“what evidence or arguments do they provide for the extra-terrestrial origin of it?”
If you reread my post you will see that I did not use the word “extra-terrestrial”.
I said “non human intelligence”.
There is a big difference.
Here is a discussion of the topic—though you may not consider it “evidence” it is interesting nonetheless:
https://thejournalofcosmology.com/Puthoff.pdf
Thank you for sharing that document. It is interesting.
Under section (5), hypothesis (1)...
Other than the biological specimen point, I don’t see anything in there that uniquely supports extraterrestrials. To me, it all seems to fit with my hypothesis.
I used to have some belief in the ancient civilization hypothesis however there is one fact that to me completely destroys that theory....food.
If there was actually an ancient global civilization, potatoes, tomatoes, tobacco, maize, apples, etc...should have been on both sides of the Atlantic during first contact with the new world. The fact that it wasn’t, convinces me that an ancient global civilization didn’t exist.