Find research datasets worth reusing
Search datasets from major research repositories and use ShareScore to quickly assess how well each record supports discovery, access, and reuse.
1,481
datasets available to search
ShareScore release 0.9.0
Dataset results
1,481 results for “data processing”
Data from: Heterogeneity of ecological patterns, processes and funding of marine manipulative field experiments conducted in Southeastern Pacific coastal ecosystems
Ecological manipulative experiments conducted in marine coastal ecosystems have substantially improved ecological theory during the last decades, and have provided useful knowledge for the management and conservation of coastal ecosystems. Although different studies report global trends in ecological patterns worldwide, Southeastern Pacific coastal ecosystems have been poorly considered. Given that the SE Pacific coast encompasses diverse coastal ecosystems, consideration of studies conducted along this range can shed light on the heterogeneity of processes regulating coastal communities. We reviewed the biotic interactions and habitat type considered, as well as the complexity in terms of spatial and temporal extent of manipulative field experimental studies conducted along the SE Pacific coast from 0°S to 56° S (Ecuador to Chile). We test the effect of funding reported by different studies as a main factor limiting experimental complexity. From field ecological studies published from 1970 to 2016, we found that 81 studies were truly manipulative, in which one or multiple factors were "manipulated". Around 77% of these studies were located between 21°S to 40°S, and conducted in intertidal rocky habitats. An increase in experimental studies was observed between 2010 and 2015, especially focused on herbivore-alga interactions, although we found that both the temporal and spatial extent of these studies have shown a decrease in recent decades. Funding grant amount reported had a positive effect on elapsed time of field experiments, but no effect was observed on spatial extent or in the biotic interactions considered. Elapsed time of experiments was different among the main biotic interactions considered i.e. herbivory, predation, and competition. We suggest that to further progress in applied ecological knowledge, it will be necessary to consider pollution and urbanization processes explicitly using a field experimental framework. This information could improve our understanding of how ecosystems present along the SE Pacific coast respond to climate change and increased levels of human interventions.
Data from: Quality control processes in allografting: a twenty-year retrospective review of a hospital-based bone bank in Taiwan
Musculoskeletal allografts are now commonly used. To decrease the potential risks of transmission of pathogenic bacteria, fungi, or viruses to the transplant recipients, certain issues regarding the management of patients who receive contaminated allografts need to be addressed. We aimed to clarify the incidence and extent of disease transmission from allografts by analyzing the allografting procedures performed in the bone bank of our hospital over the past 20 years. We retrospectively reviewed the data from our allograft registry center on 3979 allografts that were implanted in 3193 recipients throughout a period of two decades, from July 1991 to June 2011. The source of the allografts, results of all screening tests, dates of harvesting and implantation, and recipients of all allografts were checked. With the help of the Center for Infection Control of our hospital, a strict prospective, hospital-wide, on-site surveillance was conducted, and every patient with healthcare-associated infection was identified. Fisher's exact test was used to compare the infection rate between recipients with sterile allografts and those with contaminated allografts. The overall discard and infection rates were, respectively, 23% and 1.3% in the first decade (1991–2001); and 18.4% and 1.25% in the second decade (2001–2011). The infection rate of contaminated allograft recipients was significantly higher than that of sterile allograft recipients (10% vs. 1.15%, P < 0.01) in the second decade. Both infection and discard rates of our bone bank are comparable with those of international bone banks. Strict allograft processing and adequate prophylactic use of antibiotics are critical to prevent infection and disease transmission in such cases.
Data from: Zebrafish differentially process colour across visual space to match natural scenes
Animal eyes have evolved to process behaviorally important visual information, but how retinas deal with statistical asymmetries in visual space remains poorly understood. Using hyperspectral imaging in the field, in vivo 2-photon imaging of retinal neurons, and anatomy, here we show that larval zebrafish use a highly anisotropic retina to asymmetrically survey their natural visual world. First, different neurons dominate different parts of the eye and are linked to a systematic shift in inner retinal function: above the animal, there is little color in nature, and retinal circuits are largely achromatic. Conversely, the lower visual field and horizon are color rich and are predominately surveyed by chromatic and color-opponent circuits that are spectrally matched to the dominant chromatic axes in nature. Second, in the horizontal and lower visual field, bipolar cell terminals encoding achromatic and color-opponent visual features are systematically arranged into distinct layers of the inner retina. Third, above the frontal horizon, a high-gain UV system piggybacks onto retinal circuits, likely to support prey capture.
Data from: Point process models for presence-only analysis
1. Presence-only data are widely used for species distribution modelling, and point process regression models are a exible tool that has considerable potential for this problem, when data arise as point events. 2. In this paper we review point process models, some of their advantages, and some common methods of fitting them to presence-only data. 3. Advantages include (and are not limited to): clarification of what the response variable is that is modelled; a framework for choosing the number and location of quadrature points (commonly referred to as pseudoabsences or \background points") objectively; clarity of model assumptions and tools for checking them; models to handle spatial dependence between points when it is present; ways forward regarding difficult issues such as accounting for sampling bias. 4. Point process models are related to some common approaches to presenceonly species distribution modelling, which means that a variety of different software tools can be used to fit these models, including MAXENT or generalised linear modelling software.
Data from: Stochastic and deterministic processes drive wetland community assembly across a gradient of environmental filtering
The role of deterministic and stochastic processes in community assembly is a key question in community ecology. We evaluated the effect of an abiotic filter (hydroperiod) on the partitioned diversity of three taxonomic groups (birds, vegetation, macroinvertebrates) from prairie pothole wetlands in Alberta, Canada, which naturally vary in water permanence. We observed that alpha and gamma diversity were higher in permanent than temporary wetlands (16-25% and 34-47% respectively, depending on the taxon). This suggests an influence of deterministic constraints on the number of species a wetland can support. Taxa which cannot persist in shallow, temporary wetlands are excluded by the deterministic constraints that a shortened hydroperiod imposes. In contrast, we observed that beta diversity was significantly higher (2-12%) in temporary wetlands than permanent ones, and temporary wetlands supported more unique combinations of community composition than permanent wetlands, despite having a smaller regional species pool. This observation contradicts prior mesocosm studies that found beta diversity mirrored the pattern in gamma diversity along an environmental filtering gradient. We conclude that deterministic processes are more influential in more stable permanent wetlands, whereas stochastic processes play a more important role in assembly in dynamic temporary wetlands that must disassemble and re-establish annually. Considering three distinct taxonomic groups differing in their relative mobility, our large-scale field study demonstrates that both stochastic and deterministic processes act together to influence the assembly of multiple communities and that the relative importance of the two processes varies consistently along a gradient of environmental filtering.
Data from: Introgression of mtDNA in Urosaurus lizards: historical and ecological processes
Introgression of mtDNA appears common in animals but the implications of acquiring a novel mitochondrial genome are not well known. This study investigates mito-genome introgression between the lizard species Urosaurus graciosus, a thermal specialist, and U. ornatus, a species that occupies a wider range of thermal environments. As ectotherms, their metabolic rate is strongly influenced by the thermal environment; with mitochondria being linked to metabolic rates, overall energy budgets could be impacted by introgression. I use mitochondrial gene trees, inferred from Bayesian analyses of Cyt-B and ND1 gene sequences, along with morphology and microsatellites from nineteen populations of these two species to address if the direction and location of mito-nuclear discordance match predictions of introgression resulting from past population expansions. MtDNA is expected to move from resident species into expanding or invading species. Second, does having a heterospecific form of mitochondria impact body size, a trait strongly associated with fitness? Multiple independent introgression events of historic origin were detected. All introgression was unidirectional with U. ornatus-type mtDNA found in U. graciosus parental type individuals. This result was consistent with population expansions detected in U. graciosus but not U. ornatus. Females with heterospecific mtDNA were significantly smaller than homospecific forms and heterospecific males had a different relationship of body mass to body length than those with homospecific mtDNA. These changes indicate a potential selective disadvantage for individuals with heterospecific mitochondria and are consistent with the theoretical expectation that deleterious alleles are more likely to persist in expanding populations.
Data from: A synthesis of ecosystem aboveground productivity and its process variables under simulated drought stress
1. Projected increases in drought duration and intensity under climate change considerably affect aboveground productivity (ANPP) and associated process variables (photosynthesis rates (Pn), stomatal conductance (gs), soil respiration (Rs), and soil water content (SWC)). 2. Although ANPP has been extensively studied across the ecosystems, there is little consensus on how the spatiotemporal patterns of ANPP will be altered with increasing drought stress. Here, we present a global meta-analysis of ANPP and the four variables (610 observations from 78 studies) for drought duration, intensity, and their combination. 3. Forest-ANPP had stronger negative responses to long-term drought (34.44%; ≥ 4 yrs) than short-term drought (10.78%; ≤ 1 yr), and decreased more in Mediterranean forests than in tropical forests. Decreases in Pn and gs were strongest under long-term moderate drought. In the short term, Rs increased by 5.66% under light drought, but decreased by 14.12% and 28.43% under moderate and severe droughts. Grass-ANPP showed a nonlinear decrease with extended duration, and the rate slowed. Within light to severe intensities, ANPP decreased linearly, but became stable under extreme condition. In the short term, ANPP reduced more seriously with increasing drought intensity (12.01-30.34%). With aggravation of drought stress, the reductions in Rs and SWC increased. There was significant heterogeneity in grassland responses to drought stress. The greatest decreases in ANPP, Pn, and gs were observed in North America, and the reductions in Rs and SWC were greater in Western Europe. Shrub-ANPP showed stronger negative responses to long-term moderate drought (12.59%). Pn and gs declined significantly with increasing drought intensity. Variations in Rs to drought duration, intensity, and their combination were more complex, either showing positive or negative responses (dominated). 4. Synthesis. Forest-ANPP shows high sensitivity to long-term moderate drought, whereas grass-ANPP is more responsive to short-term drought. Compared to forests and grasslands, shrub-ANPP exhibits less sensitivity to droughts. Different responses of ecosystems were predominantly driven by physiological mechanisms or species differences in turnover time, community architecture, and drought adaptation strategies. Given these findings, future studies should focus on nonlinear patterns, response thresholds, and adaptation mechanisms when predicting and modelling feedback between ecosystems and climate change.
Data from: Phylogenetic and morphological relationships between nonvolant small mammals reveal assembly processes at different spatial scales
The relative roles of historical processes, environmental filtering, and ecological interactions in the organization of species assemblages vary depending on the spatial scale. We evaluated the phylogenetic and morphological relationships between species and individuals (i.e., inter- and intraspecific variability) of Neotropical nonvolant small mammals coexisting in grassland-forest ecotones, in landscapes and in regions, that is, three different scales. We used a phylogenetic tree to infer evolutionary relationships, and morphological traits as indicators of performance and niche similarities between species and individuals. Subsequently, we applied phylogenetic and morphologic indexes of diversity and distance between species to evaluate small mammal assemblage structures on the three scales. The results indicated a repulsion pattern near forest edges, showing that phylogenetically similar species coexisted less often than expected by chance. The strategies for niche differentiation might explain the phylogenetic repulsion observed at the edge. Phylogenetic and morphological clustering in the grassland and at the forest interior indicated the coexistence of closely related and ecologically similar species and individuals. Coexistence patterns were similar whether species-trait values or individual values were used. At the landscape and regional scales, assemblages showed a predominant pattern of phylogenetic and morphological clustering. Environmental filters influenced the coexistence patterns at three scales, showing the importance of phylogenetically conserved ecological tolerances in enabling taxa co-occurrence. Evidence of phylogenetic repulsion in one region indicated that other processes beyond environmental filtering are important for community assembly at broad scales. Finally, ecological interactions and environmental filtering seemed important at the local scale, while environmental filtering and historical colonization seemed important for community assembly at broader scales.
Data from: The effect of Speed of Processing training on microsaccade magnitude
Older adults experience cognitive deficits that can lead to driving errors and a loss of mobility. Fortunately, some of these deficits can be ameliorated with targeted interventions which improve the speed and accuracy of simultaneous attention to a central and a peripheral stimulus called Speed of Processing training. To date, the mechanisms behind this effective training are unknown. We hypothesized that one potential mechanism underlying this training is a change in distribution of eye movements of different amplitudes. Microsaccades are small amplitude eye movements made when fixating on a stimulus, and are thought to counteract the "visual fading" that occurs when static stimuli are presented. Due to retinal anatomy, larger microsaccadic eye movements are needed to move a peripheral stimulus between receptive fields and counteract visual fading. Alternatively, larger microsaccades may decrease performance due to neural suppression. Because larger microsaccades could aid or hinder peripheral vision, we examine the distribution of microsaccades during stimulus presentation. Our results indicate that there is no statistically significant change in the proportion of large amplitude microsaccades during a Useful Field of View-like task after training in a small sample of older adults. Speed of Processing training does not appear to result in changes in microsaccade amplitude, suggesting that the mechanism underlying Speed of Processing training is unlikely to rely on microsaccades.
Data from: Nuclear and mitochondrial sequence data reveal and conceal different demographic histories and population genetic processes in Caribbean reef fishes
Mitochondrial and nuclear sequence data should recover historical demographic events at different temporal scales due to differences in their effective population sizes and substitution rates. This expectation was tested for two closely related coral reef fish, the tube blennies Acanthemblemaria aspera and A. spinosa. These two have similar life histories and dispersal potentials, and co-occur throughout the Caribbean. Sequence data for one mitochondrial and two nuclear markers were collected for 168 individuals across the species' Caribbean ranges. While both species shared a similar pattern of genetic subdivision, A. spinosa had 20-25-times greater nucleotide sequence divergence among populations than A. aspera at all three markers. Substitution rates estimated using a relaxed clock approach revealed that mitochondrial COI is evolving at 11.2% pairwise sequence divergence per million years. This rapid mitochondrial rate had obscured the signal of old population expansions for both species, which were only recovered using the more slowly evolving nuclear markers. However, the rapid COI rate allowed the recovery of a recent expansion in A. aspera corresponding to a period of increased habitat availability. Only by combining both nuclear and mitochondrial data were we able to recover the complex demographic history of these fishes.
Data from: Linking functional diversity and ecosystem processes: a framework for using functional diversity metrics to predict the ecosystem impact of functionally unique species
1.Functional diversity (FD) metrics are widely used to assess invasion ecosystem impacts, but we have limited theory to predict how FD should respond to invasion. A key challenge to effectively using FD metrics is the complexity of conceptualizing alterations to multi-dimensional trait space, making it difficult to select a priori the most appropriate metric for specific ecological questions. 2.Here, we provide expectations on how invasion should change four commonly used FD metrics—functional richness (FRic), evenness (FEve), divergence (FDiv), and dispersion (FDis)—and then test these expectations in a lab decomposition experiment. We simulate invasion of a forest by understory plants by adding leaf litter from 18 natives and nonnatives to a representative canopy tree litter mixture to test changes in FD and decomposition. 3.All four metrics changed predictably with invasion. Species that were more functionally unique or when added at greater proportions had larger impacts on FD. Overall, FRic, FEve, and FDiv were poor choices for understanding impacts of nonnative species. FDis was the only metric that both changed predictably with addition of understory litter and correlated intuitively with changes in carbon mineralization. Furthermore, ranking species based upon how much they changed FDis of the litter mixture provided a fair assessment of which species had the largest impact on decomposition. As such, functional dispersion may be a key tool for predicting a priori which nonnatives will have the greatest impact on ecosystem processes. 4.Synthesis: We highlight the need to assess the suitability of each FD metric for the specific ecological question at hand. Our work reveals the pitfalls of considering multiple metrics or randomly choosing a single metric without suitability assessments. At the same time, it suggests a framework for metric assessment that should help lead to selection of a metric or metrics that provide robust a priori insights into how invasion by nonnative species can impact ecosystem processes.
Data from: Genetic variation and population structure in the endangered Hermann's tortoise: the roles of geography and human-mediated processes
The Hermanni's tortoise (Testudo hermanni) is an endangered land tortoise distributed in disjoint populations across Mediterranean Europe. We investigated its genetic variation by typing one mitochondrial locus and nine nuclear microsatellites in approximately 300 individuals from 22 localities. Our goal was to understand the relative impact of natural and human-mediated processes in shaping the genetic structure, and to identify the genetic priorities for the conservation of this species. We found that i) all geographic areas are highly differentiated, mainly as a function of their distance but with a clear genetic discontinuity (Fst values larger than 0.4) between the Eastern and the Western subspecies; ii) the contact zone between subspecies is located farthest to the west than previously believed, and it probably coincides with the delta of the largest Italian river; iii) extinction events due to climatic conditions in the Upper Palaeolithic and subsequent human-mediated translocations in the Neolithic possibly explain the unexpected similarity among Spain, Sicily and Corsica. For conservation purposes, the large majority of genetic pools appears autochthonous, although hybridization among subspecies, related to extensive 20th century trade of tortoises across Europe, is observed in Spain and some Italian samples. Most populations do not seem at immediate risk of low genetic variation, except the French population, which has very low nuclear genetic diversity (heterozygosity = 0.25) and where 50 out of 51 sampled animals shared the same mitochondrial sequence. In general, restocking and reintroduction plans should carefully consider the genetic background of the individuals.
Data from: Ant diversity in Neotropical savannas: hierarchical processes acting at multiple spatial scales
1. Understanding what creates and maintains macroscale biodiversity gradients is a central focus of ecological and evolutionary research. Spatial patterns in diversity are driven by a hierarchy of factors operating at multiple scales. Historical and climatic factors drive large-scale patterns of diversity by affecting the size of regional species pools, while habitat heterogeneity or microhabitat characteristics further influence species coexistence at small scales. 2. We tested the degree to which the species-energy, historical factors, habitat heterogeneity and local environment hypotheses explain observed patterns of ant diversity across hierarchical spatial scales. 3. We sampled ground-dwelling ants at 29 sites within a Neotropical savanna region, the Brazilian Cerrado. We measured species density – an abundance-dependent diversity metric – and rarefied species richness – an abundance-independent metric – at spatial scales with varying grain sizes. For each hypothesis, two correlates were used to predict ant diversity patterns: i) species-energy: rainfall and productivity; ii) historical factors: historical variation in rainfall and refugial areas; iii) habitat heterogeneity: heterogeneity in greenness and diversity of land cover; iv) local factors: contents of sand and coarse fragments in the soil. 4. Ant diversity patterns correlated to net primary productivity and to the proportion of coarse fragments in the soil, corroborating the species-energy and local environment hypotheses, respectively. Soil negatively influenced species density, but not rarefied species richness, which was positively influenced by productivity. We found scale dependencies in the effects of soil/productivity on species density; productivity best predicted species density patterns at large scales, since sampling completeness offset the abundance-driven effects of soil. 5. Considering abundance differences may help to discern the mechanisms underlying the relationship between macroscale diversity patterns and its ecological drivers. Plant productivity affected ant diversity independently of abundance, possibly by limiting the size of regional species pools. On the other hand, soil properties had an abundance-dependent effect on ant diversity, indicating a sampling mechanism. Our findings are consistent with predictions of the hierarchical theory of diversity. Large-scale patterns of productivity limit regional diversity, an effect that cascades down to finer spatial scales, where soil properties influence the number of coexisting species.
Data from: Fine-scale refuges can buffer demographic and genetic processes against short-term climatic variation and disturbance: a 22 year case study of an arboreal marsupial
Ecological disturbance and climate are key drivers of temporal dynamics in the demography and genetic diversity of natural populations. Microscale refuges are known to buffer species' persistence against environmental change, but the effects of such refuges on demographic and genetic patterns in response to short-term environmental variation are poorly understood. We quantified demographic and genetic responses of mountain brushtail possums (Trichosurus cunninghami) to rainfall variability (1992–2013) and to a major wildfire. We hypothesized that there would be underlying differences in demographic and genetic processes between an unburnt mesic refuge and a topographically exposed zone that was burnt in 2009. Fire caused a 2-year decrease in survival in the burnt zone, but the population grew after the fire due to immigration, leading to increased expected heterozygosity. We documented a fire-related behavioural shift, where the rate of movement by individuals in the unburnt refuge to the burnt zone decreased after fire. Irrespective of the fire, there were long-term differences in demographic and genetic parameters between the mesic/unburnt refuge and the nonmesic/burnt zone. Survival was high and unaffected by rainfall in the refuge, but lower and rainfall-dependent in the nonmesic zone. Net movement of individuals was directional, from the mesic refuge to the nonmesic zone, suggesting fine-scale source–sink dynamics. There were higher expected heterozygosity (HE) and temporal genetic stability in the refuge, but lower HE and marked temporal genetic structure in the exposed habitat, consistent with reduced generational overlap caused by elevated mortality and immigration. Thus, fine-scale refuges can mediate the short-term demographic and genetic effects of climate and ecological disturbance.
Data from: Arabidopsis hybrid speciation processes
The genus Arabidopsis provides a unique opportunity to study fundamental biological questions in plant sciences utilizing the diploid model species A. thaliana and A. lyrata. However, only a few studies have focused on introgression and hybrid speciation in Arabidopsis, although polyploidy is a common phenomenon within this genus. More recently, there is growing evidence of significant gene flow between the various Arabidopsis species. So far, we know A. suecica and A. kamchatica as fully stabilized allopolyploid species. Both species evolved during Pleistocene glaciation and deglaciation cycles in Fennoscandinavia and the amphi-Beringian region, respectively. These hybrid studies were conducted either on a phylogeographic scale, or hybridization was reconstructed experimentally in the laboratory. With our study we focus at a regional and populational level. Our research area is located in the foothills of the Eastern Austrian Alps, where two Arabidopsis species, A. arenosa and A. lyrata ssp. petraea, are sympatrically distributed. Our hypothesis of genetic introgression, migration, and adaptation to the changing environment during the Pleistocene has been confirmed: We observed significant, mainly unidirectional gene flow between the two species, which has given rise to the tetraploid A. lyrata. This cytotype was able to escape from the narrow ecological niche occupied by diploid A. lyrata ssp. petraea on limestone outcrops by migrating northward into siliceous areas, leaving behind a trail of genetic differentiation.
Data from: Early diving behaviour in juvenile penguins: improvement or selection processes
The early life stage of long-lived species is critical to the viability of population, but is poorly understood. Longitudinal studies are needed to test whether juveniles are less efficient foragers than adults as has been hypothesized. We measured changes in the diving behaviour of 17 one-year-old king penguins Aptenodytes patagonicus at Crozet Islands (subantartic archipelago) during their first months at sea, using miniaturized tags that transmitted diving activity in real time. We also equipped five non-breeder adults with the same tags for comparison. The data on foraging performance revealed two groups of juveniles. The first group made shallower and shorter dives that may be indicative of early mortality while the second group progressively increased their diving depths and durations, and survived the first months at sea. This surviving group of juveniles required the same recovery durations as adults, but typically performed shallower and shorter dives. There is thereby a relationship between improved diving behaviour and survival in young penguins. This long period of improving diving performance in the juvenile life stage is potentially a critical period for the survival of deep avian divers and may have implications for their ability to adapt to environmental change.
Data from: Mixture models of nucleotide sequence evolution that account for heterogeneity in the substitution process across sites and across lineages
Molecular phylogenetic studies of homologous sequences of nucleotides often assume that the underlying evolutionary process was globally stationary, reversible and homogeneous (SRH), and that a model of evolution with one or more site-specific and time-reversible rate matrices (e.g., the GTR rate matrix) is enough to accurately model the evolution of data over the whole tree. However, an increasing body of data suggests that evolution under these conditions is an exception, rather than the norm. To address this issue, several non-SRH models of molecular evolution have been proposed, but they either ignore heterogeneity in the substitution process across sites (HAS) or assume it can be modelled accurately using the Γ distribution. As an alternative to these models of evolution, we introduce a family of mixture models that approximate HAS without the assumption of an underlying predefined statistical distribution. This family of mixture models is combined with non-SRH models of evolution that account for heterogeneity in the substitution process across lineages (HAL). We also present two algorithms for searching model space and identifying an optimal model of evolution that is less likely to over- or under-parameterize the data. The performance of the two new algorithms was evaluated using alignments of nucleotides with 10,000 sites simulated under complex non-SRH conditions on a 25-tipped tree. The algorithms were found to be very successful, identifying the correct HAL model with a 75% success rate (the average success rate for assigning rate matrices to the tree's 48 edges was 99.25%) and, for the correct HAL model, identifying the correct HAS model with a 98% success rate. Finally, parameter estimates obtained under the correct HAL-HAS model were found to be accurate and precise. The merits of our new algorithms were illustrated with an analysis of 42,337 second codon sites extracted from a concatenation of 106 alignments of orthologous genes encoded by the nuclear genomes of Saccharomyces cerevisiae, S. paradoxus, S. mikatae, S. kudriavzevii, S. castellii, S. kluyveri, S. bayanus, and Candida albicans. Our results show that second codon sites in the ancestral genome of these species contained 49.1% invariable sites, 39.6% variable sites belonging to one rate category (V1), and 11.3% variable sites belonging to a second rate category (V2). The ancestral nucleotide content was found to differ markedly across these 3 sets of sites, and the evolutionary processes operating at the variable sites were found to be non-SRH and best modelled by a combination of 8 edge-specific rate matrices (4 for V1 and 4 for V2). The number of substitutions per site at the variable sites also differed markedly, with sites belonging to V1 evolving slower than those belonging to V2 along the lineages separating the 7 species of Saccharomyces. Finally, sites belonging to V1 appeared to have ceased evolving along the lineages separating S. cerevisiae, S. paradoxus, S. mikatae, S. kudriavzevii, and S. bayanus, implying that they might have become so selectively constrained that they could be considered invariable sites in these species.
Data from: Proteomic evidence of a paedomorphic evolutionary process within a marine snail species: a strategy for adapting to extreme ecological conditions?
The exposed and sheltered ecotypes of the marine snail Littorina saxatilis from European rocky shores are considered a key model system to study adaptation and ecological speciation. Previous studies showed that two ecotypes (RB and SU) of this species in NW Spain have differently adapted to different shore levels and microhabitats. In order to understand how this divergent adaptive process has been accomplished, we followed a quantitative proteomic approach to investigate the proteome variation in a number of different biological factors, i.e. ecotype, ontogeny and their interactions. This approach allowed testing the hypothesis that one of the ecotypes has evolved by paedomorphosis, and also whether or not the molecular mechanisms related to ecotype differentiation are set up in early developmental stages. Additionally the identification of some candidate proteins by mass spectrometry provides some functional insights about these evolutionary processes. Results from this study provided evidence of higher ontogenetic differentiation at proteome level in the RB (metamorphic) than in SU (paedomorphic) ecotype that point to the possibility of juvenile stage retention in this latter ecotype. The level of protein expression (proteome) differences between ecotypes maintained nearly constant from late embryonic stages to adulthood, although some proteins involved in these changes considerably differed in embryonic compared to other ontogenetic stages. Paedomorphosis may be the evolutionary response of the SU ecotype of solving the trade-off during sexually immaturity that is caused by the evolution of small size arising from adaptation to the wave exposed habitat. Some potential candidate genes of adaptation related to energetic metabolism have been identified, providing a promising baseline for future functional analyses.
Data from: Comparison of spatial and temporal genetic differentiation in a harmful dinoflagellate species emphasises impact of local processes
Population genetic studies provide insights into intraspecific diversity and dispersal patterns of microorganisms such as protists, which help understanding invasions, harmful algal bloom development and occurrence of seafood poisoning. Genetic differentiation across geography has been reported in many microbial species indicating significant dispersal barriers among different habitats. Temporal differentiation has been less studied and its frequency, drivers and magnitude are poorly understood due to a lack of integral studies. The toxic dinoflagellate species /Gambierdiscus caribaeus/ was sampled during two years in the Florida Keys, and repeatedly from 2006 to 2016 at St. Thomas, US Virgin Islands (USVI), including a three-year period with monthly sampling, to compare spatial and temporal genetic differentiation. Samples from the USVI site showed high temporal variability in local population structure, which correlated with changes in salinity and benthic habitat cover. In some cases, temporal variability exceeded spatial differentiation, despite apparent lack of connectivity and dispersal across the Greater Caribbean Region based on the spatial genetic data. Thus, local processes such as selection might have a stronger influence on population structure in microorganisms than geographic distance. The observed high temporal genetic diversity challenges the prediction of harmful algal blooms and toxin concentrations, but illustrates also the evolutionary potential of microalgae to respond to environmental change.
Data from: The role of ecology, neutral processes and antagonistic coevolution in an apparent sexual arms race
Some of the strongest examples of a sexual 'arms race' come from observations of correlated evolution in sexually antagonistic traits among populations. However, it remains unclear whether these cases truly represent sexually antagonistic coevolution; alternatively, ecological or neutral processes might also drive correlated evolution. To investigate these alternatives, we evaluated the contributions of intersex genetic correlations, ecological context, neutral genetic divergence and sexual coevolution in the correlated evolution of antagonistic traits among populations of Gerris incognitus water striders. We could not detect intersex genetic correlations for these sexually antagonistic traits. Ecological variation was related to population variation in the key female antagonistic trait (spine length, a defence against males), as well as body size. Nevertheless, population covariation between sexually antagonistic traits remained substantial and significant even after accounting for all of these processes. Our results therefore provide strong evidence for a contemporary sexual arms race.
ScienceDex guides
Understand access before you commit
These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.