Data from: Spatial and temporal drivers of phenotypic diversity in polymorphic snakes

Color polymorphism in natural populations presents an ideal opportunity to
study the evolutionary drivers of phenotypic diversity. Systems with
striking spatial, temporal, and qualitative variation in color can be
leveraged to study the mechanisms promoting the distribution of different
types of variation in nature. We used the highly polymorphic ground snake
(Sonora semiannulata), a putative coral snake mimic with both cryptic and
conspicuous morphs, to compare patterns of neutral genetic variation and
variation over space and time in color polymorphism to investigate the
mechanistic drivers of phenotypic variation across scales. We found that
strong selection promotes color polymorphism across spatial and temporal
scales, with morph frequencies differing markedly between juvenile and
adult age classes within a single population, oscillating over time within
multiple populations, and varying drastically over the landscape despite
minimal population genetic structure. However, we found no evidence that
conspicuousness of morphs was related to which color pattern was favored
by selection or to any geographic factors, including sympatry with coral
snakes. We suggest that complex patterns of phenotypic variation in
polymorphic systems may be a fundamental outcome of the conspicuousness of
morphs and that explicit tests of temporal and geographic variation are
critical to the interpretation of conspicuousness and mimicry.