system
Given the following post, respond as if you're commenting on Reddit:
human
[Avatar 1 &2]Pandora is DEFINITELY the result of massive genetic engineering and not natural. Was it created by the Navi in the past or something or someone else? Spoilers for Avatar 1 and 2.

Before you worry over spoilers from the title and did not see Avatar 2 yet, worry not.  This is not in any way shape or form discussed in the movie. This is not hinted at directly or indirectly and from a Doylist perspective I doubt Pandora is artificial but we don't do Doylist views here, we do Watsonian views and from a Watsonian perspective there is no way that Pandora could be the result of evolution.  So there were no spoilers in the title, but there definitely will be now so heads up for that.


I'm going to make one big assumption going into this, that the laws of nature and physics and chemistry and biology work the same in the Avatar universe as they do in our own. If they don't and some strange quirk of chemistry or something could produce results which to us seem impossible.

What I want to know is, is Pandora the result of a technologically advanced Navi in the distant past becoming post technological and becoming primitive after making a world for themselves or did some other species make Pandora as it is and why?


Why am I so sure that Pandora is not natural?  Is it because of the world-mind of Aeywa which is made up of lots of life forms working together?  Actually... no.  Well no, not primarily.  It seems implausible but even in the real world trees sometime share resources through their roots and send information to each other about environmental conditions, so if you fast forward a few tens or hundreds of millions of years it doesn't seem impossible just very unlikely.


What seems impossible is the freaking whale USB.  


A common argument for intelligent design in the past was that the world seems to be so perfectly designed for us, which is silly, species which came before us slowly adapted to conditions over time and we today are a species well adapted to our environment as a result.  


Those freaking whales in Avatar 2 have a feature of their biology which is impossible to evolve on their own. One which is TOO complicated and wouldn't provide any benefit before reaching the current level of complexity.


For those who have not seen yet, the whales have a USB slot on the back of their throats, sort of near where a human has a uvula that they can unlock and  
Navi can connect that USB slot the same way they can connect everything else in the planet, which is already damn suspicious of course. But for that USB slot in the back of their mouth to be present that would have to mean but there was some kind of environmental pressure to allow system that complicated to either appear spontaneously, which is impossible, or for the precursors leading up to it to be beneficial in some way. This is an actual thing in biology. Modern eyes are way too complex to have arisen on their own all the once, but even primitive eyes which were nothing more than spots to detect light would allow microscopic organisms to detect which way is up which is beneficial for various reasons and slowly over a great deal of time they improved.  Eyes actually evolved several times.


The wings of birds and bats or too complicated to suddenly appear, but things leading up to them could be useful and they slowly changed over time and became more complicated.   Feathers help with temperature control long before they helped with flight, longer flaps between the limbs of primitive mammals in the case of bats can help already arboreal mammals glide between trees.


Eyes and wings are too complicated to suddenly appear but less primitive versions provided a benefit so they slowly changed over time becoming more complex


A USB slot in a nearly impossible to each place in the back of the throat of a carnivore which only the NAVI can access?  Impossible.  There was no possible benefit to a less primitive structure in such a ridiculous location I can think of which means it has to be artificial.

Who made Pandora as it is and why?
gpt
I think the mistake here is to try and analyse Pandoran life in Earth terms, and indeed that was the mistake that Humans made when they interfered in Pandora in the first place. 

Pandoran life should be viewed as something like a hive mind, a living example of the Gaia hypothesis. They are individual beings to a degree, but they are also 'cells' in a larger organism, Eywa, that shares their memories, consciousness, thoughts and emotions. This does not just extend to the Na'vi but all Pandoran creatures. 

I think it is possible, actually probable, that Eywa excerpts considerable control over the ecosystem, either unconsciously or on a superconscious level that we can't understand (or both). Eywa likely influences the development of animals and plants on Pandora to suit the greater whole, to keep the systems in balance. 

So the 'USB' you speak of (the neural queue) is likely a feature Eywa finds advantageous to the greater being as a whole, since this means creatures can contribute to its shared consciousness, becoming its eyes, ears - nodes in the network. So it's maintained across all of the animal species on the planet so that they can share in the collective consciousness both with eachother and with Eywa itself. 

Any animal with a 'defective' neural queue would likely be locked out, left to die, and be reabsorbed. There is thus an extremely strong selection pressure to keep it, and keep it working and 'compatible' with all the other creatures on the planet.

And we don't even know if Pandoran creatures are capable of mutation and evolution - it may be that in a sense, they are intelligently designed by Eywa, or at least heavily 'domesticated' by the hive mind, shaped to suit its needs.

So yes, there is an element of genetic engineering, or at least generic selection, going on - just probably not in the way you thought!