The study of what people did early on is amazing with more and more genuine scientific evidence cropping up all the time. In fact evidence from genes, remains and language is growing much faster than daft ideas from the fringe.

"The Americas had civilization long before the Europeans, including my ancestors, came and screwed it all up."

I guess people have said this before but their is often an assumption on the part of some Europeans that "Americans" screwed things up, when of course the Screwing up was done essentially by "Europeans" who had gone to America.

The "Beachcomber Hypothesis" is very strong. That we left Africa to get to Arabia when the sea was low and traveled along beaches taking food from the seas pretty well all the way to Australia. This is supported by genetic, archaeology and language studies. Clearly various groups went north and east.