Systematic typological comparison as a tool for investigating language history

Similarities between languages can be due to 1) homoplasies because of a limited design space, 2) common ancestry, and 3) contact-induced convergence. Typological or structural features cannot prove genealogy, but they can provide historical signals that are due to common ancestry or contact (or both). Following a brief summary of results obtained from the comparison of 160 structural features from 121 languages (Reesink, Singer & Dunn 2009), we discuss some issues related to the relative dependencies of such features: logical entailment, chance resemblance, typological dependency, phylogeny and contact. This discussion focusses on the clustering of languages found in a small sample of 11 Austronesian and 8 Papuan languages of eastern Indonesia, an area known for its high degree of admixture.