We have exactly one story of how this process occurred in the universe (so far)- our own.

Our story in short is of a derived social primate with binocular vision, a workable set of hands transitioning by phases from foraging to scavenging to predation using tools at every stage rather than developing any biological kit other than a brain and body suitable for diurnal endurance hunting.

Viewed in reverse, its a plausibly straightforward process. In other words, not that hard to conceive of it occurring by stages. At every next stage, niches were available - bones full of marrow laying around unclaimed, predators sleeping in the heat of the day with prey abundant, the ability to forage in compensation for any shortfalls on the meat line of pursuit, varying climactic conditions driving a brutal winnowing for adaptability on the main organ of selection, also the social/sexual selection.

Can you envision a process whereby a cetacean or cephalopod or ungulate or carnivore or arthropod or some other order/clade - or alien analogs/alternatives- could, in any comparably straightforward process, or even less straightforward process for that matter, find its own gradient to evolve a comparable socially-based intelligence?

In simpler English: Can you plausibly imagine such an alternative to a peer species arising, and if so, how might that be?


  • The aliens, or next wave of sentient animal to arise on this planet, could have arisen from scratch on a young planet, or post planetary extermination event (e.g. nearby supernova) or from a pruning of existing life such as occurred via the k/t mass extinction event. Sentience, in any case, comes late in any life process, at least in our singular example. The late stage is the key, not the long process before.

I have a strong bias, and it is a bias, toward what I've seen work, have some notion that I understand roughly how it works, and thus tend to view phenomena, where unique, as having certain likely intrinsic requirements - such as water/carbon based life being astronomically more probable than any conceivable alternative, as one example. But that may just be a failure of my own imagination. Others, in my opinion, ignore constraints, or aren't aware of them, and let their imaginations run wild :)


closed as too broad by JBH, RonJohn, ArtificialSoul, Jared K, L.Dutch - Reinstate Monica Oct 4 '18 at 16:02

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • $\begingroup$ Welcome to Worldbuilding.SE! We're glad you could join us! When you have a moment, please click here to learn more about our culture and take our tour. Please note that this question is off-topic as it's way, way, way, way, way too broad. SE's Q&A model is one-specific-question/one-best-answer. The only viable answer to your question is "yes." Any request for detail and a book would need to be written to answer it. See our help center for more details. $\endgroup$ – JBH Oct 4 '18 at 14:25
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    $\begingroup$ You're assuming that such life would actually fit into our current taxonomy of Plants, Animals, etc? Is that a constraint that you want us to work under or is it one that you suggest we ignore? $\endgroup$ – Mathaddict Oct 4 '18 at 14:31
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    $\begingroup$ @Mathaddict - no, as far as taxonomy - it could be an entirely new tree of life, or a paring back ot the existing one, as after the k/t mass extinction event. the main thing is the planet as configured. everything else is wide open. as the first commentor said, its a very broad speculative question. but i was able to ask it fairly concisely. don't think answers have to be encyclopedic either. broad contour thinking is fine. $\endgroup$ – theRiley Oct 4 '18 at 14:49
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    $\begingroup$ Scientists are discovering more and more than many mammal animals have a quite complex social organization and are highly intelligent in their own way. Is it comparable to what we humans have? Well, the question is still being debated, as is the definition of 'intelligence' itself. $\endgroup$ – Sava Oct 4 '18 at 14:50
  • $\begingroup$ @Sava indeed - all kinds of surprising novel behaviors are being observed constantly. We used to tend to think of animals as wired into a lane, based upon their predominant pattern - but we now know that is simplistic - there is an adaptive latency there in many mammalian species. $\endgroup$ – theRiley Oct 4 '18 at 14:54

The Fermi Paradox may be an answer to your question. And it isn't good.

The question is probably the biggest question of all. Unfortunately, we see no evidence of alien civilisations in the Universe. Given its vastness in space, and also in time, one would have expected at least one to be visible. However, we do not.

No blinking stars in morse code, no mysterious radio signals that cannot be explained naturally. No beacons, no stars acting unpredictably. In essence, the data currently supports the view that technical intelligence (note: not life) is so rare that in the 13 billion years the Universe has been around, and of the trillions of galaxies, we seem to be the first.

One just needs also to look at our planet. How come no other species has developed technical intelligence? Of our own species, would you say we have been around for 1.5 million years, yet only in the last few thousand we managed to develop evidence of cities and technology.

Of course, we can speculate on the nature of intelligence. Your question states sentient intelligence - this is different and is accepted in the scientific community that many animals are indeed sentient, as they have the ability to feel.

You also refer to social intelligence - this has already been demonstrated to be evident in almost all animals.

You seem however to be inferring Technical Intelligence - the ability to develop technology. There are many theories on this, and people are still researching and developing it but perhaps:

  • You need a species which is so deficient, it needs to alter the environment to survive. Humans are woeful, we can't eat much, have low temperature tolerance, are not very fast, and our young are completely defenceless. Also remember dinosaurs were around for 250 million years, but never developed technical intelligence too, perhaps they were too good at eating.
  • You need a way, and a need, for knowledge to pass down generations. This has been shown in some animals too, however there needs to be enough communication ability to transmit ideas through language.
  • You need an incredible series of events, combined with time, that eventually makes intelligence stick. It has been demonstrated that humans developed fire independently more than 60 times, then forgot it. Eventually it stuck and we were able to expand to colder climates and move on to cooking and baking (and therefore cities).
  • There is a discussion of brain size - although hardly conclusive at the moment. It is generally accepted that brain size may have something to do with technical intelligence but there is no explanation of the mechanism this might be due to.
  • You need a way to manipulate things adequately enough (like hands). Dolphins have great social intelligence, but probably can't do much with it.

All of the above are not necessarily comprehensive, but also they are independent of issues such as water, carbon or any other physical process, other than that life needs to exist. It is entirely possible that the above dot points can be achieved in a totally alien environment, using different materials and different evolutionary paths.

For instance, once life is established, you could pass down information down the generations through light and colour, instead of speech. You could manipulate tools with tentacles, in lieu of hands.

However, unfortunately as said earlier, the Paradox does not seem to support this view.

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    $\begingroup$ you have a firm grasp of the domain :) yes, we should stipulate technical intelligence, i suppose - that is a real definitional problem. maybe 'intelligent in a way similar to human society' is vague enough to be descriptive, however self-referential.. the possible alternative behavior and expressions might be very different from our own in many details, but would have to constructive, interactive, retentive. perhaps other adjectives apply. this can be part of the open question. $\endgroup$ – theRiley Oct 4 '18 at 16:13
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    $\begingroup$ the fermi paradox falls flat when you realize actually detecting an alien civilization is not easy, there might be hundreds of intelligence we just aren't noticing. It is not as if we are actively sending a signal afterall. $\endgroup$ – John Oct 4 '18 at 16:19
  • $\begingroup$ @John That is indeed one possible explanation. However that explanation does not deal with the principle of Exclusivity. In all the trillions of stars in trillions of galaxies, one civilisation couldn't invent a Von Neumann probe - it beggars belief. Similarly, in all the trillions of stars in trillions of galaxies, over billions of years, why have no alien civilisations left any beacons? Unfortunately the principle of Exclusivity breaks down most other explanations of the Fermi Paradox, including us not noticing them. $\endgroup$ – flox Oct 4 '18 at 16:34
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    $\begingroup$ exclusivity forgets how space time works we aren't listening to the whole galaxy but to a tiny sphere (less than 40 light years) created by the limits of speed of light and how long we have been looking. If thousands of intelligences evolved at the exact same time we did, we would have no idea. And its not just needing a signal but the right kind of signal for what we are looking for the right distance from us. $\endgroup$ – John Oct 4 '18 at 16:40
  • $\begingroup$ @John For the sake of this discussion, I will suggest that perhaps all supernova are actually attempts by advanced civilizations to send such a large signal that it can be detected across a much larger portion of the visible universe. So we are detecting these civilizations left and right, but we are misunderstanding them and not taking them for the beacons they are. $\endgroup$ – Loduwijk Oct 4 '18 at 18:05

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