Although a Philippine language group was tacitly assumed by most scholars for much of the twentieth century, more recent evidence-based attempts to determine the position of the languages of the Philippines within the Austronesian language family have generated an ongoing debate. In 1982, Lawrence A. Reid proposed an Austronesian family tree with five primary branches: Atayalic, Tsouic, Other Formosan, Bilic, and Amis-Extra-Formosan. Not only did this proposal make the Bilic languages of southern Mindanao extremely remote relatives of other languages in the Philippines, but it also asserted that the languages of northern Luzon (called "Outer Philippines") form a primary branch of a proposed Extra-Formosan group as against the residue ("Malayo-Polynesian"), leaving the idea of a Philippine subgroup in total disarray. Four years later Reid's position was challenged by David Zorc, who argued on the basis of 98 proposed lexical innovations that, apart from Sama–Bajaw, all languages of the Philippines form a genetic unit with the Sangiric, Minahasan, and Gorontalic languages of northern Sulawesi. More recently Malcolm Ross has also questioned Proto-Philippines, holding that the languages of the Batanes islands between Taiwan and Luzon are an in situ continuation of the initial Austronesian settlement of the Philippines. These claims conflict with masses of counterevidence, which supports the reality of a Philippine group and implies that sometime after the initial phase of Austronesian settlement Proto-Philippines expanded at the expense of other related languages in the archipelago.