sootnose asked:
I’d like to know more about how the exoskeleton works, i.e. where the plates should have seams, where they should overlap etc. for them to be able to move in an effective manner. Also, what about the parts uncovered by the exoskeleton, in that drawing of yours they’re blood coloured, but wouldn’t that pose a quite severe problem in Karkat’s case?
I am not an engineer! I am not an anatomy dork, either, so these doodles reveal my thought process when putting together an illustration with exoskeleton trolls, which goes like “oh shit, that bit’s gotta bend too, let me just split the plate along here, yeah, good, carry on.”
I figure that the milky translucent connective tissue between the exoskeletal plates distorts the color of the blood enough that Karkat does okay. Or possibly he has a super-strict cosmetics regimen and wears a lot of turtlenecks!
New xenobiologistforhire post! I’m gonna crosspost these here I guess?
I’M CAVING
XENOBIOLOGIST FOR HIRE IS RETURNING AT A NEW LOCATION
ASKS ARE OPEN OVER THERE
www.xenobiologistforhire.tumblr.com
I will probably make a big fancy post about this at some later date, but right now I am working on crossposting all the old XfH posts to it and trying to work out how I will be organizing it.
With XfH off of my main blog I will be able to answer more casual asks and I am, in general, pretty excited.
If you are only following me for the xeno headcanons (and you are still here, sorry about the extremely long hiatus, jeez) you now have another option!
Okay I’m done with the microscope!
No more Xenobiologist for Hire asks!
The askbox will re-open at a later date, sorry to everyone whose questions didn’t get answered.
phnarg asked: Just curious, what information in canon makes you believe they are insectivores? I already love the idea of them eating bugs though, hehe
Anonymous asked: relative sizes (height-wise, or build [or both]) of trolls based on hemocaste, mayhaps? (and justification, of course). ps you rock
Warmer blood: higher metabolism, cooler blood: slower metabolism.
This has some bearing on how fast a troll can grow and how much a troll needs to eat. Well-fed warmbloods get tall and muscley, and underfed ones get knobbly and lean. The higher castes have a harder time building up muscle and if they’re eating well (which is usually) they get some sweet curves.
There’s a whole bunch of individual variation, though, and any data is of course only an average trend and not super-well reflected in canon. Diverse body types all up and down the hemospectrum!
pokemonxae asked: I can't remember if it was in the comic or not, but I've heard the idea of blood color corresponding to body temperature in trolls thrown about. How could this work?
In detail, here!
In incredibly self-indulgent molecular biology detail with a certain amount of handwaving, fair warning.
seserakh asked: what's up with all those different kinds of troll teeth? does each blood color have specialized diets or somethin?
I have been thinking about this and my tentative answer is that trolls just have really leaky wnt signalling?
Here are some pictures of what fucked up wnt signaling does to teeth:
Evolutionarily I am not really sure what to make of it but it’s nice to have a molecular mechanism! Maybe trolls have been post-agricultural revolution for a big enough chunk of evolutionary time that teeth variations ceased being subjected to selection pressure and a mess of phenotypes just sort of sprang up de novo?
mostshockingtwistyet asked: Why does gl'ybdglb kill by caste?
Uuuuhhh. Hm.
Different blood types have different clotting properties so lower castes die faster of massive brain hemorrhage?
(Alternatively, magic magic magic.)
I am trapped with the microscope for all of tonight and thus I’m opening Xenobiologist for Hire up for questions very briefly for short answers! I’m just going to be answering asks straight out of my askbox, not full write-ups.
It’ll close again when I get to go home and stop worrying about these hepatocytes. (They’re not so much dividing as not dividing and it is quite stressful at the same time that it is boring!)
Lots of people just wrote in with “cherubs, how do they work!”
Like ten, by a quick count.
Since there are a lot of more specific things you could think about with cherubs, I’m going to run with just one part, which is the body sharing swap, which I cannot be assed to go into canon to check if it’s a peculiarity of the Calliope and Caliborn situation but igaf,* I’m assuming that this is a species that has radical personality shifts** in tune with their circadian rhythm.
From a biological standpoint, it helps to discard the sarswapagus as a bit of cultural baggage, and clearly they can swap outside of it because of the name thing.
Parasites are kind of a cheat (and I have used them a lot), so let’s say that the shift is like, along with the 48 hour circadian rhythm of the cherub. Tons and tons of animals have biological clocks, plants have biological clocks, and they can time anything from a couple of hours to a couple of months and file the information away for later when it will be useful. Anyway in cherubs its regulated by a kind of dual hormonal system in antagonistic relationship.
This hormonal cycle is very stable and synched up with the lifespan of the cherub’s erythrocytes!
Human erythrocytes cycle like, every 3 months or so, and cannot live longer than that because they lack a nucleus and therefore can’t do important things like make new proteins.
Cherub erythrocytes have a life cycle of like, a couple of days, because they are unstable cell fragments or something. The erythrocytes are produced by two lineages, the red one and the green one, and have different pigmentation (and different isozymes*** of the oxygen carrying protein.) So there’s a transition between the two populations of cells that’s kept in sync by the daily (or whatever) hormone shift.
A whole bunch of brain and blood chemistry alters with the switch (like, uh, a bunch of receptors on different cell types notice the hormone shift and there’s a massive kinase cascade), which is maybe an evolutionary holdover from cherubs beginning on a planet with really intense differences between day and night, or an extremely short year, or something that necessitated two very different strategies within each organism.
Xenobiologist for Hire asks are currently closed!
*”It’s idiosyncratic magic,” while sometimes a more fun answer, pretty much ends there and there is nothing to dig into.
**i think the idea that Calliope and Caliborn are the same brain with different chemistry is pretty interesting, I bet that memory storage in cherubs is totally different from human biology.
***not too classy to namedrop my username’s origin
Anonymous asked you:
hey there! could i ask for your take on sopor slime and troll sleeping arrangements?
blackflirtlarping asked you:
What are your theories on sopor slime and troll sleep in general?
collapsiblechrist asked you:
What about recuperacoons, troll sleep cycles and the effects of sopor slime? What happens if a troll sleeps outside of it, etc.
So recuperacoons make very little sense if you’re at all worried about drowning in your sleep. It’d be like falling asleep in the bath every night and being surprised when you asphyxiated a month in. Wow, nobody predicted that would be a bad idea at all.
Lungs aren’t super well equipped to handle viscous slime, so the obvious solution is to not breathe at all while you sleep. You have to get oxygen from somewhere, though, even if your metabolism bottoms out and you do a really spectacular catatonic state. During sleep troll oxygen consumption goes way down, and they appear kind of dead, but they still respirate a little bit to keep up brain maintenance etc. For insect trolls, this means that the spiracles have a bunch of hydrophobic hairs arrayed around the outside that keeps spoor slime (and other unpleasant wet things) out of them, which leaves an interface where oxygen can diffused into the trachea. For less alien trolls, your other option is to absorb some oxygen through the skin.
Evolutionarily this suggests primordial amphibious trolls, who, in the daytime, would retreat to the dark, submerged clusters of mangrove roots or underwater cave systems, where it was harder for predators to drag them out and kill them.
The soporific effect of the slime is an interesting side effect of living in a society that has been technologically advanced for a long time, leading to species-wide chemical dependance. Sopor is a great delivery mechanism for all sorts of drugs, from skin and hair products to antibiotics.* Troll skin and hair is generally pretty hydrophobic, so the stuff doesn’t cling to them as badly as it might every morning, although getting in with your clothes on is asking for those clothes to never be the same again.**
Have a xenobiology question of your own? ASK IT HERE
*the stuff is packed with antibiotics anyway, because if it wasn’t it’d be a microbial soup and would smell like the inside of a neglected 37 degree incubator, or, for those who never did microbiology lab, like every bad sock in the world all at once.
**they sleep naked I guess?
g-isabellae asked you:
So, I believe the whole idea that fetal development recapitulates phylogeny has been pretty thoroughly debunked. But, what if seatrolls and land trolls had/have some sort of axolotl/salamander relationship to each other, like if you pumped a bunch of hormones into seadwellers they would become landdwellers, and among other things their lifespans would drastically shorten? Is this feasible? Could hemocaste lifespan differences, etc. be seen as a case of varying levels of adult/land hormones?
Epigenetics, 100% all the way. There is some hardcore genomic remodeling that goes down between seadweller and landdweller phenotypes. So I would say with the right hormones or growth factors, you could definitely induce pluripotent seatroll stem cells from land troll fibroblasts. At a whole organism level, well. That’s harder.
Anonymous asked you:
what the fuck is auspisticeship???
A social construct.
sasammygirl asked you:
Okay, so, assuming Eridan and Tavros’ ancestor didn’t dye their hair, how in the world could they have patches of color on top of black? :?
Some sort of piebald trait to deplete the melanin in a patch of their hair and then I guess they make colorful carotenoids constitutively all over? Maybe the hair and skin is a dumping ground for used up pigment, and it’s usually invisible because it’s covered up by the dark melon coloring.
skrulls asked you:
woah, as a huge fish nerd, I really liked your troll gill post. Have you ever thought about whether trolls could have a labyrinth fish-like setup?
If you’ve got vascular trolls, definitely a good system.
anhydrouscitricacid asked you:
Would trolls have the same organ system as humans? They (seem?) to be meat eaters, and their planet seems to have either low oxygen supply, or no oxygen. Would this also mean they have different organs, in perhaps a different arrangement?
Alien organ soup! They need to rock all the same functions, though, so there should be a lot of human analogs, at least.
Anonymous asked you:
Trolls vs humans in a reproduction-off. Who wins?
Trolls reproduce using R reproductive strategy: devote all your energy into making a lot of babies, then leave them to fend for themselves and hope that the toughest survive to adulthood. Humans use K; make only a few offspring and devote all the energy you saved to rearing the precious babes. Both are pretty good methods; success depends on the playing field. In a hostile environment with a lot of competition for resources, maybe humans win. In a race to repopulate an empty, fertile planet, trolls win by a fucking landslide.
karma-houdini asked you:
In your linguistic model, can trolls sing? How does freestyle rap sound? Is there such thing as ‘rhyming words’ in Alternian? I just think xenobiology is fascinating and you might find fanfics in your tag someday.
Troll music sounds fucking weird. But probably the most eerie part of it is that they never pause for breath.
Anonymous asked you:
How do sea trolls not have their skin get all wrinkly all the time?
Same way fish don’t get wrinkly! Sea trolls have a better system for dealing with changes in osmotic pressure than human tissue.
ETA: the-ones-that-come-true: “Actually, fingers getting wrinkly being due to osmotic processes has been debunked—current thought is that it’s actually a process to make it easier to grip things, an exaggerated version of the ridges.” So fuck if I even know.
Anonymous asked you:
Since trolls seem to have the same horns as their ancestors (i.e., Aradia and Aradia!cestor both have rams’ horns, all the Serkets have that distinctive “pincer” shape, etc.), how would that be explained? (And how does it change the answer you initially gave for horn shape?)
a) Narrative conceit
b) Wnt signaling and a fuckload of very complicated genetics.
meltingdata asked you:
So how do you explain Vriska’s eye situation there? Horrifying spider biology?
Nah she’s just got a perforated iris, happens relatively frequently as a developmental defect in animals.
twitchy-spazz-mituna-captor asked you:
Question. A friend and I are talking about human/troll relationships and the potentiality for offspring. Would something like that even be possible or are the differences between the species too great for something like that to happen. Any thoughts?
The biological feasibility of Human/Troll hybrids is NOPE.
Have a xenobiology question of your own? ASK IT HERE
geckopirateship asked you:
Would you ever consider doing Carapace biology?
dickshivers asked you:
How would carapace exterior sensitivity work like would they just feel pressure or what?
Anonymous asked you:
so do you have any opinions/speculations on carapace biology?
Carapaces: lots like my insect troll headcanons, scaled down and even more canon-compliant!
hematite-owls asked you:
Any ideas about troll ears, how they work and why they evolved so similar to humans’ in appearance and whatnot?
church1md asked you:
What do you think of the elflike ears that are portrayed in many pieces of fanart. Would they have some biological purpose?
Anonymous asked you:
how do troll ears work?
Let’s start with a cool fact about insect hearing: their tympanal organ can be anywhere on the body, and is frequently on the thorax! Plus, reptiles and amphibians, in addition to simple membrane-covered ear canals, can pick up air and ground vibration through their lower jaws and their forelegs. What a good explanation for trolls not having any ears in comic, right?
However, insects, frogs and snakes haven’t got spectacular hearing compared to mammals, and mammals do tend to have external ear-bits, which help funnel vibrations towards the hearing organs. (Plus, fuck it, ears are fun to draw!)
You can argue for any kind of ear shape you want, though! There are lots of ways to make a good ear. Look at all these animal ears:
Not to scale.
For sea dweller fins, I like the 3-tined ears because I think they’re more fun to draw that way, even if I admit maybe not the most canonically accurate.
For added cool, line the ear fins with electroreceptors! Fun electroreception is a great reason to give seadwellers a modified organ, especially since their external ear structures would be pretty useless for their original function when submerged, and without secondary function would diminish like sea lion ears.
Have a xenobiology question of your own? ASK IT HERE
mutonmessiah asked you:
I need an explanation as to how blood colour can affect life span. Can you give me anything?
sollust asked you:
xenobiology question: why does the lifespan of a Troll get so much longer as they go higher on the Hemospectrum? And is it really plausible that Condesce could live for millenia? Or is that all fakey magic fakeness?
Anonymous asked you:
This is a really strange question, but if trolls have different blood colors, then do you think other bodily substances such as bile, mucus, and urine would be different depending on the blood color too? Or is blood the only color variable here?
Time for a fresh blood color headcanon; I am going to attempt to knock out a whole bunch of my favorite concepts in one elegant system.* I am still fond of these genetics, but Xenobiologist for Hire is explicitly not internally consistent so that I can pull shit like this.
The key here is oxygen radical species, which are highly toxic because the electron on a lone oxygen is really grabby, and the assumptions that their sun is really nasty plus whatever trolls are using as a metabolic oxidative phosphorylation system is sloppier than in earth organisms and leaves behind a whole bunch of rude electrons.
Here’s a chart:
