- I was curious to see where exactly horseshoe crabs are classified (executive summary: we should've called 'em "turtle spiders"), and I discovered something interesting. They don't have white blood cells. Because I don't think they have any blood cells, the copper stuff in their blood (hemocyanin) is dissolved in their blood plasma rather than coating cells like our hemoglobin does. Instead, they use what're called "amoebocytes", which, despite the name, are not symbiotic protozoa (that'd be cool, though). No, they're called that because they move like amoebas. They do the jobs a white blood cell does in a vertebrate's immune system, probably somewhat differently.
But it got me to thinking, and, though it has not yet come up, I think my felinoids are going to use something similar. I imagine their doctors measure things like infections or auto-immune disorders by measuring the "amoebocyte count", rather than white blood cell count.
- They also, I think I've mentioned before, have biogenic silica for bones, in structures analogous to the mineral part of your bones (sponges are an animal that makes similar structures out of silica). Of course that means that they don't need calcium in their diet, they need silica; I imagine the felinoids, and other carnivores, have the ability to metabolize it directly, just like how most of the calcium in a cat's diet comes from its prey's bones. They also probably have silicic acid in their milk.
I wonder, given that their bones are made of orange silica, is their milk orange? I'm pretty sure silicic acid is clear, and what makes milk white is, I believe, the colloid of fat droplets, so I guess it'd still be white. Also, they don't have our association of white with death (though it is, of course, significant in lots of other ways)—orange is the color they associate with death. They also use "bones" in idioms where we'd say "heart", as in "he didn't put any bone in it" rather than "his heart wasn't in it".
- Remember how I said red=danger has nothing to do with blood, and everything to do with how you're a monkey and red attracts your attention, because of berries? Yeah, well, the felinoids use neon green as an attention color, just because it's the color their eyes see best in (ours too, actually, we just have that "red=food" instinct).
Their displays code enemies as orange, but allies as fuchsia...which is the color of their blood. See, their soldiers wear fuchsia uniforms, and have since ancient times, to symbolize that the uniform, not the wearer, takes on the "stain" of the blood they have to spill. And yes, their modern military has the ability to change their cloaks and uniforms to camouflage (before, the cloak, coat, and pants were just reversible).
The pattern on the uniforms, and also on their armor (ambush predators prefer to be able to camouflage everything), is based on their markings, which are a bit like those of an ocelot, but the same on the chest and stomach as on the back (they're bipeds, remember). It's perfectly adequate as a silhouette breaker (the main purpose of camouflage is to make it harder to pick out outlines in bad lighting or at a distance, it's not like some super invisibility thing), and it also gives the psychological advantage of looking a bit like heroic nudity. Remember those ancient Greco-Roman breastplates sculpted like bare chests? Yeah, like that.
- You know that eye contact thing? How people are always told that Asians and Native Americans will avoid eye contact? Yeah, actually, it's only with older or otherwise higher-status people. Among their peers, avoiding eye contact means exactly what it does in the West: you're up to something. Also, incidentally, I think the "don't avoid eye-contact" thing might be either Celtic or Roman, because many Slavic cultures prefer to avoid it, just like Asians and Native Americans. But in Celtic and Roman societies (Germans too?), all freemen were (at least theoretically) equal. I bet their slaves still avoided eye contact, though.
I bring it up because how dominance works is something people forget in writing aliens. Since aliens are likely to be gregarious, the question is, do they have dominance hierarchies? Great apes have extremely rigid dominance, probably because a young male can usurp his father, since he can mate with the females other than his mother (don't make eye contact with an ape, or it might attack you, since it assumes you're asserting dominance). Humans' instinct for avoiding eye contact, as above, derives from that, but modified for the fact we're rational (and, possibly, for the fact we seem to have spent some of our evolutionary history as canid-type alpha-pair pack hunters).
I think lions have similar dominance behavior to great apes, since the dominant male is still at risk of being driven out by one of his sons—a good reason for avoiding polygamy, that, the fact a son can get his Oedipus on ("kill your father, get his chicks") without committing incest. But lions are ambush predators and so eye contact can prevent being attacked ("I can see you, you can see me, we better get along"). The exception being if it's actively stalking you, since eye contact there means "oh shit I'm made I better attack now".
Canid pack hunters, since their groups are based around permanent, monogamous, nuclear families, have a more relaxed dominance structure—the extremely aggressive dominance behavior observed with wolves is because most of the wolves being studied were in captivity, and had to patch together packs with unrelated animals. In the wild, wolf and jackal pups just begin to play rougher as they grow up, and establish dominance that way, because all their pack mates, other than their parents, are their siblings. The reason they attack you if you make eye-contact with them is that still means dominance, and you're not a member of their family.
- Anyway, my felinoids are more like jackals (pack-dwelling ambush predators), while the gift-economy dromaeosaurs are more straight-up wolves. Humans, though gregarious apex predators who seem to be shifting toward monogamous alpha-pairs, spent most of their evolutionary history as silverback-and-harem polygamists. Thus their dominance behavior (arising as it does from anti-patricidal defensiveness) is more extreme than that of the more purely pack-based aliens, whose dominant males never had to drive their sons away as rivals, since the only adult females in the social group were the sons' blood-kin. I think the evangelical Heideggerian aliens are more like cape hunting dogs, i.e. they have submission hierarchies rather than dominance and the two sexes track their status separately.
Incidentally it occurred to me there might be some basis for intelligent herbivorous herd animals: elephants. Actually I think the Grunts in Halo are basically tiny elephants. But I'm not certain even that'd work, because, while elephants are as smart as apes (no, seriously), there might be something specific about the way pack-hunters learn that's necessary to the brain of a sapient creature. Hyenas, for example, score much higher on cooperative tests than apes; it may be that cooperation on tasks, which is unquestionably a major portion of human intelligence, isn't a part of the repertoire of foragers. Has anyone tested elephants on cooperative task-completion?
- It seems to me that you have to call the expressions of an alien smiling, frowning, scowling, and so on, even if they don't look anything like when a human does it. Take the felinoids: smiling is ears up, whiskers forward, and especially big smiles also have the eyes partially close. Frowning is the ears turned back, while scowling is the ears flattened against the head. The equivalent of cocking an eyebrow is cocking an ear. Laughter sounds like coughing while purring (roughly the "prusten" sound tigers make), and yes, all sapient species have a sense of humor, learning to like cognitive dissonance (which is the basis of humor) is a major factor in the ability to innovate, sorry Whedon.
I don't have the dromaeosaurs' expressions worked out as extensively, but their smile is raising the feathers under their eyes (which can't close; when they sleep, they dilate their pupils all the way, like snakes). Incidentally I made an error recently, when I said their "voicing" involved two different air-channels through their sinuses. I was going off an old version of my notes. Actually their "voice" involves air sacs like those of a bullfrog, except internal, that are only inflated on certain sounds. Also their nasals are all unvoiced.
- Again, it cannot be stressed enough, every sapient has a sense of humor. Learning to defuse the fear-response that's triggered by cognitive dissonance—which is what they're pretty sure humor is, from a neurological standpoint—is vital if you're going to innovate or experiment in any way. See, most animals don't like new things, ask anyone what dogs and cats do when you move. New things, after all, can be dangerous, and evolution has rewarded organisms for erring on the side of caution.
Seriously, though, why are all aliens so humorless? The only exceptions I can name are C. J. Cherryh's hani, who are still more smart-alecky than funny ha-ha, and that one Elite in Halo 2 who makes a joke about Zealots' habit of kicking down doors and demanding duels ("So much for a stealthy advance.") Oh, and Londo Mollari.
Piece of advice, study ancient and foreign comedy, and then come up with something aliens consider funny. They tried to come up with gags for aliens other than Londo, who again was just a smartass, in Babylon 5, but with highly limited success. But we can do better. Hie thee hence and watch you some un-dubbed Keroro Gunsou or Cromartie High.
De Advenae Vitae II
SF exo-bio-dealy. Chemistry, language, all such things.