Literacy (and specifically the ability to comprehend writtten language) is not intelligence and should not be confused with such. It is a skill at using a particular type of tool; that is, books and other written media. That such media is persistent and easy to disseminate widely in roughly geometric fashion versus oral and observational traditions that are limited to a specific peer group certainly has contributed to the success of humanity as a whole, but there is no evidence whatsoever that this has made us in any way fundamentally more intelligent, except of course as measured by our ability to demonstrate literacy. For a Kalahari San, for instance, literacy of the written word is completely irrelevant to their social lifestyle, and all knowledge of history, crafts and trades, hunting, et cetera is related by spoken word, song, and display. That they are highly accomplished at living in an often challenging environment indicates that this lack of literacy does not inhibit their innate problem solving abilities and adaptability, which are the key measures of practical intelligence.
A sentient aquatic species would certainly have different tools than a terrestrial one by virtue of living in a dramatically different environment, and different means of manipulating that environment; for instance, an aquatic species would almost certainly not use fire or highly energetic exothermic reactions to manipulate the environment for obvious reasons. However, there is no reason that an aquatic species could not develop intelligence equivalent to Homo sapiens in terms of cognition, problem solving ability, and communication, and in fact, there are “smart fish”, if you generically extend the notion of “fish” to cephalopods. Instead of fire and writing, such species might evolve use electrochemical differentials and direct synthesis of long chain molecules for analogous purposes. That octopuses are not building rockets and adding modules to the International Space Station (yet) is not an indication that this is not possible but just that this particular path of evolution and the precursors from which it developed did not happen to go in that particular direction.
BTW, it is a common and often implicit assumption that intelligence represents some kind of end goal or apex of evolutionary development. However, the vast majority of species alive today, and many which are extinct but existed for many times the duration that modern genus Homo has been around, cognition and self-awareness was not a defining feature of their success. It isn’t clear that intelligence will ultimately make humanity successful unless it improves our adaptability to the point that we survive an extinction level event that will kill off a mass of other species, which given our position as a apex predator is perhaps unlikely as long as we are restricted to just this planet; the sudden extinction of cereals and domestic animals, a rapidly mutating virulent plague, or even a modest (in geological terms) shift in average global temperature or atmospheric composition could potentially extinguish the entire species in the span of a few generations or less.
Most animals that are ‘smart’ are smart almost exclusively when it comes to survival and reproduction. What makes human intelligence unique is that it is not thus limited.
That is a patently untrue statement. The animal kingdom is rife with examples of creatures which demonstrate cognitative abilities which go beyond basic requriements for individual survival and reproduction, from the problem-solving abilities of cephalopods and corvus to the social communication of psittacines and canines. The notion that “intelligence” is somehow unique to humans, or even primates, is only valid if you confine the concept of intelligence to a very narrow definition.
Oh pray, read to me the octopus’s poetry, the lioness’s tract on equality, the beetle’s songs. All animal behavior except in the primates is directly or indirectly useful for survival or reproduction.
Again, the notion that “intelligence” is somehow unique to humans, or even primates, is only valid if you confine the concept of intelligence to a very narrow definition.
I read the your post. Again, if you are going to define “intelligence” so narrowly as to confine it to only activities which human beings do, then yes, only humans are “intelligent”. Also, no true Scotsman puts sugar in his porriage.
However, if you look at intelligence in the general sense of the abililty to communicate and coordinate in a social context, conceptualize and solve complex problems, and otherwise demonstrate hurestic and pattern recognition abilities that go beyond instinct and innate stimulus response, humanity is distinguished only by the degree of capability, not essential characteristic.
I think your eagerness to try to make your point about “impossible, eh?” is making you miss the point.
Different environments have different needs. Bird intelligence, by many accounts quite impressive even with brains that are not by mass so big, is not adapted for the same sorts of problems as whales face. Whale intelligence faces a different set of issues than human intelligence does. If there was a test that measured whale intelligence for whales from the whale perspective humans would rank as pretty damn dumb. Defining intelligence as like us is unhelpful.
Stranger recognizes the need for a more abstract understanding of what intelligence is but even his definition does not recognize the domain specific nature of it and the difficulty in appreciated let alone measuring something in domains somewhat alien to our own.
Human “level” is a metric not a domain, melchior. Indeed whatever level of intelligence certain whales have it is in a different domain. We are not smart in that domain and they are not smart in ours.
For humans the costs of large brains was worth it for the advantages it brought, whether more driven by the advantage of being able to produce tools, or language, or the social arms race of cheating and cheat detecting in tribal groups, or all. The sort of intelligence we developed is adapted to producing those specific advantages. What drives intelligence evolution in aquatic species? Enough to make it worth its evolutionary cost.
There are myriads of possible reasons why a trait may not develop. You simply cannot cite “it never evolved” as evidence for “it cannot ever evolve”. That’s just stupid. The space of possible evolutionary paths is vast, and only a tiny, tiny fraction of it has been explored by life on Earth. If you like the fitness landscape metaphor, there are no doubt huge peaks of fitness separated from current life forms by deep, uncrossable valleys.
Ultimately, evolution is driven by random mutations, which is a point so fundamental it shouldn’t even need to be pointed out. If the mutations leading to intelligence never happen, then selective pressure is irrelevant.
Let me attempt one more explanation to get my point through to you. You are a Sploot, an alien race of human-level intelligence that evolved in the vacuum of space. You are visiting Earth to test your hypothesis that it is possible for Sploot-level intelligence to evolve on a planet, either on land or on water. The trouble is, you happened to pick fifty million years ago to visit. After an exhaustive search, you would conclude that there is no Sploot-level intelligence on Earth. Using Melchior’s “logic”, you would then conclude that it is utterly impossible for intelligence to evolve on a planet, either on land or in water. You would, of course, be completely and totally WRONG, because that “logic” is complete and total crap.
That’s human-like intelligence. The OP asked about human-level intelligence. Those aren’t the same thing.
And the fact that no aquatic life form has never developed human-level intelligence isn’t really meaningful, given that only one species in the history of the entire planet has ever developed human-level intelligence, and we don’t have a real good idea why that happened in the first place. There’s no particularly solid reason to assume that non-aquatic environments were necessary for it to occur.
Certainly, we can already see that high (if not human) level intelligence can occur in sea life - the oft mentioned octopus is arguably as smart as any land creature except humans. There’s no end to land animals that aren’t as smart as humans. Why should we assume that the factor that held back the octopus is the water, and not any of the factors that held back every single non-human mammal in history?
Only one Douglas Adams reference in the whole thread, and not the most salient:
Yeah, it’s funny, but I guess I’d have to ask: What is meant by “human level intelligence?”
DSeid made it interesting by observing the meta-intelligence of human civilization which is ultimately what Adams was getting at. If we leveled the playing field and took away human civilization, somehow got a population of humans from infancy into adulthood in a nonhumanized environment, how would they do compared to a group of dolphins or whales raised likewise? Would one necessarily stand out over the others as objectively smarter? Or is it just the lucky accident of civilization (the only one ever since stuff started breathing on this rock) that put us where we are now?
And I think your eagerness to find differences is making you make things more complicated than they need to be. The OP asks about “human level” intelligence. Any tool making animal with an ability to think abstractly and communicate complex thoughts to members of its species would be at “human level intelligence”.
There is nothing about living in water that makes any of those things impossible.
I’ve been lurking over this thread while I thought it over, and it seems to me that the ocean has only one major limitation to intelligence compared to land: oxygen.
Human brains consume enormous amounts of calories and it takes oxygen to do that. Water carries nowhere near the amount of oxygen that air does even in the best circumstances and there are worst-case scenarios like algal blooms that can totally starve an area of oxygen.
This seems to be reinforced by the fact that the smartest critters in the sea all breathe air. And the fact that seals, dolphins and whales are still intelligent after tens of millions of years in the ocean should prove that aquatic environments do not inherently prevent intelligence.
I wouldn’t take this so far to say that water-breathing intelligence is impossible, exactly - so many historical statements about “impossible” life have already been proven wrong - but it certainly provides an additional selective pressure against something that is already a one-in-a-billion chance.