's be serious: In most zombie fiction, when someone dies after being bitten by a zombie (or even if they just die in general, as in The Walking Dead), they rather quickly become a zombie themselves. And honestly, if you're a five-minute- or even five-hour-old zombie, your flesh, blood, and internal organs are still going to be warm, fresh, and tasty. The idea that turning zombie immediately makes you icky and inedible to other zombies is, in my mind, a tough one to swallow.