| 1. |
- Caplat, Paul, et al.
(författare)
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Looking beyond the mountain: dispersal barriers in a changing world
- 2016
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Ingår i: Frontiers in Ecology and the Environment. - : Wiley. - 1540-9295 .- 1540-9309. ; 14:5, s. 262-269
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Tidskriftsartikel (refereegranskat)abstract
- Dispersal barriers have demographic, evolutionary, and ecosystem-wide consequences. With ongoing changes in the environment, some dispersal barriers will likely disappear while new ones will appear, and it is crucial to understand these dynamics to forecast species' distributions and adaptive potential. Here we review recent literature on the ecological and evolutionary aspects of dispersal to highlight key dynamics of dispersal barriers in the face of global change. After defining dispersal barriers, we explain that a better understanding of their dynamics requires identifying the barrier types that are most susceptible to change and predicting species' responses. This knowledge is a prerequisite for designing management strategies to increase or reduce connectivity, and maintain adaptive potential. Our intent is to motivate researchers to explicitly consider dispersal barriers in order to better forecast the dynamics of species and ecosystems subject to global change.
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| 2. |
- Dudaniec, Rachael, et al.
(författare)
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Applying landscape genetics to the microbial world
- 2016
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Ingår i: Molecular Ecology. - : Wiley. - 0962-1083. ; 25:14, s. 3266-3275
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Forskningsöversikt (refereegranskat)abstract
- Landscape genetics, which explicitly quantifies landscape effects on gene flow and adaptation, has largely focused on macroorganisms, with little attention given to microor- ganisms. This is despite overwhelming evidence that microorganisms exhibit spatial genetic structuring in rela- tion to environmental variables. The increasing accessi- bility of genomic data has opened up the opportunity for landscape genetics to embrace the world of microorgan- isms, which may be thought of as ‘the invisible regula- tors’ of the macroecological world. Recent developments in bioinformatics and increased data accessibility have accelerated our ability to identify microbial taxa and characterize their genetic diversity. However, the influ- ence of the landscape matrix and dynamic environmental factors on microorganism genetic dispersal and adapta- tion has been little explored. Also, because many microorganisms coinhabit or codisperse with macroorgan- isms, landscape genomic approaches may improve insights into how micro- and macroorganisms recipro- cally interact to create spatial genetic structure. Conduct- ing landscape genetic analyses on microorganisms requires that we accommodate shifts in spatial and tem- poral scales, presenting new conceptual and methodologi- cal challenges not yet explored in ‘macro’-landscape genetics. We argue that there is much value to be gained for microbial ecologists from embracing landscape genetic approaches. We provide a case for integrating landscape genetic methods into microecological studies and discuss specific considerations associated with the novel challenges this brings. We anticipate that microor- ganism landscape genetic studies will provide new insights into both micro- and macroecological processes and expand our knowledge of species’ distributions, adaptive mechanisms and species’ interactions in chang- ing environments.
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| 3. |
- Dudaniec, Rachael Y., et al.
(författare)
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Signatures of local adaptation along environmental gradients in a range-expanding damselfly (Ischnura elegans)
- 2018
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Ingår i: Molecular Ecology. - : Wiley. - 0962-1083. ; 27:11, s. 2576-2593
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Tidskriftsartikel (refereegranskat)abstract
- Insect distributions are shifting rapidly in response to climate change and are undergoing rapid evolutionary change. We investigate the molecular signatures underlying local adaptation in the range-expanding damselfly, Ischnura elegans. Using a landscape genomic approach combined with generalized dissimilarity modelling (GDM), we detect selection signatures on loci via allelic frequency change along environmental gradients. We analyse 13,612 single nucleotide polymorphisms (SNPs), derived from restriction site-associated DNA sequencing (RADseq), in 426 individuals from 25 sites spanning the I. elegans distribution in Sweden, including its expanding northern range edge. Environmental association analysis (EAA) and the magnitude of allele frequency change along the range expansion gradient revealed significant signatures of selection in relation to high maximum summer temperature, high mean annual precipitation and low wind speeds at the range edge. SNP annotations with significant signatures of selection revealed gene functions associated with ongoing range expansion, including heat shock proteins (HSP40 and HSP70), ion transport (V-ATPase) and visual processes (long-wavelength-sensitive opsin), which have implications for thermal stress response, salinity tolerance and mate discrimination, respectively. We also identified environmental thresholds where climate-mediated selection is likely to be strong, and indicate that I. elegans is rapidly adapting to the climatic environment during its ongoing range expansion. Our findings empirically validate an integrative approach for detecting spatially explicit signatures of local adaptation along environmental gradients.
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| 4. |
- Lancaster, Lesley T, et al.
(författare)
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Gene expression under thermal stress varies across a geographic range expansion front.
- 2016
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Ingår i: Molecular Ecology. - : Wiley. - 0962-1083. ; 25:5, s. 1141-1156
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Tidskriftsartikel (refereegranskat)abstract
- Many ectothermic species are currently expanding their distributions polewards due to anthropogenic global warming. Molecular genetic mechanisms facilitating range expansion under these conditions are largely unknown, but understanding these could help mitigate expanding pests and disease vectors, or help explain why some species fail to track changing climates. Here, using RNA-seq data, we examine genome-wide changes in gene expression under heat and cold stress in the range-expanding damselfly Ischnura elegans in northern Europe. We find that both the number of genes involved and levels of gene expression under heat stress have become attenuated during the expansion, consistent with a previously-reported release from selection on heat tolerances as species move polewards. Genes upregulated under cold stress differed between core and edge populations, corroborating previously-reported rapid adaptation to cooler climates at the expansion front. Expression of sixty-nine genes exhibited a region x treatment effect; these were primarily upregulated in response to heat stress in core populations but in response to cold stress at the range edge, suggesting that some cellular responses originally adapted to heat stress may switch to cold stress functionality upon encountering novel thermal selection regimes during range expansion. Transcriptional responses to thermal stress involving heat shock and neural function genes were largely geographically conserved, while retrotransposon, regulatory, muscle function and defence gene expression patterns were more variable. Flexible mechanisms of cold stress response and the ability of some genes to shift their function between heat and cold stress might be key mechanisms facilitating rapid poleward expansion in insects. This article is protected by copyright. All rights reserved.
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| 5. |
- Lancaster, Lesley T., et al.
(författare)
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Latitudinal shift in thermal niche breadth results from thermal release during a climate-mediated range expansion
- 2015
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Ingår i: Journal of Biogeography. - : Wiley. - 1365-2699 .- 0305-0270. ; 42:10, s. 1953-1963
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Tidskriftsartikel (refereegranskat)abstract
- AimClimate change is currently altering the geographical distribution of species, but how this process contributes to biogeographical variation in ecological traits is unknown. Range-shifting species are predicted to encounter and respond to new selective regimes during their expansion phase, but also carry historical adaptations to their ancestral range. We sought to identify how historical and novel components of the environment interact to shape latitudinal trends in thermal tolerance, thermal tolerance breadth and phenotypic plasticity of a range-shifting species. LocationSouthern and central Sweden. MethodsTo evaluate phenotypic responses to changes in the thermal selective environment, we experimentally determined the upper and lower thermal tolerances of >2000 wild-caught damselflies (Ischnura elegans) from populations distributed across core and expanding range-edge regions. We then identified changing correlations between thermal tolerance, climate and recent weather events across the range expansion. Niche modelling was employed to evaluate the relative contributions of varying climatic selective regimes to overall habitat suitability for the species in core versus range-edge regions. ResultsUpper thermal tolerance exhibited local adaptation to climate in the core region, but showed evidence of having been released from thermal selection during the current range expansion. In contrast, chill coma recovery exhibited local adaptation across the core region and range expansion, corresponding to increased climatic variability at higher latitudes. Adaptive plasticity of lower thermal tolerances (acclimation ability) increased towards the northern, expanding range edge. Main conclusionsOur results suggest micro-evolutionary mechanisms for several large-scale and general biogeographical patterns, including spatially and latitudinally invariant heat tolerances (Brett's rule) and increased thermal acclimation rates and niche breadths at higher latitudes. Population-level processes unique to climate-mediated range expansions may commonly underpin many broader, macro-physiological trends.
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