KotA, I really think you should get some better information regarding the evolution of culture an technology before making any speculation regarding possible alien involvment. Leave the woo pseudoscience behind and take a serious look in to the issue.
A good starting point would be "The Prehistory of the Mind: The Cognitive Origins of Art, Religion and Science " by Steven Mithen.
Now, a slightly OT rant.
I am really disgusted by people who can't "see" or believe how our species became what it is today, how it reached all its achievements, all the good and the bad parts, by itself without the help of some "superior beings", be them aliens, gods, angels, whatever. Heck, why should we belive our antecessors were not able, say, to create culture and technology by themselves? Why should we decrease the skills, intelligence and the luck of our antecessors? Why should we appeal to some "higher guidance"?
I'm very proud of my species beating the odds and being the evolutionary product of a blind proccess which started at some pool of goo billions of years ago. I'm very proud of the cultures and technologies built by my species without any halp of aliens, gods, angels, demons, spirits, whatever. Much prouder than I would be if we had been so dumb that we would need help to find out how to make spears, clothes, etc.
Look, I am NOT saying we couldn't have arrived without help... It is 'possible' that all that you see around you developed from pond scum, a little solar energy, and a lot of time...BUT that isn't what our history suggests.
What appauls ME is people ever so willing to dismiss millenia of written history, artwork, and even mythology that states the same thing the worlds over: "A long time ago, beings came out of the heavens, and interacted with men, to improve him & the way he lived."
While that isn't an exact quote, the very same notion is found in almost every creation story every written or passed down.
Scientists the world over dissmiss ALL such accounts, because they lack sincere testible proof. Personally, I think they'd all benefit from the lesson learned by the man who found Troy. IF you are looking for the truth, then I suggest you look in the direction these historical clues point toward...
There's a difference between "Heaven" and "the heavens".
The problem isn't the evidence, but rather how religious scholars interpreted the texts.
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Now, as for how adanced Homo Erectus was:
Homo Erectus did NOT wear clothes, of any kind. His tools were little more than simple hammer stones, and possibly sharp scraper rocks they found. From the evidence I have seen and studied, there was little or no 'fashioning' of tools.
Neanderthals on the other hand were the first to shape stones, and even lash them to strong sticks to make the first axes and hammers.
Cro Magnon Man- Homo Sapien, not yet fully 'us', did NOT come from the Neanderthal's line, but rather from the eariler Erectus line, and rather than simply draping animal skins across themselves, they had taylored clothes some of which were even adorned. Some even came up with farming along with irrigation methods.
So, how or why the 'leap' forward...? I mean, putting Neanderthal between us and Erectus, looks correct. We needed the years of draping simple animal skins across us, if only to realize that there was an even better way of dressing. We went from being simple hunters & gathers to, in some case, advanced farming. (*Forgive the huge generalizations.)