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GEOGRAPHIC VARIATION IN THE SONGS OF NEOTROPICAL SINGING MICE: TESTING THE RELATIVE IMPORTANCE OF DRIFT AND LOCAL ADAPTATION
Author(s) -
Campbell Polly,
Pasch Bret,
Pino Jorge L.,
Crino Ondi L.,
Phillips Molly,
Phelps Steven M.
Publication year - 2010
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.2010.00962.x
Subject(s) - intraspecific competition , biology , adaptation (eye) , local adaptation , evolutionary biology , variation (astronomy) , sympatry , interspecific competition , genetic variation , geographic variation , genetic drift , ecology , genetic divergence , selection (genetic algorithm) , population , genetic diversity , sympatric speciation , genetics , physics , demography , neuroscience , sociology , astrophysics , gene , artificial intelligence , computer science
Patterns of geographic variation in communication systems can provide insight into the processes that drive phenotypic evolution. Although work in birds, anurans, and insects demonstrates that acoustic signals are sensitive to diverse selective and stochastic forces, processes that shape variation in mammalian vocalizations are poorly understood. We quantified geographic variation in the advertisement songs of sister species of singing mice, montane rodents with a unique mode of vocal communication. We tested three hypotheses to explain spatial variation in the song of the lower altitude species, Scotinomys teguina : selection for species recognition in sympatry with congener, S. xerampelinus , acoustic adaptation to different environments, and stochastic divergence. Mice were sampled at seven sites in Costa Rica and Panamá; genetic distances were estimated from mitochondrial control region sequences, between‐site differences in acoustic environment were estimated from climatic data. Acoustic, genetic and geographic distances were all highly correlated in S. teguina , suggesting that population differentiation in song is largely shaped by genetic drift. Contrasts between interspecific genetic‐acoustic distances were significantly greater than expectations derived from intraspecific contrasts, indicating accelerated evolution of species‐specific song. We propose that, although much intraspecific acoustic variation is effectively neutral, selection has been important in shaping species differences in song.