Adherents to this model look at early material and try to trace continuity in morphology from those early populations to later populations in the same geographic area.
In this model, there are paralleled changes in all penecontemporary populations, with enough genetic migration to maintain close species bonds, while still allowing the suite of racial features we see today.) did not contribute a significant amount of genetic material to later populations that led to modern humans (some claim no genetic ancestry to these groups and their descendants at all, a “strict” replacement model).
Some see direct competition and extermination of the native populations, some see passive replacement due to better adaptive strategies, and some see genetic admixture with the preponderance of genetic material coming from the incoming human populations, eventually replacing and assimilating them into the greater collective.
In this view there is a specific speciation event that occurred which led to the origin of There are various models which embody combinations of these ideas, different “strict” interpretations of the two theories, etc.
The behavioral evidence is an old one, and is crumbling into dust as paleoanthropology enters the 21st century.