Polyploid speciation and whole genome duplications are major drivers of biological diversity. After polyploid species are formed, the interactions between diploid and polyploid lineages may generate additional diversity in novel cytotypes and phenotypes. In anurans, mate choice by acoustic communication is the primary method by which individuals identify their own species and assess suitable mates. As such, the evolution of acoustic signals is an important mechanism for contributing to reproductive isolation and diversification in this group. The North American gray treefrog complex, consisting of the diploid Hyla chrysoscelis and the tetraploid Hyla versicolor, has long been used to study reproductive isolation and research on this system has consistently driven this field forward. Here, we estimate the biogeographic history of this group, focusing specifically on the geographic origin of whole genome duplication and the expansion of lineages out of refugia following climate oscillations and retreats of the Laurentide ice sheet. We then test for lineage-specific differences in mating signals by applying comparative methods to a large acoustic data set collected over 52 years that includes >1500 individual frogs. Finally, we expand upon our results in light of recent estimates of the complex’s genomic evolution to describe the history of diversification in gray treefrogs throughout the Quaternary.

Acoustic data was collected over 52 years using a number of microphones and recording systems. Calls were analyzed using custom software to extract character values and avaraged for each individual. Both raw character values and temperature corrected values are available when appropriate. Call data used for PCM were averaged across all individuals within the county the genetic sample presided in (or in an adjacent county, calls from Wood Co. TX were assigned to the Smith County TX H. chrysoscelis genetic data). 

Trees used in this analyses were from a previous study, and can be accessed here or the original dryad repository: https://doi.org/10.5061/dryad.1rn8pk0s6