Historical linguistics is a subfield of linguistics in which an investigation of the history of languages is used to learn about how languages are related, how languages change, and what languages were like hundreds and even thousands of years ago — even before written records of a language.
Donald Ringe has been pursuing several lines of research for more than a decade. He continues to publish on Indo-European comparative and historical linguistics, basically in the "traditional" paradigm but attempting to make the work intelligible to modern linguists; the first volume of his linguistic history of English (tracing the development of Proto-Indo-European into Proto-Germanic) has just been published by Oxford University Press, and Ringe continues to publish short articles at a steady pace. He also continues to pursue work in computational cladistics with a team that now includes Tandy Warnow (Computer Science, Illinois), Luay Nakhleh (Computer Science, Rice), and Steve Evans (Statistics, Berkeley).
A large proportion of Anthony Kroch's current research deals with language change. He has developed a model of change based on grammar competition (i.e., competition between conflicting parameter settings); work on that hypothesis has led him to the discoveries that variation in the settings of different parameters is independent, that children's recovery from syntax learning errors follows a profile similar to that of syntactic change, and that Middle English exhibited two competing versions of the V2 constraint (one of which plausibly reflects adult second-language learning of English by speakers of Norse). A crucial tool in this line of research has been the construction of syntactically parsed, searchable corpora, chiefly of various stages of English, but also of French and Portuguese.
Kroch and Ringe see the need to develop a new kind of historical linguistics, not isolated from the rest of the field, which preserves the extensive and valuable findings of work in the Neogrammarian tradition. They are jointly writing a graduate textbook that will attempt to put historical linguistics on a new footing, incorporating the insights of modern theory and sociolinguistics.
Charles Yang aims to develop a set of formal models of language change that mirrors the theories of population genetics in evolutionary change. This new area of research combines research from historical linguistics, corpus linguistics, and language acquisition, which provides mechanisms of linguistic transmission. Recent work includes models of syntactic and morphological change.