I do think that they were once aliens on this planet.
Anyone ever seen the History channel special "Ancient Aliens"? Check it out, it's on demand. That's your proof right there..they are theories, but I am TOTALLY convinced now because it correlates to what Jordan Maxwell has been saying, but I had no idea this became mainstream.
I personally think that the Mayans were not human. Their knowledge of consciousness was far too advanced..it's what were just finding out today..either the knowledge was handed to them by e.t.'s. or they were E.T.'s.
Actual aircraft models were discovered also...in Columbia dating back to 500 A.D. to 800 A.D., complete with delta wings, tail fins, and rudders.
http://www.mysteriousworld.com/Conte...on/Jets260.jpg
The Egyptians also had electricity...which was supposedly not discovered for centuries later. Also, this doesn't look human to me.
http://www.alienshift.com/sitebuilde...gyptAliens.jpg
Another great mystery is Puma Punku. If these people were so primitive how in the hell did they do this? Modern engineers have admitted that they can't replicate the temple complex, nor the pyramids of Giza. The cuts on the stones of Puma Punku are so precise and perfect. These stones that were used to build PumaPunku are also around 440 tons each, they must have had machinery, anti-gravity devices or SOMETHING. These stones were also granite...the only thing harder than that is diamond..that's the only way they could have cut the grooves in them. Most importantly, how was a temple complex made using 440ton stones destroyed?
http://www.world-mysteries.com/mpl_61.jpg
Hopi cosmology explains how and why these civilizations were destroyed.
One thing is clear..there were ancient civilizations that were as advanced as we are. They had airports, electric batteries and the whole nine! http://www.davidicke.com/forum/showthread.php?t=11442