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- Schweizer, Manuel, et al.
(author)
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Genome-wide evidence supports mitochondrial relationships and pervasive parallel phenotypic evolution in open-habitat chats
- 2019
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In: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 139
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Journal article (peer-reviewed)abstract
- In wheatears and related species ('open-habitat chats'), molecular phylogenetics has led to a comprehensively revised understanding of species relationships and species diversity. Phylogenetic analyses have suggested that, in many cases, phenotypic similarities do not reflect species' relationships, revealing traditionally defined genera as non-monophyletic. This led to the suggestion of pervasive parallel evolution of open-habitat chats' plumage coloration and ecological phenotypes. However, to date, the molecular evidence for the phylogenetic relationships among open-habitat chats is mainly limited to mitochondrial DNA. Here, we assessed whether the mitochondrial relationships are supported by genome-wide data. To this end, we reconstructed the species tree among 14 open-habitat chat taxa using multi-species coalescent analyses based on similar to 1'300 SNPs. Our results confirm previous ones based chiefly on mitochondrial DNA; notably the paraphyly of the Oenanthe lugens complex and the clustering of individual species formerly placed in the genera Cercomela and Myrmecocichla within Oenanthe. Since several variable morphological and ecological characteristics occur in multiple places across the open-habitat chat phylogeny, our study consolidates the evidence for pervasive parallel evolution in the plumage coloration and ecology of open-habitat chats.
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| 2. |
- Schweizer, Manuel, et al.
(author)
-
Parallel plumage colour evolution and introgressive hybridization in wheatears
- 2019
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In: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 32:1, s. 100-110
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Journal article (peer-reviewed)abstract
- Genetic and phenotypic mosaics, in which various phenotypes and different genomic regions show discordant patterns of species or population divergence, offer unique opportunities to study the role of ancestral and introgressed genetic variation in phenotypic evolution. Here, we investigated the evolution of discordant phenotypic and genetic divergence in a monophyletic clade of four songbird taxa-pied wheatear (O. pleschanka), Cyprus wheatear (Oenanthe cypriaca), and western and eastern subspecies of black-eared wheatear (O. h. hispanica and O. h. melanoleuca). Phenotypically, black back and neck sides distinguish pied and Cyprus wheatears from the white-backed/necked black-eared wheatears. Meanwhile, mitochondrial variation only distinguishes western black-eared wheatear. In the absence of nuclear genetic data, and given frequent hybridization among eastern black-eared and pied wheatear, it remains unclear whether introgression is responsible for discordance between mitochondrial divergence patterns and phenotypic similarities, or whether plumage coloration evolved in parallel. Multispecies coalescent analyses of about 20,000 SNPs obtained from RAD data mapped to a draft genome assembly resolve the species tree, provide evidence for the parallel evolution of colour phenotypes and establish western and eastern black-eared wheatears as independent taxa that should be recognized as full species. The presence of the entire admixture spectrum in the Iranian hybrid zone and the detection of footprints of introgression from pied into eastern black-eared wheatear beyond the hybrid zone despite strong geographic structure of ancestry proportions furthermore suggest a potential role for introgression in parallel plumage colour evolution. Our results support the importance of standing heterospecific and/or ancestral variation in phenotypic evolution.
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