Evolutionary Principles and the Diversification of Linguistic Form

Languages, like genes, are documents of history. The rich history of humanity’s speech communities is inscribed in the remarkable diversity of linguistic forms we see today. This diversity is generated by evolutionary processes that, like biological evolution, take place in space and time. In this talk I show how evolutionary methods designed to analyse the spread of viral outbreaks can be used to model the spread and diversification of languages. Bayesian phylogeographic models will be used to test two hypotheses for the origin of the Indo-European language family. The conventional view places the homeland in the Pontic steppes about 6000 years ago. An alternative hypothesis claims that the languages spread from Anatolia with the expansion of farming 8000 
to 9500 years ago. I will show that that the inferred timing and root location of the Indo-European language trees fit with an agricultural expansion from Anatolia beginning 8000 to 9500 years ago. These results highlight the critical role that evolutionary models can play in resolving debates about language origins and human history.