| 61. |
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| 62. |
- Cássia-Silva, C., et al.
(författare)
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Higher evolutionary rates in life-history traits in insular than in mainland palms
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Isolated islands, due to the reduced interspecific competition compared to mainland habitats, present ecological opportunities for colonizing lineages. As a consequence, island lineages may be expected to experience higher rates of trait evolution than mainland lineages. However, island effects on key life-history traits of vascular plants remain underexplored at broad spatiotemporal scales, even for emblematic island clades such as palms. Here, we used phylogenetic comparative methods to evaluate potential differences in size and macroevolutionary patterns of height and fruit diameter among mainland, continental, and volcanic island palms. Further, phylogenetic beta-diversity was used to determine if lineage turnover supported an adaptive radiation scenario on volcanic islands. Volcanic island palms were taller than their continental island and mainland counterparts, whereas continental island palms exhibited smaller fruit size. Height and fruit size of palms evolved under evolutionary constraints towards an optimal value. However, scenarios of adaptive radiation and niche conservatism were not supported for the height and fruit size of volcanic and mainland palm clades, respectively, as expected. Instead, continental island palms exhibited higher evolutionary rates for height and fruit size. Insular palm assemblages (continental and volcanic) are composed of unique lineages. Beyond representing evolutionary sources of new palm lineages, our results demonstrate that insular habitats are important in shaping palm trait diversity. Also, the higher phenotypic evolutionary rates of continental island palms suggest disparate selection pressures on this habitat type, which can be an important driver of trait diversification over time. Taken together, these results stress the importance of insular habitats for conservation of functional, phylogenetic, and taxonomic diversity of palms. © 2020, The Author(s).
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| 63. |
- Cássia-Silva, C., et al.
(författare)
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Niche conservatism drives a global discrepancy in palm species richness between seasonally dry and moist habitats
- 2019
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 28:6, s. 814-825
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Rapid global environmental change predicts increasingly seasonal climate in the tropics, causing expansion of seasonally dry habitats and leading to shifts in species distribution and potential extinction. Here, we use a macroevolutionary framework to understand the processes driving palm diversity patterns between moist and seasonally dry tropical habitats. We hypothesize that the discrepancy in species richness between habitats is explained by higher speciation rates in moist habitat and that niche conservatism prevents frequent shifts between habitats. Location: Global. Time period: Last 100Ma. Major taxa studied: Arecaceae. Methods: We used trait-dependent diversification models to test whether different habitats affect palm speciation rates. Furthermore, palm assemblages were divided into three regions (Africa, Australasia and Neotropics) to test for niche conservatism and evaluate phylogenetic dissimilarity. Results: We found no relationship between speciation rate and habitat type. We detected phylogenetic signal for habitats at both global and continental scales, indicating that closely related species were more similar than expected by chance. Colonization of seasonally dry habitats occurred c.60Ma, yet most clades only diversified after c.30Ma. The high phylogenetic dissimilarity between habitat types at both global and continental scales was driven by high lineage turnover, at least for Africa and the Neotropics. Main conclusions: We found a lack of differential speciation rates in setting the seasonally dry and moist palm-richness discrepancy. However, over evolutionary history most palm lineages fail to colonize seasonally dry habitats owing to a tendency to retain ancestral habitat. Indeed, seasonally dry palm assemblages are the result of the diversification of particular lineages. Likewise, long-term dry periods appear to induce shifts in taxonomic and functional diversity, and we emphasize that the expansion of dry habitats might also imply a loss of palm clades, hence a reduction in phylogenetic diversity. © 2019 John Wiley & Sons Ltd
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| 64. |
- Dawson, Deborah A., et al.
(författare)
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New methods to identify conserved microsatellite loci and develop primer sets of high cross-species utility - as demonstrated for birds
- 2010
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Ingår i: Molecular Ecology Resources. - : Wiley. - 1755-098X .- 1755-0998. ; 10:3, s. 475-494
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a new approach to create microsatellite primer sets that have high utility across a wide range of species. The success of this method was demonstrated using birds. We selected 35 avian EST microsatellite loci that had a high degree of sequence homology between the zebra finch Taeniopygia guttata and the chicken Gallus gallus and designed primer sets in which the primer bind sites were identical in both species. For 33 conserved primer sets, on average, 100% of loci amplified in each of 17 passerine species and 99% of loci in five non-passerine species. The genotyping of four individuals per species revealed that 24-76% (mean 48%) of loci were polymorphic in the passerines and 18-26% (mean 21%) in the non-passerines. When at least 17 individuals were genotyped per species for four Fringillidae finch species, 71-85% of loci were polymorphic, observed heterozygosity was above 0.50 for most loci and no locus deviated significantly from Hardy-Weinberg proportions. This new set of microsatellite markers is of higher cross-species utility than any set previously designed. The loci described are suitable for a range of applications that require polymorphic avian markers, including paternity and population studies. They will facilitate comparisons of bird genome organization, including genome mapping and studies of recombination, and allow comparisons of genetic variability between species whilst avoiding ascertainment bias. The costs and time to develop new loci can now be avoided for many applications in numerous species. Furthermore, our method can be readily used to develop microsatellite markers of high utility across other taxa.
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| 65. |
- De Lima Ferreira, Paola, et al.
(författare)
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Target sequence capture of Barnadesioideae (Compositae) demonstrates the utility of low coverage loci in phylogenomic analyses
- 2022
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Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903. ; 169
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Tidskriftsartikel (refereegranskat)abstract
- Target sequence capture has emerged as a powerful method to sequence hundreds or thousands of genomic regions in a cost- and time-efficient approach. In most cases, however, targeted regions lack full sequence information for certain samples, due to taxonomic, laboratory, or stochastic factors. Loci lacking molecular data for a large number of samples are commonly excluded from downstream analyses, even though they may still contain valuable information. On the other hand, including data-poor loci may bias phylogenetic analyses. Here we use a target sequence capture dataset of an ecologically and taxonomically diverse group of spiny sunflowers (Asteraceae, or Compositae: Barnadesioideae) to test how the inclusion or exclusion of such data-poor loci affects phylogenetic inference. We investigate the sensitivity of concatenation and coalescent approaches to missing data with matrices of varying taxonomic completeness by filtering loci with different proportions of missing samples prior to data analysis. We find that missing data affect both the topology and branch support of the resulting phylogenies. The matrix containing all loci yielded the overall highest node support values, independently of the amount of missing nucleotides. These results provide empirical support to earlier suggestions based on single genes and data simulations that taxa with high amounts of missing data should not be readily dismissed as they can provide essential information for phylogenomic reconstruction. © 2022 The Authors
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| 66. |
- Diele-Viegas, L. M., et al.
(författare)
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Community voices: sowing, germinating, flourishing as strategies to support inclusion in STEM
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Understanding gaps in academic representation while considering the intersectionality concept is paramount to promoting real progress towards a more inclusive STEM. Here we discuss ways in which STEM careers can be sown and germinated so that inclusivity can flourish.
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| 67. |
- Dotto, Tiago S., et al.
(författare)
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Control of the Oceanic Heat Content of the Getz-Dotson Trough, Antarctica, by the Amundsen Sea Low
- 2020
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Ingår i: Journal of Geophysical Research: Oceans. - 2169-9275 .- 2169-9291. ; 125:8
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Tidskriftsartikel (refereegranskat)abstract
- The changing supply of warm Circumpolar Deep Water (CDW) to the West Antarctic continental shelf is responsible for the basal melting and thinning of the West Antarctic ice shelves that has occurred in recent decades. Here we assess the variability in CDW supply, and its drivers, from a multiyear mooring deployed in, and a regional ocean model spanning, the Getz-Dotson Trough, Amundsen Sea. Between 2010 to 2015, the CDW within the trough underwent a pronounced cooling and freshening, associated with changes in thermohaline properties on isopycnals. Variability in the rate of CDW inflow is controlled by local wind forcing of a shelf break undercurrent, which determines the hydrographic properties of inflowing CDW via tilting of density surfaces above the continental slope. Local wind is coupled to the Amundsen Sea Low (ASL) low-pressure system, which is modulated by large-scale climatic modes via atmospheric teleconnections. For the period analyzed, a deeper ASL was associated with westward wind anomaly at the shelf break. Changes in the sea surface slope decelerated the shelf break undercurrent, resulting in less heat accessing the continental shelf and, consequently, a cooling of the Getz-Dotson Trough. Therefore, the present work suggests that the fate of the West Antarctic ice shelves is closely tied to the future evolution of the ASL.
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| 68. |
- Dotto, T. S., et al.
(författare)
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Wind-Driven Processes Controlling Oceanic Heat Delivery to the Amundsen Sea, Antarctica
- 2019
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Ingår i: Journal of Physical Oceanography. - : American Meteorological Society. - 0022-3670 .- 1520-0485. ; 49:11, s. 2829-2849
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Tidskriftsartikel (refereegranskat)abstract
- Variability in the heat delivery by Circumpolar Deep Water (CDW) is responsible for modulating the basal melting of the Amundsen Sea ice shelves. However, the mechanisms controlling the CDW inflow to the region's continental shelf remain little understood. Here, a high-resolution regional model is used to assess the processes governing heat delivery to the Amundsen Sea. The key mechanisms are identified by decomposing CDW temperature variability into two components associated with 1) changes in the depth of isopycnals [heave (HVE)], and 2) changes in the temperature of isopycnals [water mass property changes (WMP)]. In the Dotson-Getz trough, CDW temperature variability is primarily associated with WMP. The deeper thermocline and shallower shelf break hinder CDW access to that trough, and CDW inflow is regulated by the uplift of isopycnals at the shelf break-which is itself controlled by wind-driven variations in the speed of an undercurrent flowing eastward along the continental slope. In contrast, CDW temperature variability in the Pine Island-Thwaites trough is mainly linked to HVE. The shallower thermocline and deeper shelf break there permit CDW to persistently access the continental shelf. CDW temperature in the area responds to wind-driven modulation of the water mass on-shelf volume by changes in the rate of inflow across the shelf break and in Ekman pumping-induced vertical displacement of isopycnals within the shelf. The western and eastern Amundsen Sea thus represent distinct regimes, in which wind forcing governs CDW-mediated heat delivery via different dynamics.
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| 69. |
- Freitas, C. G., et al.
(författare)
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Adjacency and Area Explain Species Bioregional Shifts in Neotropical Palms
- 2019
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Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Environmental and geographical variables are known drivers of community assembly, however their influence on phylogenetic structure and phylogenetic beta diversity of lineages within different bioregions is not well-understood. Using Neotropical palms as a model, we investigate how environmental and geographical variables affect the assembly of lineages into bioregions across an evolutionary time scale. We also determine lineage shifts between tropical (TRF) and non-tropical (non-TRF) forests. Our results identify that distance and area explain phylogenetic dissimilarity among bioregions. Lineages in smaller bioregions are a subset of larger bioregions and contribute significantly to the nestedness component of phylogenetic dissimilarity, here interpreted as evidence for a bioregional shift. We found a significant tendency of habitat shifts occurring preferentially between TRF and non-TRF bioregions (31 shifts) than from non-TRF to TRF (24) or from TRF to TRF (11) and non-TRF to non-TRF (9). Our results also present cases where low dissimilarity is found between TRF and non-TRF bioregions. Most bioregions showed phylogenetic clustering and larger bioregions tended to be more clustered than smaller ones, with a higher species turnover component of phylogenetic dissimilarity. However, phylogenetic structure did not differ between TRF and non-TRF bioregions and diversification rates were higher in only two lineages, Attaleinae and Bactridinae, which are widespread and overabundant in both TRF and non-TRF bioregions. Area and distance significantly affected Neotropical palm community assembly and contributed more than environmental variables. Despite palms being emblematic humid forest elements, we found multiple shifts from humid to dry bioregions, showing that palms are also important components of these environments.
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| 70. |
- Freitas, C., et al.
(författare)
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Incongruent Spatial Distribution of Taxonomic, Phylogenetic, and Functional Diversity in Neotropical Cocosoid Palms
- 2021
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Ingår i: Frontiers in Forests and Global Change. - : Frontiers Media SA. - 2624-893X. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Biodiversity can be quantified by taxonomic, phylogenetic, and functional diversity. Current evidence points to a lack of congruence between the spatial distribution of these facets due to evolutionary and ecological constraints. A lack of congruence is especially evident between phylogenetic and taxonomic diversity since the name and number of species are an artificial, yet commonly used, way to measure biodiversity. Here we hypothesize that due to evolutionary constraints that link phylogenetic and functional diversity, areas with higher phylogenetic and functional diversity will be spatially congruent in Neotropical cocosoid palms, but neither will be congruent with areas of high taxonomic diversity. Also, we hypothesize that any congruent pattern differs between rainforests and seasonally dry forests, since these palms recently colonized and diversified in seasonally dry ecosystems. We use ecological niche modeling, a phylogenetic tree and a trait database to test the spatial congruence of the three facets of biodiversity. Taxonomic and phylogenetic diversity were negatively correlated. Phylogenetic and functional diversity were positively correlated, even though their spatial congruence was lower than expected at random. Taken together, our results suggest that studies focusing solely on large-scale patterns of taxonomic diversity are missing a wealth of information on diversification potential and ecosystem functioning.
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