[Return just the main response. Take out the pre-text and the post-text]

Summarize

"I think something to take into consideration in this kind of thought experiment, is how such a biosphere got to a point of abundant intelligent.  As different routes to this kind of end might produce different specific results.

Are the various intelligent species descended from a single common ancestor (or even a very small pool thereof), and thus have commonalities of lineage, physiology and likely brain-structure? Perhaps it would be something like “man after man”, with its various specialized human descendants.  Perhaps it would be some kind of highly derived caste-society, each species the descendant of some social class or caste, or other specific sub-set of the ancestral species.  If arranged hierarchically, this kind of society could have some kind of leadership species or “apex intelligence”, literally born and evolved to lead.  Perhaps they could instead represent evolutions in different directions.  Species of solitary super-geniuses, collectivist hive-minds perhaps something truly exotic like family-oriented intelligence with some kind of genetic memory all might operate on the same planet.  Being totally separate species, would such being even be ideological about their societies?  Would they see the other species as some kind of managing “other”, or just another part of the natural world?

Alternately, are the various species descended from a wide array of ancestral forms but in an environment that promotes most (or even all) species to evolve high intelligence as an adaptation?  Giant social hive-societies, solitary octopus-like minds, intelligent pack-hunters, self-aware herd-creatures, all might exist side-by-side, possibly even ancient sedentary intelligences might all be found.  Is it across the whole planet?  Is it a particular habitat or environment?  Does each intelligence have its own habitat?  Would such intelligences become readily aware of each other?  Could the possibly exist in complete ignorance of each others intelligence, if not form geographical separation, then from sheer landlines of their worlds fellow-intelligences?

Also how these intelligences typically interact might shape them, and possibly move toward or away from different kinds of outcomes.

Did intelligences between different species evolve out of competitive conditions, where various intelligent species are all trying to out-smart each other?  This does seem to be the most likely scenario to evolve, if not an apex intelligence, then an intelligent apex predator of other intelligences.  Perhaps there would be dual apex intelligences, an apex predator and apex prey, locked in a sort of evolutionary cold-war of tropic levels.

Did intelligence in different species primarily evolve out of some kind of cooperative condition?  Was it some kind of early mutual self-domestication?  Predators might hunt prey species for intelligent scavengers that give them some kind of protection.  There might be an ant and aphid situation, with one species producing a food substance for another species.  Perhaps some kind of sedentary intelligence might use motile species, while providing them shelter? Was it environmental symbiosis?  Are some species  dependent on others to reproduce?  Do endo-symbiotes have the ability to directly influence over host species?  How social are their inter-relationships?  How dependent on each other socially and biologically would they be?

Mind you none of these necessarily exclude the possibility of the other occurring as well or some mixed or “in-between” situation occurring, but they could make for interesting models of potential states for this kind of system.

I will say that in an environment of multiple intelligences I do see the specialization of intelligence as a likely adaptation.  At the very least different species will develop differing relationships, that will lend one to specialize in one way and another species in a different way.  Factors like environment and common ancestry, or lack thereof, would probably shape just how much alike or different their particular forms of intelligence are.  Also the ability to teach parrots to talk and gorillas to use sign language suggest that a useful specialization in an environment of diverse intelligences might be translator or courier, one able to communicate across various species.  They would probably be a “keystone” intelligence, tying the entire intelligent ecology together.

A sense of species self-identity would be something interesting to examine.  Humans seem to have a concept of the “human world” and the “natural world”, or at the very least that we occupy a special place in the natural world.  Would a species that evolved in an environment of an abundance of intelligent species think this way?  Would each one see themselves as “special”? Would they just see themselves, and all other intelligences as just other parts of “nature”?  Could species-identity work like ethnic or national identity in such an environment, with alliances and conflicts along species lines?  Would societies be dependent on being composed of different species to fulfill different roles?"