Avatar driver hours and "matechoosing"

[Human No More]

I've said it before... Neytiri said Jake may choose a woman. That doesn't mean she has no choice - Jake did say 'but first, this woman must also choose me' - that may well be some kind of specific part of choosing not related to the fact that he chose Neytiri. After all, Neytiri did mention specific women - possibly ones that were looking for a mate and/or interested in Jake. The survival guide says that choosing a mate can sometimes take years - I'd assume that female Na'vi have the same right to choosing someone, and it's only if the one that was chosen accepts that they mate.

About mutation rate, the radiation level is low (but higher than Earth) due to the very strong magnetic field, but it's likely all Pandoran life has a higher tolerance than humans as they evolved in the higher-radiation environment - there are species on Earth which can survive significantly higher radiation levels than most, some of which aren't even specifically adapted for extreme environments, so I'd expect to be relatively stable. The extended families would reduce most inbreeding, and some Na'vi mating with some from other clans would keep things widely distributed.