The strength of the phylogenetic signal in syntactic data

Abstract

While phonological change has played a central role in assessing linguistic relatedness since the nineteenth century, the usefulness of syntactic change for this purpose has remained debated – despite recent work on the question with a variety of results. In our study, we analyze the phylogenetic signal of syntactic data using state-of-the-art Bayesian algorithms and the SSWL database (Koopman 2012–). With the phylogenetic model, we infer a minimally biased family tree. We find that, generally, the phylogenetic signal in the syntactic dataset is low. The model fails to infer larger-order subgroupings that would be found further back in time. This is in contrast to the clear-cut groupings we can obtain from running this type of model on phonological databases. This raises the question how well these syntactic properties encode phylogenetic information. As it stands, the model fails to provide evidence for strong phylogenetic signal despite the rich dataset and methods.