Altaic substratum; (2) Korean was related to the other three at the same level they were related to each other; (3) Korean had split off from the other three before they underwent a series of characteristic changes. Roy Andrew Miller's 1971 book Japanese and the Other Altaic Languages convinced most Altaicists that Japanese also belonged to Altaic. Since then, the "Macro-Altaic" has been generally assumed to include Turkic, Mongolic, Tungusic, Korean, and Japanese. In 1990, Unger advocated a family consisting of Tungusic, Korean, and Japonic languages, but not Turkic or Mongolic. However, many linguists dispute the alleged affinities of Korean and Japanese to the other three groups. Some authors instead tried to connect Japanese to the Austronesian languages. In 2017, Martine Robbeets proposed that Japanese (and possibly Korean) originated as a hybrid language. She proposed that the ancestral home of the Turkic, Mongolic, and Tungusic languages was somewhere in northwestern Manchuria. A group of those proto-Altaic ("Transeurasian") speakers would have migrated south into the modern Liaoning province, where they would have been mostly assimilated by an agricultural community with an Austronesian-like language. The fusion of the two languages would have resulted in proto-Japanese and proto-Korean. In a typological study that does not directly evaluate the validity of the Altaic hypothesis, Yurayong and Szeto (2020) discuss for Koreanic and Japonic the stages of convergence to the Altaic typological model and subsequent divergence from that model, which resulted in the present typological similarity between Koreanic and Japonic. They state that both are "still so different from the Core Altaic languages that we can even speak of an independent Japanese-Korean type of grammar. Given also that there is neither a strong proof of common Proto-Altaic lexical items nor solid regular sound correspondences but, rather, only lexical and structural borrowings between languages of the Altaic typology, our results indirectly speak in favour of a “Paleo-Asiatic” origin of the Japonic and Koreanic languages." The Ainu language In 1962, John C. Street proposed an alternative classification, with Turkic-Mongolic-Tungusic in one grouping and Korean-Japanese-Ainu in another, joined in what he designated as the "North Asiatic" family. The inclusion of Ainu was adopted also by James Patrie in 1982. The Turkic-Mongolic-Tungusic and Korean-Japanese-Ainu groupings were also posited in 2000–2002 by Joseph Greenberg. However, he treated them as independent members of a larger family, which he termed Eurasiatic. The inclusion of Ainu is not widely accepted by Altaicists. In