Post provided by Ben Whittaker & Chloe Robinson

“There’s no such thing as monsters” you whisper to yourself while creeping into bed, regretting your decision to spend the whole night watching horror movies. Thunder rumbles in the distance as rain begins tapping on the windowpane. The lamps flicker and black out. “Just a power cut” you chuckle nervously, clutching the bed covers up to your face. Laid in the darkness, you become aware of every creak and bump echoing throughout the empty house. But what is that shuffling sound? Is it coming closer? The shuffling stops right outside your bedroom door, which gently rattles and then slowly groans open. A dreadful chill runs down your spine. “There’s no such thing as monsters?”

In this special Halloween post, blog editors Chloe Robinson and Ben Whittaker conjure stories of the real-life monsters that have inspired movie makers. Continue reading at your own peril and be warned that Methods in Ecology and Evolution holds no liability for ensuing nightmares, hauntings, or extra-terrestrial abduction.  

“Unclouded by conscience, remorse, or delusions of morality” (Xenomorph, Alien 1979)

After crash-landing on a distant moon, the crew of the Nostromo spacecraft search across rocky wastelands for the source of a distress signal they’d been sent to investigate. They locate an abandoned spaceship and discover a misty chamber filled with egg-like capsules. One of these eggs hatches to release a Facehugger, which tightly attaches itself onto the face an unsuspecting crew member. Back aboard the Nostromo, the infected man receives medical care and the crew return to normal duties. That is until the aptly named Chestburster erupts from the body of the infected crew member and escapes into the ship. Chaos and gore ensue as the creature morphs into an adult Xenomorph and begins picking off the crew one by one, growing to complete its life cycle. All seems lost until Ripley (the last surviving crewmember) carries out a daring mission to destroy the alien before it can infect a new human host.

The Xenomorph has a complex life cycle, though each stage shares disturbing similarities with real world counterparts. The tongue-eating louse is a marine isopod and a strong contestant for the title of world’s grossest parasite. Larval lice swim through the gills of unsuspecting host fishes, crawl up into the mouth, and then attach themselves onto the tongue to feed on blood until the tongue tissue dies. The louse then sits as a replacement tongue and continues feeding on the host’s blood until death. Unlike the Facehugger these parasitic lice do not infect humans, though they do infect the fish we eat and would make a gut-churning addition to any dinner plate. 

The alien Xenomorph (centre: Wookieepedia) undergoes a life cycle with similar real world counterparts. Tongue-eating lice (top; credit: Andy Heyward) and parasitoid wasps (left; credit: Kim Hoelmer) share biology with early life stages, whereas, moray eels (right; credit: khaolakexplorer) share anatomy with adults.

The Chestburster erupting from its human host is perhaps one of the most iconic scenes in the cinematic history of horror, yet this scene is based on the grizzly fate of many insects. Parasitoid wasps lay their eggs inside hosts (typically caterpillars), which will then hatch inside the host’s flesh and feed on its blood as they grow. When the parasitoids are ready to emerge, they release enzymes to paralyse the host and then chew their way out. These sophisticated host-parasitoid interactions are the product of coevolution, with the wasps developing resistance to host defences over just a few generations to maintain high levels of infectivity. The wasps are even being used as a form of pest-control to reduce crop damage by insect pests.

One of the stranger aspects of the adult Xenomorph is a set of double jaws, with a smaller mouth extending out from the larger mouth – much to the fatal surprise of the Nostromo crew. A similar biological weapon can be found among tropical coral reefs. Many teleost fish rely on water suction to swallow their prey, however, elongated slim species cannot create much suction force which stunts their ability to hunt. Pharyngeal jaws are the ace card of moray eels, which launch these specialised teeth-covered gill plates out from their mouth to capture prey without using suction force. This allows these eels to hunt among narrow crevices or even up onto the shoreline. Whether it be tongue-eating lice, parasitoid wasps, or moray eels, evolution has formed strange living creatures which rival the darkest monsters from fiction.    

“Feed me! Feed me! Feed me Seymore!” (Audrey 2, Little Shop of Horrors 1986)

Times are hard in downtown Skid Row (New York) and naïve Seymour Krelborn purchases a mysterious exotic plant in hope of attracting customers to his failing floristry business. Naming this new curiosity “Audrey 2”, Seymour makes the unpleasant discovery that he must feed his enigmatic bloom with fresh human blood. As the sinister plant thrives it draws in customers from far and wide, and Seymore becomes a local celebrity. However, the balance of power shifts as Audrey2’s appetite grows beyond Seymore’s control. Eventually Seymore learns of the plant’s extra-terrestrial origins and its malicious plan for global domination.  

Botanical with a bite! Audrey 2 plays with its human prey (credit: Thrillist/Warner Bros).]

Carnivorous plants, including venus flytrap, sundew, and pitcher plants, have evolved trapping mechanisms to catch unsuspecting prey and absorb nutrients while they are slowly digested. Thankfully, Audrey 2 is the only known carnivorous plant with an appetite for humans, though in reality these plants feed on bigger prey than just unsuspecting insects. Pitcher plants in Canada have been found snacking on salamanders, while skeletons of frogs and lizards have been discovered inside Malaysian pitcher plants, and even small rodents and birds occasionally feature on the menu.      

Audrey 2’s bloodlust is only a part of what makes this monster so terrifying. The nightmare of an alien plant invading cities and subjugating entire ecosystems is not only plausible, but likely happening in your local neighbourhood. Species like Kudzu, Himalayan balsam, and Japanese knotweed are all examples of invasive plants which are spreading at alarming speeds and damaging native ecosystems. These invasive plants outcompete native species for resources which reduces the overall diversity of floral, pollinator, and grazer species. Furthermore, some invasive plants show greater ability to adapt to climate change, which might tip the balance in favour these aliens over the coming years. With Audrey 2’s diabolical descendants wrapping root and tendril around Earth’s ecosystems, this is one monster who keeps us wide awake at night.     

This is not a war. This is an extermination.” (Tripod alien, War of the Worlds 2005)

Ever get that feeling you’re being watched? Well according to this movie, you’re not entirely paranoid. Intelligent extra-terrestrials had been watching Earth for a while, decided they like the look of what they saw and set off from Mars to take over the Blue Planet. After arriving in a bolt of lightning, these “tripod” aliens attack major cities and begin terraforming Earth (someone’s got to – I guess), using human victims as compost. The mulch-loving Martians operating these tripods ultimately meet their demise through lack of natural resistance to our planet’s many microbes.

Australian box jellyfish (left, credit: Yanagihara & Shohet (2012)) and “Tripod” alien artist depiction (right, credit: David Simon).

The tentacular nature of these destructive, probing alien tripods was by no means incidental. Their appearance was actually inspired by jellyfish, mainly to present the notion that they were moving gracefully as if underwater. Despite the clear size difference between even the largest Lion’s mane jellyfish and the alien tripods, both can pack a punch. In the same way that the tripod’s ‘limbs’ were used to capture people and feast on their innards, jellyfish use their tentacles to sting and capture prey such as small fish species and crustaceans. The modes of locomotion between the tripods and jellyfish may differ (‘leg’ versus bell propulsion), however they are alike in the fact that both incapacitate humans. The Australian box jellyfish (Chironex fleckeri), is considered the most venomous marine animal. This species has body sizes reaching up to one foot in diameter and thick, bootlace-like tentacles up to 10 feet long (eek!). Box jellyfish possess the ability to actually swim instead of being carried along by ocean currents, (albeit only at 4 knots) and possess clusters of eyes – setting them apart from any other jellyfish species in the world. Whether it be beast or machine, both are clearly aliens in the terrestrial human world and frankly, we are not sure which we’d rather encounter for real…

Beast with the psychology of a lost toddler gone bezerk” (Clover, Cloverfield 2008)

We are closing this biologically bizarre blog post with the pièce de resistance of movie monsters. This final film features a farewell party that is rudely interrupted by an ‘earthquake’ (spoiler: it isn’t an earthquake), resulting in the beheading of the Statue of Liberty. The earthquake is in fact a Godzilla-like, flea-ridden monster wreaking havoc on Manhattan. As most people evacuate the city, a group of friends run into the danger to help rescue a fallen comrade, resulting in predictably dire consequences.

This reptilian beast lives up to its 350 million year old ancestry, with the final post-credit words of the film stating, “It’s still alive”. However, Clover is a far cry from a simple reptile, and instead represents a mishmash of wildlife, presented in a Frankenstein-like fashion. Taking inspiration from ‘biological plausibility’, Clover is inspired but no less than 5 different species.

Starting from the top, Clover has no ‘true’ ears and instead has a membrane designed to resemble the tympanic membrane in frogs and toads. When sound reaches this tympanic membrane, it vibrates the fluid in their inner ear, sending an electrical signal to the frog/toad brain, allowing them to interpret the sound. Not all frogs and toads however have a tympanum – some species use their mouth and lungs to listen to and transmit sound. With a tympanum on Clover, no doubt it could hear people coming from a mile away and was a great advantage for sieging the city. The mouth of Clover is no doubt one of the most unsettling features of this monster, and no surprise the inspiration for this set of gnashers was inspired by two equally formidable species – the piranha and anglerfish. Poor piranhas have an undeservingly bad reputation for their teeth, however, these interlocking teeth are incredibly efficient at stripping meat from bone. A recent study also found that beneath their pearly whites are an entire new set of teeth, meaning if there is damage or wear to a single tooth, they replace the whole set a row at a time. There is no doubt that with this set of teeth, Clover would have had zero trouble making a meal out of Manhattan.

Clover (centre; credit: Wikizilla) is composed of many different species. Teeth are inspired by anglerfish (top left; credit: David Shale/Minden Pictures) and piranha (bottom left; credit: Shore Excursions Group), panicked behaviour and overall body colour inspired by rampaging elephants (top; credit: AP ), panicked expression inspired by horses (top right; credit: EquiManagement) and ‘ear’ membrane inspired by frog/toad tympanic membrane (bottom left; credit: Carl Howe).

The more subtle features such as the eyes were inspired by ‘a spooked horse’ and the overall panicked behaviour was meant to mimic an elephant rampaging in a city. The aim of these links were to portray that Clover was in fact more of a lost and scared being in a strange place as opposed to a blood-thirsty monster. In fact, during the film, there were more lives lost to the rampant ‘alien fleas’ compared to the damage created by a spooked Clover. These fleas, or ‘Human Scale Parasites’ were dog-sized with spider-like legs and ant pincers (again, eek!). The toxins injected into humans from these flea bites caused bleeding of the eyes and eventual… explosion – side effects which are not far removed from the bite effects of a boomslang snake.

Goodnight and sleep tight

We hope you enjoyed this exploration into the darker side of the natural world, and wish you pleasant festivities however you choose to celebrate the autumnal season. For more content on the latest methods in ecology and evolution check out the MEE blog, podcast, and social media.