#troll physiology

if you presume that trolls did biologically evolve in a realistic way that makes sense for whatever you presume was their evolutionary history and environment

unless by some astronomically minute tiny TEENY ITSY BITY MICROSCOPTIC CHANCE

they ALSO evolved from primates that had the exact same facial proportions and nasal shapes as real world primates

Since the dawn of SBURB, and Trollkind and Humankind (not the weapons) began interacting, we’ve all taken steps to learn about the other’s culture. Their physiology, their culture, their technology, all we can. This has benefited hundreds. Thousands even.

However, every culture has their secrets. The questions nobody wants to ask or answer. Things that outsiders need to earn the privilege of learning. Or maybe I’m just embellishing so people actually reads these posts. But still, nobody really knows the question I will ask, that hundreds before have asked.

Do Trolls have two dicks?

Ever since we learned Trolls have 4 types of romance and 2 of them are actually for reproduction, a joke arose that Trolls have two dicks. We don’t know if the original joke was told by a Human with funny logic or a Troll who was stating a fact, so it’s still not clear. Furthermore, do female Trolls have dicks? There’s virtually no sexual dimorphism to the point I wonder if Trolls are actually Hermaphrodites, so it would make just as much sense.

Damn bitch calm down. I'm not a Troll biologist or a trained doctor or anything that would help you here. I'm not even sure what you want me to do exactly. Are you looking for advice? Don't do that again.

I’m going to start out with some assumptions I’m making, followed up with my evidence for them. Then, I’ll build my ideas based off of those assumptions. I welcome any corrections/questions/add-ons anyone may have. :3

Assumptions: Variation in troll blood color is, at least in part, from variation in a pigment. Presence of the pigment does not necessarily indicate presence of blood because it may only be a constituent of blood. Furthermore, this pigment gets flippin’ errywhere in their bodies.

Evidence: Unless Meenah was pissing blood (which would be a health concern) and Karkat was crying blood (which would be fucking metal), we see it in canon. (I think Hussie might have said this outright on his old formspring, but I couldn't find it.) This shows that, when not associated directly with blood, the color is diluted. Also, when we see various characters perforated or bisected, we don’t see any colors that aren't their blood color or a shift in value of that color. Not exactly guaranteed to be anatomically accurate given the simplified style of the comic, but also not explicitly contradictory to my assumption.

I don't think troll blood color is determined, or even heavily influenced by, whatever they use as oxygen carriers. It doesn't make sense to me to have 12 different kinds of oxygen binding molecules evolved in one species, not to mention having them develop matching pigments in some other capacity. So, I've got two main ideas on how troll blood works.

Idea 1: Troll blood color is analogous to human blood type.

First, a brief explanation of human blood types, or more specifically, ABO blood groups. (Hemotologists, feel free to skip ahead or check my work.) The A and B in ABO refer to types of antigens that can be on our red blood cells (also called erythrocytes, or red blood corpuscles if you’re a pedant, or RBCs if you’re already writing too much in the parentheses and need to cut down on words- oops). The O in ABO is when you don’t have either A- or B-antigens on your RBCs (then you have H-antigens, which are the precursors to A and B antigens). Anyway! We get different phenotypes based on what antigens are produced and attached to the surface of our RBCs. These let our immune system recognize foreign cells because they’ll have different antigens on them. These antigens are also found in other places in the body, not just stuck to RBCs.

So, blood pigment could play a role in troll immunology. If the pigment is an antigen, specifically one found on their blood cells, that would explain the richer color of blood when compared with color of tears. There’s also antibodies to consider, which might also be color coded in trolls.

Advantages:

Simplicity- With this idea, trolls could could be using hemoglobin as an oxygen transporter and have regular ol’ RBCs under that colorful layer of antigens. If you like your trolls human-like (at least in physiology), there you go. I suppose you could also have them all use hemocyanin, but I don’t know if that would cause other complications. (I guess you’d have really brightly colored blood when it was deoxygenated because hemocyanin is clear then, but I’m getting away from my point.) Also, variance in blood color is less complicated because the functional part of their blood is all the same.

Possibilities- Want something to go wrong with a troll? Humans have a lot of disorders already, and if trolls are similar, chances are they could have the same problems! (Why, Karkat, why did you have to cry red tears? If they were clear, the Bombay effect would have been the perfect explanation!)

Disadvantages:

Boringness- If you don’t like your trolls human-like, well, this presents a problem!

Practicality- You’ll probably have to be okay with a certain amount of hand-waving about why they’ve got such a high concentration of antigens and why this doesn’t eff with their body chemistry to be okay with this idea. Or you could add your own explanations in place of the hand-waving, if you’re a drinking-cylinder-half-full type of person.

Incompleteness- Though this may explain hemoglobin, it doesn't explain myoglobin, which makes your muscles red. And if we’re going with “trolls = grey skinned humans with horns”, they ought to have yellow fat, too. Personally, I like my trolls to be as monochromatic inside as possible, so I’ve got this listed under disadvantage. (Then again, it would be cool to see a troll medical text with all those colors inside… Anyway.)

Idea 2: Troll blood is clear, or mostly clear, with the exception of this pigment.

We have some examples of oxygen carrying molecules that are clear in at least one form on Earth, maybe Alternia evolved one that was clear in both its oxygenated and deoxygenated state? (Maybe we have one on Earth I don’t know about? If somebody knows, tell me~.)

Advantages:

Interesting- Alien bio! Insert your own explanations of the effects of this mystery oxygen carrier and this mystery pigment!

Simplicity- You still have the same basic template for all the hemocastes.

Disadvantages:

Simplistic- The strength is also the weakness: there’s not a lot to go on here.

*sigh* Oh well, in my brief search, I only saw one thing that was even the same topic I was thinking of, and they went in a different direction with it.