The Journal of Language Contact has as its subhead “Evolution of languages, contact and discourse” and as its motto the excellent quote (from Hugo Schuchardt, specialist in mixed languages, pidgins, creoles, and lingua franca) “Es gibt keine völlig ungemischte Sprache” (‘There is no completely unmixed language’):
We wish JLC to focus on the study of language use and language change in accordance with a view of language contact whereby both, empirical data (the precise description of languages and how they are used) and the resulting theoretical elaborations (hence the statement and analysis of new problems) become the primary engines for advancing our understanding of the nature of language. This will also involve associating linguistic, anthropological, historical, and cognitive factors. We believe that such an approach would make a major new contribution to understanding language change at a time when there is a notable increase of interest and activity in this field.
Hey, maybe they can solve the problem of the newest language!