No One Would Survive A Zombie Apocalypse, Science Says

Almost everyone would be zombie chow within 100 days, according to disease model

Pictured above: Everyone, give or take a hundred days. — Christophe Simon, AFP/Getty Images
Jan 09, 2017 at 5:40 PM ET

In the face of an apocalypse, it’s no doubt tempting to think you may be one of the exceptional few to endure. When it comes to zombies, though, it seems that, nah, we’d all likely be toast within a hundred days — at least according to a quirky study recently published by students at the University of Leicester in the UK.

The undergrads turned to a relatively simple model often used by epidemiologists to map out how quickly diseases spread and applied it to your now-typical Hollywood zombie virus outbreak. Under the assumptions that a single zombie kicks things into gear on day 1, and that each zombie had a 90 percent chance of infecting a new victim once a day, they estimated that it would only take 20 days before the infection became noticeably widespread within a population. From then on, humankind would be exponentially engulfed by the zombie plague. By day 100, only 181 survivors total would still be around.

And even if you fudged the numbers so that it takes longer for the infection to take hold in generally separated parts of the world, we’d still be left with only 273 survivors by 100 days time.

“Wait,” you might protest, “What if we had been preparing all this time by exhaustingly re-reading Max Brooks’ ‘The Zombie Survival Guide?’”

Well, in a separate paper, the students actually accounted for the possibility that people would fight back by removing the heads or destroying the brains of their zombie attackers. They also decreased the chances of a new zombie infection each day, to account for the growing familiarity survivors would have with avoiding bites, as well as figured that some amount of new people would still be born in zombieland. To their great surprise, they found that maybe, just maybe, people might be able to outlast the apocalypse under those conditions, albeit at the cost of losing nearly everyone on earth.

Assuming that zombies only had an average lifespan of a year (up from 20 days in the original model), they estimated that it would take a little over 3 years to fully wipe them out, and another 27 years before the human population started steadily climbing up back again.

Of course, all this is presuming that we’re playing by the generous zombie rules established by most current media portrayals like Danny Boyle’s “28 Days Later,” which treat zombies as an infection that spreads via bite or blood. If we harken back to the granddaddy of zombie canon — George A. Romero’s original “Dead” trilogy — in which people become zombies simply by dying of any cause, then things get more dire.

In any case, should you ever hear shambling feet and pained groans aching for brains outside your bedroom window, you might want to get your affairs in order. Chances are, no matter what kind of zombies you’re facing, you won’t make it.