Not only that, but there was trade and migrations across the Bering straight before Columbus too, as evidenced by the spread of the Yupik people/Paleo-Eskimos.

Indonesia (Makassar) also traded with aboriginal Australians but this started in earnest in the 1700s. Still, it’s reasonable to conclude the entire earth was tenuously connected (technologically and historically if not actively) already even in the 1400s aside from some very isolated islands.