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- Liu, Yuanzhen, et al.
(författare)
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Genomic variation in montane bumblebees in Scandinavia : High levels of intraspecific diversity despite population vulnerability
- 2024
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Ingår i: Molecular Ecology. - : John Wiley & Sons. - 0962-1083 .- 1365-294X. ; 33:4
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Tidskriftsartikel (refereegranskat)abstract
- Populations of many bumblebee species are declining, with distributions shifting northwards to track suitable climates. Climate change is considered a major contributing factor. Arctic species are particularly vulnerable as they cannot shift further north, making assessment of their population viability important. Analysis of levels of whole-genome variation is a powerful way to analyse population declines and fragmentation. Here, we use genome sequencing to analyse genetic variation in seven species of bumblebee from the Scandinavian mountains, including two classified as vulnerable. We sequenced 333 samples from across the ranges of these species in Sweden. Estimates of effective population size (NE) vary from ~55,000 for species with restricted high alpine distributions to 220,000 for more widespread species. Population fragmentation is generally very low or undetectable over large distances in the mountains, suggesting an absence of barriers to gene flow. The relatively high NE and low population structure indicate that none of the species are at immediate risk of negative genetic effects caused by high levels of genetic drift. However, reconstruction of historical fluctuations in NE indicates that the arctic specialist species Bombus hyperboreus has experienced population declines since the last ice age and we detected one highly inbred diploid male of this species close to the southern limit of its range, potentially indicating elevated genetic load. Although the levels of genetic variation in montane bumblebee populations are currently relatively high, their ranges are predicted to shrink drastically due to the effects of climate change and monitoring is essential to detect future population declines.
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| 3. |
- Montero-Mendieta, Santiago, et al.
(författare)
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Phylogenomics and evolutionary history of Oreobates (Anura: Craugastoridae) Neotropical frogs along elevational gradients
- 2021
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Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier. - 1055-7903 .- 1095-9513. ; 161
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Tidskriftsartikel (refereegranskat)abstract
- Mountain ranges offer opportunities for understanding how species evolved and diversified across different environmental conditions. Neotropical frogs of the genus Oreobates (Anura: Craugastoridae) are adapted to highland and lowland habitats along the Andes, but many aspects of their evolution remain unknown. We studied their evolutionary history using ∼18,000 exons enriched by targeted sequence-capture. Since capture success was very variable across samples, we evaluated to what degree differing data filtering produced robust inferences. The inferred evolutionary framework evidenced phylogenetic discordances among lowland species that can be explained by taxonomic misidentification or admixture of ancestral lineages. Highland species showed smaller effective populations than lowland frogs, probably due to greater habitat fragmentation in montane environments. Stronger genetic drift likely decreased the power of purifying selection and led to an increased proportion of nonsynonymous mutations in highland populations that could play an important role in their adaptation. Overall, our work sheds light on the evolutionary history and diversification of this group of Neotropical frogs along elevational gradients in the Andes as well as on their patterns of intraspecific diversity.
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