Though I make no speculation on the Thalan I've had the idea that the Precursors are actually Humans and that it's a continuous cycle.

The end of this war would result in all other life ending and the Humans becoming the Precursors and seeding the galaxy with life, including their own original 'forms'.

The Precursors look like humans, but they are not humans. You're right about the continuous cycle though. Maybe I should dig up some of Frogboy's old post again? He explained most of this stuff already.

As for the Thalan, they are an insectoid race from a future dimension. They have come to our space-time to prevent the destruction of the universe, claiming that the humans are responsible for it.

Edit: In the TotA tech tree of the Thalan it was mentioned, that they have multiple appendages. I'm quite disappointed that they changed that.

https://forums.galciv2.com/127754/page/1/ Is that close enough?

Though a time loop is a possibility, it's not what I'm talking about. I'm talking about adding to an iteration.

1 precursor > human > +1 goto 2
2 precursor > human > +1 goto 3
3 precursor > human > +1 goto 4
4 precursor > human > +1 goto 5
5 precursor > human > +1 goto 6
6 etc...

(the numbers represent time, it doesn't go back to 1)

Edit: Reading the link Wintersong gave, it more likely is a time loop then.

I think bipedal Thalans is a retcon. If you look at Hithesius (?) in GCII, it really does appear by the angles that his weight is resting on the appendages protruding from his shoulders.

It's a retcon that is most unsatisfactory to me.

From the GalCiv II  manual, page 88:

Regarding the Thalan
The Thalan are a mysterious race that literally popped out of nowhere in
2224. They quickly established a homeworld and while seemingly friendly
are very concerned about the Terran Alliance. According to reports, the
Thalan are from another dimension – a future dimension in which following
a great ―crusade‖ by the Humans, the galaxy is destroyed as a result of
individuals within the Terran Alliance. They claim to have come to this
galaxy to prevent this but say they have come approximately five years too
early.

Frogboy, in your post #12 you say the human crusade destroys the universe, in post #13 you say it destroys the galaxy. Can you clarity this please?

I love the concept of eternal return ("This has all happened before . . .").   Looking forward to finding out the next chapter in your story. 

I've looked and looked at pics and the video that exists of the Thalans but I couldn't spot any zippers. So I think they're real.

I definitely look forward towards the story playing out.

Can someone post here the thread on the Altarians? I cannot get the link to work, (Impulsedriven) and would prefer to just read it here in a thread.... 

http://draginol.impulsedriven.net/article/171522/Of_the_Altarians

This link does not work for me...(sigh)

So, wait, the Thalan aren't the reincarnated souls of all the Praying Mantises that get squished by Humans?

Not this human, though.  I take care to avoid stepping on them Mantises, they help with pest control...

Brad did mention they come from another universe, though, so perhaps in that universe the Praying Mantises evolved to human size...

Try this link. In any case, it doesn't say anything you couldn't read in the Altarian and Drath tech trees in TotA.

I think that is just a coincidence. However, it was heavily implied several times in the DL campaign, that the Drengin were indeed puppets of the Dread Lords. For the Korath, it was definitely the case in the DA campaign.