| 1. |
- Hart Reeve, Andrew, et al.
(författare)
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The formation of the Indo-Pacific montane avifauna
- 2023
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- The processes generating the earth’s montane biodiversity remain a matter of debate. Two contrasting hypotheses have been advanced to explain how montane populations form: via direct colonization from other mountains, or, alternatively, via upslope range shifts from adjacent lowland areas. We seek to reconcile these apparently conflicting hypotheses by asking whether a species’ ancestral geographic origin determines its mode of mountain colonization. Island-dwelling passerine birds at the faunal crossroads between Eurasia and Australo-Papua provide an ideal study system. We recover the phylogenetic relationships of the region’s montane species and reconstruct their ancestral geographic ranges, elevational ranges, and migratory behavior. We also perform genomic population studies of three super-dispersive montane species/clades with broad island distributions. Eurasian-origin species populated archipelagos via direct colonization between mountains. This mode of colonization appears related to ancestral adaptations to cold and seasonal climates, specifically short-distance migration. Australo-Papuan-origin mountain populations, by contrast, evolved from lowland ancestors, and highland distribution mostly precludes their further colonization of island mountains. Our study explains much of the distributional variation within a complex biological system, and provides a synthesis of two seemingly discordant hypotheses for montane community formation.
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| 2. |
- Irestedt, Martin, 1968-, et al.
(författare)
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A crowd-sourced genomic project to assess hybrid content in a rare avian vagrant (Azure Tit Cyanistes cyanus (Pallas, 1770))
- 2023
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Ingår i: Avian Research. - : Elsevier. - 2053-7166. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to correlate plumage variation with the amount of genomic hybrid content in hybrids between Azure Tits Cyanistes cyanus (Pallas, 1770) and European Blue Tit Cyanistes caeruleus (Linnaeus, 1758), by re-sequencing the genomes of museum specimens of non-hybrids and presumed hybrids with varying plumages. The project was funded by crowdsourcing and initiated when two presumed Azure Tits, observed by hundreds of Swedish birdwatchers, were rejected as hybrids based on minor plumage deviations assumed to indicate hybrid contents from the European Blue Tit. The results confirm that hybrids with intermediate plumages, so called Pleske’s Tits, are first generation hybrids (F1 hybrids). Individuals, whose plumages are similar to Azure Tits, but assessed as hybrids based on minor plumage deviations, are all backcrosses but vary in their degree of hybrid content. However, some individuals morphologically recognized as pure Azure Tits expressed similar degrees of hybrid content. The results indicate that: (1) hybrid content may be widespread in Azure Tits in the western part of its habitat distribution; (2) plumage deviation in backcrosses is not linearly correlated with the genetic degree of hybrid origin; and (3) all Azure Tits observed in Europe outside its natural distribution may have some degree of hybrid origin. We therefore suggest that it is very difficult to phenotypically single out hybrids beyond first generation backcrosses. We argue that decreased sequencing costs and improved analytical tools open the doors for museomic crowd-sourced projects that may not address outstanding biological questions but have a major interest for lay citizens such as birdwatchers.
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| 3. |
- Lähteenaro, Meri, et al.
(författare)
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Phylogenomic species delimitation of the twisted-winged parasite genus Stylops (Strepsiptera)
- 2023
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Ingår i: Systematic Entomology. - 0307-6970 .- 1365-3113.
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Tidskriftsartikel (refereegranskat)abstract
- The twisted-winged parasite genus Stylops has a history of different species concepts with varying host specificity resulting in diverse species diversity estimates in different regions of the Holarctic. The adoption of a supergeneralist species concept in Europe, proposing synonymization of all Western Palaearctic Stylops species, did not facilitate taxonomic clarity and obscured the available life-history data in the region for decades. Lack of molecular data has allowed divergent opinions on species hypotheses and little opportunity for evaluating them in this morphologically challenging genus. To solve these discrepancies and gain novel information about host associations, we applied whole-genome sequencing to 163 specimens, representing a significant portion of putative European species. We evaluate the existing and conflicting species hypotheses with molecular species delimitation using Species bOundry Delimitation using Astral (SODA) and use a maximum likelihood phylogeny to investigate host associations of the species. Furthermore, we evaluate the effect of a number of loci used in SODA for the number of inferred species. We find justification for synonymization of multiple species and indications of undescribed species, as well as new host–parasite relationships. We show that the number of inferred species in SODA is exceedingly and positively correlated with the number of loci used, urging for cautious application. The results of our study bring clarity to the Western Palaearctic species diversity of Stylops. Furthermore, the comprehensive molecular dataset generated in this study will be a valuable resource for future studies on Stylops and the evolution of parasites in general.
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| 4. |
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| 5. |
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| 6. |
- Nylander, Johan A A
(författare)
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Ett fynd av leucistisk snok : En mycket ovanlig genvariant
- 2022
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Ingår i: Snoken. - 0347-7630. ; 51:2, s. 4-7
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- An observation of a female leucistic Grass snake (Natrix natrix (L.)), found in Kungsängen, Uppland, Sweden on August 26, 2022, is discussed. The observation is the first for Sweden and possibly the first for the species.
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| 7. |
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| 8. |
- Ericson, Per G P, et al.
(författare)
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Parallel Evolution of Bower-Building Behavior in Two Groups of Bowerbirds Suggested by Phylogenomics
- 2020
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Ingår i: Systematic Biology. - 1063-5157 .- 1076-836X. ; 69:5, s. 820-829
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Tidskriftsartikel (refereegranskat)abstract
- The bowerbirds in New Guinea and Australia include species that build the largest and perhaps most elaborately decorated constructions outside of humans. The males use these courtship bowers, along with their displays, to attract females. In these species, the mating system is polygynous and the females alone incubate and feed the nestlings. The bowerbirds also include 10 species of the socially monogamous catbirds in which the male participates in most aspects of raising the young. How the bower-building behavior evolved has remained poorly understood, as no comprehensive phylogeny exists for the family. It has been assumed that the monogamous catbird clade is sister to all polygynous species. We here test this hypothesis using a newly developed pipeline for obtaining homologous alignments of thousands of exonic and intronic regions from genomic data to build a phylogeny. Our well-supported species tree shows that the polygynous, bower-building species are not monophyletic. The result suggests either that bower-building behavior is an ancestral condition in the family that was secondarily lost in the catbirds, or that it has arisen in parallel in two lineages of bowerbirds. We favor the latter hypothesis based on an ancestral character reconstruction showing that polygyny but not bower-building is ancestral in bowerbirds, and on the observation that Scenopoeetes dentirostris, the sister species to one of the bower-building clades, does not build a proper bower but constructs a court for male display. This species is also sexually monomorphic in plumage despite having a polygynous mating system. We argue that the relatively stable tropical and subtropical forest environment in combination with low predator pressure and rich food access (mostly fruit) facilitated the evolution of these unique life-history traits.
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| 9. |
- Singh, Abhijeet, et al.
(författare)
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High-Throughput Sequencing and Unsupervised Analysis of Formyltetrahydrofolate Synthetase (FTHFS) Gene Amplicons to Estimate Acetogenic Community Structure.
- 2020
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Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- The formyltetrahydrofolate synthetase (FTHFS) gene is a molecular marker of choice to study the diversity of acetogenic communities. However, current analyses are limited due to lack of a high-throughput sequencing approach for FTHFS gene amplicons and a dedicated bioinformatics pipeline for data analysis, including taxonomic annotation and visualization of the sequence data. In the present study, we combined the barcode approach for multiplexed sequencing with unsupervised data analysis to visualize acetogenic community structure. We used samples from a biogas digester to develop proof-of-principle for our combined approach. We successfully generated high-throughput sequence data for the partial FTHFS gene and performed unsupervised data analysis using the novel bioinformatics pipeline "AcetoScan" presented in this study, which resulted in taxonomically annotated OTUs, phylogenetic tree, abundance plots and diversity indices. The results demonstrated that high-throughput sequencing can be used to sequence the FTHFS amplicons from a pool of samples, while the analysis pipeline AcetoScan can be reliably used to process the raw sequence data and visualize acetogenic community structure. The method and analysis pipeline described in this paper can assist in the identification and quantification of known or potentially new acetogens. The AcetoScan pipeline is freely available at https://github.com/abhijeetsingh1704/AcetoScan.
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| 10. |
- Caputo, Andrea, et al.
(författare)
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The genetic diversity and evolution of diatom-diazotroph associations highlights traits favoring symbiont integration
- 2019
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Ingår i: FEMS Microbiology Letters. - : Oxford University Press (OUP). - 0378-1097 .- 1574-6968. ; 366:2
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Tidskriftsartikel (refereegranskat)abstract
- Diatom diazotroph associations (DDAs) are a widespread marine planktonic symbiosis between several diatom genera and di-nitrogen (N2)-fixing bacteria. Combining single cell confocal microscopy observations and molecular genetic approaches on individual field collected cells, we determined the phylogenetic diversity, distribution and evolution of the DDAs. Confocal analyses coupled with 3-D imaging re-evaluated the cellular location of DDA symbionts. DDA diversity was resolved by paired gene sequencing (18S rRNA and rbcL genes, 16S rRNA and nifH genes). A survey using the newly acquired sequences against public databases found sequences with high similarity (99–100%) to either host (18S rRNA) or symbiont (16S rRNA) in atypical regions for DDAs (high latitudes, anoxic basin and copepod gut). Concatenated phylogenies were congruent for the host and cyanobacteria sequences and implied co-evolution. Time-calibrated trees dated the appearance of N2 fixing planktonic symbiosis from 100–50Mya and were consistent with the symbiont cellular location: symbioses with internal partners are more ancient. An ancestral state reconstruction traced the evolution of traits in DDAs and highlight that the adaptive radiation to the marine environment was likely facilitated by the symbiosis. Our results present the evolutionary nature of DDAs and provide new genetic and phenotypic information for these biogeochemically relevant populations.
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