What is "the cognitive capacity to survive"? Throughout the animal kingdom (and, depending on your definition of "cognitive", possibly beyond), there is a tremendous variety of cognitive capacities, most of which seem to help the creatures that carry them survive. If you're a sexually reproducing organism and your species is too rare for randomly disposing of your semen or pollen in the water or air to be a viable option, any cognitive mechanism that helps you distinguish conspecifics from other objects in the environment at above chance level will help you reproduce. Is that "the cognitive mechanism to survive"? Whenever you're not the top predator, any reflex that helps you not getting eaten by someone above you on the food chain helps you survive - even if it's something as simple as "run away from everything that's bigger than you and that's not an established fixture on your mental map (i.e., that hasn't been there yesterday)", or "don't leave the cover of the forest". Is that the one? If you're an animal that lives in packs/schools/herds, cooperating within but where interaction between members of different packs are typically unfriendly, knowing friend from foe will help you survive. There's many more specific cognitive responses that are adaptive solutions to specific environmental challenges.
But that's not what we're talking about.
What we need to talk about if we want to talk about the preconditions for the evolution of a potentially civilisation building, spacefaring species is a sort of generic reasoning ability that can be creatively applied to novel subject matters (even if not always effortlessly), combined with a communication system that has to be partially learned (a fully innate one could only accomodate novel concepts on evolutionary timescales). It's not obvious that that would be selected for a lot of the time, over and above specific responses to common threats and challenges. It doesn't seem to have popped up a lot of times on this planet, at least.
That's not really what I'm discussing, though. The original point was:
- Life on a different planet would in all likelihood move in *similar* directions to life on earth.
Not only would physical limits cause a similar appearance, but the nature of conditions that first allow life to be generated, and then consume the world it's in, would more than likely entail a movement from water to land, and for some lines of life an increasingly complex nervous system.
Nowhere in my original post was there any type of teleological thinking, but it was interpreted that way. For that reason I suggested that the ability to better manipulate our environment (cognitive capacity) is a selective pressure, which sounds like directional thinking, but all I was really suggesting is that *intelligence is a thing that happens*.
Forget intelligence altogether. We can then identify all kinds of other traits that would cause reproductive success: being a good swimmer, being small, flying, climbing trees ... etc and so on. Assuming life can only come into existence in one way, and can only exist on one kind of planet, it would move in directions that fit niches in that planet, just as life on our planet has done. And in that way it would move in similar directions as life on our planet.
But then going back to the teleological, humans are the apex of life line of thinking, which is obviously nonsense, you could still assume that a human like species would eventually evolve because a more complex, well functioning nervous system causes more reproductive success.
