Evolutionary dynamics in the dispersal of sign languages
Temas
Detalles
While the evolution of spoken languages is well understood and has been studied using traditional historical comparative methods as well as newer computational phylogenetic methods, evolutionary processes resulting in the diversity of contemporary sign languages are poorly understood, and scholars have been largely unsuccessful in grouping sign languages into monophyletic language families. To date, no published studies have attempted to use language data to infer relationships amongst sign languages on a large scale. Here, we report the results of a phylogenetic analysis of 40 contemporary and 36 historical sign language manual alphabets coded for morphological similarity. Our results support grouping sign languages in the sample into six main European lineages, with three larger groups of Austrian, British, and French origin, as well as three smaller groups centering around Russian, Spanish, and Swedish. The British and Swedish lineages support current knowledge of relationships amongst sign languages based on extra-linguistic historical sources. With respect to other lineages, our results diverge from current hypotheses by indicating (i) independent evolution of Austrian, French, and Spanish from Spanish sources; (ii) an internal Danish subgroup within the Austrian lineage; and (iii) evolution of Russian from Austrian sources.