An international multimedia phenomenon since 1954, the Godzilla franchise returned on the big screens just in time for its 60th anniversary last year, with a rather surprising story including some new exotic characters. The classic “monster against the city” scenario is twisted and turned so that the iconic creature loses the “bad guy” label to some new, strange and terrifying appearances that almost steal the show. Godzilla wins the fight and successfully retains its title of “king of the monsters”. But its enemies win something greater – the attention of pop science geeks interested in decoding their unconventional workings.
The characteristics of the titular creature doesn’t allow for too much scientific debate, as you’d expect from a giant, aquatic reptile, that walks bipedally on land and produces some form of destructive plasma/atomic ray from its gut (what even is that?!). The other guys, on the contrary, are a far richer source of controversy and offer so many possibilities for extrapolation.
According to the film makers, the main idea behind the Massive Unidentified Terrestrial Organisms, or MUTOs, is that they are entirely unique and original monsters, unlike anything that has ever roamed the Earth. So let’s closely examine the final products of an entire year’s worth of work to see to what extent their goal is achieved.
The first impression the MUTOs make is that of a general arthropod: relatively small, roughly triangular head such as that of a mantis and multiple pairs of long, thin legs. However, apart from some superficial sections briefly visible on the male MUTO’s underside during a short scene, they lack segmentation, which is a basic characteristic of arthropods. Instead of clear delimitations of head, thorax and abdomen, the monsters are provided with unitary, muscular bodies reminding us more of a vertebrate constitution.
But the resemblance ends here, as one of the key rules of vertebrates is broken: the MUTOs possess far too many limbs. The male has four legs and the fourth pair of limbs modified into fleshy, bat-like wings inspired by a stealth aircraft. The flight ability of a creature of that shape and size is very questionable, but fictional monster aerodynamics involves a painful amount of biophysics and mathematics that would push this article dangerously close to the edges of boredom.
Added to the substantial difference in size between the male and female MUTO, this detail unveils a completely unknown territory of sexual dimorphism. In our very own reality, female-biased differences for size are very common in insects and spiders and sometimes encountered in reptiles, with females green anacondas Eunectes murinus holding the vertebrate record at five times bigger (in both length and girth) than their male counterparts. Male-biased sexual dimorphisms for flight are known from some species of moths, such as the tussock moth, Orgyia recens or the winter moth, Operophtera brumata, where the females are not only flightless, but also greatly reduced in size.
With this combination of dimorphisms, the film makers have unintentionally opened many speculation possibilities regarding the MUTO reproductive biology at a species level: a sex-ratio biased towards small males ranging across wide territories and fiercely competing for a naturally low number of large, localized females. The film doesn’t give enough information to check these assumptions, but what it does insist upon is the signals used by the creatures to communicate.
Echolocation, also known as “biosonar”, is the process through which an animal computes its surroundings by emitting sounds (often imperceptible to the human ear) and analysing the echoes. Bats are indeed the grandmasters of echolocation. MUTOs use echolocation to produce mating calls, which raises two problems of validity. Firstly, while extremely useful for navigating through the environment, the biosonar is just not meant to convey information about the signal producer, therefore evidence of communication as a function of echolocation is next to nonexistent. Secondly, the distance to which animals can detect objects through echolocation is limited. In the film, the calls produced by the male MUTO in Japan are intercepted by the female still encased in a spore, deposited in a radioactive waste containment facility in Nevada. So the signal travels undisturbed across the ocean and through thick walls of maximum security buildings. Not going to happen.
Defying the rules of acoustics, the two creatures travel towards each other, wreaking havoc along the way and successfully initiate a courtship behavior widespread among the insects and spiders they vaguely-but-not-really physically resemble. Nuptial gifts are an important component of reproduction, serving various functions, such as a nutritional supplement, ultimately benefiting the offspring or keeping the female busy eating while the male transfers sperm. The male MUTO conforms to this model and, during a heart-warming scene overloaded with affection, presents the female with a delicious nuclear bomb for her to lay eggs around, providing a food source for future baby MUTOs. Because, that’s right, they feed on radiation.
The science-fantasy entertainment industry is already saturated with unnatural phenomena attributed to radiation. With last year’s Godzilla, this is taken one step further and, although it might look like a solid base to build fictional monster ecology upon, it’s got some unforgivable flaws. According to the film, Godzilla and the MUTOs alike evolved in a period in Earth’s history when environmental radiation was ten times higher than in the present day and they adapted to exploit it as a food source. No matter on which side you turn this idea, it does not make the remotest sense.
Radiation levels were indeed much higher early in the planet formation: 7.85 times than the present day. This is only one of the characteristics of the young, hostile Earth, which prevented anything more complex than bacteria from evolving for many hundreds of millions of years. Radiation disrupts cellular processes and causes mutations, sometimes incredibly nasty, in carbon-based life forms as we know them. Some organisms might have better repair mechanism, therefore enabling them to withstand higher levels, but nothing comes even close to harvesting it as a food source. Sorry, Gareth Edwards and the team, but this doesn’t work at all.
Not that the rest of the collection of traits borrowed from real organisms would work incredibly well in the same creature, but it is actually a good attempt at delivering something new to the general public ever hungry for sensation. Overall, the MUTOs satisfy the zoologist nerd, offering enough opportunities to both shout at the screen in disappointment or slowly clap their hands in a “I see what you did here!” manner.