| 1. |
|
|
| 2. |
- Irestedt, Martin, et al.
(författare)
-
Phylogeny, biogeography and taxonomic consequences in a bird-of-paradise species complex, Lophorina-Ptiloris (Aves: Paradisaeidae)
- 2017
-
Ingår i: Zoological Journal of the Linnean Society. - : OXFORD UNIV PRESS. - 0024-4082 .- 1096-3642. ; 181:2, s. 439-470
-
Tidskriftsartikel (refereegranskat)abstract
- Biogeographical history and taxonomic delimitation in the Australo-Papuan bird-of-paradise Lophorina-Ptiloris species complex is examined with a combination of DNA and morphological markers. The results suggest that the complex started to diverge in the mid-Pliocene, driven by initial isolation and adaptation to altitudinally different habitats. As in many other New Guinean avian taxa, phylogeographic structure is more varied in montane Lophorina than foothill Ptiloris. With the exception of populations of Lophorina in the eastern New Guinean cordillera, phylogenetic patterns from molecular data and morphological discontinuities are consistently concordant, as are molecular species delimitation tests with previous morphology-based circumscription of taxa in Ptiloris. In Lophorina, however, both molecular data and significant, re-discovered morphological traits identify several taxa as more deeply differentiated than hitherto thought. Accordingly, we use these data in an integrative taxonomic approach to re-delimit taxa in the entire clade, including the recognition of three species in the previously monospecific Lophorina. In Lophorina, the identity of several type specimens is reviewed, one new subspecies is described from the Vogelkop, and the identity of the species name superba Pennant is resolved by neotypification, with correction of its author.
|
|
| 3. |
- Xu, Luohao, et al.
(författare)
-
Dynamic evolutionary history and gene content of sex chromosomes across diverse songbirds
- 2019
-
Ingår i: Nature Ecology & Evolution. - : NATURE PUBLISHING GROUP. - 2397-334X. ; 3:5, s. 834-844
-
Tidskriftsartikel (refereegranskat)abstract
- Songbirds have a species number close to that of mammals and are classic models for studying speciation and sexual selection. Sex chromosomes are hotspots of both processes, yet their evolutionary history in songbirds remains unclear. We characterized genomes of 11 songbird species, with 5 genomes of bird-of-paradise species. We conclude that songbird sex chromosomes have undergone four periods of recombination suppression before species radiation, producing a gradient of pairwise sequence divergence termed ‘evolutionary strata’. The latest stratum was probably due to a songbird-specific burst of retrotransposon CR1-E1 elements at its boundary, instead of the chromosome inversion generally assumed for suppressing sex-linked recombination. The formation of evolutionary strata has reshaped the genomic architecture of both sex chromosomes. We find stepwise variations of Z-linked inversions, repeat and guanine-cytosine (GC) contents, as well as W-linked gene loss rate associated with the age of strata. A few W-linked genes have been preserved for their essential functions, indicated by higher and broader expression of lizard orthologues compared with those of other sex-linked genes. We also find a different degree of accelerated evolution of Z-linked genes versus autosomal genes among species, potentially reflecting diversified intensity of sexual selection. Our results uncover the dynamic evolutionary history of songbird sex chromosomes and provide insights into the mechanisms of recombination suppression.
|
|
