Neutral and selective drivers of colour evolution in a widespread Australian passerine

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Aim Rump plumage coloration of the Eastern Yellow Robin (Eopsaltria australis), a widespread Australian songbird, varies from bright yellow in the tropical north to olive-green in the temperate south. Here, we test whether col- our variation: (1) correlates most strongly with neutral genetic variation and so is best explained by historical processes, (2) reflects selection associated with different visual environments (dense versus open habitats) and/or (3) reflects selection associated with climatic variation.
Location Eastern Australia.
Methods We quantified colour variation using reflectance spectrometry and visual models. We performed geographical cline analysis of colour and neutral genetic variation (genome-wide single nucleotide polymorphisms). We tested for correlations of colour variation with climate, vegetation density, geographi- cal location and genetic variation. We accounted for covariation and spatial autocorrelation, and conducted analyses at continental and regional spatial scales.
Results Clinal variation of colour traits and neutral genetic markers were lar- gely concordant. At the continental scale, colour variation was strongly associ- ated with neutral genetic structure and geography, and to a lesser extent with environment. At the regional scale, environmental variation was a better pre- dictor of colour variation than it was at the larger scale.
Main conclusion At the continental scale, colour variation is strongly associ- ated with large-scale population history. In contrast, at the regional scale, where the influence of history and geography is weaker, environmental varia- tion has a role in facilitating the maintenance of colour variation. Our results highlight the need to assess selective and neutral alternatives at multiple spatial scales when studying geographical variation.
Original languageUndefined/Unknown
JournalJournal of Biogeography
Issue number3
Pages (from-to)522-536
Number of pages15
Publication statusPublished - 1 Dec 2016
Externally publishedYes

ID: 246097508