Researchers have over recent decades been using inter-disciplinary approaches to assess the evidence that early voyagers had come to the Americas, leaving a legacy of cultural traits. That evidence has been mounting. To give a few examples: the Harvard scholar David Kelley has shown irrefutable similarities between Eurasian and Mesoamerican calendar astronomy systems. It defies belief that these systems could have been independently invented, given the intricacies involved. Kelley also argues that linkages can be traced between northern India and the area around Guatemala about 2000 years ago.
Terry Jones and Kathryn Klar have presented linguistic and archaeological evidence for early Polynesian contacts with Southern California. Then there is the ground-breaking work on trans-oceanic voyaging in prehistoric America by that distinguished anthropology professor Alice Kehoe, about which more in my next post.