Worldbuilding 101: Alien biologies
Another post by your one favourite alien Limax, Vivian! This time it is about alien biologies! Won’t tell mine just yet 😏
Alien
Alien in this context when I speak about biology means “Not from Earth– it is pronounced E-arth right? Anyway, there are many ways to do this, and I will give a few classes and methods to do so, along with some pros and cons on various methods plus how they work.
Nature is the best source for inspiration
No matter how strange an idea you ever think you’ve come up with for a species is, I promise you that there is some life form on earth that is even weirder. I mean it, literally. There are so many strange things that have existed and continue to exist. There are dozens of ways of breathing, there are at least a dozen ways to deal with blood, and there are a myriad of ways to divide functions between organs. The vertebrate’s division of biological functions and labour into organs is not the only one but only one of at least several dozen. Here are just a few examples:
Sequential hermaphroditism: some animals are born one sex and then change to the other later in life
Open circulatory systems: they don’t have veins and arteries but instead blood and other bodily fluids are mixed and pushed around by the heart.
Cloaca: sex, eggs, sperm, faeces, urine, everything goes out the same orifice, nice eh?
More than two sexes or even one: what it says on the tin.
Chewing structures: some are neither vertical nor use teeth–look at insects for example, circular mouths exist as well.
Agelessness: some organisms will not die unless killed externally.
These are a very small fraction of all that exists.
Humanoid
We are all humanoids, even I, being alien! I would prefer to call it “Limoid”, but you know, you humans always gotta make it all about yourselves. 🙄 Oh well, while I am stuck here, I gotta use your language, so humanoid it is. Anyway, what does “Humanoid” mean? Broadly speaking, it can be understood as to say any body structure that externally adheres to having two legs, two arms, a main torso with a head on top, and that uses bipedal locomotion. That is, the hands or arms are not used for normal locomotion.
Why?
I can hear you say
Oh my Divinum, Vivian! You’re all about creativity in worldbuilding, yet you are now talking about one of the most overused tropes in worldbuilding history! There are more interesting things than this, you’re losing your edge!
Thank you for thinking that I do have a worldbuilding edge. 🙇♀️ Much appreciated! Yes, I like a lot of crazy things, but sometimes, not crazy works too! There is a reason why humanoids are so popular. We humanoids, especially you humans, become more empathetic toward beings that recognise us. How much more do you love your cat or dog, compared to an insect or a spider? Did a lot of you suddenly shiver at the thought of a large crawling spider on your table? What if it is big enough to pounce onto your hand? Yeah, it starts getting disgusting and such. In some stories, having these crazy weird alien ones work because that is the point of the story! But for stories where we are meant to empathise with aliens more and do so quickly, humanoid is the way to go because they can be different enough to be interesting, but close enough that we relate.
Spice it up
Just because we make it humanoid doesn’t that mean we gotta make it boring! There are infinitely many ways that we can spice up a humanoid design. Keep in mind that the humanoid shape is mostly an external and facial one where we can change various things to make it interesting. I will go over a few areas where it can be done, but it is not exhaustive. I will likely make blog posts on each and every one of these alone in addition to practicums and more, but here’s the basics to give you all some ideas.
Senses
What are the normal senses you think of?
Touch
Sight
Smell
Hearing
Taste
Sure, we can technically split these up a lot more, and there are about a dozen others you are not aware of most of the time, but let’s keep it simple and focus on the nigh constantly aware ones and sensible groupings which is what we got here.
Notice anything? Out of all the senses, only one is not exclusive to the head. Touch can be sensed everywhere you have skin. The technical term for this grouping of senses is “cephalization”, or the evolutionary tendency for senses that assist in hunting and eating to be located near the mouth and where the brain develops to minimise latency, which is the time between when a sensory organ picks up some stimuli and the brain receives the electric input from the nerves. But! This is not always the case. A lot of cephalopods and other animals are actually capable of tasting with their arms and other limbs in order to judge what they have grabbed before putting it into the mouth. Imagine if you could dip your finger into something and know the flavour instantly! Neat, huh? Please don’t do it anyway, kinda disgusting you’d put your finger in, what is wrong with you!?
But the thing is, a lot of animals have more than these five senses, yes MORE! And wider ranging ones than yours. You hear from 20hz to 20khz, many hear more. You see light from 400nm to 700nm, insects and birds see into the 300nm range. You humans use 3 cones to see colours, there is a shrimp that uses 12 cones! The amount of cones, even if you still only do the same part of the light spectrum, can fundamentally change how colour perception works, which can be fun to imagine and play with. There are of course animals like electric eels that can sense electric fields–they can literally SENSE that you are THINKING. Because your brain is producing electricity, and thus electric fields, they can pick it up. Birds have a magnetic field sense, at least some of them, to help guide migration. The amount of senses and how to change them is enormous!
Breathing
Humanoids breathe oxygen; what more can be done? Hold up! Okay, they need to do that and likely will do it so we can interact with them easily (or not, if you want to make it difficult, which is fun too!). But HOW they breathe can differ a lot. Arthropods, for example, do NOT have active respiration, meaning they don’t pull in air and actively work to keep themselves going. They let air and diffusion do the work through stochastic processes and physics.
Land vertebrates have active respiration, so all done, right? No. Birds’ and mammals’ breathing are very different, for example. In mammals, air goes in, mixes near the blood to take in oxygen, and then all is exhaled all at once and another breath comes in. Birds are more complicated. They do it in 2 steps. They move the air that they just breathed in into one chamber of their lung, where the most oxygen poor blood encounters it first. Because it is so oxygen poor, it is hungry for oxygen, and thus can pull out what little is left in the air. Then, they inhale a new breath of oxygen-rich air into their “main” lung, where it meets up with the blood from the now-oxygen poor air, so the blood is now slightly more oxygenated than it would be for mammals. But because the air is so oxygen rich, it means the blood can still keep on taking oxygen from the air. The air from the oxygen poor chamber is then exhaled, and the cycle begins anew.
So if you are not playing with WHAT they breathe, you can play with HOW they breathe. There are many ways that can make a lot of difference if you are creative.
Chemistry
How creative can we be here? A lot. The most obvious way is blood: what metal does it use, and what colour does it get? We don’t need to get down into the nitty gritty with chemical structures (Handwavium solves that for us!), but you can look into metal ions and colours and see what could be possible. It is not 100% perfect, but it is a good estimate of the colours of blood.
What more is there? Well there are a lot of things! We can do silicon instead of carbon, sulphur too, and many others, but that can get dicey unless you want to do a lot of research or have some handwavium paste ready. An easy way to make two lifeforms, even if we assume nigh everything is identical between earth life and the alien, is chirality. What is that, you ask? Ever noticed how you cannot put a left glove on a right hand? That a right hand in a mirror looks like a left hand? This is chirality, or “handedness”. All complex organic molecules have it and creatively you’ve named them… left or right handed. Scientists are the most creative bunch! The fun thing with this is that if you met a world identical to this one, but ALL chirality was mirrored, what would happen? Unless stuff turned out to be very toxic in the new chirality, you would starve to death. Eat as much as you want, but starvation will kick in because your body is fundamentally incapable of consuming anything that is of the wrong chirality. A lot of medications do not work in the wrong chirality; it is quite important. This is an option to make it interesting among many. I will of course do more on these things later.
Digestion
Food goes in the mouth, out the backend, how can it be so difficult? Yeah, you know what I will say, sure that is how digestion generally will work, but you can divide up organs and their ordering. One thing to look up, for example, is what they eat. If they eat nutrient poor stuff, their digestive tract and system will be long and complicated. Remember cows' four stomachs? This is why! Grass is bad to eat, so they have a complicated system to deal with it. Carnivores often have a very straight forward digestive tract as that requires little work to be absorbed. Depending on what you imagine and make up, it can differ. Imagine a humanoid species that regurgitates food into their mouth to chew again before swallowing again! Okay, not the thing you want at the dining table, but hey, it is interesting!
Reproduction
Sexy time! Or is it? We can start with the elephant in the room. Do you need to have sex? Well, no! But evolutionarily speaking, it is exceedingly beneficial to have it. It allows a greater mixing of genes which not only helps speed evolution up but also helps protect against illnesses and parasites. But you know what, we are doing humanoids, so sod off evolution! We are having fun! MUAHAHAHA!
You can very well have it so that the species only has one sex that still mixes genes. This is kinda like hermaphroditism but still not quite because it is not the species having BOTH at once, it is a species ONLY having one, and thus it has to do both jobs at once. An alternative for one sex, however, is also parthenogenesis, which is a 5 dollar word for saying “giving birth without a male”, which exists in some bisexed species. One lizard has even switched completely to this. But for a monosexed species, this would entail identical clones are made with each generation.
You can of course do two sexes, it is classical, tried and true. For land vertebrates, unless they are amphibian or tied to water and such, internal fertilisation is required, same goes for having one sex, by the way. Which does mean sexy time 😏 You can still do interesting things here. The sex roles have flipped in some species, you can make the dimorphism (difference in look between sexes) so extreme that it looks like they are two different species. There are literally a collection of species where juvenile, adult male and adult female, all 3 look so different that scientists thought for ages that they had a bunch of species that lacked the other two until they finally realised, they are in fact simply that extreme in their dimorphism.
While in most evolutionary senses, involving all sexes when it is more than 2 literally gives no additional evolutionary gain, so it is unlikely to evolve. But hey, maybe a fluke of evolution happened in your world? I am not one to judge! (I have done this myself with a species I love!) Anyway, there are also many simple species to examine, “Simple” here only means not very large or not having many organs at best. However, some in fact have more than 2 sexes! A slime mould has 507 sexes! But they don’t need all 507 in a giant orgy for sexy time, they only need 2 compatible sexes, and they have a system to determine that. You can do similar with more sexes if you want, too! Be creative!
Neoteny and humanoid do not mix
This is about the ickiest subject in this entire post, but I feel it needs addressing due to my autistic need to be thorough and my love for worldbuilding. What is neoteny? It is an evolutionary process where the ability for sexual reproduction goes down in age over generations and eventually goes into the childhood stages of the development of an organism. The usual end result in said species is that the old adulthood form is replaced by its former childhood form, and a new childhood form starts developing instead. In common parlance, what used to be a child is now a sexually mature adult. Now with that, I hope you all can instantly see the huge issue with humanoids having neoteny happening to them.
I rarely ever speak in absolutes, and I love weird stuff for my aliens, but this is one I will never do. I would say to anyone, do not ever do it! Never have a humanoid species be neotenous! You are all thinking it now, you are all feeling the feeling! If you are not, please go and seek help! Neoteny might be a perfectly valid evolutionary thing, but for consumers of media, this does not matter. If you as a worldbuilder include this, you just stamped yourself as a massive paedophile (and rightly so), and everyone will go “NOPE!” and throw away whatever media that was containing it. It does not matter that it is natural to the species, or exists in nature. It really disturbs us all, and that is why I say never ever include it! Even the extremely remote chance or possibility of sex between a neotenous individual and a non-neotenous species member provokes all your red flags, and good on you! We do not want that possibility, we don’t want to imagine it possible, we don’t want to dare consume anything that has even the slightest potential to include this.
However, I will say there is ONE exception where it MIGHT work. I still advise against generally using it, but again, I am a completionist. This is if the species reproduces entirely non-sexually. Keep it friendly, keep it child safe in how they do it. Remove everything as far as reasonably possible that anything sexual could or would naturally happen with these neotenous individuals, and this includes their minds. Make the concept of anything like “sex” utterly alien and bizarre to them. Heck, make even the prospect of sex repulse them as much as the prospect of…what we all are thinking on this topic. This can work if done right because by taking these steps, you as a worldbuilder are, in a way, promising the consumers that you know the issues, you know what all will think, and you are intentionally making it so it is not a thing. All of these together can give a sufficient promise to many consumers that consuming your world will not contain THAT thing.
Why would I even bring this topic up if it’s such a hard no? Again, completionism in me. The concept of neoteny is amazing, and it can be used on non-humanoid species. Things that are different and alien enough from humans that it does not trigger these innate feelings you humans have. We limaces are honestly the same, freaks us out too! You can use it in the evolution and/or development of species in your world and give them more meaning. But please, leave it alone for humanoid species.
Kingdoms
We have now left humanoids, yet we have barely started on them! I know, but I will do more later. Instead, we will focus on what a kingdom is when it comes to life. Broadly speaking, a kingdom is “a large group of lifeforms that share some very basic traits, often on a cellular or developmental level”. It is not a perfect definition, but it will suffice for now. I will give an overview on all of the kingdoms earth have and how you can mix or make up new ones. I will only focus on multicellular ones, as single celled ones are rarely interesting for us.
For the 3 kingdoms of earth, there are 5 properties that, to my knowledge, perfectly encapsulate them. If it fails, please feel free to comment below and tell me of exceptions.
Animal
Heterotrophic
Motile (For a part of their life)
Blastula Stage
No cell walls
No chloroplasts
What does all of this mean? -trophic is a suffix meaning “to eat” or “eats”, “heterotrophic” means “eat others”. And that is what animals do: they eat other lifeforms to sustain themselves. Motile is a fancy word for “can move”, and animals do it for a portion of their life at bare minimum, usually either juvenile form only or through their entire life. Blastula stage is a very unique thing that animals have during embryonic development where the embryo forms into a special sphere-like structure called…you guessed it, a blastula. It is believed this stage helps differentiate cells more and thus give animals a much greater richness in different tissue types and cell types.
Fungi
Heterotrophic
Sessile
No Blastula stage
Cell wall
No Chloroplasts
Like animals, fungi are heterotrophic as they need other lifeforms to live. This is one reason why fungi are the decomposers of most ecosystems. They are however sessile, meaning they NEVER move in their entire life. Where the spore (they use spores over seeds) land, they grow, and that is it. Stuck for life there, but hey, they like it! They have cell walls, which is a protective layer around the cell that makes it much more rigid and made out of chitin. They lack blastula stage and thus do not have that many forms of tissue, but they do differentiation in tissue to some degree.
Plant
Autotrophic
Sessile
No Blastula Stage
Cell wall
Chloroplasts
Autotrophic, despite its name, does not “eating oneself”, that is autocannibalism, word of the day! Autotrophic means they derive their energy and needs from the environment one way or another. The technical term for plants is “phototrophic” because they use light to get it. This is done in their chloroplasts, which they have. I will gladly go into details on chloroplasts and such later! If you’re interested, comment below. They also have cell walls to serve the same function as for fungi, but instead of chitin, they use cellulose to do the same job.
Mix
Mixing these kingdoms is often done, and planimals (plant-animal) and fungimal (fungi-animal) are staples of science fiction and more. The big issue in most cases is that it is, at most, superficial aesthetics that are mixed. Movement of animals, but flowers and the likes of plants. Planimals are the most common one. Same goes for fungimals where they have mushroom hats as a common thing.
It is rather BORING. I understand it, but look at it, what does it mean to be that species? You can use the aesthetics of each kingdom and mix them, but imagine what it would mean. Planimals might be able to go longer without food because they are at least partially phototrophic, photosynthesis could never sustain a planimal indefinitely alone anyway. Maybe their diet becomes more focused on acquiring needs that photosynthesis cannot provide, so they don’t eat plants but are full on carnivores instead of omnivores? For Fungimals, maybe their cell walls make their skin tougher than normal skin. Maybe they can eat dead stuff like wood, trees, and more because of their more fungus based digestive system to mimic how they are the decomposers of our world? There are options, make it more interesting than just an aesthetic!
New
Wanna make up your own kingdom? Huzzah! 💜 You are my kind of worldbuilder! But where do you start? Depends on what you want! You can split the autotrophic branches; there are more than phototrophic, after all. Here are some examples that are real, and a few fantastical ones I made up.
Chemotrophic - Picks up chemical from the environment that they then use for energy
Radiotrophic - Picks up radiation to turn it into energy
Thermotrophic - Uses a temperature difference to gain energy
Electrotrophic - Uses electricity and movement of electrons to gain energy
Magitrophic - Uses mana/magic to gain energy
Phlebotitrophic - Uses phlebotium to gain energy
You can then mix the aforementioned properties in our three kingdoms above with the various trophics to gain more kingdoms. Keep in mind that most autotrophic lifestyles, except maybe the last two, are not conducive to a motile lifestyle at the pace we enjoy. But maybe they are instead motile in short sprints and take a long time to build up the energy reserves to move? There are of course more options, but here are some ideas, and here is an image to help further!
An illustrated list of terms used to describe the eating characteristics of plants and animals based on various other criteria
Summa summarum
Whether you make lifeforms to inhabit your world or to make people to interact with, the diversity of life knows no bounds. You think human diversity with all its parts is huge? Life has you bested a thousand times over! You can make so many choices even in a humanoid to make them interesting, unique, memorable and not just “human with makeup on”. How they eat, how they live, how they perceive the world can all be altered in ways that will boggle the mind. I will go much deeper into everything as time moves on, but for now, this broad strokes view will hopefully help give you some ideas! Life is diverse, your world can be just as diverse or more so, if you allow imagination to take you where it wants and not where things have been. Imagine, and as I said to a friend:
Make me feel for the strange, not the mundane
And you’ll be amazing. Whether it is only a little strange or very strange, enjoy!
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Copyright ©️ 2023 Vivian Sayan. Original ideas belong to the respective authors. Generic concepts such as anything based in our world as well as suggested new senses are copyrighted under Creative Commons with attribution, and any derivatives must also be Creative Commons. However, all language or exact phrasing is individually copyrighted by the respective authors. Contact them for information on usage and questions if uncertain what falls under Creative Commons. We’re almost always happy to give permission. Please contact the authors through this website’s contact page.
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