Those blond, beautiful folks of ancient times, the ones found at the slave markets in Knossos.......what do you think they were?
The Nazi claimed them for their purity (beauty.)
The Romans used them to create the city that still lives; without the clocca maxima designed by the blond engineers (Etruscans then) Rome would resemble Petra.
The pyramids had a purpose and the Bosnia discoveries come the closest to revealing what they were. Using nature and the power of flowing water, they were able to keep their bodies free of toxins.
Since they were not violent, one is drawn to the conclusion they were engineered clones. Engineered to be beautiful, (we are so shallow and love beauty) engineered to be engineers hence the pyramids, and engineered to be non violent which assured their temporary presence. What else could they be but clones?
We have come close enough in our actual experimental science that this is totally believable.