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Geoffrey Hart

Food Webs: A Parable

by Geoffrey Hart

Those who survived the early days of the apocalypse received a short, sharp lesson: that there’s an ecology of interlocking food webs in nature, and just because you don’t know the rules that govern such systems, it doesn’t mean they don’t apply to you.

When the zombies began to appear, the government initially assumed it was nothing more than LARPing run amok — never mind the vigorous denials by LARPers once they got over their surprise that the government knew who they were. But as the body count — and the bodies — began rising, living corpses began accumulating in hospital ERs and morgues. It soon became difficult for the government to deny that something bad was happening — not that this prevented them from denial. The final straw came when the first members of the 1% started losing close relatives. Then the government sat up and took notice.

The National Guard was mobilized; then, when they proved insufficiently numerous for the task, the army. The lessons learned from SARS and the Covid-19 pandemic of 2020 helped slow the plague’s spread, but it took precious weeks before the government understood that this situation was qualitatively different. With outbreaks like SARS and Covid-19, control could be achieved through curfews and travel restrictions. The first zombies were also one-percenters, though with a very different spin on the phrase, and like their wealthier namesakes, they ignored curfews and travel restrictions.

Whatever a zombie’s origin, stopping one required blasting them into tiny fragments. Explosive devices, improvised or otherwise, worked, as did shotguns loaded with buckshot. (Suggestions had been circulating for some time about adopting the same approaches for one-percenters in the original sense of the phrase. Whether that inspired the zombie control program, we must leave to the historians.) Unfortunately, though blasting a zombie into bits stopped the vector, it had little effect on the pathogen; on the contrary, dividing an infected corpse into a great many small bits just spread the pathogen faster. First-responders learned the hard way that the residues had to be incinerated, and quickly. It took time to scale up production of flamethrowers and incendiaries that would be safe for expensive property, not to mention for civilian use, yet still effective for crowd control. Only then did the surviving sanitation workers begin to significantly slow the plague’s spread.

While all this was going on, researchers were doing what researchers always do: competing to be first with the Nobel Prize–­winning solution: isolating the pathogen and figuring out how to block it. The winner — so to speak — was the Romero research lab at Columbia University. Unfortunately, in their zeal to win the race, they failed to follow containment protocols as scrupulously as might have been desirable, and dead scientists are ineligible for the Nobel. (The eligibility of living dead scientists remains a problem for future generations. And it looks like there will be future generations, if we’re lucky and careful.)

By the time the Romero lab’s notes were recovered from offsite backups — the lab itself having been sterilized too zealously by terrified National Guardsmen — several other labs had identified the pathogen — a weaponized, broad-spectrum strain of the entomological zombie fungus Ophiocordyceps unilateralis with a dash of bacterial quorum sensing thrown in for good measure. Once the geneticists got involved, the footprints of CRISPR technology were unmistakable, but whether one blamed the Iranians, Russians, North Koreans, or Earth First! depended largely on one’s position within the political spectrum; the available evidence provided no smoking guns. When the plague broke out in Russia, then Europe, no one was sure whether this was karma or just plain bad luck.

The mechanism of the disease’s spread was, as is often the case, devilishly simple: Fungal spores blown on the wind were inhaled or entered the body through undercooked food or a wound. They incubated overnight, leading to a raging fever, and by late the next morning, the host was brain-dead or nearly so  — and very hungry. Given the anaerobic nature of the host environment — a living but non-breathing corpse — the fungus had to survive in a metabolically inefficient manner, and therefore needed enormous quantities of energy to function and reproduce. Thus, it drove its hosts to obtain more and ever more food. About the only good consequence was that the enormous energy expenditure made the zombies easy to detect at night; with infrared scopes, they blazed like beacons.

A fortunate side-effect of this macabre infection was that it diverted the host’s metabolism towards feeding and reproduction, and away from anabolism and immune responses. As a result, the host quickly began to decay. Each zombie gradually slowed down as its muscle fibers stopped functioning, leading to rapid depletion of its energy reserves once it could no longer catch and pull down living prey. Finally, when its decayed limbs could no longer drag it along the ground in pursuit of prey, the zombie stopped moving. But as soon as its host became immobile, the fungus shifted strategy towards reproduction, and the host quickly sprouted fruiting bodies. Spores released onto the wind, or consumed by carrion birds and spread via their feces — or by their bites, when the fungus infected them too — renewed the infection cycle. Bites and scratches that broke the skin also worked, and were far more common in the early days of the plague, before we’d learned to find secure refuges and keep the zombies beyond arm’s length.

The spread would have been slower for a non-windborne plague. Sure, you could wear a facemask to exclude the spores, and that worked for a time. It kept me alive long enough to write this. But survivors had their needs too: you had to take your mask off some time, whether to eat, to visit the dentist, to make love with your spouse or a convenient stranger in defiance of death — or just to breathe freely when the claustrophobia the masks created or confinement to our homes overcame the drive towards self-preservation. If you were unlucky, you woke one day as a zombie and had a few minutes or perhaps an hour to realize the horror of what was happening to you. Or perhaps you woke with your loved ones staring hungrily at you out of feverish, already-decaying faces right before they sank their teeth into you. Fungal diseases were notoriously difficult to treat, and this one had been engineered for immunity to the available antifungals, making treatment next to impossible.

The government found a solution. It was the Fish and Wildlife Service, operating with — ironically — a skeleton staff after yet another round of budget cuts, that proposed it. They understood intimately that everything in nature has something that eats it. In this case, they noted that wolves were highly efficient carnivores and had worked wonders in areas such as the Greater Yellowstone Ecosystem where they’d been released. Captive breeding of wolves was a proven technology, and unlike most other large predators, wolves were happy to consume dead meat if their preferred prey weren’t available — as was the case when they were released into the country’s plague-stricken cities. Moreover, their immune systems were sufficiently robust to handle the kinds of pathogens that naturally infected the corpse of (say) a moose that had sat out in the sun for the several days it took a pack to consume it. If the wolf cubs were raised on zombie flesh, then once they were released into an urban environment, they recognized the zombies as a food source, and quickly became highly efficient predators of zombies.

Within a year, thousands of wolves had been released into the worst-affected cities, where they rapidly began thinning the zombie population and breeding more wolves. An unexpected benefit of this approach was that, as was the case with their traditional prey, the wolves favored the slow-moving zombies, which were easier and less risky to bring down; this also slowed the spread of the plague by preventing the living dead from progressing to the decay stage, when fruiting bodies would form. There was still no progress on developing a vaccine or an effective antifungal, but at least the rate of new infections stabilized at a survivably low level.

The government had hoped the cities would become livable once more, but they’d reckoned without an inconvenient consequence of their desperation to implement any control mechanism that could give them a fighting chance. Of course, those of us who lived outside the big cities could have told them what was going to happen: at some point, thousands of starving wolves that had been trained to consider upright bipedal organisms as their natural prey would run out of the food they’d been trained to hunt. Then, wolves being clever dogs, they would find a replacement.

But that was a problem for another day.



Geoffrey Hart works as a scientific editor, specializing in helping scientists who have English as their second language publish their research. He also writes fiction in his spare time, and has sold 24 stories thus far. Visit him online at