 But they proposed that rather than a monolithic "Austronesian expansion" as posited by the "Out of Taiwan" model, it was instead a process of cultural diffusion and assimilation that brought linguistic and cultural changes (particularly rice cultivation) but had relatively minor genetic impact (an average of 20%) on preexisting populations in ISEA.Their study also still concluded that populations from ISEA did expand northwards earlier during the catastrophic rise events of the Late Pleistocene, dispersing into mainland southern China and then into Taiwan.This was concurrent with other migrations of indigenous maritime-oriented ISEA populations entering Taiwan from the south through the Philippines.