the humans (living on caprica?) created the cylons. the cylons rebelled and went back to earth and took human form. these cylons then created their own version of cylons and gave them human form, who also rebelled and blasted the original cylons out of earth?
man, when they say it's all happened before and it will happen again, they don't kid around
they did both, i think. the 13th colony was the original cylon colony. the final five were part of that colony, and they recreated resurrection tech. they also took a couple of centurians (the machine versions of the cylons in their population) and made them into skin jobs.
i'm confused about exactly when the original 13 colonists became skin jobs themselves. maybe that was from before, in a previous cycle of the timeline