The biology, ecology, and biochemistry of Cthulhu and Godzilla
H. P. Lovecraft's character Cthulhu is a gargantuan life-form that is clearly animal-like, if not a true terrestrial animal (his origins are presumed to be extraterrestrial). He is enormous, about the size of Godzilla or larger. If he is an air-breather -- and from the stories it's clear that his biochemistry requires oxygen, just as ours does -- given his massive size and the cube-square law, it isn't clear how he is able to get enough oxygen from our atmosphere to function. That atmosphere is about 21% oxygen by volume, which is not enough to allow invertebrates such as insects and spiders to grow beyond their present-day sizes, because their respiratory systems and processes simply can't assimilate enough oxygen from the atmosphere to permit that. Yet, like Godzilla, Cthulhu's respiratory system easily manages to extract enough oxygen from our atmosphere to function so well that he can run down fast ships and tear apart any obstacle between himself and whatever he is focused on. The question is, how?
In spite of his tentacled appearance, Cthulhu is clearly an air-breather. Otherwise he could not have been imprisoned underwater, in the sunken city of R'lyeh (Godzilla, of course, doesn't have that problem, as he has voluntarily made a home for himself on Monster Island), nor could he emerge from R'leh when the stars are right to destroy civilization, kill off most of humanity, and enslave the ragged remnant of our species. So he's an air-breather, all right, and he needs a lot of oxygen to power his tremendous bulk and deploy it so handily.
But how could he do so if his respiratory system resembles that of today's Earth-normal animal life, whether vertebrate or invertebrate? The open respiratory system of insects just couldn't do the job, and even the book-lungs of arachnids would be useless for the job -- the reason that even during the Carboniferous, when atmospheric oxygen levels approached 35%, that terrestrial arthropods got no bigger than about three or four times the size of the most massive of today's terrestrial arthropods. (And never mind marine arthropods -- Cthulhu is not adapted for marine life in the way that, say, crustaceans and molluscs are, with their gills and copper-based blood chemistry.) Cthulhu's blood is almost certainly iron-based, like that of humans and other terrestrial vertebrates. But how could it possibly be an efficient enough carrier of oxygen to provide all the oxygen necessary to power the fantastic chemical reactions in his body necessary to allow him to move as he does or even just survive, given his huge bulk?
Part of what allows life of any kind to exist on Earth at standard temperatures and pressures are enzymes. These facilitate biochemical reactions at rates which would not be possible in standard conditions. Without them the reactions necessary to maintain the metabolism of any Earthly organism could not take place in less than many years, even centuries. With them, however, those reactions are completed within small fractions of a second, enabling the body to carry out all the myriads of chemical processes it must if life is to be sustained and the organism is to be able to do all the things necessary to its existence. Within the cell, they take place in their thousands and tens of thousands every second, doing all the things necessary to the cell's survival and its ability to replicate. They power neurons in the brain, myofibrils in the muscles, the tissues of the endocrine glands, the osteoblasts that form bone, the osteocytes that comprise bony structures, the osteoclasts tasked with bone resorption, and the cellular machinery of all the rest of the body's tissues and organs. Without enzymes, however, none of this endless, frantic activity could take place at a pace necessary to sustain life. Is it possible that Cthulhu's body possesses enzymes that make his biochemical processes, especially those of oxygen acquisition, transport, and use fantastically more efficient than any in the biochemical arsenal of any form of native Earthly life?
And then there's the matter of air pockets. Birds' bones are honeycombed with air pockets, and the same was true of many dinosaurs, perhaps all of them. That sort of structure is not seen in mammals, amphibians, fish, or reptiles, each of which have evolved and adapted in different ways to utilize atmospheric gases. Mammals became viviparous at some point in the Triassic, perhaps as a way of protecting their embryonic offspring from the extremely challenging conditions that held on land then, and ensuring that they would have enough oxygen to properly complete their development. Reptiles and amphibians continued to lay eggs, and their respiratory systems did not seem to change much even in the face of the end-Permian catastrophe and the low-oxygen conditions of the Triassic and much of the Jurassic -- and their modern descendants are either herbivores or ambush predators, not gifted with the terrible swiftness and agility of Mesozoic animals such as Allosaurus and Utahraptor. Perhaps Cthulhu's enormous body contains equally enormous air-pockets resembling those of birds and their theropod ancestors.
And why not both? After all, Cthulhu isn't native to Earth. He can breathe our air and consume our flesh -- the latter guarantees the former, for otherwise his biochemistry couldn't handle such food at all -- but there are no known limits to the sort of tricks his biochemistry is capable of, or the devices his morphology might include. His biochemistry is certain to be far more efficient than ours at acquiring and using oxygen to meet his metabolic needs, which strongly implies a biochemical solution to the problem, e.g., enzymes of a sort that native Earth life probably doesn't have, and possibly others, as well. And there is nothing that militates against the possibility of many of his tissues being honeycombed with air pockets -- for one thing, that sort of honeycomb structure can actually make connective tissue such as bone or other supportive structures much stronger than if they were solid, and for another, his vast abdominal cavity could perhaps include chambers that store large amounts of air so that they are available during times of high demand, when breathing along can't get the oxygen into his system he needs.
However, none of that can be absolutely laid to rest without a complete dissection or autopsy of the body of the organism under discussion, who is not likely to be taken down for that purpose without a battle exceeding the horrors of World War III. So in the meantime we must conclude, with Inspector John R. Legrasse, that "Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn." And please don't ask me about Godzilla -- nobody wants to know about Godzilla!
In spite of his tentacled appearance, Cthulhu is clearly an air-breather. Otherwise he could not have been imprisoned underwater, in the sunken city of R'lyeh (Godzilla, of course, doesn't have that problem, as he has voluntarily made a home for himself on Monster Island), nor could he emerge from R'leh when the stars are right to destroy civilization, kill off most of humanity, and enslave the ragged remnant of our species. So he's an air-breather, all right, and he needs a lot of oxygen to power his tremendous bulk and deploy it so handily.
But how could he do so if his respiratory system resembles that of today's Earth-normal animal life, whether vertebrate or invertebrate? The open respiratory system of insects just couldn't do the job, and even the book-lungs of arachnids would be useless for the job -- the reason that even during the Carboniferous, when atmospheric oxygen levels approached 35%, that terrestrial arthropods got no bigger than about three or four times the size of the most massive of today's terrestrial arthropods. (And never mind marine arthropods -- Cthulhu is not adapted for marine life in the way that, say, crustaceans and molluscs are, with their gills and copper-based blood chemistry.) Cthulhu's blood is almost certainly iron-based, like that of humans and other terrestrial vertebrates. But how could it possibly be an efficient enough carrier of oxygen to provide all the oxygen necessary to power the fantastic chemical reactions in his body necessary to allow him to move as he does or even just survive, given his huge bulk?
Part of what allows life of any kind to exist on Earth at standard temperatures and pressures are enzymes. These facilitate biochemical reactions at rates which would not be possible in standard conditions. Without them the reactions necessary to maintain the metabolism of any Earthly organism could not take place in less than many years, even centuries. With them, however, those reactions are completed within small fractions of a second, enabling the body to carry out all the myriads of chemical processes it must if life is to be sustained and the organism is to be able to do all the things necessary to its existence. Within the cell, they take place in their thousands and tens of thousands every second, doing all the things necessary to the cell's survival and its ability to replicate. They power neurons in the brain, myofibrils in the muscles, the tissues of the endocrine glands, the osteoblasts that form bone, the osteocytes that comprise bony structures, the osteoclasts tasked with bone resorption, and the cellular machinery of all the rest of the body's tissues and organs. Without enzymes, however, none of this endless, frantic activity could take place at a pace necessary to sustain life. Is it possible that Cthulhu's body possesses enzymes that make his biochemical processes, especially those of oxygen acquisition, transport, and use fantastically more efficient than any in the biochemical arsenal of any form of native Earthly life?
And then there's the matter of air pockets. Birds' bones are honeycombed with air pockets, and the same was true of many dinosaurs, perhaps all of them. That sort of structure is not seen in mammals, amphibians, fish, or reptiles, each of which have evolved and adapted in different ways to utilize atmospheric gases. Mammals became viviparous at some point in the Triassic, perhaps as a way of protecting their embryonic offspring from the extremely challenging conditions that held on land then, and ensuring that they would have enough oxygen to properly complete their development. Reptiles and amphibians continued to lay eggs, and their respiratory systems did not seem to change much even in the face of the end-Permian catastrophe and the low-oxygen conditions of the Triassic and much of the Jurassic -- and their modern descendants are either herbivores or ambush predators, not gifted with the terrible swiftness and agility of Mesozoic animals such as Allosaurus and Utahraptor. Perhaps Cthulhu's enormous body contains equally enormous air-pockets resembling those of birds and their theropod ancestors.
And why not both? After all, Cthulhu isn't native to Earth. He can breathe our air and consume our flesh -- the latter guarantees the former, for otherwise his biochemistry couldn't handle such food at all -- but there are no known limits to the sort of tricks his biochemistry is capable of, or the devices his morphology might include. His biochemistry is certain to be far more efficient than ours at acquiring and using oxygen to meet his metabolic needs, which strongly implies a biochemical solution to the problem, e.g., enzymes of a sort that native Earth life probably doesn't have, and possibly others, as well. And there is nothing that militates against the possibility of many of his tissues being honeycombed with air pockets -- for one thing, that sort of honeycomb structure can actually make connective tissue such as bone or other supportive structures much stronger than if they were solid, and for another, his vast abdominal cavity could perhaps include chambers that store large amounts of air so that they are available during times of high demand, when breathing along can't get the oxygen into his system he needs.
However, none of that can be absolutely laid to rest without a complete dissection or autopsy of the body of the organism under discussion, who is not likely to be taken down for that purpose without a battle exceeding the horrors of World War III. So in the meantime we must conclude, with Inspector John R. Legrasse, that "Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn." And please don't ask me about Godzilla -- nobody wants to know about Godzilla!