As an anthro student in the late 80s, I would have given Thor Hyerdahl's theory of Mediterranean cultures influencing South and Meso-American cultures more credence if he had not also come out and said that the reason why Neanderthalensis had thick, heavy brow ridges was to keep rain out of the eyes.
Their adaptation to the Ice Age is simply different than our own eh.
More recently (just before he died) Thor came up with the idea that the Aesir were actual people who'd come from what is now Azerbaijan in Roman times. He ended up finding caves in Azerbaijan with what most believe to be Scandinavian symbology.
Whether he was right or wrong on that, a linguist at Indiana University made a truly major discovery ~ he found that the 9 existing Sa'ami languages (spoken mostly in far Northern Norway) have a well known cognate called Sumerian, and really aren't part of the Finno-Ughric subgroup of the Altaic-Uralic group of languages spoken throughout central Asia (although Sa'ami does share much of its vocabulary with those languages).
He also found a cognate American Indian language which is apparantly still spoken by some people in a tribe currently located in California.
However, that wasn't his biggest find ~ he determined that the Sumerians also designed the first character set used for a written language in China, and did the same job for the Egyptians.
The Sa'ami didn't invent writing, but they did produce pictographs/ideographs on the undersides of cliff faces and other places in Finland thousands of years ago. One of them portrays a classical Polar story about the woman who failed to find suitible husbands for her daughters. The result was she was turned into stone and the girls slept with ol'dad.
Where have we heard that story before?
This continues to be a hot story among the natives in Siberia.
I don't think Hyerdahl had any Sa'ami ancestry or he'd latched onto that stuff first. Still, there seems to be some sort of zone for animal herds that extends from the Arctic to the Caspian.
If you ever get the chance check out the Art Museum at Indiana University. They have a large plexiglas board up with imbedded artifacts from the Fertile Crescent. One of them is a little statue of a reindeer!
If neolithic people in Eur-Asia could get around like that, certainly the American Indians could go pretty much where they pleased.