Similar to the Jewish Diaspora or when the modern Europeans displaced the basque people over most of Europe, or the Bantu in Subsaharan Africa. The first Native Americans crossed the land bridge about 10,000 years ago. It seems hard to believe that those cultures remained stagnant and unchanged in their areas for 10,000 years.
PaleoIndians migrated to the New World closer to 20,000 years ago than 10,000 years ago. There exists no evidence of people in the New World prior to that migration.
It seems hard to believe that those cultures remained stagnant and unchanged in their areas for 10,000 years.
I don't think I understand what you are getting at here. Native Americans changed dramatically in social complexity, subsistence technologies, art, how they modified their environment and a myriad of other traits over the 18,000 years or so that they have resided in the Americas.