Evolutionary processes in language and culture -
The distribution of individual traits of languages is in part the product of historical contingencies. Some languages leave many descendents, some few. In order to investigate the evolution of individual traits of languages we need to build up a picture of the overall history of the language family.
Bayesian phylogenetic methods infer historical relationships by seeking the phylogenetic hypothesis most likely to produce data like the observed data given a particular model of the evolutionary process. Model choice allows incorporation of realistic assumptions about the processes of language change, including geography, demography, cultural variation, and contact. Bayesian methods in general are valuable whenever there is a need to extract information from data that are uncertain or subject to any kind of error or noise, including measurement error and experimental error, as well as noise or random variation intrinsic to language/cultural systems. Bayesian phylogenetic inference allows quantification of uncertainty and the investigation of conflicting phylogenetic signals, as well as estimation of chronology.