I’ve been giving some thought as to how an alien intelligence could be really alien from what we’re used to with humans on Earth; hardly an original idea, to the point I almost subvert it by making my “Thalassans”, an avian intelligence native to Proxima Centauri, similar to humans in crucial respects, even if their basic body plan and external appearance is far more archosaur-like, as opposed to being inspired more by deep-sea creatures or insects.
Indeed, the dinosaur lineage has proven fruitful for imagining plausible creatures very different from the human baseline yet still relatable; as a blogger once ably pointed out, your average denizen of the Star Wars universe is very much dinosaur-like.
I’m inspired by dinosaurs, birds included, for my “Thalassans” too. Like modern birds, they lack “dentition”, i.e. teeth. Instead they have a beak-like structure, perhaps with sawtooth-style serrations in the beak itself to chew their food more effectively. This “pseudotooth” structure is not found on Earth today, but did exist in certain seabirds earlier in the Cenozoic. Subtly yet delightfully alien, in my view.
Lacking teeth on Earth makes the use of “gastroliths”, rocks taken into the digestive tract to help break down food, more advantageous. Only here there is a harsh environmental constraint; since their world is an ocean planet devoid of land, where would they collect rocks? Well, Thalassa does have floating airborne reefs at lower altitudes and one could envisage the sea itself containing pearl-like structures grown by native life-forms, but my mind has turned instead to a more exotic kind of symbiosis: we know on Earth from an early stage that microbial life is perfectly capable of building up minerals. The stromatolites, for example. Heck, the more general process of “biomineralization” even occurs within our own bodies as humans, in the form of the growth and maintenance of bones. We also know that, like all animal life, our digestive process is in large measure a product of “gut flora”, an ecosystem of microbial symbiotes that help us break down our food within our digestive tracts. What if the concept was taken even further by mother nature on this planet? Perhaps the Thalassans enjoy gut flora that mineralize suitable compounds into gastroliths that grow inside the gut tract. Ooh…
Naturally this process will tend to produce stones that grow ever-larger as suitable mineral elements are absorbed, but like birds one assumes they can expel gastrolith-like objects from the digestive tract. So as part of regular physiological process, once gastroliths reach a certain size, they’re expelled out through the throat, through the mouth, and out of the beak. Since these stones will have been built up in layers over time, and have been subjected to erosional forces that act evenly across all sides, a smooth and spherical shape could be expected, akin to mineralized counterparts of sailors’ eyeballs.
Like the bird mess we’re sometimes pelted with on Earth, it’s entirely possible these gastroliths are simply allowed to fall into the sea, but much more likely, given this is an intelligent species, is that they would be collected, perhaps being strung along a necklace like jewelry. Since my species is, like certain jellyfish and lobsters, not subject to any aging process, i.e. they’re biologically immortal, the number of gastroliths they wear might be the only truly reliable sign of an individual’s age.
Indeed, immortality, in terms of being immune from aging, might be a common, even basal feature of an entire major lineage of animal life. Thalassa is subjected to high radiation from its parent star, Proxima Centauri, when it flares, so DNA repair must have evolved to be robust. This, in my vision, has a side effect of making resistance to aging far more common. Which means that individuals tend to be long-lived compared to Earthly counterparts, which in terms of ecological incentive changes everything. To wit, this is a world whose ecology is much less “r-selected” and much more “K-selected”. Compared to mammals on Earth, the dominant lineage of animals here are much longer-lived, slower-maturing, and reproduce more slowly, with much higher parental investment being required.
The net result in my vision, is a world where a more bird-like mating pattern might be much more ubiquitous, and perhaps carried to alien extremes. Thalassans would be strictly monogamous, mating for life with only one other individual, and they would have only one child at a time. This might seem like a fragile strategy by Earth standards, but they can take a century or longer average lifetime for granted when they’re still effectively young adults; any higher reproduction rate would be ecologically destabilizing and have been selected against very early in the lineage’s history. A longer “middle childhood” phase devoted to learning seems likely; Thalassans have greater raw intelligence than humans, so all factors point toward it being decades before an individual reaches maturity.
Since life expectancy is long and high parental investment is required, it might be biologically fixed that every individual is effectively an only child: they would have siblings in most cases, but the parents could only biologically have another child after the eldest reaches maturity, which means each child would be raised alone within the nuclear family. Like Paleolithic humans, they hunt in packs of loosely related and friendly individuals, so there are other children to socialize and play with, but no very close relatives in infancy or childhood.
Which brings up an interesting question: would such a species, which has had such a life strategy almost from the ground up, this world’s equivalent of the Cambrian explosion, have an incest taboo? I don’t raise it to be provocative; but in humans the so-called “Westermarck effect” has been observed, where humans have instinctive sexual aversion to individuals they were raised with as small children, presumably a biological adaptation to prevent incest between siblings, which leads to much less fit offspring, genetically speaking. But if the species has never really had siblings…hmm.
One might object that parent-child and uncle-niece pairings might still be a factor, but the strict monogamy of this species militates against that possibility as well. The norm biologically might be to find your one mate very early in life, and the most likely possibility would be for each partner to be roughly the same age, since, like humans, this species is only moderately sexually dimorphic and, unlike humans, is strictly monogamous. We see shades of this in Earth birds, once again. Only here it might be carried to a fantastic extreme.
Indeed, considering this is an intelligent species, evolution might fancy making the imprinting in youth much stronger than in known Earth birds. In my vision, I’m thinking about a psychology where one’s mate for life is selected and bonded to one before sexual maturity is reached, i.e. in the stage of life that’s equivalent to our middle childhood.
The net effect is that sibling incest is virtually impossible because no siblings exist at this stage (for first-borns) or are already mated (in the case of later-borns), and parental incest is virtually impossible because of age differences mattering at a biological level, rather than primarily social as is the case for us humans. So both of the most severe, from a genetic perspective, forms of incest are done away with, without the need for a “Westermarck effect” adaptation.
That doesn’t mean we’re out of the woods; especially with siblings that are widely spaced in age, uncle-niece or aunt-nephew pairings become more likely, not less, owing to avuncular couples more often being about the same, correct age to mate. But avuncular relations are second-degree relatives, sharing 25% of their DNA, which is much less than the 50% a parent-child or brother-sister pair would share. And it’s the same as “double first cousins”, which also share 25% of their DNA (compared to 12.5% for normal first cousins), which cross-culturally among humans are not subject to a very strong taboo against mating. Some societies declare it incest, others don’t. Without the “Westermarck effect” putting its thumb on the scale, it’s likely such relationships would be universally permissible in Thalassan society.
Not common, mind you, since it would require quite a coincidence for avuncular pairs to both be the right age at the same time, but this is a species where “incest” just isn’t a category; instead the truly taboo, exotic, and alien possibilities to them would be remarrying after your beloved passes away, having a litter of children instead of just one at a time, or marrying someone who’s a different age from you after you’re already reached sexual maturity. Perhaps, to them, such relationships would seem disgusting, whereas his boy falling like a ton of bricks for his aunt (or a niece for her uncle) and them mating for life would be totally normal. Indeed, considering genetic sexual attraction is likely still in effect, it might be socially and culturally deemed to be the ideal pairing. Alien, indeed…
Another question is what they’d deem to be sexually attractive in the first place, in their strange way where juveniles mate but consummation is reserved for afterward once biological adulthood sets in. This isn’t too alien; many, if not most humans already have a clue what they like before adulthood. This species, once again, takes it to an alien extreme.
The system of biological sex is male and female, determined by XX/XY, similar to humans and many other Earth animals. Perhaps with quirks, such as the XX and XY chromosomes being repeated in a chain (some spiders on Earth can have up to twelve), with the basic developmental program being embedded in the sex chromosomes; we see shades of this in some Earth life-forms, and a lineage that developed radiation resistance could easily have evolved redundancy at some point. This would also have the side effect of making the basic developmental program much more “locked-in” in terms of evolutionary path than even Earth tetrapods (the reason we don’t see four-limbed animals evolving additional pairs of limbs or whatever is because the “HOX” genes determine that and program embryonic development, and so are extremely hard to change without something or another going catastrophically wrong).
But I digress. What would these juveniles prize in the opposite sex? Intelligence implies brains, which have neural tissue that’s nourished by fat. Humans, notably, are about the only animal species that uses subcutaneous fat as an attraction cue, and this may well be related to our exceptional intelligence. This is most present in human females, and Thalassans might take this to an extreme. They have feathers and wings and are aerodynamic, but we can envisage subcutaneous fat in aerodynamically compatible parts of the body being the curves that signal an appealing person. Analogous to humans, but expressed in a very non-human way. Which brings us to the males.
Youth and suppleness, but also strength, are prized here, so if we’re taking an avian analogue to humans, how would this be expressed? I’ve thought of a cool possibility: consider that in my vision, Thalassans can fly over a wide pressure range. At the ocean surface in their world the pressure is 50 bars, and their atmosphere is almost 100% oxygen. Thalassans are native to the middle altitudes, so for them a surface skim would be the equivalent of a deep dive like penguins perform on Earth. Conversely, at the 0.1 bar level the total pressure is a rarefied one-tenth of what it is on Earth at its sea level, but the partial pressure of oxygen is similar to Earth at 15,000 feet. Easy for a bird. And likely even easier here, since they’re adapted to a wide pressure range.
They might even use it to advantage in hunting (they’re primarily hunters; their diet is extremely fat-rich, all the better to nourish those big brains, and so their diet is very animal-heavy, loosely analogous to Earth Inuit humans); consider that at 0.1 bars of pressure, the terminal velocity, using a peregrine falcon scaled up as an analogue, would be on the order of 1000 miles per hour. Notably, this easily exceeds the speed of sound.
As high-speed pack hunters, Thalassans would be optimized for the subsonic realm for a host of reasons, but biomechanically, they could go supersonic. Which is catnip for sexual selection, the net result perhaps being that males would develop into a more supersonic-optimized delta-wing shape during their courting years, and they put on a mating display where they go supersonic on a death dive, creating a sonic boom, which may well induce tremors of attraction to the lucky girl in earshot…
The high speeds these Thalassans, especially juvenile males, can achieve suggests that they can zoom-climb upward to very high altitudes as well. Potentially, by my back-of-the-envelope calculations, as far as the 1 millibar level or so. Presuming they’re warm-blooded, this would be well above the Armstrong limit for their species.
Their bodies are hardy enough that ebullism might occur only slowly, and they can hold their breath long enough to not pass out very quickly, but I’m sure this would only inspire their most daring male juveniles to try to ascend higher and higher, the adventuresome sorts stalling out with some regularity in near-vacuum, at the edge of outer space, which might be quite the spiritual experience for their race…especially when you consider that the omnipresent aurora above their skies are powerful enough and low enough to create noticeable heat and electrical charge at the 1 millibar altitude band.
Perhaps myth takes for granted that this is the end of the sky they live in and the surface of the spirit world beyond. Perhaps where the souls of the dead are still dancing in ethereal splendor, every hiss, crackle, or surge of warmth perhaps being some kind of message for those who still dare to slip the surly bonds of earth and listen to that which is beyond…
Not that they need much help to do that, quite possibly. As flyers who spend their entire lives on the wing, they would likely never sleep like we do, but rather rest one hemisphere at a time, and as a result they may well be effectively half-dreaming most of the time. Cognition would no doubt be rapidly corrected by input from physical reality, but the world of bodies and senses might be perceived as existing on a continuum with the world of dreams and imagination, rather than switching between them in discrete states like we do.
All of which paints a picture of an alien intelligence that is loosely analogous to humans, and in many ways would seem eerily human-like, but also diverge in crucial respects. Pushing the boundaries of what we think an animal or an intelligence “should” be like and testing it against the constraints of the alien environment is really what leads to the best worldbuilding for an alien species; at least that’s the takeaway from this exercise which has occupied my mind off-and-on for the past few weeks. And perhaps there’s a lesson to be learned here, which I might apply elsewhere to some of my other planets that live, as the Thalassans’ ancestral spirits do, in the realm of dreams…