Sexual signal evolution and patterns of assortative mating across an intraspecific contact zone.

Contact zones provide important insights into the evolutionary processes that underlie lineage divergence and speciation. Here, we use a contact zone to ascertain speciation potential in the red-eyed treefrog (Agalychnis callidryas), a brightly coloured and polymorphic frog that exhibits unusually high levels of intraspecific variation. Populations of A.

Natural and anthropogenic landscape factors shape functional connectivity of an ecological specialist in urban Southern California.

Identifying how natural (i.e., unaltered by human activity) and anthropogenic landscape variables influence contemporary functional connectivity in terrestrial organisms can elucidate the genetic consequences of environmental change.

Genetic isolation by distance underlies colour pattern divergence in red-eyed treefrogs (Agalychnis callidryas).

Investigating the spatial distribution of genetic and phenotypic variation can provide insights into the evolutionary processes that shape diversity in natural systems. We characterized patterns of genetic and phenotypic diversity to learn about drivers of colour-pattern diversification in red-eyed treefrogs (Agalychnis callidryas) in Costa Rica. Along the Pacific coast, red-eyed treefrogs have conspicuous leg colour patterning that transitions from orange in the north to purple in the south.

Minimal prezygotic isolation between ecologically divergent sibling species.

Divergence in mating signals typically accompanies speciation. We examine two ecologically divergent sibling species of crickets to assess the degree and timing of the evolution of prezygotic reproductive isolation. occurs in rocky habitats throughout western North America with long-winged individuals capable of long-distance dispersal; is endemic to red-rock sandstone areas of south-eastern Utah and north-eastern Arizona and has short-winged individuals only capable of limited dispersal.

Genetic and phenotypic evidence of a contact zone between divergent colour morphs of the iconic red-eyed treefrog.

Hybrid zones act as natural laboratories where divergent genomes interact, providing powerful systems for examining the evolutionary processes underlying biological diversity. In this study, we characterized patterns of genomic and phenotypic variation resulting from hybridization between divergent intraspecific lineages of the Neotropical red-eyed treefrog (Agalychnis callidryas). We found genetic evidence of a newly discovered contact zone and phenotypic novelty in leg colour-a trait suspected to play a role in mediating assortative mating in this species.

You cannot have it all: Heritability and constraints of predator-induced developmental plasticity in a Neotropical treefrog.

Many organisms have evolved phenotypic plasticity but examples of a heritable genetic basis or genetic constraints for plasticity across environments remain scarce. Tadpoles of the Neotropical treefrog Dendropsophus ebraccatus alter tail coloration and shape differently in response to fish or aquatic insect predators. To assess the genetic basis of plasticity we raised 1020 tadpoles from 17 maternal half-sib pairs (34 unique families) individually with chemical cues of fish or aquatic insects, or with cue-free control water.

Uniformity in premating reproductive isolation along an intraspecific cline.

Premating reproductive isolation (RI) may reduce gene flow across populations that have differentiated in traits important for mate choice. Examining RI across genetic and phenotypic clines can inform the fundamental evolutionary processes that underlie population and lineage differentiation. We conducted female mate-choice studies across an intraspecific red-eyed treefrog cline in Costa Rica and Panama with 2 specific aims: (1) to characterize RI across the cline and examine the relationship between premating RI and genetic and phenotypic distance and (2) to evaluate our results within a broader evolutionary and taxonomic perspective through examination of other RI studies.

Regional variation in drivers of connectivity for two frog species (Rana pretiosa and R. luteiventris) from the U.S. Pacific Northwest.

Comparative landscape genetics has uncovered high levels of variability in which landscape factors affect connectivity among species and regions. However, the relative importance of species traits versus environmental variation for predicting landscape patterns of connectivity is unresolved. We provide evidence from a landscape genetics study of two sister taxa of frogs, the Oregon spotted frog (Rana pretiosa) and the Columbia spotted frog (Rana luteiventris) in Oregon and Idaho, USA.

Fire Does Not Strongly Affect Genetic Diversity or Structure of a Common Treefrog in the Endangered Florida Scrub.

Fire regimes influence natural populations of organisms in diverse ways, via direct effects on population dynamics as well as indirect effects on habitat and ecosystem processes. Although many amphibian species have evolved to persist in fire-dependent ecosystems, the effects of fire on the genetic diversity of amphibian populations remain relatively unexplored. We examined how different aspects of fire history relate to population genetic diversity and structure of an abundant anuran, Hyla femoralis, in a large, intact area of Florida scrub containing hundreds of seasonally inundated ponds.

Variation in male spermiation response to exogenous hormones among divergent populations of Red-eyed Treefrogs.

Background: The non-lethal collection of sperm from live males is an important component for multiple captive-breeding techniques, including assisted reproductive technology (ART) protocols, sperm cryopreservation and in vitro fertilization. However, in amphibians, the type and amount of hormone necessary to induce spermiation can be highly variable, even among closely related species. We are unaware of any studies that have examined the spermiation response to exogenous hormones across highly differentiated populations within a species.

Effects of changing climate on aquatic habitat and connectivity for remnant populations of a wide-ranging frog species in an arid landscape.

Amphibian species persisting in isolated streams and wetlands in desert environments can be susceptible to low connectivity, genetic isolation, and climate changes. We evaluated the past (1900-1930), recent (1981-2010), and future (2071-2100) climate suitability of the arid Great Basin (USA) for the Columbia spotted frog (Rana luteiventris) and assessed whether changes in surface water may affect connectivity for remaining populations. We developed a predictive model of current climate suitability and used it to predict the historic and future distribution of suitable climates.

Genetic diversification, vicariance, and selection in a polytypic frog.

Spatial patterns of heritable phenotypic diversity reflect the relative roles of gene flow and selection in determining geographic variation within a species. We quantified color differentiation and genetic divergence among 20 populations of the red-eyed tree frog (Agalychnis callidryas) in lower Central America. Phylogenetic analyses revealed 5 well-supported mitochondrial DNA clades, and we infer from our phylogeny that geographic barriers have played a large role in structuring populations.

Discordant patterns of evolutionary differentiation in two Neotropical treefrogs.

Comparative studies of codistributed taxa test the degree to which historical processes have shaped contemporary population structure. Discordant patterns of lineage divergence among taxa indicate that species differ in their response to common historical processes. The complex geologic landscape of the Isthmus of Central America provides an ideal setting to test the effects of vicariance and other biogeographic factors on population history.

Fine scale gene flow and individual movements among subpopulations of Centrolene prosoblepon (Anura: Centrolenidae).

Dispersal capabilities determine and maintain local gene flow, and this has implications for population persistence and/or recolonization following environmental perturbations (natural or anthropogenic), disease outbreaks, or other demographic collapses. To predict recolonization and understand dispersal capacity in a stream-breeding frog, we examined individual movement patterns and gene flow among four subpopulations of the Neotropical glassfrog, Centrolene prosoblepon, at a mid-elevation cloud forest site at El Copé, Panama. We measured male movement directly during a two year mark-recapture study, and indirectly with gene flow estimates from mitochondrial DNA sequences (mtDNA).