Sorry, messed up the quotes, this is mine that The Castellan
is responding to.
Surely, the native myths and that American Indians are human, make it more likely that the aliens aren't aliens, but an ancient advanced human civilization. They're knowledge of human psychology is why they stay intermittently involved with Earth. To let us evolve as much as possible with self determination, but interfering enough to keep the baser violent aspects of human nature to get the better of us. Thus the rare visits of 'gods' like Kukulkan, Krishna, Jesus, Buddha and other advanced society changing great minds of the past.
The Castellan wrote:
Well, judging from cave painting, statues and so on, many of them were not human looking either. I am not saying it's not the case, but I don't see how that reason is more acceptible than an actual ET visitation.
Simply applying Occams razor, there's we know humans are here and evolved here. There's nothing needed to prove their existence. True extra-terrestrials require proof of existing at all, that existing they have the technology and will to come here, coming here that there would be any interest in interacting with us. Sure, they may exist, but there needs to be more than supposition. As mentioned earlier, primitive man wouldn't know what to make of our own modest technology. What would they, or us, make of human civilization 10,000 years from now, adapted to life in space with technology to match?