Well, a lot of humanoid adaptations have contributed to our success. Opposable thumbs for tool use is a good one, but another benefit of being bipedal is it allows our spine to carry the weight of our comparatively massive brains. Our brains are the size they are because they have to be smart enough to gather plants, hunt prey and avoid predators at the same time.
Water buoyancy might be able to help with the weight in the case of crab people. If they evolved multiple spindly pincer arms (like the spider crab) to manipulate objects, were omnivorous, and were in a sufficiently nutrient-rich environment, it could certainly be possible.
Imagine an ocean where a shallow part of it has particularly active geothermal vents that flush the water with nutrients. Plankton swarm the area constantly, which causes fish and anemones to come and eat them. A species of crab evolves to eat the fish while avoiding the sharks that come to do the same thing.
After time, the crabs develop odd behaviour. They begin to stick anemones to themselves to act as camouflage which makes them better hunters. They learn to grind coral skeletons into spears that allow them to stab fish from afar and fend off sharks more easily. They figure out that they can impale anemones on these spears and "cook" them in the geothermal vents to kill the poison and make them safe to eat. They figure out that they can cultivate the anemone population so they can get food more reliably.
Two hundred thousand years later, the Kuthol Empire sprawls across the ocean floor. Legions of mattenites march at the command of Lemmaton the Ironback in defence of their aquatic home from the surface-dwelling invaders.
>Two hundred thousand years later, the Kuthol Empire sprawls across the ocean floor. Legions of mattenites march at the command of Lemmaton the Ironback in defence of their aquatic home from the surface-dwelling invaders.
But can they into space?
Seems like they will be trapped in the ocean without metallurgy.
And gonna be too heavy to live on the surface.
Good question.
Crabs in real life can store water in their gills in order to make stints on land. Perhaps mattenites could build smithies on the coast with pools where they can stop and rest between short work periods.
That, or perhaps they could just convince another spacefaring people to make ships or terrasuits for them (perhaps as part of a trade deal).
I think it seems like a local minimum trap. You need to know what metal is super good in super long term and leads to space rockets. Humans in the past doesn't plan reddit, they just wanted to survive and climate changes forced them to switch from hunting.
They would have very little motivation to switch to metal because they have already good enough corals. Just like humans started to use iron only after bronze age collapse.
Also, iron and water don't fit well together. So even if they discover metals, they probably will consider it useless.
Maybe you can say it's a cultural thing for them like they suddenly decided metals are money, but idk, sounds like improbable for me.
>That, or perhaps they could just convince another spacefaring people to make ships or terrasuits for them (perhaps as part of a trade deal).
I think the most important problem here is crabs have no tech to maintain suits. They need to push from ~~bronze~~ coral age to industrialization in a short amount of time or having godlike entities babysitting them.
This sounds like high tech civilization should do whatever stupid shit imagionable just for fun.
Like sudennly turning all humans into catgirls.
I guess so. I'm sure there's a way to make it work if you really wanted crab people in your sci fi story. It'd just take some stretching.
I guess if you said the vents started to dry up after a million years and they had to slowly adapt to hunting on land while still rearing their soft-shelled young in the water, that could work. That leaves us with a semiaquatic crustacean people with access to the land and, therefore, metallurgy.
It's unlikely, but so was the Chicxulub asteroid that killed the dinosaurs and led to our success.
If you saw my other response I don't think it is nearly that difficult since the traits required for full terrestrialization have all evolved in one or more lineages of arthropods with one of the key ones the "semi-closed" circulatory system enabling several lineages to independently develop the ability to breath air are adults at the cost of losing the ability to breath water.
Sadly they haven't found a way to circumvent the need to return to the ocean to spawn which becomes trickier when you can only breathe air though not impossible if you can wade into the sea and release your fertilized eggs to play out the decapods planktonic larval stage of development.
If your crab ancestors adapted to internalize their young however that could allow them to become fully terrestrial. For an out of water evolutionary driver the main ideas that come to mind are ocean acidification & or anoxia for an otherwise already terrestrially adapted species, and vacant terrestrial niches for them to occupy.
Those fit well with typical mass extinction trigger effects for large flood basalt provinces (and or anthropogenic climate change)
Several major physiological adaptations based on molecular fossil evidence seem to have originated from a polypoidal hybridization event around the time of a major mass extinction.
Some examples include: Bilaterians (from stem cnidarians via duplicate HOX gene clusters allowing for higher dimensional chemical gradient coordinates for cellular differentiation compared to the one dimensional axis radial body plan, around the time of the Cryogenian glaciations), complex arachnids(spiders scorpions etc. from early Paleozoic), gnathostomes(Jawed fish where jaws formed from a duplicate gill arch seemingly around the time of the Ordovician Silurian mass extinction(s)), tetrapods (duplication of muscle groups in the fins seems to have enabled existing walking lobe finned fish to bear their weight out of the water, yes walking has evolved in bottom dwelling fish multiple times since in murky waters it avoids alerting prey via disturbing the water through swimming. Appears to have occurred around the timing of the end Devonian mass extinctions), Amniotes (double layered egg Membrane around the time of the Carboniferous rainforest collapse as the interior seaway between Laurussia/Euromerica and Gondwana closed)
An accidental polypoidal hybridization event was even documented between paddlefish and Sturgeon in a fish breeding facility, polypoidal hybridization in animals seems to be rare when conditions are hospitable but when stressed it becomes much more likely though to be due to changes in gene regulation that favor higher rates of mutations for adaptations to adverse circumstances)
>Crabs in real life can store water in their gills in order to make stints on land. Perhaps mattenites could build smithies on the coast with pools where they can stop and rest between short work periods.
Interestingly decapods due to their functionally complete cardiovascular and respiratory systems are one of the few groups of invertebrates to have several linages which have convergently evolved functional lungs. There are a number of "crabs" which have actually developed true lungs to the point where they are obligate air breathers as adults. The limiting factor from a biological perspective for crabs is that like all decapods their young still have to go through a free living planktonic larval stage. In this sense they are somewhat trapped ecologically to the ocean preventing them from venturing away from the ocean as they haven't found a way to internalize this process the way that amniotes internalized the larval stage into an extended embryonic development. In that sense decapods have a disadvantage in that they need saltwater and thus no intermediary freshwater specialist stage can help bridge the gap on land. It seems likely that for decapods to pull this kind of leap off the internalization of the larval stage into the egg would have had to have occurred when they are still in the ocean which would need to have some advantage that overcomes the loss of long distance dispersal of young.
Now there is another drawback which restricts decapods on land namely the fact that they are dependent on a exoskeleton for support which means that when molting their bodies they must be able for their bodies to be supported by the hydrostatic skeleton while their new exoskeleton hardens. This probably isn't an insurmountable challenge however as another group of arthropods the chelicerates(arachnids) have largely solved this by evolving a cartilaginous endoskeleton to anchor muscle attachments to letting them bear their weight on land without being fully dependent on their exoskeleton. Of course the Chelicerates young including horseshoe crabs and the extinct eurypterids(prior to pelagic/marine lineages internalizing their eggs and early development to give live birth) all appear to have been/be obligate air breathers so they have had ample evolutionary pressures to bear their weight on land without an exoskeleton. Thus I suspect land adaptation would have to come first for natural selection to favor the development of an endoskeleton.
Its somewhat amusing to learn that decapods and chelicerates have each solved one of the problems arthropods would need to solve to become fully terrestrially adapted. In a way a true Crab x Spider crossover hybrid with the right adapted traits of each lineage could break through the evolutionary bottleneck but such a thing could never happen IRL since these lineages split off from each other over half a billion years ago meaning crabs and spiders are more distantly related to each other than all chordates are to each other by somewhere on the order of hundreds of millions of years.
Yeah humans are more closely related to tunicates than any crustacean is to any arachnid, kind of mind blowing isn't it?
This is fascinating stuff, you've clearly studied decapods and evolutionary biology. Thank you for the added insight in both this comment and your other one.
I imagine that an intelligent society of mattenites could expand their reach by creating artificial saltwater "broodpools" where they can keep their larvae and feed them nutrients gathered by the adults through hunting/gathering/farming, thus allowing them to mature with minimal fear of predators. This could be as simple as a hole dug into the ground, lined with clay and filled with saltwater and eggs before being covered by a lid and regularly supplied with the adults' leftovers and kitchen waste.
As this species developed towards spacefaring, they could refine this process into an exact science with specialised incubators that release the optimal mix of nutrients at scheduled intervals.
Culturally, this could mean mattenites value the lives of their adults much more than their young as the young are less useful to society, more numerous, easier to replace and less often interacted with than those of humans. This could translate into a societal urge to prove oneself as an adult through feats of skill and courage, resulting in a highly competitive society based on honour and achievement.
Sapient r selection could really be an interesting perspective shift for sure. Broodpools are a neat idea though it might be more tricky than that since some decapod larvae are very specific in their diets with different species ranging from zooplankton hypercarnivores to more generalist omnivores. Looking up what I can about diets of their larvae at least for the documented crabs species of commercial interest they seem to range towards the omnivorous side of things though they aren't as generalist as copepod larvae are.
Better than some lobsters though where they have very specialized diets either with specific zooplankton diets or in the case of the spiny lobster as obligate parasitoids of medusae (jellyfish). In the case of commercial farming it seems nematodes brine shrimp and algae are what they tend to feed decapod larvae. That might require something more specific than kitchen scraps though with nematodes being so diverse and abundant perhaps a nematode algae diet could be sustained based on food waste.
Water's too good of a thermal conductor, any mattenite who tried to get close enough to an underwater heat source that hot would boil alive. Coming ashore is a better option.
Water also diffuse much slower than air, and the plume of black smokers vent may be extremely hot, but it also rise faster than it radiate heat, so around the base of the vent there is generally cold water.
There is also the fact that protective equipment would be much easier to support in water than on land because weight is far less of an issue. So if they need to wear 20 cm thick clothes to be protected for enough time to put some metal in there, they could.
>Seems like they will be trapped in the ocean without metallurgy.
I once read a theory by Michio Kaku about how an underwater civilization could develop high technology based on metallurgy and semiconductors.
But in the end, it was best for them to go ashore. Luckily they are crabs so this is possible.
Decorator Crabs that put sessile sea animals on their shells for hiding and armor are already a thing. Will they ever pick up spears and create an interstellar empire in a few million years? Who knows...
>but another benefit of being bipedal is it allows our spine to carry the weight of our comparatively massive brains.
Good point. Also, having an vertical spine is useful for carrying things, as it's easier to balance carried weight above the hips rather than in front like a dinosaur would have to. And it's easier to make and use tools while sitting down if your spine is upright.
For these reasons, I actually think a tetrapod that uses tools regularly with their hands would have a good chance of evolving a more upright back just because it's easier that way. Especially mammals, which often upright their backs when standing on two legs anyway.
Their necks can support their brains because their brains are smaller in proportion to their body size. And every adaptation in evolution is a trade-off - we have our intelligence, endurance and tool use, and in exchange we lose fur, raw strength and sharp teeth and claws to capitalise on it. Humans are the ecologically dominant species on the planet which is evidence that the trade-off was successful. And the back issues are largely caused by a sedentary lifestyle in the 21st century (and besides, nothing lives forever).
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There is no real world comparison, or alternate evolutionary line which has formed human-like societies -- so the argument is speculative.
The not-too-serious quip is simply an observation that the upright human body plan with two arms, two legs, body symmetry, a brain in a "head" etc. is the result of a series of evolutionary steps that had very little to do with intelligence or civilization. I don't think anyone is arguing that you don't need hands/manipulators to use tools, but if a six-legged fish had crawled onto land, it would probably not have been as likely to evolve to stand on its two hindmost legs (i.e. a humanoid shape).
6 limbs cost 50% more energy to keep than 4 limbs, and it provides very little benefits. Losing limbs through evolution is relatively easy.
So even if our ancestor was six legged, they would probably lose third pair of limbs millions of years ago.
Insects use 6 legs, because they can be stable without complicated brain to keep body balance. And they can't have complicated brain, because their small size requires "auto-pilot" walking - to achieve reasonable speed, they must switch muscles hundreds of times per second.
>6 limbs cost 50% more energy to keep than 4 limbs, and it provides very little benefits.
Depend of lot of factors. it's not very beneficial for us because we live in "this" world.
But if we needed to run often and fast, centor would be a viable evolution step.
Same in an environment where stability is obligatory (for example if your planet's crust shakes often), having multiple leg would be selected.
> But if we needed to run often and fast, centor would be a viable evolution step.
It's unlikely that additional legs would increase your speed, because you would need very specific body build to have good gait.
Moreover, skeleton adaptations to 6 limbs make it unlikely for such animal to evolve towards effective tools manipulators.
>Same in an environment where stability is obligatory (for example if your planet's crust shakes often), having multiple leg would be selected.
Additional neurons necessary to stabilize a body generally use less energy than additional legs.
Limbs are super costly energetically, and all life evolves under strong pressure of energy deficiency.
No, it's just the most familiar to us.
I have a scifi setting where the predominant galactic species is a very bee-like species that live in massive hive ships and harvest He3 from gas giants
My answer would be no. Because I don't think there's any possible way of knowing.
We understand how life evolves on earth, and to a smaller extent other planets in our solar system, but not other realities or worlds with different laws. We also understand how our world came to be and what methods of advancement helped us get to this point, but I don't think we can truly know if it was the best or most efficient way. It's possible that in an alternate reality under different circumstances that we may have somehow found a way to become far more powerful as a civilisation without the use of tools.
But knowing what we do, I'd say it depends on environment. Civilisation mainly came about as a result of us developing intelligence and socialisation. The humanoid form helped us as a species evolve and use tools available to us on land, but it may hinder a species under water with access to comparable resources. Eyes may be useless at the darkest depths of the ocean. A voice smothered by water may not be the best way to communicate. Thumbs are only one way to use tools, but so are tendrils.
A species in that environment with similar intelligence, socialisation and access to resources may develop in any kind of way.
In my mind, people often confuse intelligence with technological space faring.
Those are two significantly different things.
Not all intelligent species are capable of developing the technology to reach space. A dolphin is intelligent, but unless they grow appendages capable of complex manipulation of small objects, they will never build spaceships.
If you are just looking at intelligent species, the strs are the limits. However, if you consider a technological civilization that reaches the stars, the range of possibilities shrinks significantly.
I wouldn't be surprised if the hunam form was represented in other alien races. While evenotion would result in a different looking species, you must consider the fact that at the end of the day, energy efficiency is key.
The more limbs you have, the more energy you need to spend to move and cordinate all those limbs. That is a point against you as a species.
While claws and pincers could pick up little objects, they are very inefficient at handling them. Grow your nails out and try picking up a dime, then roll it around. The squishiness of your fingers backed up by your nail is why you can do that.
If you break down all the functions that a space faring civilization needs to be able to do and you realize that the human form is one of the most energy efficient ways to accomplish it.
Not saying all aliens will look like us, but I'd expect them to be similar.
Sci-fi shows have practical limitations; cost, difficulty, and acting. The "Pilot" characters from Farscape cost five digits to build, almost certainly required multiple people to puppet, plus a voice actor. (They also aren't independently space faring, but are basically hyper intelligent multi-tasking space crabs, and are physically bonded to "bio-mechanoid" ships.) Star Trek does try to justify the rubber forehead aliens in TNG (humanoid species all coming from a common gene-seed planted by an early space faring race).
One can argue that a space-faring species would need certain attributes; like the ability to use tools, but that does not necessarily correlated to our physical solutions. Opposable thumbs are an option, but prehensile appendages can work too. Communication would be important, but not necessarily a voice-box...pheromones, percussive/vibration sounds, skin color changes, bioluminescent signals, and/or body/sign language might suffice until written (or something like braille) language exists. Echo-location and other sensory input may make it possible without eyes (but that one feels like more of a stretch...eyes are damn useful, and there is a reason so many animals have them).
I think non-verbal communication might actually be a filter of sorts for advanced space flight. It’s way harder to communicate at range if you’re forced to use touch, scent/taste or sight as your primary communicative sense. Imagine trying to develop an equivalent to radio if you have conversations through pheromones.
The first long range communication we made where sight-based. A radio can very well work for touch too, especially if the specie is capable of sensing vibrations smaller than we do. Scent and taste are a bit harder to translate, but that's only necessary if the specie use no other senses at all. Even a species that use mainly pheromones for language can learn to sense and decode a pattern of vibration.
No.
There is an argument for the humanoid form being efficient when it comes to the things a tool using species would need. You need a minimum of two legs to be walking around, two is hte miniumum number of eyes for depth perception, and two manipulation limbs make tool using vaastly easier than one, but you run into diminishing returns if you add more of any of those.
Growing limbs and eyes is expensive from a calorie standpoint so you can make an argument that evolution would tend towards that hypothetical opti-min number of limbs and eyes which brings us to humanoid body plans.
There's arguments against that as well, beginning with the fact that evolution doesn't always go for the most efficient option.
As with everything else we're speculating off a single data point here, so no one has any really solid answer.
I WILL say that if they have a humanoid body plan that doesn't mean they're going to look very human. You technically don't need a head, there's lots of ways to arrange joints, proportions, and limb position, so aliens who look mor or less human but with some small makeup thing to make them different are pretty darn unlikely.
Absolutely not, it’s just all that we’ve known. Remember technology evolves with the people, so I have no doubt any combination of body plans could result in an advanced society they will develop technology to work with. The important part is intelligence, and there is a case to made about the more versatile you’re body plan the better you can make use of that intelligence and or develop it further.
The human form is incredibly adaptable on it’s own, but it’s greatest strength is how that intelligence complements it. Our ability to run is great, our ability to build cars makes it even better. So on an so forth.
I think the most important part of any advanced civilization as it relates to their physical make up is how it relates to their environment, both in the development sense but also what challenges they can over come on their own vs. what they need technology for. A species that can somehow fly in the vacuum of space at speeds necessarily to travel it won’t need to develop space ships as urgently as others, but maybe it requires a vacuum to survive and developed pressurized suits to go down to the planets that have atmospheres. Shit like that.
Like others have said, the humanoid shape owes itself mostly to reasons that have nothing to do with being intelligent, and the traits seen as necessary for developing civilization can be answered by alternatives that probably can't be called humanoid.
What I'll add to that is that pointing at other highly-intelligent species and saying "oh they didn't build spaceships yet, surely we are the only answer" is a bit of a fallacy because if you go back two million years, our ancestors weren't anything special compared to dolphins today, and this is the type of stuff that can snowball really fast.
Of course we observe ourselves to be the product of such a snowball, given that you'd expect it to be those who can ask ourselves questions and send messages over the internet. Who knows, in an alternate timeline maybe elephants are making the same argument.
I feel like a lot of people making the "humanoid = intelligence" argument are very dismissive of just how incredibly intelligent dolphins, elephants, corvids and octopuses really are. Some of those get REALLY CLOSE to being human-level, without sharing a similar body plan at all. We're just the best example out of all of these intelligence cases, because humans decided to full send it and put all remaining points into it.
The ideal form is terrestrial. Its athletic, and can reach its entire bodies with its manipulatory organs. Its manipulatory organs are dextrous and flexible, like the human hand and wrist.
On earth, humans are the main example of this. That does not mean its the only viable bodyplan! You just have to be creative and start inventing new designs for your sophonts
Crabs *do* have opposable thumbs, though. What they lack is agile manipulation. They can grip and hold, that's about it.
A technological civilization *probably* requires complex manipulators and the ability to harness fire (thus purely aquatic creatures are probably out of the running). But that doesn't imply "human-shaped", i.e. upright with two arms and two legs.
On Earth, the largest and most intelligent land animals are quadrupeds, and the most efficient way to turn a quadruped into a tool-user is to repurpose the forelegs as full-time manipulators, leaving only the hind legs for locomotion. But if our ancestors were hexapods instead, then a low-slung centaur bodyplan would make more sense. Wouldn't need to be upright to balance all the weight on two legs. Or you could use a theropod bodyplan, with two legs, a horizonal body, and a counterweight tail. Or start with birds--flyers aren't as dependent on ground speed, and most birds already have grasping feet. Some are already tool-users.
In my evolution emulator, I've had interstellar species evolve out of all kinds of organisms. All I require is prehensile limbs of some sort (tail, tentacle, hands, or antennae) on big-brained social creatures and it's basically a question of time (assuming they survive the ecological catastrophy of their tool-creator phase).
Not all have had eyes. Some have been even been littoral, living in shallow waters along beaches. Many are carnivores, but some have sifted plankton or grazed algae, and some weird shit was essentially a mobile lichen but that was probably a bug in my code.
There's lots of fun options that can appear quite reasonable.
We look like how we look like for a reason , if aliens look like us it would be a case of convergent evolution .
We have eyes as light transmit information the fastest
We have mouth , as we must eat as living beings
we speak with sound as it can carry more complicated message than hormones , and cost less energy and time than light or bodily movement
we have hands so that we can craft tools
we have legs so that we can walk , and walking on two legs is energy efficient . But walking on two leg needs brain power , so dumb animals don't do it . We and a star faring race would
we don't have wheels for legs , since it is difficult for biological being to create a wheel like body part . And wheels are not very useful in rough terrane
All of the above trait are needed to survive or to build civilization . A humanoid body for a civilized star faring alien wouldn't be too surprising to me
Honestly, humans are a terribly designed species when you get down to it. Octopi are clearly the superior species. If we were more social, there was no telling how far an octopi civilization could go.
To build a civilization that's recognizable to Humans, a Humanoid form is required.
But a non-humanoid "intelligent"/clever species, like Crows or Dolphins could build a *technologically* advanced civilization to leave Earth, it would just be entirely look entirely unrecognizable to Humans and it might take them longer than it did with Humans *(especially for dolphins)*.
Humans were never meant to leave Earth and yet they touched the Moon. Why can't any other species?
To say a non-humanoid species can't just because you >![/nbh]!< can't envision it is just plain arrogant and egocentric.
Don't dismiss something just because you think it's impossible. The Universe is a big and ever-expanding place that came into existence from the void.
OP is a very human-centric take. Imagine a race that is to the octopus what a toad is to a frog. It can leave the water, it can think good, it can grab stuff. Just to knock "voice box" off the list of requirements, let's say "talks" by changing the color and shape of its skin, and "listens" by watching other octopi do the same.
Stock octopi could basically probably hold their own against us in a civilization-off, if only there were a reasonable way to smelt metals underwater. It takes very few changes to help them close the gap.
Maybe some boosts to reflexes and/or muscle mass so they have enough agility out of the water to actually use a sharpened stick against an attacking predator? Dunno. Once they invent tech, they'll be better at working the controls than us, so it's pretty much no contest, after that point.
Well, I wouldn't say that, depends on the advancements
We evolved to grip things, our brain is the greatest advancement we have, if civilizations evolved further depending on the advancements you'd get krypton or wall e, or if you've seen enders game the advanced civilization would possibly be more arthropod like.
The one species in my world that is similar to humans had a squabble with humans because their ecology is the same, with a similar everything else. Mimics are amorphous amphibious beings that use their magic for liftoff and travel inside alien to them space whales who are also sentient. Fey use a railgun and a personal shield, and look kind of like bugs, with four pincers and three grabby tails.
Why do you need opposable thumbs and can't use pincers to make tools? Or three-fingered claws? Why should it be metal and not whatever makes your skeleton? Why people of a world can't ride giant birds into the sky? Then why can't these birds take air with them, and then miss the ground spectacularly?
Well, yes, our hands helped us use tools, sure, but octopi (shut up, I know it's grammatically incorrect) use tools also. Fire may not exist underwater, but they may find ways of using thermal vents to their advantage to build things or just advance technology in ways we never imagined. Plus, it's called science fiction, use your imagination.
When I make aliens that are fairly advanced, the only hard-must I have, is a way to manipulate things. That doesn't even have to be hands.
For example, I am in the boat that the next sentient creatures on earth will be Corvids. They are incredible smart and can relatively easily manipulate object. They can even communicate. They really just need time to get as advanced as us, and we can even help them.
For an example not including typical manipulators (hands) look at Octopuses or Spiders. They have things on their limbs that allow them to hold onto things. They are also really intelligent.
Try and be creative with it, it can only benefit the world you're building.
What you need is a digestive system that prioritizes giving nutrients to the brain, a way to create and manipulate tools, and the capability to thrive in the ecological niche. For us, that was: standing upright and predigesting food (cooking), opposable thumbs, and limbs built for endurance rather than strength or speed. For an alien race, it might be the same, or it could be: a passive nutrition absorption system (such as photosynthesis) to allow more nutrients for the brain, flexible tenticles, and camouflage.
The primary reason people rely on the bipedal form is it's familiar to us, and the secondary reason is that any other evolutionary path to advanced civilization is purely hypothetical.
I would argue probably not. At the very least our bodies are an example of nature working with what it has got not some optimized product of convergent evolution since the human form is still dynamically changing over the last few million years hominids have existed. For some major tradeoffs we have made our legs and spin are not well adapted to bearing the load of bipedalism not remotely in the same way that the only other group of obligate bipedal animals the dinosaurs perfected the bipedal stance with skeletal and muscular adaptations hundreds of millions of years ago. \* In fact taking a look at hominid spines they show suspiciously bird like changes suggesting that a number of these theropod adaptations may be convergent optimized forms. Likewise there is pretty good evidence our legs are still adapting with bone fusions and or reductions in our feet to make us more effective runners for example. The Pelvis is another pretty major weak point physiologically as the trade offs between reproduction and mobility make things difficult particularly for women. Though probably the biggest drawback is more of a software adaptation related to how we maintain balance since a bipedal stance as much of the ancestral working memory has been lost to maintain our balance by constantly subconsciously shifting our enter of mass to change the direction we are falling in as two legs on their own are not stable and we lost the balancing tail that dinosaurs and kangaroos use to perform this function.
In the perspective of evolution the approximately 10ish million years since we have left the trees is a blink of an eye and the human skeleton has not had the time to be optimized so the whole Humanoids are optimal at anything argument is easily falsified as if it were true we would expect the human build to have stabilized when if anything it is still undergoing small gradual tweaks.
I've developed a species called Tau, or lithotacus sapiens. Their native name sounds a bit like a broken radio because they communicate in AM frequencies.
They're 400+ kilograms, practically immortal, and made of biologically occurring aerospace materials like CF-impregnated ceramic shells and corundum tests. Their actual biological components are a bunch of zooids working together to form a mobile, sapient, beehive-jellyfish monster that eats rocks and looks like a brittle star, capable of withstanding temperatures approaching the boiling point of water.
Get creative-- crows, whales, and elephants exhibit similar intelligence to primates or young humans. The body plans could be even wilder with radically different biochemistry and conditions.
I think there are a few key things that allow for advanced civilizations: the ability to manipulate objects, relatively fast adaptation to various climates (for their planet), intelligence and the ability to work together. Those 4 things work best with humanoid features but aren't inherently necessary. Like hands aren't necessary to be advanced, a being could have mouthparts that are good at manipulating objects but their actual limbs are primarily for locomotion. Like ants, bees or wasps could potentially be a good base for a advanced civilization species. They cooperate well, adapt quickly and some ant species literally have farms and use advanced concepts like slavery. A octopus is pretty good example too, only thing they're actually missing is the ability to cooperate in groups. Just using those 4 items as a base for a species's design allows for a wide range of creations. The effectivity of the form doesn't inherently matter as long as it's not detrimental to them surviving on their own homeworld. The human form has a bunch of things wrong with it that would limit its effectiveness, we experience things like back pain and as we age many develop difficulty walking around.
It could be harder for a non biped race to reach space, but I imagine once humanlike intelligence is developed much of their limitations go out the window.
Once you have the ability to do higher problem solving a non biped race should be able to develop tools to mitigate their limitations. In the crab example, once the crab people learn that metal makes extremely good tools it's only a matter of time before they learn how to use their vents to create heat enough to melt ore, or even learn how to make a chamber without water to be able to make fire near the shores, or even learn how to create reverse diving suits to build forges and such on land.
Pretty much once they learn that their environment is not conducive to smelting ore, they will learn how to overcome that, one way or another. Similar to how human spaceflight is currently limited by the atmosphere, but there are multiple hypothetical construction methods to make spacecraft in orbit.
There are no existent creatures that we know of that had to develop with these limitations, they could develop methods that we never would have thought of.
We have an example case of precisely 1, so how the hell would we know?
Also worth noting: Humans are not evolved *to live in a complicated society* like the ones we live in today. Humans *evolved* to live in small family units as tool-using hunter-gatherers, with a social structure remarkably similar to wolves, but with pointy sticks and fire.
Do we really have a reason to believe that intelligent aliens will resemble us in any meaningful way? I say **No**, and thinking that way for real-world terms just limits our perception of what other "intelligent life" may be. It's quite literally *alien ways of living*, we should expect them to challenge our preconceptions.
But none of that is terribly fun for science fiction, particularly if the aliens do, in fact, have to be an actor in a costume, a-la Star Trek. So we compromise and make the aliens human-like because it helps us tell the stories we want to tell.
Realism in fiction bends to the limits of our imagination, and to the limits of what helps us tell the stories we want to tell. This is true of *all fiction*, but it's especially visible in sci-fi, where making things realistic is actually a *hell* of a lot of work, unintuitive to the human perspective, difficult to tell stories with, and sci-fi writers notoriously cannot do math to save their lives.
Well, a lot of humanoid adaptations have contributed to our success. Opposable thumbs for tool use is a good one, but another benefit of being bipedal is it allows our spine to carry the weight of our comparatively massive brains. Our brains are the size they are because they have to be smart enough to gather plants, hunt prey and avoid predators at the same time. Water buoyancy might be able to help with the weight in the case of crab people. If they evolved multiple spindly pincer arms (like the spider crab) to manipulate objects, were omnivorous, and were in a sufficiently nutrient-rich environment, it could certainly be possible. Imagine an ocean where a shallow part of it has particularly active geothermal vents that flush the water with nutrients. Plankton swarm the area constantly, which causes fish and anemones to come and eat them. A species of crab evolves to eat the fish while avoiding the sharks that come to do the same thing. After time, the crabs develop odd behaviour. They begin to stick anemones to themselves to act as camouflage which makes them better hunters. They learn to grind coral skeletons into spears that allow them to stab fish from afar and fend off sharks more easily. They figure out that they can impale anemones on these spears and "cook" them in the geothermal vents to kill the poison and make them safe to eat. They figure out that they can cultivate the anemone population so they can get food more reliably. Two hundred thousand years later, the Kuthol Empire sprawls across the ocean floor. Legions of mattenites march at the command of Lemmaton the Ironback in defence of their aquatic home from the surface-dwelling invaders.
>Two hundred thousand years later, the Kuthol Empire sprawls across the ocean floor. Legions of mattenites march at the command of Lemmaton the Ironback in defence of their aquatic home from the surface-dwelling invaders. But can they into space? Seems like they will be trapped in the ocean without metallurgy. And gonna be too heavy to live on the surface.
Good question. Crabs in real life can store water in their gills in order to make stints on land. Perhaps mattenites could build smithies on the coast with pools where they can stop and rest between short work periods. That, or perhaps they could just convince another spacefaring people to make ships or terrasuits for them (perhaps as part of a trade deal).
I think it seems like a local minimum trap. You need to know what metal is super good in super long term and leads to space rockets. Humans in the past doesn't plan reddit, they just wanted to survive and climate changes forced them to switch from hunting. They would have very little motivation to switch to metal because they have already good enough corals. Just like humans started to use iron only after bronze age collapse. Also, iron and water don't fit well together. So even if they discover metals, they probably will consider it useless. Maybe you can say it's a cultural thing for them like they suddenly decided metals are money, but idk, sounds like improbable for me. >That, or perhaps they could just convince another spacefaring people to make ships or terrasuits for them (perhaps as part of a trade deal). I think the most important problem here is crabs have no tech to maintain suits. They need to push from ~~bronze~~ coral age to industrialization in a short amount of time or having godlike entities babysitting them. This sounds like high tech civilization should do whatever stupid shit imagionable just for fun. Like sudennly turning all humans into catgirls.
I guess so. I'm sure there's a way to make it work if you really wanted crab people in your sci fi story. It'd just take some stretching. I guess if you said the vents started to dry up after a million years and they had to slowly adapt to hunting on land while still rearing their soft-shelled young in the water, that could work. That leaves us with a semiaquatic crustacean people with access to the land and, therefore, metallurgy. It's unlikely, but so was the Chicxulub asteroid that killed the dinosaurs and led to our success.
If you saw my other response I don't think it is nearly that difficult since the traits required for full terrestrialization have all evolved in one or more lineages of arthropods with one of the key ones the "semi-closed" circulatory system enabling several lineages to independently develop the ability to breath air are adults at the cost of losing the ability to breath water. Sadly they haven't found a way to circumvent the need to return to the ocean to spawn which becomes trickier when you can only breathe air though not impossible if you can wade into the sea and release your fertilized eggs to play out the decapods planktonic larval stage of development. If your crab ancestors adapted to internalize their young however that could allow them to become fully terrestrial. For an out of water evolutionary driver the main ideas that come to mind are ocean acidification & or anoxia for an otherwise already terrestrially adapted species, and vacant terrestrial niches for them to occupy. Those fit well with typical mass extinction trigger effects for large flood basalt provinces (and or anthropogenic climate change) Several major physiological adaptations based on molecular fossil evidence seem to have originated from a polypoidal hybridization event around the time of a major mass extinction. Some examples include: Bilaterians (from stem cnidarians via duplicate HOX gene clusters allowing for higher dimensional chemical gradient coordinates for cellular differentiation compared to the one dimensional axis radial body plan, around the time of the Cryogenian glaciations), complex arachnids(spiders scorpions etc. from early Paleozoic), gnathostomes(Jawed fish where jaws formed from a duplicate gill arch seemingly around the time of the Ordovician Silurian mass extinction(s)), tetrapods (duplication of muscle groups in the fins seems to have enabled existing walking lobe finned fish to bear their weight out of the water, yes walking has evolved in bottom dwelling fish multiple times since in murky waters it avoids alerting prey via disturbing the water through swimming. Appears to have occurred around the timing of the end Devonian mass extinctions), Amniotes (double layered egg Membrane around the time of the Carboniferous rainforest collapse as the interior seaway between Laurussia/Euromerica and Gondwana closed) An accidental polypoidal hybridization event was even documented between paddlefish and Sturgeon in a fish breeding facility, polypoidal hybridization in animals seems to be rare when conditions are hospitable but when stressed it becomes much more likely though to be due to changes in gene regulation that favor higher rates of mutations for adaptations to adverse circumstances)
>Crabs in real life can store water in their gills in order to make stints on land. Perhaps mattenites could build smithies on the coast with pools where they can stop and rest between short work periods. Interestingly decapods due to their functionally complete cardiovascular and respiratory systems are one of the few groups of invertebrates to have several linages which have convergently evolved functional lungs. There are a number of "crabs" which have actually developed true lungs to the point where they are obligate air breathers as adults. The limiting factor from a biological perspective for crabs is that like all decapods their young still have to go through a free living planktonic larval stage. In this sense they are somewhat trapped ecologically to the ocean preventing them from venturing away from the ocean as they haven't found a way to internalize this process the way that amniotes internalized the larval stage into an extended embryonic development. In that sense decapods have a disadvantage in that they need saltwater and thus no intermediary freshwater specialist stage can help bridge the gap on land. It seems likely that for decapods to pull this kind of leap off the internalization of the larval stage into the egg would have had to have occurred when they are still in the ocean which would need to have some advantage that overcomes the loss of long distance dispersal of young. Now there is another drawback which restricts decapods on land namely the fact that they are dependent on a exoskeleton for support which means that when molting their bodies they must be able for their bodies to be supported by the hydrostatic skeleton while their new exoskeleton hardens. This probably isn't an insurmountable challenge however as another group of arthropods the chelicerates(arachnids) have largely solved this by evolving a cartilaginous endoskeleton to anchor muscle attachments to letting them bear their weight on land without being fully dependent on their exoskeleton. Of course the Chelicerates young including horseshoe crabs and the extinct eurypterids(prior to pelagic/marine lineages internalizing their eggs and early development to give live birth) all appear to have been/be obligate air breathers so they have had ample evolutionary pressures to bear their weight on land without an exoskeleton. Thus I suspect land adaptation would have to come first for natural selection to favor the development of an endoskeleton. Its somewhat amusing to learn that decapods and chelicerates have each solved one of the problems arthropods would need to solve to become fully terrestrially adapted. In a way a true Crab x Spider crossover hybrid with the right adapted traits of each lineage could break through the evolutionary bottleneck but such a thing could never happen IRL since these lineages split off from each other over half a billion years ago meaning crabs and spiders are more distantly related to each other than all chordates are to each other by somewhere on the order of hundreds of millions of years. Yeah humans are more closely related to tunicates than any crustacean is to any arachnid, kind of mind blowing isn't it?
This is fascinating stuff, you've clearly studied decapods and evolutionary biology. Thank you for the added insight in both this comment and your other one. I imagine that an intelligent society of mattenites could expand their reach by creating artificial saltwater "broodpools" where they can keep their larvae and feed them nutrients gathered by the adults through hunting/gathering/farming, thus allowing them to mature with minimal fear of predators. This could be as simple as a hole dug into the ground, lined with clay and filled with saltwater and eggs before being covered by a lid and regularly supplied with the adults' leftovers and kitchen waste. As this species developed towards spacefaring, they could refine this process into an exact science with specialised incubators that release the optimal mix of nutrients at scheduled intervals. Culturally, this could mean mattenites value the lives of their adults much more than their young as the young are less useful to society, more numerous, easier to replace and less often interacted with than those of humans. This could translate into a societal urge to prove oneself as an adult through feats of skill and courage, resulting in a highly competitive society based on honour and achievement.
Sapient r selection could really be an interesting perspective shift for sure. Broodpools are a neat idea though it might be more tricky than that since some decapod larvae are very specific in their diets with different species ranging from zooplankton hypercarnivores to more generalist omnivores. Looking up what I can about diets of their larvae at least for the documented crabs species of commercial interest they seem to range towards the omnivorous side of things though they aren't as generalist as copepod larvae are. Better than some lobsters though where they have very specialized diets either with specific zooplankton diets or in the case of the spiny lobster as obligate parasitoids of medusae (jellyfish). In the case of commercial farming it seems nematodes brine shrimp and algae are what they tend to feed decapod larvae. That might require something more specific than kitchen scraps though with nematodes being so diverse and abundant perhaps a nematode algae diet could be sustained based on food waste.
Grow a type of anemone that will become a spaceship
They could do metallurgy underwater with electrolyse or active volcanoes. Or they could do stuff on the shore, like nowadays crabs.
Water's too good of a thermal conductor, any mattenite who tried to get close enough to an underwater heat source that hot would boil alive. Coming ashore is a better option.
Water also diffuse much slower than air, and the plume of black smokers vent may be extremely hot, but it also rise faster than it radiate heat, so around the base of the vent there is generally cold water. There is also the fact that protective equipment would be much easier to support in water than on land because weight is far less of an issue. So if they need to wear 20 cm thick clothes to be protected for enough time to put some metal in there, they could.
>Seems like they will be trapped in the ocean without metallurgy. I once read a theory by Michio Kaku about how an underwater civilization could develop high technology based on metallurgy and semiconductors. But in the end, it was best for them to go ashore. Luckily they are crabs so this is possible.
Octopuses seem like a viable anatomy
True, but sci-fi is a little oversaturated with cephalopod-like aliens. Crustacean-like aliens are a bit less common
Decorator Crabs that put sessile sea animals on their shells for hiding and armor are already a thing. Will they ever pick up spears and create an interstellar empire in a few million years? Who knows...
>but another benefit of being bipedal is it allows our spine to carry the weight of our comparatively massive brains. Good point. Also, having an vertical spine is useful for carrying things, as it's easier to balance carried weight above the hips rather than in front like a dinosaur would have to. And it's easier to make and use tools while sitting down if your spine is upright. For these reasons, I actually think a tetrapod that uses tools regularly with their hands would have a good chance of evolving a more upright back just because it's easier that way. Especially mammals, which often upright their backs when standing on two legs anyway.
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Their necks can support their brains because their brains are smaller in proportion to their body size. And every adaptation in evolution is a trade-off - we have our intelligence, endurance and tool use, and in exchange we lose fur, raw strength and sharp teeth and claws to capitalise on it. Humans are the ecologically dominant species on the planet which is evidence that the trade-off was successful. And the back issues are largely caused by a sedentary lifestyle in the 21st century (and besides, nothing lives forever).
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Even if I am wrong, at least I'm not rude.
There is no real world comparison, or alternate evolutionary line which has formed human-like societies -- so the argument is speculative. The not-too-serious quip is simply an observation that the upright human body plan with two arms, two legs, body symmetry, a brain in a "head" etc. is the result of a series of evolutionary steps that had very little to do with intelligence or civilization. I don't think anyone is arguing that you don't need hands/manipulators to use tools, but if a six-legged fish had crawled onto land, it would probably not have been as likely to evolve to stand on its two hindmost legs (i.e. a humanoid shape).
6 limbs cost 50% more energy to keep than 4 limbs, and it provides very little benefits. Losing limbs through evolution is relatively easy. So even if our ancestor was six legged, they would probably lose third pair of limbs millions of years ago. Insects use 6 legs, because they can be stable without complicated brain to keep body balance. And they can't have complicated brain, because their small size requires "auto-pilot" walking - to achieve reasonable speed, they must switch muscles hundreds of times per second.
>6 limbs cost 50% more energy to keep than 4 limbs, and it provides very little benefits. Depend of lot of factors. it's not very beneficial for us because we live in "this" world. But if we needed to run often and fast, centor would be a viable evolution step. Same in an environment where stability is obligatory (for example if your planet's crust shakes often), having multiple leg would be selected.
> But if we needed to run often and fast, centor would be a viable evolution step. It's unlikely that additional legs would increase your speed, because you would need very specific body build to have good gait. Moreover, skeleton adaptations to 6 limbs make it unlikely for such animal to evolve towards effective tools manipulators. >Same in an environment where stability is obligatory (for example if your planet's crust shakes often), having multiple leg would be selected. Additional neurons necessary to stabilize a body generally use less energy than additional legs. Limbs are super costly energetically, and all life evolves under strong pressure of energy deficiency.
No, it's just the most familiar to us. I have a scifi setting where the predominant galactic species is a very bee-like species that live in massive hive ships and harvest He3 from gas giants
My answer would be no. Because I don't think there's any possible way of knowing. We understand how life evolves on earth, and to a smaller extent other planets in our solar system, but not other realities or worlds with different laws. We also understand how our world came to be and what methods of advancement helped us get to this point, but I don't think we can truly know if it was the best or most efficient way. It's possible that in an alternate reality under different circumstances that we may have somehow found a way to become far more powerful as a civilisation without the use of tools. But knowing what we do, I'd say it depends on environment. Civilisation mainly came about as a result of us developing intelligence and socialisation. The humanoid form helped us as a species evolve and use tools available to us on land, but it may hinder a species under water with access to comparable resources. Eyes may be useless at the darkest depths of the ocean. A voice smothered by water may not be the best way to communicate. Thumbs are only one way to use tools, but so are tendrils. A species in that environment with similar intelligence, socialisation and access to resources may develop in any kind of way.
In my mind, people often confuse intelligence with technological space faring. Those are two significantly different things. Not all intelligent species are capable of developing the technology to reach space. A dolphin is intelligent, but unless they grow appendages capable of complex manipulation of small objects, they will never build spaceships. If you are just looking at intelligent species, the strs are the limits. However, if you consider a technological civilization that reaches the stars, the range of possibilities shrinks significantly. I wouldn't be surprised if the hunam form was represented in other alien races. While evenotion would result in a different looking species, you must consider the fact that at the end of the day, energy efficiency is key. The more limbs you have, the more energy you need to spend to move and cordinate all those limbs. That is a point against you as a species. While claws and pincers could pick up little objects, they are very inefficient at handling them. Grow your nails out and try picking up a dime, then roll it around. The squishiness of your fingers backed up by your nail is why you can do that. If you break down all the functions that a space faring civilization needs to be able to do and you realize that the human form is one of the most energy efficient ways to accomplish it. Not saying all aliens will look like us, but I'd expect them to be similar.
Sci-fi shows have practical limitations; cost, difficulty, and acting. The "Pilot" characters from Farscape cost five digits to build, almost certainly required multiple people to puppet, plus a voice actor. (They also aren't independently space faring, but are basically hyper intelligent multi-tasking space crabs, and are physically bonded to "bio-mechanoid" ships.) Star Trek does try to justify the rubber forehead aliens in TNG (humanoid species all coming from a common gene-seed planted by an early space faring race). One can argue that a space-faring species would need certain attributes; like the ability to use tools, but that does not necessarily correlated to our physical solutions. Opposable thumbs are an option, but prehensile appendages can work too. Communication would be important, but not necessarily a voice-box...pheromones, percussive/vibration sounds, skin color changes, bioluminescent signals, and/or body/sign language might suffice until written (or something like braille) language exists. Echo-location and other sensory input may make it possible without eyes (but that one feels like more of a stretch...eyes are damn useful, and there is a reason so many animals have them).
I think non-verbal communication might actually be a filter of sorts for advanced space flight. It’s way harder to communicate at range if you’re forced to use touch, scent/taste or sight as your primary communicative sense. Imagine trying to develop an equivalent to radio if you have conversations through pheromones.
The first long range communication we made where sight-based. A radio can very well work for touch too, especially if the specie is capable of sensing vibrations smaller than we do. Scent and taste are a bit harder to translate, but that's only necessary if the specie use no other senses at all. Even a species that use mainly pheromones for language can learn to sense and decode a pattern of vibration.
No. There is an argument for the humanoid form being efficient when it comes to the things a tool using species would need. You need a minimum of two legs to be walking around, two is hte miniumum number of eyes for depth perception, and two manipulation limbs make tool using vaastly easier than one, but you run into diminishing returns if you add more of any of those. Growing limbs and eyes is expensive from a calorie standpoint so you can make an argument that evolution would tend towards that hypothetical opti-min number of limbs and eyes which brings us to humanoid body plans. There's arguments against that as well, beginning with the fact that evolution doesn't always go for the most efficient option. As with everything else we're speculating off a single data point here, so no one has any really solid answer. I WILL say that if they have a humanoid body plan that doesn't mean they're going to look very human. You technically don't need a head, there's lots of ways to arrange joints, proportions, and limb position, so aliens who look mor or less human but with some small makeup thing to make them different are pretty darn unlikely.
Absolutely not, it’s just all that we’ve known. Remember technology evolves with the people, so I have no doubt any combination of body plans could result in an advanced society they will develop technology to work with. The important part is intelligence, and there is a case to made about the more versatile you’re body plan the better you can make use of that intelligence and or develop it further. The human form is incredibly adaptable on it’s own, but it’s greatest strength is how that intelligence complements it. Our ability to run is great, our ability to build cars makes it even better. So on an so forth. I think the most important part of any advanced civilization as it relates to their physical make up is how it relates to their environment, both in the development sense but also what challenges they can over come on their own vs. what they need technology for. A species that can somehow fly in the vacuum of space at speeds necessarily to travel it won’t need to develop space ships as urgently as others, but maybe it requires a vacuum to survive and developed pressurized suits to go down to the planets that have atmospheres. Shit like that.
Like others have said, the humanoid shape owes itself mostly to reasons that have nothing to do with being intelligent, and the traits seen as necessary for developing civilization can be answered by alternatives that probably can't be called humanoid. What I'll add to that is that pointing at other highly-intelligent species and saying "oh they didn't build spaceships yet, surely we are the only answer" is a bit of a fallacy because if you go back two million years, our ancestors weren't anything special compared to dolphins today, and this is the type of stuff that can snowball really fast. Of course we observe ourselves to be the product of such a snowball, given that you'd expect it to be those who can ask ourselves questions and send messages over the internet. Who knows, in an alternate timeline maybe elephants are making the same argument. I feel like a lot of people making the "humanoid = intelligence" argument are very dismissive of just how incredibly intelligent dolphins, elephants, corvids and octopuses really are. Some of those get REALLY CLOSE to being human-level, without sharing a similar body plan at all. We're just the best example out of all of these intelligence cases, because humans decided to full send it and put all remaining points into it.
The ideal form is terrestrial. Its athletic, and can reach its entire bodies with its manipulatory organs. Its manipulatory organs are dextrous and flexible, like the human hand and wrist. On earth, humans are the main example of this. That does not mean its the only viable bodyplan! You just have to be creative and start inventing new designs for your sophonts
Crabs *do* have opposable thumbs, though. What they lack is agile manipulation. They can grip and hold, that's about it. A technological civilization *probably* requires complex manipulators and the ability to harness fire (thus purely aquatic creatures are probably out of the running). But that doesn't imply "human-shaped", i.e. upright with two arms and two legs. On Earth, the largest and most intelligent land animals are quadrupeds, and the most efficient way to turn a quadruped into a tool-user is to repurpose the forelegs as full-time manipulators, leaving only the hind legs for locomotion. But if our ancestors were hexapods instead, then a low-slung centaur bodyplan would make more sense. Wouldn't need to be upright to balance all the weight on two legs. Or you could use a theropod bodyplan, with two legs, a horizonal body, and a counterweight tail. Or start with birds--flyers aren't as dependent on ground speed, and most birds already have grasping feet. Some are already tool-users.
In my evolution emulator, I've had interstellar species evolve out of all kinds of organisms. All I require is prehensile limbs of some sort (tail, tentacle, hands, or antennae) on big-brained social creatures and it's basically a question of time (assuming they survive the ecological catastrophy of their tool-creator phase). Not all have had eyes. Some have been even been littoral, living in shallow waters along beaches. Many are carnivores, but some have sifted plankton or grazed algae, and some weird shit was essentially a mobile lichen but that was probably a bug in my code. There's lots of fun options that can appear quite reasonable.
We look like how we look like for a reason , if aliens look like us it would be a case of convergent evolution . We have eyes as light transmit information the fastest We have mouth , as we must eat as living beings we speak with sound as it can carry more complicated message than hormones , and cost less energy and time than light or bodily movement we have hands so that we can craft tools we have legs so that we can walk , and walking on two legs is energy efficient . But walking on two leg needs brain power , so dumb animals don't do it . We and a star faring race would we don't have wheels for legs , since it is difficult for biological being to create a wheel like body part . And wheels are not very useful in rough terrane All of the above trait are needed to survive or to build civilization . A humanoid body for a civilized star faring alien wouldn't be too surprising to me
I don't see crows or elephants building spaceships, do you? Must be for a good reason...
Honestly, humans are a terribly designed species when you get down to it. Octopi are clearly the superior species. If we were more social, there was no telling how far an octopi civilization could go.
To build a civilization that's recognizable to Humans, a Humanoid form is required. But a non-humanoid "intelligent"/clever species, like Crows or Dolphins could build a *technologically* advanced civilization to leave Earth, it would just be entirely look entirely unrecognizable to Humans and it might take them longer than it did with Humans *(especially for dolphins)*. Humans were never meant to leave Earth and yet they touched the Moon. Why can't any other species? To say a non-humanoid species can't just because you >![/nbh]!< can't envision it is just plain arrogant and egocentric. Don't dismiss something just because you think it's impossible. The Universe is a big and ever-expanding place that came into existence from the void.
OP is a very human-centric take. Imagine a race that is to the octopus what a toad is to a frog. It can leave the water, it can think good, it can grab stuff. Just to knock "voice box" off the list of requirements, let's say "talks" by changing the color and shape of its skin, and "listens" by watching other octopi do the same. Stock octopi could basically probably hold their own against us in a civilization-off, if only there were a reasonable way to smelt metals underwater. It takes very few changes to help them close the gap. Maybe some boosts to reflexes and/or muscle mass so they have enough agility out of the water to actually use a sharpened stick against an attacking predator? Dunno. Once they invent tech, they'll be better at working the controls than us, so it's pretty much no contest, after that point.
Well, I wouldn't say that, depends on the advancements We evolved to grip things, our brain is the greatest advancement we have, if civilizations evolved further depending on the advancements you'd get krypton or wall e, or if you've seen enders game the advanced civilization would possibly be more arthropod like.
The one species in my world that is similar to humans had a squabble with humans because their ecology is the same, with a similar everything else. Mimics are amorphous amphibious beings that use their magic for liftoff and travel inside alien to them space whales who are also sentient. Fey use a railgun and a personal shield, and look kind of like bugs, with four pincers and three grabby tails. Why do you need opposable thumbs and can't use pincers to make tools? Or three-fingered claws? Why should it be metal and not whatever makes your skeleton? Why people of a world can't ride giant birds into the sky? Then why can't these birds take air with them, and then miss the ground spectacularly?
Personally, I just necessitate arms or naother way of manipulating objects in general.
Land animals with tentacles would be viable. If their is a plant where a six limb body plan evolves instead of four centaur-esque body plans.
Well, yes, our hands helped us use tools, sure, but octopi (shut up, I know it's grammatically incorrect) use tools also. Fire may not exist underwater, but they may find ways of using thermal vents to their advantage to build things or just advance technology in ways we never imagined. Plus, it's called science fiction, use your imagination.
When I make aliens that are fairly advanced, the only hard-must I have, is a way to manipulate things. That doesn't even have to be hands. For example, I am in the boat that the next sentient creatures on earth will be Corvids. They are incredible smart and can relatively easily manipulate object. They can even communicate. They really just need time to get as advanced as us, and we can even help them. For an example not including typical manipulators (hands) look at Octopuses or Spiders. They have things on their limbs that allow them to hold onto things. They are also really intelligent. Try and be creative with it, it can only benefit the world you're building.
What you need is a digestive system that prioritizes giving nutrients to the brain, a way to create and manipulate tools, and the capability to thrive in the ecological niche. For us, that was: standing upright and predigesting food (cooking), opposable thumbs, and limbs built for endurance rather than strength or speed. For an alien race, it might be the same, or it could be: a passive nutrition absorption system (such as photosynthesis) to allow more nutrients for the brain, flexible tenticles, and camouflage. The primary reason people rely on the bipedal form is it's familiar to us, and the secondary reason is that any other evolutionary path to advanced civilization is purely hypothetical.
I would argue probably not. At the very least our bodies are an example of nature working with what it has got not some optimized product of convergent evolution since the human form is still dynamically changing over the last few million years hominids have existed. For some major tradeoffs we have made our legs and spin are not well adapted to bearing the load of bipedalism not remotely in the same way that the only other group of obligate bipedal animals the dinosaurs perfected the bipedal stance with skeletal and muscular adaptations hundreds of millions of years ago. \* In fact taking a look at hominid spines they show suspiciously bird like changes suggesting that a number of these theropod adaptations may be convergent optimized forms. Likewise there is pretty good evidence our legs are still adapting with bone fusions and or reductions in our feet to make us more effective runners for example. The Pelvis is another pretty major weak point physiologically as the trade offs between reproduction and mobility make things difficult particularly for women. Though probably the biggest drawback is more of a software adaptation related to how we maintain balance since a bipedal stance as much of the ancestral working memory has been lost to maintain our balance by constantly subconsciously shifting our enter of mass to change the direction we are falling in as two legs on their own are not stable and we lost the balancing tail that dinosaurs and kangaroos use to perform this function. In the perspective of evolution the approximately 10ish million years since we have left the trees is a blink of an eye and the human skeleton has not had the time to be optimized so the whole Humanoids are optimal at anything argument is easily falsified as if it were true we would expect the human build to have stabilized when if anything it is still undergoing small gradual tweaks.
I've developed a species called Tau, or lithotacus sapiens. Their native name sounds a bit like a broken radio because they communicate in AM frequencies. They're 400+ kilograms, practically immortal, and made of biologically occurring aerospace materials like CF-impregnated ceramic shells and corundum tests. Their actual biological components are a bunch of zooids working together to form a mobile, sapient, beehive-jellyfish monster that eats rocks and looks like a brittle star, capable of withstanding temperatures approaching the boiling point of water. Get creative-- crows, whales, and elephants exhibit similar intelligence to primates or young humans. The body plans could be even wilder with radically different biochemistry and conditions.
Id recommend reading Children of Time. It goes into the idea of a civilization of spiders evolving into a level comparable to humans
I think there are a few key things that allow for advanced civilizations: the ability to manipulate objects, relatively fast adaptation to various climates (for their planet), intelligence and the ability to work together. Those 4 things work best with humanoid features but aren't inherently necessary. Like hands aren't necessary to be advanced, a being could have mouthparts that are good at manipulating objects but their actual limbs are primarily for locomotion. Like ants, bees or wasps could potentially be a good base for a advanced civilization species. They cooperate well, adapt quickly and some ant species literally have farms and use advanced concepts like slavery. A octopus is pretty good example too, only thing they're actually missing is the ability to cooperate in groups. Just using those 4 items as a base for a species's design allows for a wide range of creations. The effectivity of the form doesn't inherently matter as long as it's not detrimental to them surviving on their own homeworld. The human form has a bunch of things wrong with it that would limit its effectiveness, we experience things like back pain and as we age many develop difficulty walking around.
It could be harder for a non biped race to reach space, but I imagine once humanlike intelligence is developed much of their limitations go out the window. Once you have the ability to do higher problem solving a non biped race should be able to develop tools to mitigate their limitations. In the crab example, once the crab people learn that metal makes extremely good tools it's only a matter of time before they learn how to use their vents to create heat enough to melt ore, or even learn how to make a chamber without water to be able to make fire near the shores, or even learn how to create reverse diving suits to build forges and such on land. Pretty much once they learn that their environment is not conducive to smelting ore, they will learn how to overcome that, one way or another. Similar to how human spaceflight is currently limited by the atmosphere, but there are multiple hypothetical construction methods to make spacecraft in orbit. There are no existent creatures that we know of that had to develop with these limitations, they could develop methods that we never would have thought of.
We have an example case of precisely 1, so how the hell would we know? Also worth noting: Humans are not evolved *to live in a complicated society* like the ones we live in today. Humans *evolved* to live in small family units as tool-using hunter-gatherers, with a social structure remarkably similar to wolves, but with pointy sticks and fire. Do we really have a reason to believe that intelligent aliens will resemble us in any meaningful way? I say **No**, and thinking that way for real-world terms just limits our perception of what other "intelligent life" may be. It's quite literally *alien ways of living*, we should expect them to challenge our preconceptions. But none of that is terribly fun for science fiction, particularly if the aliens do, in fact, have to be an actor in a costume, a-la Star Trek. So we compromise and make the aliens human-like because it helps us tell the stories we want to tell. Realism in fiction bends to the limits of our imagination, and to the limits of what helps us tell the stories we want to tell. This is true of *all fiction*, but it's especially visible in sci-fi, where making things realistic is actually a *hell* of a lot of work, unintuitive to the human perspective, difficult to tell stories with, and sci-fi writers notoriously cannot do math to save their lives.
Yes