There is also some thought on the Idea that HUMANS not aliens are responsible for the technology. About 114000 years ago there was an interglacial period that lasted about 30000 years. This is referred to as the Eemian interglacial, at which time the earth experienced a slightly warmer, damper climate. Now what’s interesting is if you get on line and read up on glacial interglacial cycles you can come up with something along these lines......
500000 years ago Sitchin via Sumerian texts claims we were visited by an alien race that genetically altered a hominid species to create us. There is also further examination of those texts that suggest that 2 distinct lines of humans were created. A "primitive worker" and a more advanced intelligent version. You can calculate that around this time the earth was in an interglacial or warming period.
Now if you continue to trace the interglacial with the glacial you see that prior to our current Holocene there were I think 2 others between this and the one Sitchin's Aliens were enjoying.
So perhaps, the aliens took off at the end of the interglacial 500000 years ago (why would they stick around for 100000-150000 years of glaciations?) And it has been humans since then that have been recreating that extremely ancient technology over and over. However just about the time we start to reach intergalactic capabilities our planet freezes over and knocks us back again.
When we look at the possibility that 2 distinct lines of humanity were created, we can then see how survivors of the last interglacial might confuse them for a different being.
Just imagine humans with genetic capabilities and no laws or ethics comities controlling the use of that science. I bet we could come up with some off the wall creatures as well as altering our own appearance. It is also an explanation for the cave structures found in the Middle East discussed in one of the AA programs. Possibly a refuge from a very long winter. When it warms up people emerge and start anew perhaps in Sumeria. We maybe didn't need to invent technology or civilization, just recreate that which WAS given to us by an alien species, just much much further in our history then the AA theory suggests.?.