Regardless certain disagreements still exist among researchers with regards to chronology, origin, dispersal, adaptations to the island environments, interactions with preexisting populations in areas they settled, and cultural developments over time. The mainstream accepted hypothesis is the "Out of Taiwan" model first proposed by Peter Bellwood. But there are multiple rival models that create a sort of "pseudo-competition" among their supporters due to narrow focus on data from limited geographic areas or disciplines. The most notable of which is the "Out of Sundaland" (or "Out of Island Southeast Asia") model. As a generalization, authors that are based in Indonesia and Malaysia tend to favor the "Out of Sundaland" model, while authors based in Taiwan and the Pacific Islands tend to favor the "Out of Taiwan" model.