Genetic and Linguistic Coevolution in Northern Island Melanesia

Recent studies have detailed a remarkable degree of genetic and linguistic diversity in Northern Island Melanesia. Here we utilize that diversity to examine two models of genetic and linguistic coevolution. The first model predicts that genetic and linguistic correspondences formed following population splits and isolation at the time of early range expansions into the region. The second is analogous to the genetic model of isolation by distance, and it predicts that genetic and linguistic correspondences formed through continuing genetic and linguistic exchange between neighboring populations. We tested the predictions of the two models by comparing observed and simulated patterns of genetic variation, genetic and linguistic trees, and matrices of genetic, linguistic, and geographic distances. The data consist of 751 autosomal microsatellites and 108 structural linguistic features collected from 33 Northern Island Melanesian populations. The results of the tests indicate that linguistic and genetic exchange have erased any evidence of a splitting and isolation process that might have occurred early in the settlement history of the region. The correlation patterns are also inconsistent with the predictions of the isolation by distance coevolutionary process in the larger Northern Island Melanesian region, but there is strong evidence for the process in the rugged interior of the largest island in the region (New Britain). There we found some of the strongest recorded correlations between genetic, linguistic, and geographic distances. We also found that, throughout the region, linguistic features have generally been less likely to diffuse across population boundaries than genes. The results from our study, based on exceptionally fine-grained data, show that local genetic and linguistic exchange are likely to obscure evidence of the early history of a region, and that language barriers do not particularly hinder genetic exchange. In contrast, global patterns may emphasize more ancient demographic events, including population splits associated with the early colonization of major world regions

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.National Foreign Language Resource Cente