Data from: Effects of climatic and geological processes during the Pleistocene on the evolutionary history of the northern cavefish, Amblyopsis spelaea (Teleostei: Amblyopsidae)

Climatic and geological processes associated with glaciation cycles during
the Pleistocene have been implicated in influencing patterns of genetic
variation and promoting speciation of temperate flora and fauna. However,
determining the factors promoting divergence and speciation is often
difficult in many groups because of our limited understanding of potential
vicariant barriers and connectivity between populations. Pleistocene
glacial cycles are thought to have significantly influenced the
distribution and diversity of subterranean invertebrates; however, impacts
on subterranean aquatic vertebrates are less clear. We employed several
hypothesis-driven approaches to assess the impacts of Pleistocene climatic
and geological changes on the Northern Cavefish, Amblyopsis spelaea, whose
current distribution occurs near the southern extent of glacial advances
in North America. Our results show that the modern Ohio River has been a
significant barrier to dispersal and is correlated with patterns of
genetic divergence. We infer that populations were isolated in two refugia
located north and south of the Ohio River during the most recent two
glacial cycles with evidence of demographic expansion in the northern
isolate. Finally, we conclude that climatic and geological processes have
resulted in the formation of cryptic forms and advocate recognition of two
distinct phylogenetic lineages currently recognized as Amblyopsis spelaea.