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Ecological speciation along an elevational gradient in a tropical passerine bird?
Author(s) -
Caro L. M.,
CaycedoRosales P. C.,
Bowie R. C. K.,
Slabbekoorn H.,
Cadena C. D.
Publication year - 2013
Publication title -
journal of evolutionary biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.289
H-Index - 128
eISSN - 1420-9101
pISSN - 1010-061X
DOI - 10.1111/jeb.12055
Subject(s) - parapatric speciation , biology , cline (biology) , ecology , adaptation (eye) , local adaptation , reproductive isolation , passerine , songbird , gene flow , adaptive value , allopatric speciation , adaptive radiation , genetic divergence , evolutionary biology , ecological speciation , phylogenetic tree , population , genetic variation , genetic diversity , biochemistry , demography , neuroscience , sociology , gene
Local adaptation of populations along elevational gradients is well known, but conclusive evidence that such divergence has resulted in the origin of distinct species in parapatry remains lacking. We integrated morphological, vocal, genetic and behavioural data to test predictions pertaining to the hypothesis of parapatric ecological speciation associated with elevation in populations of a tropical montane songbird, the Grey‐breasted Wood‐wren ( H enicorhina leucophrys : Troglodytidae), from the Sierra Nevada de Santa Marta, Colombia. We confirmed that two distinct populations exist along the elevational gradient. Phylogenetic analyses tentatively indicate that the two populations are not sister taxa, suggesting they did not differentiate from a single ancestor along the gradient, but rather resulted from separate colonization events. The populations showed marked divergence in morphometrics, vocalizations and genetic variation in mitochondrial and nuclear loci, and little to no evidence of hybridization. Individuals of both populations responded more strongly to their own local songs than to songs from another elevation. Although the two forms do not appear to have differentiated locally in parapatry, morphological and vocal divergence along the elevational gradient is consistent with adaptation, suggesting a possible link between adaptive evolution in morphology and songs and the origin of reproductive isolation via a behavioural barrier to gene flow. The adaptive value of phenotypic differences between populations requires additional study.