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.
Evolutionary success, as demonstrated by high abundance and a wide geographical range, is related to genetic variation and historical demography. Here we assess how climatic change during the ...Quaternary influenced the demography and distribution of the Neotropical swamp palm Mauritia flexuosa. Using microsatellite loci and coalescent analyses we examined how demographical dynamics affected genetic diversity, effective population size and connectivity through time and space. Mauritia flexuosa presents significant genetic differentiation between the Amazonian and Cerrado biomes and among different river basins. Amazonian lineages are ancient compared to lineages from the Cerrado, a pattern corroborated using the fossil pollen record, where the species was absent from the Cerrado during the cold and dry periods of the last glacial cycles, then returned during the wet, interglacial phases. Coalescent simulations show that the pattern of observed genetic diversity for M. flexuosa is most likely due to a range retraction during the Last Glacial Maximum, leading to multiple refugia and resulting in high differentiation between Amazonian and Cerrado biomes. Isolation-by-distance and by-environment also shaped the distribution and evolutionary success of M. flexuosa. Our study provides new insights into the historical factors that affected geographical distribution and structure genetic diversity, contributing to long-term evolutionary success.
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 100 Ma.
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. 60 Ma, yet most clades only diversified after c. 30 Ma. 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.
Olfactory impairment is common in Parkinson’s disease (PD). The authors aimed to identify the clinical tests used to assess olfactory function and examine their ability to distinguish PD with ...different disease duration from healthy individuals with physiological aging.
Cross-sectional studies published until May 2020 that assessed the olfaction of individuals with PD using search terms related to PD, olfactory function, and assessment were searched on PubMed, PsycInfo, Cinahl, and Web of Science databases.
Twelve smell tests were identified from the reviewed studies (n = 125) that assessed 8776 individuals with PD. Data of 6593 individuals with PD and 8731 healthy individuals were included in the meta-analyses. Individuals with PD presented worse performance than healthy individuals, regardless of the smell test used. The University of Pennsylvania Smell Identification Test (UPSIT) was used by most studies (n = 2310 individuals with PD) and presented smaller heterogeneity. When the studies were subclassified according to the years of PD duration, there were no significant differences.
All smell tests were able to discriminate the olfactory function of PD from that of healthy individuals, although the UPSIT was widely used. The abnormal olfaction was not related to the disease duration. Systematic review protocol registration (PROSPERO/2020-CRD42020160878).
•Abnormal olfaction is common in Parkinson’s Disease (PD).•Physiological aging also leads to smell loss.•Clinical tests can be used to assess olfactory function in PD individuals.•Abnormal olfaction in PD is not related to disease duration.
Dioecy has evolved up to 5,000 times in angiosperms, despite the potentially high intrinsic costs to unisexuality. Dioecy prevents inbreeding, which is especially relevant on isolated islands when ...gene pools are small. Dioecy is also associated with certain dispersal traits, such as fruit size and type. However, the influence of dioecy on other life-history traits and island distribution remains poorly understood. Here, we test the effect of dioecy on palm (Arecaceae) speciation rates, fruit size, and frequency on islands.
We used phylogenetic comparative methods to estimate the ancestral state of sexual system and its impact on speciation rates and fruit size. Frequency of sexual system, effect of insularity on the probability of being dioecious, and phylogenetic clustering of island dioecious versus mainland species were inferred. Lastly, we determined the interplay of insularity and sexual system on speciation rates.
Palms repeatedly evolved different sexual systems (dioecy, monoecy and polygamy) from a hermaphrodite origin. Differences in speciation rates and fruit size among the different sexual systems were not identified. An effect of islands on the probability of the palms be dioecious was also not found. However, we found a high frequency and phylogenetic clustering of dioecious palms on islands, which were not correlated with higher speciation rates.
The high frequency and phylogenetic clustering may be the result of in situ radiation and suggest an 'island effect' for dioecious palms, which was not explained by differential speciation rates. This island effect also cannot be attributed to long distance dispersal due to the lack of fruit size difference among sexual systems, and particularly because palm dispersal to islands is highly constrained by the interaction between fruit and frugivores sizes. Taken together, we suggest that trait flexibility in sexual system evolution and the in situ radiation of dioecious lineages are the underlying causes of the outstanding distribution of palms on islands.
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.
Parkinson's disease (PD) can affect hand function since the beginning of the motor symptoms.
To compare the ability of different hand function tests to: 1) distinguish individuals with PD from ...healthy controls; 2) differentiate stages of the disease; and 3) indicate changes over time due to disease progression.
Twenty-four individuals with PD (Hoehn and Yahr: I-III) and 24 age- and sex-matched controls performed the Jebsen-Taylor Hand Function Test (JTHFT), the Nine-Hole Peg Test (9HPT), and the maximum grip and the maximum pinch strength tests using their right and left hands. Eight individuals with PD (six females and two males) were reassessed after 18 months. The ROC analyses and Mann-Whitney
tests (for disease progression) using the average performance of the hands were done.
Individuals with PD presented worse test performances than controls, except for the writing subtest of the JTHFT and the grip strength test. The JTHFT without the writing subtest (JTHFT
) was the most accurate to discriminate PD from controls (AUC = 0.899; sensitivity 75% and specificity 95.8%). The 9HPT and the simulated feeding and moving large, light objects JTHFT subtests were sensitive to distinguish stages, while the 9HPT, the moving small, common objects JTHFT subtest, and the grip strength were sensitive to changes with disease progression.
The JTHFT
was highly discriminative of the hand function impairments in PD. TwoJTHFT subtests were the most sensitives to distinguish PD stages (i.e. simulated feeding JTHFT subtest) and disease progression (i.e. moving small, common objects JTHFT subtest).
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Background: Cerrado comprises heterogeneous vegetation types. The flora of the vegetation types has distinct biogeographic origins and thus can be hypothesised to have distinct evolutionary imprints.
...Aims: We hypothesised that the flora of riparian forest was phylogenetically overdispersed, whereas those of more open habitats were phylogenetically clustered.
Methods: We built a species-level phylogeny for 1,663 species of trees, shrubs and palms and analysed the pattern of lineage distribution, alpha and beta phylogenetic diversity among Cerrado vegetation types (riparian forest, rocky savana, savana and seasonally dry forest - SDTF).
Results: We found a gradient of high phylogenetic diversity and overdispersion from riparian forests towards phylogenetic clustering in vegetation in more open and drier habitats. Habitat shifts were common along the evolutionary history of all families analysed and most families showed a high frequency of shifts from SDTF to riparian forest and savanna.
Conclusions: SDTF seems to be a transitional habitat in evolutionary terms, promoting lineage exchanges between stands of riparian forest and savanna. While riparian forest can be seen as a 'museum', that harbours ancient lineages, savanna and rocky savanna are a 'cradle' of derived lineages. Habitat shifts are an important underlying drive of high present-day Cerrado flora diversity.
Introduction: Olfactory impairment has been considered for differential diagnosis in Parkinson's disease (PD) patients. The authors aimed to identify the tests used to assess the olfactory function ...in PD patients and examine these tests' ability to distinguish them from other neurological disorders.
Areas covered: Cross-sectional studies published until May 2020 comparing the olfactory function of PD patients to other neurological disorders were searched on PubMed, PsycInfo, Cinahl, and Web of Science databases using search terms related to PD, olfactory function, and assessment. Five thousand three hundred and four studies were screened, and 35 were included in the systematic review. Six smell tests that evaluated a total of 1,544 PD patients were identified. Data of 1,144 patients included in the meta-analyses revealed worse smell performance than individuals with other neurological disorders, such as progressive supranuclear palsy and essential tremor, but not with idiopathic rapid eye movement sleep behavior disorder.
Expert opinion: The University of Pennsylvania Smell Identification Test was the most used test to assess the olfactory function of PD. Smell loss was worse in PD than in some neurological disorders. The smell tests' ability in differentiating PD from other neurological disorders still deserves more attention in future studies. Protocol register (PROSPERO/2018-CRD42018107009).
Rainforests have been a source of lineages to open and seasonally dry habitats throughout Angiosperm evolution, especially in the Neotropics. However, the underlying mechanisms that allow such shifts ...remain poorly understood at large spatial scales. Here, we test whether acaulescence (an underground stem or a very short stem concealed in the ground) has affected the colonization and speciation in Neotropical seasonally dry habitats by cocosoid palms (Cocoseae). Acaulescent species maintain their growth underground, which increases their chances of survival from prolonged seasonal dry season and frequent fires. We use an integrative approach based on trait‐dependent diversification models, phylogenetic comparative methods and ecological niche models. We found that shifts towards acaulescent growth form were accompanied by evolutionary transitions to seasonally dry habitats. Acaulescent lineages had higher speciation rates than non‐acaulescent ones. However, the interaction between acaulescence and seasonally dry habitats had no significant effect on Cocoseae speciation rates. Acaulescent palms are primarily distributed in Neotropical seasonally dry habitats and non‐acaulescent palms are concentrated in Amazonian rainforests. Our results suggest that an underground stem, with high carbohydrate and water storage capacity, is a preadaptation by which rainforest lineages were able to colonize and diversify in new fire‐prone, increasingly seasonal and drier adaptive zones. The projected global expansion of dry seasonal habitats requires an understanding of how drought‐avoidance functional traits evolve and how they are linked to seasonally dry habitats. Our results are, thus, a step forward in determining plant response mechanisms to drier and seasonal conditions.
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