I learned a new word today!

Heterotrophs can't even produce their own food smh, sounds like a skill issue if you ask me

Not to get all political but I think it's interesting to try and postulate on the future based on parallels to the past. We know slavery is unethical but one can argue that the forbidding of the practice was only made truly conceivable by technological advancement. Similarly, deep down, I think we understand that eating animals is kind of wrong, eh? Don't get me wrong, I still have a burger, but perhaps we will be seen in the same appalling perspective that we view slavers with today. But, getting ahead of that, and to turn the idea on its head while not needing to lean on current-day things... Why not apply the same logic to heterotrophy? We like to think plants feel no pain but it seems every day, we understand more and more about the mechanics of pain and suffering. Many used to think crabs and lobsters feel nothing when boiled, and that babies feel no pain at all. This has been disproven.

And the other day I saw some graphic that showed stress hormones lighting up in a plant when said plant was damaged. So are we not causing pain by eating plants, however minimal? Now let's analyze that minimal harm in the context of a future civilization. Today we are very fortunate and take many things of yesteryear for granted. Centuries ago, it was common to die of a rotten tooth or live without painkillers. What I'm saying is that, on the grand scale, suffering in our world is reducing, towards 0. So in that context, imagine this hypothetical future civilization, dealing with its own problems yet looking like a utopia in our eyes. This future world where the equivalent of a toothache is seen with as much horror and pity as a crippling injury. A hangnail is worth calling out for, even. That kind of thing. Yet at the same time, extrapolating, that this society is also much more moral than ours... Much of that, because they can afford to be. For they want for not, and have all the luxuries they take for granted, like life extension and Star Trek style replicating. In such a world, fistfights and stealing are inconceivable, no?

But, getting back to the point, if that were you, wouldn't you think eating plants is wrong? You're essentially murdering a living thing and eating its remains for your own pleasure; specially since this hypothetical civilization can probably fuel its anatomy without the need for such primitive means.

(Sorry for rant)

Pivoting a bit, I would like to take something from this headspace of a hypothetical creature like so. What I imagine is abducting the second-person protagonist and subjecting them to experiments to 'correct' them. Turning the protagonist boneless (why have bones if you have a suit?), furless (fur? how primitive!), toothless (nutrient paste will serve you perfectly fine), and worse.

Elaborating on this idea, I have some postulations about what a being might be like. First, I think a degree of alienation is important, and starting from a furry/anthro base feels 'stranger'. I am imagining furless as a necessity due to follicles being enough to interfere with delicate equipment. But also, the overall theme is the usual one, neoteny. I think, in a sense, superficial and otherwise vestigial features would need to go, to improve the being's energy efficiency and reduce weight, caloric requirements, so forth. Every ounce of weight reduction means more fuel for ships, naturally. And if these beings really insist on existing as meatbags as opposed to as infomorphs or machines, then they will spend a disproportionate amount of fuel and resources on travel and self-sustainment... So every bit helps.

Ethically, consuming less resources and light and so forth means there are more resources for other beings to use. In fact, the less the being reproduces the better, but let's lean away from the that line of thought since it trends towards just not existing at all. I don't wanna get into the nitty gritty of how to weigh things, ethically, but I think being more resource efficient and less taxing on the environment in general is always better.

So you see, that's why I feel bones gotta go. Not only are they irrelevant in 0 G, but it's much more efficient to have pressurized tentacles like a squid or so on. Bone marrow's good for blood cells but that can be solved elsewhere or produced with minimal, vestigial bones. I think four tentacles replacing each limb on the mammalian body plan would be a good idea.

Next, every sexual organ should just be removed. Irrelevant, plus reproducing trends towards being unethical, plus genitalia's production of hormones can be better managed elsewhere, like by a pituitary-like gland in the brain. Plus the use of sexual organs for pleasure trends towards bad outcomes, as pleasure could/should be acquired by more fulfilling methods, like accomplishing things. Moreover, genitalia is fundamentally problematic due to association with sex/gender-based oppression; the ideal being clearly has no sex or gender.

Third, all digestive organs should be removed ASAP, as heterotrophy is problematic. Photosynthesis can simply be accompanied via the skin, which is now exposed. Wrinkles on the skin, such as in a sphinx or dog, would help maximize surface area for respiration in this manner. This would also preclude the need for lungs.

I love this!!!!

You make good points here, and they're well thought out. I have issue, however, with passive respiration via the skin. Even if a lifeform were to respirate with its entire skin, it still wouldn't be as efficient a system as the active respiration lungs provide. Look at insects, for example. Admittedly they use spiracles instead of skin, but their passive respiration is a very inefficient system despite their overwhelming biodiversity. A lifeform like this would need to have some sort of active respiration, I feel. As for the limbs, I agree with the manipulatory tentacles idea, and the lack of bones for zero g. Hydraulic musculature would be a very simple and biomechanically sound way of doing such things, as proven by myriad insects and mollusks, though I think having every individual be reproductively viable is better than none, as technological reproduction can lead to other issues - see the Asgard from Stargate for a prime example. Now, if they were to use chemosynthesis instead of photosynthesis, I believe the respiratory issue would be irrelevant - their respiratory needs could be sprayed onto their skin instead of being passively absorbed, and problem solved.

Realistically, I think you're correct; I'm not sure if it'd really be possible to get enough energy from skin respiration, the same kind of issues you'd see with respiration in bugs would be the problem... The body is just too large relative to the surface area. But I think, it's ultimately just biological, no? Same as how right now FTL travel is impossible, and fusion is nearly impossible. I think it'd be like 10% possible to eventually be able to breathe through one's skin, but failing that, I'd be down to give up on that one in order to opt for multiple respiration openings throughout the body or something.

I leaned away from chemosynthesis after thinking about how it'd probably require a digestive tract and therefore an in-hole and an out-hole, which is counter to the aesthetic I was thinking. But you raise a good point that skin absorption of chemicals could be a good way to get around that while providing for energy needs well enough. Synthesizing their hypothetical chemical food in vats and spraying themselves with it (or any of a myriad of application methods) would be cool and dispense with the need for digestive holes.

Lastly, after my last post I mulled over how to resolve the contradiction between reproducing being kind of unethical (forcing beings into this world without their consent) and the need for the viability of species. Ultimately, I think converting other already-existing beings into members of their species would be the best way to resolve the contradiction (while fitting neatly into kink stuff lol). Previously, I've though about how an antinatalist society can resolve their contradictions by cloning themselves or recycling souls or so forth, while occasionally inducting others into their species. But in this case, I am thinking that full conversion of others into more of this hypothetical race would be best--and hangups with consent prove no issue, after all one can simply plant a hypnotic suggestion or so on to make the victim friend eager to become squishy and boneless!

Touching upon antinatalism and the contradictions from that, would be another 'politics/philosophical problem' that such future societies would have to grasp with, along with the afforementioned issues of heterotrophy and so on.

As far as a non-technological failsafe for reproduction, I think because the species would already rely on synthetic food, tech failures would be potentially catastrophic sure, but ultimately something to just live with. But I think, perhaps, the species has well-developed regenerative capabilities (able to regrow whole arms and so on). Perhaps they can convert others simply by touching victims and willing their cells to grow onto the victim, essentially forming a cancer on the victim that comes to overtake their cells. Sure would be a lot of problems with rejecting the 'graft' and whatever but that could be a good basis while tying into TF themes.

(Kind of like nanobots but leaning away from that, because I think they're rather prevalent and a little lazy. Instead, cells of the alien's own body that are developed and specialized enough to serve a bit like nanobots... So, more like xenobots, which I have mentioned before but here's the summary of the idea https://en.wikipedia.org/wiki/Xenobot)

The cellular invasion thing has actually come up in Star Trek: Voyager. Species 8472, an extradimensional, tripedal telepathic race, has an immune system so aggressive that when one slashed Ensign Kim the resultant few cells left in the wound nearly killed him. Now, would other races see this one as friendly? Likely not, but that's where the hypnosis/manipulation would come in. Also, I love discussions like this - speculative biology is one of my biggest hobbies~

Of course, like other questionably ethical things, the issue of needing to convert in order to sustain the species is easy to justify to one's self... Clearly other species just don't know what they're missing out on, converting them would be for their own good. Doing so would alleviate their suffering--Not doing so, is allowing the suffering to exist!

And given how swiftly the brainwashing can work, the vict--new friend, is barely even harmed, really!

Spec evolution is pretty fun, I followed a few subreddits on the subject for a time. If I might recommend, the Serina https://sites.google.com/site/worldofserina/home project is a real masterpiece of that kinda speculative stuff. Very interesting ideas, which I may have lifted here and there for a couple things.

This blog's work on lighter-than-air evolution is also really fascinating and comes to mind when I think of speculative biology https://exocosm.org/2021/03/giant-b.....85272216796875

Serina is amazing, but also kinda depressing at points. I personally am invested in Alex Ries' Birrin Project patreon, as well as Sawyer Lee's dragons. Both are amazing works~

I find a lot of these projects on a youtube channel called Curious Archive, and it's got so much fantastic content~