The adoption of evolutionary approaches to study language change as a type of
non-biological evolution has gained increasing interest and introduced a variety
of quantitative tools to linguistics. The focus has thus far mainly been on
language families, or ‘linguistic macroevolution,’ and taken the shape of
linguistic phylogenetics. Here we explore whether evolutionary methods could be
applicable for studying intra-lingual variation (‘linguistic microevolution’) by
testing a population genetic clustering method for analyzing the ‘population
structure’ of Finnish dialects. We compare the results with traditional dialect
divisions established in the literature and with K-medoids
clustering, which is free from biological assumptions. The results are
encouragingly similar to each other and agree with traditional views, suggesting
that population genetic tools could be a useful addition to the dialectological
toolkit. We also show how the results of the model-based clustering could serve
as a basis for further study.