Finding families: Quantitative methods in language classification

Over the past two decades, many of the major controversies in historical linguistics have centred on language classification. Some of these controversies have been concentrated within linguistics, as in the methodological opposition of multilateral comparison to the traditional Comparative Method. Others have crossed discipline boundaries, with the question of whether correlations can be established between language families, archaeological cultures and genetic populations. At the same time, increasing emphasis on language contact has challenged the family tree as a model of linguistic relatedness. This paper argues that we must quantify language classification, to allow objective evaluation of alternative methods within linguistics, and of proposed cross-disciplinary correlations; and that a first step in this quantification is represented by the 'borrowing' of computational tools from biology.