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445 results for “data constraint”
Data from: Pollinator shifts, contingent evolution, and evolutionary constraint drive floral disparity in Salvia (Lamiaceae): evidence from morphometrics and phylogenetic comparative methods
Switches in pollinators have been argued to be key drivers of floral evolution in angiosperms. However, few studies have tested the relationship between floral shape evolution and switches in pollination in large clades. In concert with a dated phylogeny, we present a morphometric analysis of corolla, anther connective, and style shape across 44% of nearly 1,000 species of Salvia (Lamiaceae) and test four hypotheses of floral evolution. We demonstrate that floral morphospace of New World (NW) Salvia is largely distinct from that of Old World (OW) Salvia and that these differences are pollinator driven; that shifts in floral morphology sometimes mirror shifts in pollinators; that anther connectives (key constituents of the Salvia staminal lever) and styles co-evolved from curved to linear shapes following shifts from bee to bird pollination; and that morphological differences between NW and OW bee flowers are partly the legacy of constraints imposed by an earlier shift to bird pollination in the NW. The distinctive staminal lever in Salvia is a morphologically diverse structure that has evolved in concert with both the corolla and style, under different pollinator pressures, and in contingent fashion.
Data from: Longer development provides first‐feeding fish time to escape hydrodynamic constraints
<div class="abstract"> <p class="abstract_para"><span><span><span><span><span><span><span><span><span><span><span><span>What is the functional effect of prolonged development? By controlling for size, we quantify first‐feeding performance and hydrodynamics of zebrafish and guppy offspring (5 ± 0.5 mm in length), which differ fivefold in developmental time and twofold in ontogenetic state. By manipulating water viscosity, we control the hydrodynamic regime, measured as Reynolds number. We predicted that if feeding performance were strictly the result of hydrodynamics, and not development, feeding performance would scale with Reynolds number. We find that guppy offspring successfully feed at much greater distances to prey (1.0 vs. 0.2 mm) and with higher capture success (90 vs. 20%) compared with zebrafish larvae, and that feeding performance was not a result of Reynolds number alone. Flow visualization shows that zebrafish larvae produce a bow wave ~0.2 mm in length, and that the flow field produced during suction does not extend beyond this bow wave. Due to well‐developed oral jaw protrusion, the similar‐sized suction field generated by guppy offspring extends beyond the horizon of their bow wave, leading to successful prey capture from greater distances. These findings suggest that prolonged development and increased ontogenetic state provides first‐feeding fish time to escape the pervasive hydrodynamic constraints (bow wave) of being small.</span></span></span></span></span></span></span></span></span></span></span></span></p> </div> <div class="abstract"> </div>
Data supporting Food web complexity weakens size-based constraints on the pyramids of life
<p>Marine ecosystems are generally expected to have bottom-heavy trophic structure (more plants than animals) due to size-based constraints arising from increased metabolic requirements and inefficient energy transfer. However, size-based (allometric) approaches are often limited to confined trophic level windows where energy transfer is predicted by size alone, and are constrained to bottom-up control at steady state. In real food webs, energy flow is more complex and top-down processes can also shape trophic structure. We expand size-based theory to account for complex food webs, and show that moderate levels of food web connectance allow for inverted trophic structure more often than predicted, especially in marine ecosystems. Trophic structure inversion occurs due to incorporation of complex energy pathways and top-down effects on ecosystems. Our results suggest that marine ecosystems should be top-heavy, and observed bottom-heavy trophic structure may be a result of human defaunation of the ocean that has been more extreme than presently recognized.</p>
Data from: Dietary constraints of phytosaurian reptiles revealed by dental microwear textural analysis
Phytosaurs are a group of large, semi-aquatic archosaurian reptiles from the Middle–Late Triassic. They have often been interpreted as carnivorous or piscivorous due to their large size, morphological similarity to extant crocodilians and preservation in fluvial, lacustrine and coastal deposits. However, these dietary hypotheses are difficult to test, meaning that phytosaur ecologies and their roles in Triassic food webs remain incompletely constrained. Here, we apply dental microwear textural analysis to the three-dimensional sub-micrometre scale tooth surface textures that form during food consumption to provide the first quantitative dietary constraints for five species of phytosaur. We furthermore explore the impacts of tooth position and cranial robusticity on phytosaur microwear textures. We find subtle systematic texture differences between teeth from different positions along phytosaur tooth rows, which we interpret to be the result of different loading pressures experienced during food consumption, rather than functional partitioning of food processing along tooth rows. We find rougher microwear textures in morphologically robust taxa. This may be the result of seizing and processing larger prey items compared to those captured by gracile taxa, rather than dietary differences per se. We reveal relatively low dietary diversity between our study phytosaurs and that individual species show a lack of dietary specialisation. Species are predominantly carnivorous and/or piscivorous, with two taxa exhibiting slight preferences for 'harder' invertebrates. Our results provide strong evidence for higher degrees of ecological convergence between phytosaurs and extant crocodilians than previously appreciated, furthering our understanding of the functioning and evolution of Triassic ecosystems.
Data Tables from contribution titled "Joint geophysical-petrological modeling on the Ivrea geophysical body beneath Valsesia, Italy: Constraints on the continental lower crust" published in Geochemistry, Geophysics, Geosystems
<p><strong>TABLE CAPTIONS</strong></p> <p><strong>Table 1: </strong>Average and specific bulk compositions of the representative exposed primitive rocks of the deep lower crust and upper mantle of the IVZ (Balmuccia and Lower Mafic Complex in Valsesia, Finero in Val Cannobina, and Sessera river in Val Sessera) used for the Perple_X calculations using the two thermodynamic models STX11 and HP02. Mn, Ni, P, and Cr were not used for the Perple_X calculations. Mg# is calculated as Mg / (Mg + Fe) (mole fractions). Symbols in the last row indicate the rock compositions that are reported (✓) and not reported (✗) in Figure 5. Average compositions are normalized to 100 wt.% on a volatile-free basis; specific compositions report original totals and H<sub>2</sub>O contents estimated based on the volumetric proportions hydrous minerals (amphibole and phlogopite) at the scale of the bulk rock. References: 1) Voshage et al. (1990); 2) Voshage et al. (1990), Shervais and Mukasa (1991), Hartmann and Wedepohl (1993), Rivalenti et al. (1995), and Mukasa and Shervais (1999); 3) Pin and Sills (1986); 4) Pin and Sills (1986), Shervais and Mukasa (1991), Hartmann and Wedepohl (1993), Rivalenti et al. (1995), and Mukasa and Shervais (1999); 5) Shervais and Mukasa (1991) and Mazzucchelli et al. (2009); 6) Sinigoi et al. (1991; 2011); 7) Hartmann and Wedepohl (1993); 8) Coltorti and Siena (1984); 9) Siena and Coltorti (1989), Lu et al. (1997a; b), and Stähle et al. (2001).</p> <p> </p> <p><strong>Table 2: </strong>Summary of <em>V<sub>P</sub></em> and <em>r</em> from the thermodynamic calculations based on representative rock compositions listed in Table 1. Mineral abbreviations: Pl = plagioclase, Spl = spinel, Grt = garnet, Ky = kyanite, Px = pyroxene, Cr-Di = Cr-diopisde, Am = amphibole, Phl = phlogopite.</p>
Data from: Nocturnal foraging lifts time-constraints in winter for migratory geese but hardly speeds up fueling
<p>Climate warming advances the optimal timing of breeding for many animals. For migrants to start breeding earlier, a concurrent advancement of migration is required, including pre-migratory fueling of energy reserves. We investigate whether barnacle geese are time-constrained during pre-migratory fueling and whether there is potential to advance or shorten the fueling period to allow an earlier migratory departure. We equipped barnacle geese with GPS-trackers and accelerometers to remotely record birds' behavior, from which we calculated time budgets. We examined how time spent foraging was affected by the available time (during daylight and moonlit nights) and thermoregulation costs. We used an energetic model to assess onset and rates of fueling, and whether geese can further advance fueling by extending foraging time. We show that d<span>uring winter, when facing higher thermoregulation costs, geese consistently foraged at night, especially during moonlit nights, in order to balance their energy budgets. In spring, birds made use of the increasing day length and gained body stores by foraging longer during the day, but birds stopped foraging extensively during the night. Our model indicates that by continuing night-time foraging throughout spring, geese may have some leeway to advance and increase fueling rate, potentially reaching departure body mass 4 days e</span>arlier. In light of rapid climatic changes on the breeding grounds, whether this advancement can be realized and whether it will be sufficient to prevent phenological mismatches remains to be determined.</p>
Data from: Evolutionary constraints on tree size and aboveground biomass in tropical dry forests
<p>1. The extent (or lack) of phylogenetic signal for key ecological traits reveals the role of evolutionary processes on present-day ecosystem function and hints on future ecological trends under climate change scenarios. This approach has been applied to South American tropical moist forests, but not to the highly threatened seasonally dry tropical forests (SDTF), despite acknowledgement of their unique evolutionary history. To fill this knowledge gap, we investigated the legacy of evolutionary processes on vital ecological characteristics among SDTF trees: regional dominance, tree size and soil preference.</p> <p>2. We used tree community data on 313 plots of SDTF (12.52 hectares) and locally collected soil data in central-eastern Brazil. For each assessed trait (three for regional dominance, three for tree size and nine for soil preference), we investigated the legacy of evolution using two different approaches: calculating the extent of phylogenetic signal and comparing the fit of four different models of evolution.</p> <p>3. Aboveground woody biomass and tree size showed strong phylogenetic signal. Most of the SDTF biomass stock was concentrated in a few large-sized and closely related tree genera. Among the soil preference variables, only phosphorus displayed significant, albeit weak, phylogenetic signal.</p> <p>4. Synthesis. Our study is the first to show that evolutionary constraints related to tree size significantly determine regional biomass stocks of SDTF in a few closely related tree lineages. This suggests that even isolated SDTF fragments with low taxonomic and phylogenetic diversity can play an important role in the global carbon cycle, storing disproportionally large amounts of carbon in trees that belong to high-biomass lineages. Whether these lineages also share climate change-induced mortality risk deserves future investigation, as they are largely responsible for the maintenance of regional SDTF biomass stocks.</p>
Data from: Developmental constraints and resource environment shape early emergence and investment in spines in saplings
Abstract <p> Background and Aims </p><p>Herbivory by large mammals imposes a critical recruitment bottleneck on plants in many systems. Spines defend plants against large herbivores and how early they emerge in saplings may be one of the strongest predictors of sapling survival in herbivore-rich environments. Yet little effort has been directed at understanding the variability in spine emergence across saplings.</p> Methods <p>We present a multi-species study examining whether and how sapling size,spine type and species' environmental niche (light and precipitation environment) influence early emergence and biomass investment in spines. A phylogenetically diverse pool of 45 species possessing different spine types (spines, prickles and thorns; that are derived from distinct plant organs: leaf, epidermis or cortex, and branch, respectively), were grown under common garden conditions, and patterns of spine emergence and biomass allocation to spines at 5 and 15 weeks after transplanting were characterized.</p> Key Results <p>Spine type and species' resource niche were the main factors driving early emergence and investment patterns. Spines emerged earliest in leaf spine-bearing species, and latest in thorn-bearing species. The probability of early spine emergence increased with decreasing precipitation, and was greater in species from open than closed habitats. Sapling investment in spines changed with plant mass but was contingent on spine type and habitat type.</p> Conclusions <p>Different spine types have strikingly different timing of expression, suggesting that developmental origins of spines play a critical role in sapling defences. Furthermore, species from different precipitation and light environments (open vs. closed habitats) showed contrasting patterns of early spine expression suggesting that resource limitation in their native range may have driven divergent evolution of early defence expression.</p> <p></p>
Data from: Evidence for complex life cycle constraints on salamander body form diversification
Metazoans display a tremendous diversity of developmental patterns, including complex life cycles composed of morphologically disparate stages. In this regard, the evolution of life cycle complexity promotes phenotypic diversity. However, correlations between life cycle stages can constrain the evolution of some structures and functions. Despite the potential macroevolutionary consequences, few studies have tested the impacts of life cycle evolution on broad-scale patterns of trait diversification. Here we show that larval and adult salamanders with a simple, aquatic-only (paedomorphic) life cycle had an increased rate of vertebral column and body form diversification compared to lineages with a complex, aquatic-terrestrial (biphasic) life cycle. These differences in life cycle complexity explain the variations in vertebral number and adult body form better than larval ecology. In addition, we found that lineages with a simple terrestrial-only (direct developing) life cycle also had a higher rate of adult body form evolution than biphasic lineages, but still 10-fold lower than aquatic-only lineages. Our analyses demonstrate that prominent shifts in phenotypic evolution can follow long-term transitions in life cycle complexity, which may reflect underlying stage-dependent constraints.
Data from: Disturbance-mediated consumer assemblages determine fish community structure and moderate top-down influences through bottom-up constraints
<ol> <li>Disturbance is a strong structuring force that can influence the strength of species interactions at all trophic levels, but controls on the contributions to community structure of top-down and bottom-up processes across such gradients remain poorly understood. Changes in the composition of predator and consumer assemblages, and their associated traits, across gradients of environmental harshness (e.g., flooding) are likely to be a particularly important influence on the strength of top-down control and may drive bottom-up constraints.</li> <li>We examined how consumers with particular traits, and the predators that consumed them, varied across a gradient of stream flooding disturbance and used experiments to assess the predation impact on those contrasting consumer communities (ultimately quantifying how flood disturbance altered the strength of top-down control).</li> <li>Consumer community composition and mobility were strongly related to flood disturbance; the biomass and drift of protected primary consumers (i.e., those with morphological defences) decreased with increasing flood disturbance. Predatory fish species had different disturbance niches, and path analysis identified that both direct flood-disturbance effects and indirect bottom-up constraints of flood-disturbance on consumers influenced predatory fish composition and biomass. Fishes generally fed most effectively on consumer types associated with their particular niche, but all fishes were strongly size-selective when feeding on protected consumers. Although protected consumers did not grow large enough to escape predation, an <i>in situ </i>experiment showed protected consumers were at a reduced risk of predation as disturbance increased compared to unprotected consumers.</li> <li>Overall, top-down control declined with flood disturbance, but the effect depended on consumer traits. Predatory fishes were only capable of exerting top-down control on protected consumers in benign habitats but impacted unprotected consumers across a larger range of the disturbance gradient. Collectively our findings suggest that a shift towards a more disturbed state will probably result in reduced predator impacts and a weakening of top-down control. Moreover, predicted increases in the frequency and intensity of climatic events causing disturbance, such as flooding, are likely to result in a community shift that disproportionately impacts protected consumers and the predators that utilise them as prey through the subsequent bottom-up constraints.</li> </ol>
Data from: Maternal oxidative stress and reproduction: testing the constraint, cost and shielding hypotheses in a wild mammal
1. Oxidative stress has been proposed as a central causal mechanism underlying the life history trade-off between current and future reproduction and survival in wild animals. 2. Whereas mixed evidence suggests that maternal oxidative stress may act both as a constraint and a cost to reproduction, some studies have reported a lack of association between reproduction and maternal oxidative stress. 3. The oxidative shielding hypothesis offers an alternative explanation, suggesting that mothers may pre-emptively mitigate the oxidative costs of reproduction by increasing antioxidant defences prior to reproduction. 4. We tested the oxidative constraint, cost, and shielding hypotheses using a longitudinal field study of oxidative stress levels in a species that breeds using daily energy income, the Columbian ground squirrel (Urocitellus columbianus). 5. Elevated maternal oxidative damage prior to reproduction was associated with higher maternal investment in litter mass at birth, but not at weaning. 6. Breeding females increased their antioxidant capacity and decreased their oxidative damage from birth to lactation compared to non-breeding females measured at the same time periods. However, lower maternal oxidative stress during lactation was not associated with higher offspring survival or mass growth over this period. 7. Our results provide little evidence for maternal oxidative stress acting as a constraint on, or cost to, reproduction in Columbian ground squirrels, but partially support the idea that oxidative shielding occurred to buffer potential oxidative costs of reproduction.
Data from: Local range boundaries versus large-scale tradeoffs: climatic and competitive constraints on tree growth
Species often respond to human‐caused climate change by shifting where they occur on the landscape. To anticipate these shifts, we need to understand the forces that determine where species currently occur. We tested whether a long‐hypothesised trade‐off between climate and competitive constraints explains where tree species grow on mountain slopes. Using tree rings, we reconstructed growth sensitivity to climate and competition in range centre and range margin tree populations in three climatically distinct regions. We found that climate often constrains growth at environmentally harsh elevational range boundaries, and that climatic and competitive constraints trade‐off at large spatial scales. However, there was less evidence that competition consistently constrained growth at benign elevational range boundaries; thus, local‐scale climate‐competition trade‐offs were infrequent. Our work underscores the difficulty of predicting local‐scale range dynamics, but suggests that the constraints on tree performance at a large‐scale (e.g. latitudinal) may be predicted from ecological theory.
Data from: Examining the microclimate hypothesis in Amazonian birds: indirect tests of the 'visual constraints' mechanism
Proposed mechanisms for the decline of terrestrial and understory insectivorous birds in the tropics include a related subset that together has been termed the "microclimate hypothesis." One prediction from this hypothesis is that sensitivity to bright light environments discourages birds of the dimly lit rainforest interior from using edges, gaps, or disturbed forest. Using a hierarchical Bayesian framework and capture data across time and space, we tested this by first determining vulnerability based on differences in within-species capture rates between disturbed and undisturbed forest for 64 bird species at the Biological Dynamics of Forest Fragments Project in central Amazonian Brazil. We found that 35 species (55%) were vulnerable to anthropogenic habitat degradation, whereas only four (6%) were more commonly captured in degraded forest. To infer visual sensitivity, we then examined two different characters: eye size (maximum pupil diameter) relative to body mass and the initiation time of dawn song, which presumably reflects a species' visual capacity under low light intensities. We predicted that species with large relative eye sizes and birds with earlier dawn songs would exhibit increased vulnerability in degraded habitats with bright light. Contrary to our predictions, however, vulnerability was positively correlated with the mean start time of dawn song. This indicates that species that wait to initiate dawn song are also more vulnerable to habitat degradation. After correcting for body size, there was no effect of eye size on vulnerability. Together, our results do not provide quantitative support for the light sensitivity mechanism of the microclimate hypothesis. More sensitive, experimental tests, such as behavioral assays with controlled light environments, especially in a comparative framework, are needed to rigorously evaluate the role of light sensitivity as an aspect of the microclimate hypothesis among Neotropical birds.
Data from: Fertilizer legacies meet saltwater incursion: challenges and constraints for coastal plain wetland restoration
Coastal wetland restoration is an important tool for climate change adaptation and excess nutrient runoff mitigation. However, the capacity of restored coastal wetlands to provide multiple ecosystem services is limited by stressors, such as excess nutrients from upstream agricultural fields, high nutrient legacies on-site, and rising salinities downstream. The effects of these stressors are exacerbated by an accelerating hydrologic cycle, expected to cause longer droughts punctuated by more severe storms. We used seven years of surface water and six years of soil solution water chemistry from a large (440 ha) restored wetland to examine how fertilizer legacy, changes in hydrology, and drought-induced salinization affect dissolved nutrient and carbon concentrations. To better understand the recovery trajectory of the restored wetland, we also sampled an active agricultural field and two mature forested wetlands. Our results show that nitrogen (N) and phosphorus (P) concentrations in soil solution were 2–10 times higher in the restored wetland compared to two mature forested wetlands, presumably due to legacy fertilizer mobilized by reflooding. Despite elevated nutrient concentrations relative to reference wetlands, the restored wetland consistently attenuated N and P pulses delivered from an upstream farm. Even with continued loading, N and P concentrations in surface water throughout the restored wetland have decreased since the initial flooding. Our results suggest that high nutrient concentrations and export from wetlands restored on agricultural lands may be a severe but temporary problem. If field to wetland conversion is to become a more widespread method for ameliorating nutrient runoff and adapting coastal plain ecosystems to climate change, we should adopt new methods for minimizing the initial export phase of wetland restoration efforts.
Supporting data: Structure-based Markov random field model for representing evolutionary constraints on functional sites
<p>Supporting data for the paper:</p> <p>Chan-Seok Jeong, Dongsup Kim. Structure-based Markov random field model for representing evolutionary constraints on functional sites. Submitted. (2015)</p> <p>See 'README' for a description of the contents.</p>
Supplementary materials for "Putting the F into FBD analysis: tree constraints or morphological data ?"
<p>This dataset contains the R code, simulated datasets and configuration files used to run the analyses presented in the manuscript "Putting the F into FBD analysis: tree constraints or morphological data ?".</p>
Data from: Sea-surface temperature pattern effects have slowed global warming and biased warming-based constraints on climate sensitivity
<p>The observed rate of global warming since the 1970s has been proposed as a strong constraint on equilibrium climate sensitivity (ECS) and transient climate response (TCR) – key metrics of the global climate response to greenhouse-gas forcing. Using CMIP5/6 models, we show that the inter-model relationship between warming and these climate sensitivity metrics (the basis for the constraint) arises from a similarity in transient and equilibrium warming patterns within the models, producing an effective climate sensitivity (EffCS) governing recent warming that is comparable to the value of ECS governing long-term warming under CO<sub>2</sub> forcing. However, CMIP5/6 historical simulations do not reproduce observed warming patterns. When driven by observed patterns, even high ECS models produce low EffCS values consistent with the observed global warming rate. The inability of CMIP5/6 models to reproduce observed warming patterns thus results in a bias in the modeled relationship between recent global warming and climate sensitivity. Correcting for this bias means that observed warming is consistent with wide ranges of ECS and TCR extending to higher values than previously recognized. These findings are corroborated by energy balance model simulations and coupled model (CESM1-CAM5) simulations that better replicate observed patterns via tropospheric wind nudging or Antarctic meltwater fluxes. Because CMIP5/6 models fail to simulate observed warming patterns, proposed warming-based constraints on ECS, TCR, and projected global warming are biased low. The results reinforce recent findings that the unique pattern of observed warming has slowed global-mean warming over recent decades, and that how the pattern will evolve in the future represents a major source of uncertainty in climate projections.</p>
Data for: Inversion for Inferring Solar Meridional Circulation: The Case with Constraints on Angular Momentum Transport inside the Sun
<p>Solar meridional circulation profiles inferred by Hatta, Hotta, and Sekii (2024) ("Inversion for Inferring Solar Meridional Circulation: The Case with Constraints on Angular Momentum Transport inside the Sun"). Detailed information about the dataset can be found in a Readme pdf file. </p>
Calibrated and uncalibrated projection data from the paper "Assessing observational constraints on future European climate in an out-of-sample framework"
<p>Individual uncalibrated and calibrated projections for each of the five methods (A-E) in the following folders:</p> <p>MethodA_proj/</p> <p>MethodB_proj/</p> <p>MethodC_proj/</p> <p>MethodD_proj/</p> <p>MethodE_proj/</p> <p> </p> <p>Also included are the out-of-sample data from the "pseudo-observations" (taken from CMIP6 models) used for the verification (see paper for full details):</p> <p>FUTUREverif/</p>
Data and Code for "A Novel Emergent Constraint Approach for Refining Regional Climate Model Projections of Flood Timing" Paper Submission to AGU GRL
<p>This contains the emergent constraint code, the offline CMIP6 hydrology data, and the shapefiles for each region used in the paper "A Novel Emergent Constraint Approach for Refining Regional Climate Model Projections of Flood Timing" submitted to AGU GRL.</p>
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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.