OK, so I've been thinking: the Avatar has the ability to bend all 4 elements, right?

Well, the parents, of course, don't even have to be benders to give birth to the Avatar.

So, let's say the next Avatar, which after Korra I think it's an Earth bender, is given birth by a Fire bending mother, and a Water nation soldier.

Let's say the soldier has no idea how the Avatar is created, when he comes home and sees his child bending more than just Fire, I think he's going to slap his cheating wife. >.<

But in all seriousness, now. We just accept that the Avatar is born, and can bend all elements. Doesn't that make you think that SOMEONE'S wife was cheating when the FIRST Avatar was born?

They don't go into too many details about the first Avatar, so what are we supposed to think? You'd think the show would explain something like that, but they didn't.

So all we can do is just make conjectures about how the first Avatar came into being.

I still think someone's wife was cheating, hardcore. A 4 way with 3 benders that weren't whatever nation she was from. And since in this time period, sex that wasn't plain old simple man on woman, only 2 people in the bed, she did it in secret, and that's why the Avatar exists.

I'm being serious, that's the best conjecture I can come up with. If anyone has something they think is more likely than what I said, that IS NOT just "the Avatar came into being, the end", then please post your thoughts.

I think the next season will try to explain the origins of the Avatar. For all we know, the Avatar was created out of a need, either at the time, or a future need. or as the Spirit World's incarnation on Earth. I don't know, but I'm sure we'll find out soon.

1714611
The Avatar is born into the next nation in the cycle every time the previous Avatar dies, so the next Avatar will be born in the Earth Kingdom, then the next will be born into the Fire Nation, and the Avatar after that must be a descendent of Aang, more specifically, the descendent of Tenzin, since is family represents the Air Nomads. And only Tenzin is an airbender.

Now, this used to be very simple in the time before Republic City, when there was almost none interbreeding among the four nations. bending is determined by a set of genetic principles even more complicated than MLP. (See this video.) The only genetics that determine who is the Avatar is the type of bending that s/he is. The only prerequisite for the next Avatar is that s/he must be genetically an earthbender. That's it.

There's no crazy love four-way that goes into determining the Avatar. From Avatar Wiki:

The Avatar is the spirit of the planet incarnated in human form.

So, the Avatar is the reincarnation of a spirit, like the Dalai Lama is thought to be. That is how the Avatar came to be, although Book 2 will explain why, which I look forward to. Now we know that the first Avatar is Wan, aka Glenn from The Walking Dead. I think your theory of adultery is highly implausible, especially for a show aimed at kids.

The Wiki doesn't DEFINITIVELY tell us HOW the Avatar is created.

You just gave me the answer I said I did not want-The spirit cycle determines the next Avatar.

I want to know HOW the spirit cycle determines the next Avatar? You didn't explain that....

Considering that, my theory is more plausible than your religous-like theory (God made the Earth, the end, for example)

1714709>>1714777
The problem with taking a non-religious route is that you can't discount religion being a factor in the Avatar universe.

Considering that many people have witnessed acts pertaining to the Spirit World, such as Uncle Iroh, the fact that Spirits even exist cannot be left out. With confirmed higher beings that were not only mentioned, but seen on screen, we can confirm that Sprits are likely the answer to the question.

Also, we have to consider the Avatar's connection to the Spirit World. All Avatars have the ability to connect, whether their connection is strong or not (as seen with Aang and Korra). We see that not only do the previous Avatars help the Avatar, but certain Spirits also helped him in various ways.

With the information given by the show, we know that the Order of the White Lotus was searching specifically in the Northern and Southern Water Tribes for the Avatar successor to Aang. For all we know, the Avatar "duty" can only be bestowed upon a bender native to the next nation in the cycle of Water, Earth, Fire, and Air.