This book explores the classification of languages into families and proposes new methods for categorization. Using computer programs borrowed from biology and evolutionary genetics, the authors analyze linguistic data to tackle longstanding issues in historical linguistics. They challenge current theories, introduce fresh perspectives, and demonstrate how modern techniques can yield unexpected insights. April and Robert McMahon, blending expertise from historical linguistics and genetics, investigate the relationship between linguistic patterns and human population genetics. From Indo-European languages to lesser-known South American languages, they examine how language can illuminate human history and relationships. Suitable for students, researchers, and general readers interested in language classification and its intersection with human history.