Well, providing that Aang and Katara get married and have kids, it depends on whether or not their children, and their children's (and so on and so forth) are Airbenders, Waterbenders, or neither. If they do, then the next Avatar after the next Fire Nation Avatar could be taught by one of his parents. If that's not so, then perhaps Aang in Spirit form?

To add, Mike & Bryan have said that the ability to bend is not a genetic trait (as evidenced by the identical twins in the episode with Aunt Wu, one was an earthbender and the other was not). Bending is an ability acquired through spiritual focus of the nation you're born into; this is why the entirety of the Air Nomads were, in fact, mostly or all airbenders. In direct correlation with the size of the nation, the largest one — the Earth Kingdom — has the fewest benders because of lack of spirituality. Even the firebenders and waterbenders (despite the Southern Tribe only having one bender) outnumber them in a relative ratio, due to to the levels of spirituality they maintain. If you're born into a nation with high levels of spirituality, the chances of your being a bender increase.

If Aang were to impart his air nomad beliefs to his children, and they to theirs, and so on, its entirely plausible that the Air Nomads would revive.

Also the next Avatar doesn't have to be related to Aang. As we see in the memories of Avatar Roku, he and Aang aren't related at all (though Zuko and Aang sort of are. xD) As far as the show has suggested, the next Avatar is chosen at random after the other one dies. The tradition is very similar to that of the beliefs regarding the Dali Lama. At the time of the prior Avatar's death, all babies born on that day will be given a choice of toys to play with - one of which is a toy that the Avatars through the generations have chosen. If the baby chooses that toy, it is a sign that it is familiar with it, and therefore is the Avatar's reincarnation. Reincarnation isn't at all relative to your genetic line, but rather on factors (such as spiritual potential).

I wasn't trying to suggest that the Avatar's have to be related. I'm not sure if the threadopener did, but I certainly did not. I was only trying to say that it was more likely, with Airbender blood in them that it would be his descendants.

I did say "to add..." as in to your post. =P but that 'more likely' has nothing to do with blood — it'd be Aang's teachings, the teachings of the Air Nomads, that would influence whether or not people are Airbenders — if they followed Aang's teaching. It's more likely that his descendants will be Airbenders, because of their lessons from Aang, but not because of the blood relation.

Oh, haha. I didn't catch that lol. You have a good point, though.

Well, technically, all the future Airbending Avatars and Airbenders themselves would all be related to Aang, especially since he is the last remaining avatar.

As for the toys.... That is only done by the Air Nomads, that is their tradition for selecting the Avatar, it isn't the same for all nations.

Regardless of the specific traditions shown, that's not the way it works. Bending and the Avatar status is not a genetic trait.

No, but if Aang is the LAST Airbender, he has to restart his entire generation.
An Airbender can't be born unless one of the parents is an Airbender, and since every Airbender from now will originate from Aang.... He's related to them.

He's the last living airbender. Yes, the new airbenders would probably have to come from his line, but it's not genetics that determines it. =]

This was a fun read. Weather or not bending is genetic, its a hard dispute, the avatar is a culmination of spirit, placed into a newborn upon the previous avatars death. This much we already know. However I think bending in itself has less to do with the spirituality of the people. Though that much is still a factor, since all air nomads are benders, and they are also very spiritual.

From the start however, bending was a learned art, and each form was learned from a different source, fire from the dragons, earth from the badgermoles and air from the sky bison. Water from the moon. At least that is as much as we know from the lore of A:tlA.

Since this lore can be deemed as some level of truth, I would think that anyone can learn to bend, as long as they have the force of spirit to help them. As for the element they would learn to bend, I beleive that is more a enviromental factor to take into account.

THe firenation home to firebenders is a volcanic island nation, where the mountains spit fire, and dragons once lived. The earthnation home of many earthbenders is a great mountainous region where they build their home and cities from stone, and many work in mines. But they are a LARGE nation and much of that nation is also covered in forests and swampland. Thus the swamp land waterbenders. (see where my environmental ideas come from here) And of course our waterbenders in the arctic lands of north and south. The people who live on frozen lands and hunt from the cold icy waters. And the air nomads living on mountains high building their lands on the edge of existence.

Now with this much clear as day before you there are some things we can see as rebuttals, the earth kingdom people who now live in the airnomad temple; if enviroment is a factor why no airbenders from them? Ok, well take into account that these people are new to that temple and are also treating it in a far different way than the air nomads did. Uhhm two possible outcomes I can foresee; One, Several generations or more into the future airbending comes to their people, its use would be far different than its original, due to their more advanced living style. (by this time I would expect there to be more technology thanks to the mechanist and descendant/students ect... The second outcome I can see is that these people never develope bending abilities through their generations thanks in part to their reliance on the technology advancements of the mechanist ect...

As for the other air temples, if they were to become inhabited again and people were to follow the ways the air nomads once taught, or at least lived in a calm peaceful yet spirited way, there would surely be a rise of the air benders once again.

As for genetics and bending, I wold agree not related at all, however a quasi relation can be assumed in the fact that many times the child of a bender is a bender. This relation while may seem just coincidence, would be more likely to be due to the close proximity they have to a benders spirit prenatally. Though thats all just speculation.

even though the creators themselves have said it's thus?

It's obviously a factor, but I don't feel its the most prominent factor.

that's what i'm saying though, the creators have said specifically that bending is determined by spirituality...

And I am saying that, while spirituality may be a deciding factor as to weathor or not someone can bend, everything else (minus avatar status) is determined through eviromental factors...

If Spiritualty => X Then
Can_Bend == true
Else
Can_Bend == false

And I'm too lazy to code out the rest of the equation... D:

I'm not sure I understand where you're coming from. =/

ok, to break it down, a certain level of spirituality, or at least exposure to such should be required to actually be able to bend, however the environment is the key factor as to what you learn to bend.

Ahh okies, fair fair. I happen to agree. =]

So does that mean that if people move into the air temples than, in theory at least, some of them should be able to learn airbending? And with that being said, why are none of the refugees at the northern air temple can bend anything, though I guess the next generation of people living there could be airbenders...I think I just answered my own question. XD