Geographic variation in advertisement calls of a Microhylid frog – testing the role of drift and ecology

Abstract

Acoustic signals for mating are important traits that could drive population differentiation and speciation. Ecology may play a role in acoustic divergence through direct selection (e.g., local adaptation to abiotic environment), constraint of correlated traits (e.g., acoustic traits linked to another trait under selection), and/or interspecific competition (e.g., character displacement). However, genetic drift alone can also drive acoustic divergence. It is not always easy to differentiate the role of ecology versus drift in acoustic divergence. In this study, we tested the role of ecology and drift in shaping geographic variation in the advertisement calls of Microhyla fissipes. We examined three predictions based on ecological processes: (1) the correlation between temperature and call properties across M. fissipes populations; (2) the correlation between call properties and body size across M. fissipes populations; and (3) reproductive character displacement (RCD) in call properties between M. fissipes populations that are sympatric with and allopatric to a congener M. heymonsi. To test genetic drift, we examined correlations among call divergence, geographic distance, and genetic distance across M. fissipes populations. We recorded the advertisement calls from 11 populations of M. fissipes in Taiwan, five of which are sympatrically distributed with M. heymonsi. We found geographic variation in both temporal and spectral properties of the advertisement calls of M. fissipes. However, the call properties were not correlated with local temperature or the callers' body size. Furthermore, we did not detect RCD. By contrast, call divergence, geographic distance, and genetic distance between M. fissipes populations were all positively correlated. The comparisons between phenotypic Q st (P st) and F st values did not show significant differences, suggesting a role of drift. We concluded that genetic drift, rather than ecological processes, is the more likely driver for the geographic variation in the advertisement calls of M. fissipes.

Whistle variation in Mediterranean common bottlenose dolphin: The role of geographical, anthropogenic, social, and behavioral factors

“…To perform PCA, the function prcomp of the R package Rstats (R Core Team, ) was used. The association between the two PCs and the geographical (locality), anthropogenic (noise levels in the three bands and boat presence), social (group size and calf presence), and behavioral variables was tested using a generalized linear mixed model (GLMM—following Jansen, Plath, Brusquetti, & Ryan, ; Lee, Shaner, Lin, & Lin, ) with a gaussian distribution. The GLMMs are an extension of generalized linear models that allow for the inclusion of random effects, by modeling the covariance structure that is generated by the grouping of data (Zuur et al, ).…”

Diversifying selection drives parallel evolution of gill raker number and body size along the speciation continuum of European whitefish

“…The genetic architecture of traits, together with the adaptive genetic variation, upon which various selection pressures are exerted, will set the frame for the response to natural selection (Nosil, Funk, & Ortiz‐Barrientos, ). However, divergence of populations, and eventually speciation, can also occur via random genetic drift (Lee, Shaner, Lin, & Lin, ; Uyeda, Arnold, Hohenlohe, & Mead, ). Because of this complexity, the mechanisms by which evolution modulates phenotypic and genotypic frequencies in the divergence process are not well understood.…”

Reduced geographic variation in roars in different habitats rejects the acoustic adaptation hypothesis in the black‐and‐gold howler monkey (Alouatta caraya)

“…Here, we explored the alternative hypothesis that genetic divergence between populations could be responsible for differences in roar structure. Previous studies identified geographic distance and/or the presence of barriers such as rivers and mountains, which can prevent gene flow, as causes promoting geographic variation in calls (Bernal, Guarnizo, & Lüddecke, ; Irwin, Thimgan, & Irwin, ; Keighley, Langmore, Zdenek, & Heinsohn, ; Lee et al, ; Wich et al, ). In these cases, a clear correlation between genetic distance and vocal divergence between different populations was found.…”

“…Evidence gathered over the years provided partial support to this theoretical framework (reviewed in Ey & Fisher, 2009), in part because other factors beyond vegetation type and/or environmental sound come into play influencing vocalization structure. On one hand, long-range vocalizations can be shaped by local ecological constraints imposed mainly by vegetation structure (Ey, 2008;Morton, 1975;Tobias et al, 2010;Wiley & Richards, 1978) and/ or environmental sounds (Brenowitz, 1982;Slabbekoorn & Smith, 2002), and on the other hand, long-range calls can be influenced by other factors such as anatomy (i.e., body size: in primates Mitani, Hunley, &Murdoch, 1999 andbirds: Ryan &Brenovitz, 1985), vocal learning/cultural drift (in primates de la Torre & Snowdon, 2009;Briseño-Jaramillo, Estrada, &Lemasson, 2015, andbats Xie et al, 2017), and genetic drift (in primates Wich, Schel, &Vries, 2008 andmicrohylid frogs: Lee, Shaner, Lin, &Lin, 2016).…”