Phenotypic and genomic diversification with isolation by environment along elevational gradients in a neotropical treefrog

Understanding how geographic and environmental heterogeneity drive local
patterns of genetic variation is a major goal of ecological genomics and a
key question in evolutionary biology. The tropical Andes and inter-Andean
valleys are shaped by markedly heterogeneous landscapes, where species
experience strong selective processes. We examined genome-wide
SNP data together with behavioral and ecological traits (mating calls and
body size) known to contribute to genetic isolation in anurans in the
emerald-eyed treefrog, Boana platanera, distributed
across an environmental gradient in Central Colombia (northern South
America). We analyzed the relationships between
environmentally (temperature and
precipitation) associated genetic and phenotypic differentiation
and the potential drivers of isolation by environment along an
elevation gradient. We identified candidate SNPs associated with
temperature and body size, which follow a clinal pattern of genome-wide
differentiation tightly coupled with phenotypic variation: as
elevation increases, B. platanera exhibits larger body
size and longer call duration with more pulses but lower pulse rate and
frequency. Thus, the environmental landscape has rendered a scenario where
isolation by environment and candidate loci show
phenotypic divergence in this tropical
frog along an elevation gradient in the Colombian
Andes. Our study sets the basis for evaluating the role of
temperature in the genetic structure and local adaptation in tropical
treefrogs and its putative effect on life cycle (embryos, tadpoles,
adults) along elevation gradients.