Riddle me this: # of extremities on Avatar's species

[Skeleon]

Yeah, I pointed that out to my brother, too. It makes little sense.
However, he reminded me that near the beginning of the movie, we see "ape-like" creatures with 6 extremities, their two upper extremities somewhat fused to their middle ones. Maybe those are the step inbetween?

What evolutionary advantage losing limbs should have is beyond me, especially since they still live in the same habitat as those apes (not like whales losing their hindlegs after moving back into the water). That doesn't mean it couldn't happen, though.
However, personally, I assume the CGI-workers simply wanted an easier time.

 

[Jovlo]

If Darwin saw avatar, he would sigh.
Not only does the six legged thing not make sense, the dial-up connection between all lifeforms makes even less sense.
How would something like that be able to evolve? Where does it start?

 

[SnucklesMan]

I read on WikiPedia that Na'vi were required to cut off their extra limbs for a sacrifice. Just kidding. Maybe it's because it's made by humans and humans aren't perfect.