Hello everyone, this is my first post. I hope that there is no rule or tradition against starting a new thread as one's first post: if there is I apologize. However, I think I do have a rather interesting hypothetical.
Suppose the group of Asian hunters who crossed the Berring Land Bridge either never made it or failed to establish lasting human population there. If all Native Americans are descended from them, then we are faced with two large, empty continents until some more established powers find them. Conversely, if we buy in to the Solutrean hypothesis or one of the Pacific models, we would have a different group of people settling the New World. As far as I can see it, I imagine one of three things would happen:
A. Pacific islanders did settle in the Americas. When Europeans arrive in the 15th century, they find strange, strange-looking (to them) natives. Thus, things go mostly as they do in OTL.
B. The lands are completely empty. Ice-age megafauna may still exist, even in extremely large numbers. I suspect the nations of Europe would settle in to this land quite comfortably: without the need to subdue natives, free land and resources might be quite a draw to Europeans. American society would likely develope on a "closer to Europe" line: though in OTL colonists sometimes mingled with the Indians (resulting in nations like modern-day Mexico) and other times did not, but nonetheless saw them as a kind of example of a different society (modern-day America). Without their example, the Americas might seem more like a new part of Europe than a New World.
C. Europeans arrive and meet...Europeans. Personally, I don't think Solutrean "natives" would be treated much better than the natives in OTL: they would still be pagans, still speak a strange language, and still be in the way. However, after they are mostly wiped out by disease, they might be more able to integrate in to European culture: convert, learn English, Spanish, Portugues, Dutch, etc., and you're just another white person. Of course, they might still be seen as low class, but they would probably not be the object of a campaign to kill them off.
Other than that, I can perhaps see a larger population in eastern Asia, due to the descendents of the hunters who did not leave. However, I expect that the Native Americans are descended from a sufficiently small group that there is not likely to be much effect. If there were, I suppose either pressure on Europe from the East results in quicker discovery of the New World, or pressure in the East results in settlement of more and more Pacific islands, perhaps culminating in discovery of the New World from the other side (and subsequent Asian colonization). However, if the population that left Asian is small enough, I suspect that them remaining in Asia could eliminate the human settlement of North America without having a large effect on the rest of the world.
If anyone has any thoughts, I'd love to hear them.