So is it possible this was a wave of humans that died out?
I thought genetic analysis (admittedly not a precision tool) had found evidence of several waves of migration into North America within the accepted time range... could this early wave had been one that ended in extinction? And then subsequent waves finally survived and established themselves?
Had this earlier wave been successful, it would seem that subsequent waves would have all mixed with it and it would show up in the genetic analysis as a commonality between all native americans, but a commonality that had diverged from the asian lineage 5000 years earlier...?
WAY outside my field, so I may be missing something...