Sex-linked genomic variation and its relationship to avian plumage dichromatism and sexual selection.

摘要: Sexual dichromatism is the tendency for sexes to differ in color pattern and represents a striking form of within-species morphological variation. Conspicuous intersexual differences avian plumage are generally thought result from Darwinian sexual selection, extent that often treated as surrogate intensity selection phylogenetic comparative studies. Intense predicted leave footprint on genetic evolution by reducing relative diversity sex chromosome autosomes. In this study, we test association between sex-linked using eight species pairs with contrasting levels dichromatism. We estimated Z-linked autosomal these non-model restriction-site associated (RAD) loci covered ~3 % genome. find monochromatic birds consistently have reduced genomic variation phylogenetically-paired dichromatic robust mutational biases. Our results consistent several interpretations. If present-day stronger birds, our suggest its impact offset other processes lead proportionately lower species. discuss possible factors may contribute discrepancy phenotypes Conversely, it -- measured variance male reproductive success set taxa examined, potentially reflecting importance song, behavior non-plumage traits targets selection. This counterintuitive finding suggests relationship complex highlights need more comprehensive survey vary markedly social mating systems.