Original sentence: In the late 20th century, some scholars theorized a long period of interaction, which resulted in many complex changes in genetics, languages, and culture among the peoples.The indigenous Melanesian populations are thus often classified into two main groups based on differences in language, culture or ancestral origins: the Papuan and Austronesian groups
Edited sentence: In the late 20th century, some scholars incorrectly theorized a long period of interaction, which resulted in many complex changes in genetics, languages, and culture among the peoples.The indigenous Melanesian populations were thus thought to have had one of two main ethnological ancestries: the Papuan and Austronesian groups