In my opinion, we are on topic, since we are debating the science fiction of Avatar, and Avatar is the topic. Besides, it's agreed that the current line of discussion is fun, isn't it?
M1chael and Wombat et al are right. Respectfully, Cracker Funk is wrong.
=D Heheh.
The "infinite" randomness of mutations, there not being any such things as "paths," as in destinations(?), and four year degrees notwithstanding, I'm afraid, Cracker Funk, that you are suffering from something similar to what I've coined the Claw Fallacy.
The Claw Theorem says that we must make our fictional aliens otherworldly, and the way to do that is to give them "lobster" claws. But, how can said lobster-clawed aliens climb up out of their primordial forests, or whatever the hell those folks have up in there, and make spaceships to fly to earth and cause science fiction mischief? How many movies have we seen in which technologically advanced aliens run around the galaxy with their lobster claws for hands, and we’re supposed to believe that they built spaceships and shoot ray guns? Or, they have hands with two or three scary looking fingers, each with enormous claws at their tips?
Can somebody please tell me how exactly they were able to make with those big, unhandy claws of theirs, one: chalk boards, two: chalk, and then, three: work out all those complex physics and chemistry problems in classrooms filled with claw-handed students in order to, after the requisite accumulation of knowledge, probably over centuries, four: make it possible to design and build an interstellar space vehicle in which they could travel here in order to harvest our hypothalamuses?
Such a species ain't gonna have claws for hands. How would they hold their screw drivers?
That is the Claw Fallacy. The Claw Fallacy accepts what Wombat said about only having our own biosphere as a measure. That's science. I don't have to tell anyone here how important observation is to science. Science observes what is observable, not what nebulous fantasies we can cook up when imagining how things might be radically different in some far flung part of the universe. Now, a clever writer might come up with reasonable alternatives, I guess. Perhaps the aliens could have tentacles that could hold their screw drivers. Perhaps, if there is such a thing, they could use their telepathy. But the point of the Claw Fallacy is that those tentacles or that telepathy had better have at least as much control and dexterity as the human hand, or else! Or else what? Well, they won't be adaptive, that’s what. At least, they won't be adaptive for building spaceships.
Okay, I know no one's arguing that the Pandorans should have had claw-hands. Back to Pandora and the humanoid business.
Yes, life on other planets with different rules might very well be quite different. But, how different can those rules be? I'll bet not much. The laws of physics are the laws of physics, for example. And, however random mutations might be, the fact is that for species like ourselves, whatever random mutations that do occur, and, more importantly, are kept, had better be adaptive. For all I know, Cracker Funk, you're right about emphasizing the super duper randomness of mutations. But as far as the evolution of species go, the only mutations that really matter are those that are adaptive and are consequentially kept according to the law of the jungle and who successfully reproduces before they die. I would imagine that this would be true for both sexual and asexual reproduction.
That is natural selection. Natural Selection is what's important when you want to, as a science fiction creator, evolve, so to speak, an alien species on a planet like Pandora, who can have meaningful interactions with invading humans and thus drama commence. The meaningful interaction part is pretty important since the audience is a human audience, after all.
Part of the reason why so many very earnest speculators about intelligent alien life forms make the assertion (assumption) that they must be so very different than us, I’m afraid, is because of some underlying idea that it's somehow unethical to think otherwise, as if to do so would be something like ethnocentrism, or terracentrism, if you will. Horse apples. Back to my, and I think Wombat's, point, all we have for sure to go by is what we know for sure, which is based upon what we can actually observe and study --our own planet, our own biosphere, our own example of the tree of life, and the physics and the chemistry which is available to us to observe and work out.
My strong inclination is to think that if there is any life out there, and I think that's a very big if, and no matter how many galaxies there are, it will exist within more or less similar parameters as life as we know it here.
So, M1chael is right. Given a biosphere that is reasonably like ours, which -is- likely to be the case for a complex biosphere given the so far knowable laws of physics etc, then it is perfectly reasonable to expect that the humanoid design could turn up on Pandora, as well.
Let's not get hung up on things being "humanoid" or "hominid." Let's just consider it the "primate" configuration. This is what we know for sure: In the biosphere available for us to observe, the "monkey" or "primate" design has been very damn successful. It produced our species which has hands which can write, make flint tools, and maybe even build interstellar spaceships.
Sure, the Pandorans weren't building spaceships, but the point is that given just how successful and adaptive the primate "design" has been given the only perimeters of life that we can say for sure exist in this universe, it is perfectly reasonable to not be surprised if natural selection would come with something similar on an alien, but similar planet.
Yes, it might be a stretch to have Pandorans and Clingans being just so very similar to our own species, but that's what suspension of disbelief is for! Anyways, wasn't there an episode of Next Generation that posed an explanation for why the Star Trek species were so similar... specifically, that they had all been seeded by someone else? An interesting topic in itself.
Anyways, sorry for another absurdly long post. It just happens to be a subject that I enjoy.