Single-locus species delimitation and ecological niche modeling provide insights into the evolution, historical distribution, and taxonomy of the Pacific Chorus Frogs

Authors

Robert C. Jadin, University of Wisconsin - Eau ClaireFollow
Sarah A. Orlofske, University of Wisconsin - Stevens Point
Tereza Jezkova, Miami University - Oxford
Christopher Blair, CUNY New York City College of TechnologyFollow

Document Type

Article

Publication Date

1-12-2021

Abstract

The Pacific chorus frogs are a complex of three wide-ranging species (i.e. Hyliola hypochondriaca, Hyliola regilla, Hyliola sierra) whose current taxonomy remains unresolved. We conducted species delimitation analyses of these taxa using fragments of the cytochrome b and 12S–16S mtDNA genes to assess the species diversity. Importantly, we included samples from new locations throughout the range to better understand species distributions and identify potential contact zones among clades. Our analyses revealed three slightly parapatric but distinct species-level clades. Molecular dating revealed that these species began diverging in the Pleistocene c. 1.4 Mya with H. hypochondriaca and H. sierra diverging more recently c. 0.8 Mya. We found that populations from western Montana and Idaho originated recently from populations to the southwest that belong to H. sierra, rather than from H. regilla populations directly to the west. Population sizes of each species expanded c. 130–80 Kya with H. hypochondriaca exhibiting a more pronounced expansion beginning c. 100 Kya than the more gradual expansion of the other two species. The climatic niche models suggest that distributions of the three species were similar during the last interglacial (LIG) as they are today. During the Last Glacial Maximum (LGM), H. hypochondriaca and H. sierra occupied a larger range than they do today whereas H. regilla occupied a smaller refugium, shifted south from the current distribution. This study highlights the continued effectiveness of utilizing single-locus data sets for species delimitation and biogeographic analyses.

Comments

Accepted manuscript of Jadin, Robert C., Sarah A. Orlofske, Tereza Jezkova, and Christopher Blair. "Single-locus species delimitation and ecological niche modelling provide insights into the evolution, historical distribution and taxonomy of the Pacific chorus frogs." Biological Journal of the Linnean Society (2021) https://doi.org/10.1093/biolinnean/blaa209