Data from: Persistence in peripheral refugia promotes phenotypic divergence and speciation in a rainforest frog

It is well established from the fossil record and phylogeographic analyses
that late Quaternary climate fluctuations led to substantial changes in
species' distribution, but whether and how these fluctuations
resulted in phenotypic divergence and speciation is less clear. This
question can be addressed through detailed analysis of traits relevant to
ecology and mating within and among intraspecific lineages that persisted
in separate refugia. In a biogeographic system (the Australian Wet
Tropics, AWT) with a well-established history of refugial isolation during
Pleistocene glacial periods, we test whether climate-mediated changes in
distribution drove genetic and phenotypic divergence in the rainforest
frog, Cophixalus ornatus. We combine paleomodeling and multilocus genetics
to demonstrate long-term persistence within, and isolation among, one
central and two peripheral refugia. In contrast to other AWT vertebrates,
the three major lineages differ in ecologically relevant morphology and in
mating call, reflecting divergent selection and/or genetic drift in the
peripheral isolates. Divergence in mating call, and contact zone analyses,
suggest that the lineages now represent distinct species. The results show
that climate shifts can promote genetic and phenotypic divergence, and
potentially speciation, and direct attention towards incorporating
adaptive traits into phylogeographic studies to better resolve the
mechanisms of speciation.