Files used in the analyses from A role of asynchrony of seasons in explaining genetic differentiation in a Neotropical toad

The process of diversification can be studied at the phylogeographic level
by attempting to identify the environmental features that promote and
maintain population divergence. Here we investigate diversification
in Rhinella granulosa, a Neotropical toad from northeastern
Brazil, by testing a range of hypotheses that encompass different putative
mechanisms reducing gene flow among populations. We sequenced single
nucleotide polymorphisms and examined individual predictions related to
the role of geographic barriers (rivers), ecological gradients, historical
habitat stability, and spatial variation in climate seasonality, also
known as the asynchrony of seasons
hypothesis. This hypothesis postulates that temporal
asynchrony of wet and dry seasons over short distances causes parapatric
populations to become isolated by time. After determining genetic
structure, inferring past distributions, ranking demographic models, and
estimating the power of monthly climatic variables, our results identified
two populations that are not associated with geographic barriers, biome
gradients, or historical refugia. Instead, they are predicted by spatial
variation in monthly rainfall and minimum temperature, consistent with the
asynchrony of seasons hypothesis, supported also by our comparative
framework using multiple matrix regression and linear mixed
effects modeling. Due to the toad’s life history, climate likely mediates
gene flow directly, with genetic differentiation being provoked by neutral
mechanisms related to climate driven population isolation, and/or by
natural selection against migrants from populations with different
breeding times. The asynchrony of seasons hypothesis is seldom considered
in phylogeographic studies, but our results indicate that it should be
tested in systems where breeding is tightly coupled with
climate.