An Analysis of Troll Biology
Hi, I’m insane and have developed an interest in speculative biology. Homestuck is also one of my oldest special interests, so of course I have to combine the two and figure out what, exactly, is happening with trolls biologically.
Of course, I am a human, and extraterrestrial life has not been discovered yet. As such, I will be basing this analysis on Earth’s biology, because that’s all I have. I am aware that evolution would go differently on a radically different planet, and, as such, I will be having a far laxer view of strict categories.
I will be referencing Alternia specifically, although this should all apply to Beforus, too.
The rest will be under the cut, because this post will be long.
Class
Trolls are odd. They generally seem more bug-like, but have mammallian features, some breathe underwater, and some can’t. What’s going on?
Well, it turns out the last oddity actually explains it -- trolls are amphibians. Amphibians have lungs and gills. Landwellers are like most amphibians, having gills as larvae and then losing them in adulthood. Seadwellers are the less common type, that keep gills into adulthood. The fins of seadwellers may be a secondary trait that evolved, and the more mammalian features (such as breasts) may be a coincidental form of sexual dimorphism.
Evolution
Like Earth, I believe life began on Alternia in the water, for basically the same reasons it did here -- easier access to energy sources, easier for elements to bond and therefore create things like DNA/RNA, etc. Adding onto this, the heat of the Alternian sun likely made the depths of the ocean more accessible for life to flourish, as the radiation and heat would more quickly break down things like DNA/RNA.
I believe trolls evolved from a creature that was sort of a Metoposaurus-Cynodont mix, due to having very mammalian (specifically, primate-like) features, but functioning more like amphibians. I also believe that trolls and lusii have a common ancestor, due to the existence of the mother grub sort of functioning like a queen bee. Upon the split between lusii and trolls, despite the many differences they shared, they still developed a highly codependent relationship, with lusii functioning as parents for trolls. The biological connection between lusii and trolls are further supported by this connection existing on Beforus, despite the fact that Beforus did not undergo the rigorous rage-amplification that Alternia did.
For the sake of brevity, I’ll give a name to the genus trolls are apart of -- Jotunn. I believe that early Jotunn species were scattered across the world, however I believe the direct ancestor of trolls, or Jotunn antecessor, were equally aquatic and terrestrial. Jotunn species likely had rhino-like skin, as modern trolls’ skin pigment does not seem to be effected by blood (see: Karkat), and the harsher environment of Alternia would likely necessitate this type of evolution.
Jotunn antecessor likely had gills, but no fins. Their blood color was likely in-between purple (the caste that is the closest to water), and violet (the most common waterborne caste). Like modern trolls, Jotunn antecessor likely had pitch black hair, candy corn-like horns, yellow-orange sclera. Oddly enough, I believe Jotunn antecessor was actually diurnal! Yellow-orange sclera is often indicative of animals hunting during the day, for example, owls. As more trolls spread on land, this may have been kept as a communicative feature, similarly to how humans have white sclera to make body language more distinct. Jotunn antecessor likely had a more marine diet as a result, with the water functioning as a way to hide from the Alternian sun. Jotunn antecessor also probably had some electricity-based powers, as a lot of the caste abilities can be connected to electricity.
Modern trolls likely evolved due to Jotunn antecessors exploring more parts of Alternia. As they did so, they encountered more Jotunn species, and likely interbred with them, creating many aspects of modern trolls. For example, the ancestors of seadwellers likely stayed underwater, and begun mating with Jotunn species that had things like fins. Though seadwellers kept their ability to breathe on land, they gained certain optimizations for living underwater, so most seadweller cultures lived underwater, but did regularly come out to trade.
Landweller ancestors went out of the water, and interbred with land-exclusive Jotunn species. This lead to them no longer having functioning gills -- indeed, landwellers now likely lose their gills as wigglers, like tadpoles and certain species of salamanders. They did, however, develop certain traits that optimized living on land.
Modern trolls are likely nocturnal due to landwellers. Landwellers are more common than seadwellers, and as landwellers became nocturnal, seadwellers had to follow suit, or no longer be able to trade with landwellers. This also gained them a hunting advantage, as most prehistoric Alternian sea creatures were diurnal due to the ocean protecting them from the sun.
Rainbowdrinkers likely evolved due to jadebloods needing to see eachother in the caverns, so glowing was useful.
Blood color differences were likely the result of Jotunn interbreeding + mutations. It’s implied that Karkat’s non-mutant blood color is lime, so it’s possible that candy red blood evolved into limebloods.
Blood Differences
Blood differences imply a different basis of blood color. Bluer/cooler blood tones may be based on copper and use hemocyanian, warmer/redder blood tones may be based on iron and use hemoglobin, yellower blood tones likely have higher concentrations of vanabin, greener blood tones have higher concentrations of biliverdin, and violet-er blood tones have higher concentrations of hemerythrin.
This would also explain the lack of a pure green caste, because higher concentrations of biliverdin can damage DNA, cells, and neurons.
Mind control powers may be caused by influencing the brain’s activity by emitting electromagnetic radiation that then alters their brain to signal their body to do a certain act, like a more advanced form of bio-robots. Levitation may be electromagnetic.
