What does the Assimilation Model propose about H. sapiens migration?

The Assimilation Model proposes that as Homo sapiens migrated out of Africa, they did not simply replace older hominin species, such as Neanderthals and Denisovans, but instead interbred with them. This model suggests that while modern humans spread across various regions, they assimilated and incorporated genetic material from these archaic populations, leading to the genetic diversity observed in contemporary human populations. Such interbreeding has been supported by genetic evidence showing that many modern humans carry DNA that can be traced back to these earlier hominins. This understanding of migration emphasizes a more complex narrative than mere replacement, highlighting the importance of interactions between different human species during the migration process.