WMG / Nadia: The Secret of Blue Water

The Ancient Atlanteans are the Thirteenth Tribe of Kobol.

It does rather fit the whole "life here began out there" thing since it was the alien Atlanteans were the ones who created the humans of Earth in this series. Plus, it wouldn't be surprising that one reason that Atlantis collapse was because they tried to create their own take on the Cylons that rebelled against them.