In defense of Nuclear Austronesian (and against Tsouic)

Ross (2009) proposed the Nuclear Austronesian hypothesis, whereby Puyuma, Tsou and Rukai are each single-member first-order subgroups of Austronesian and all other Austronesian languages belong to a Nuclear Austronesian subgroup. The basis of this subgrouping is a complex innovation whereby certain Proto Austronesian nominalizers came also to mark indicative verbs. This paper falls into two parts. The first surveys kinds of evidence that historical linguists use in subgrouping and proposes metrics (§2) that are then applied to the innovations that support Nuclear Austronesian (§3) and other recent first-order subgroupings of Austronesian (principally Formosan) languages (§4). The second part argues that the commonly accepted Tsouic subgroup, which is incompatible with the Nuclear Austronesian hypothesis, is not supported by the evidence. Instead it reflects longterm contact between Tsou on one hand and Kanakanavu and Saaroa on the other (§5). In conclusion, it is tentatively suggested that the southern part of the Taiwan highlands appears to be the oldest Austronesian homeland area.