On the disintegration of (proto-)languages

Abstract

Do languages split into dialects and subsequently into new languages at regular rates? Does such a regular splitting rate also apply to speech communities ancestral to the world's current language families? Do linguistic phylogenies exhibit intermediate levels (“genera”) which are somehow objectively identifiable? These questions are rarely raised, much less answered. In this article we present a simple method that provides insights into all the questions, drawing upon data from a world-wide sample of languages. It will be shown that splitting rates are approximately regular even if the languages studied are proto-languages spoken at very different points in prehistory and different places in the world. Ancestors of the world's linguistic families tend to have similar life-times. An intermediate transitional level corresponding to the point where genera appear can be objectively inferred from differences among descendant languages even without previously having established the structure of the phylogenetic tree.