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.
655
datasets available to search
ShareScore release 0.9.0
Dataset results
655 results for “constrain”
Data from: Coarse dark patterning functionally constrains adaptive shifts from aposematism to crypsis in strawberry poison frogs
Ecological specialization often requires tight co-evolution of several traits, which may constrain future evolutionary pathways and make species more prone to extinction. Aposematism and crypsis represent two specialized adaptations to avoid predation. We tested whether the combined effects of color and pattern on prey conspicuousness functionally constrain or facilitate shifts between these two adaptations. We combined data from 17 natural populations of Strawberry poison frogs, Oophaga pumilio with an experimental approach using digitalized images of frogs and chickens as predators. We show that bright coloration often co-occurs with coarse patterning among the natural populations. Dull green frogs with coarse patterning are rare in nature but in the experiment they were as easily detected as bright red frogs suggesting that this trait combination represent a transient evolutionary state towards aposematism. Hence, a gain of either bright color or coarse patterning leads to conspicuousness but a transition back to crypsis would be functionally constrained in populations with both bright color and coarse patterning by requiring simultaneous changes in two traits. Thus, populations (or species) signaling aposematism by conspicuous color should be less likely to face an evolutionary dead-end and more likely to radiate than populations with both conspicuous color and coarse patterning.
Data from: Limited oxygen availability in utero may constrain the evolution of live-birth in reptiles
Although viviparity (live birth) has evolved from oviparity (egg laying) at least 140 times in vertebrates, nearly 120 of these independent events occurred within a single reptile taxon. Surprisingly, only squamate reptiles (lizards and snakes) are capable of facilitating embryonic development to increasingly advanced stages inside the mother during extended periods of oviducal egg retention. Viviparity has never evolved in turtle lineages, presumably because embryos enter and remain in an arrested state until after eggs are laid, regardless of the duration of egg retention. Until now, the limiting factor that initiates and maintains developmental arrest has remained elusive. Here, we show that oviducal hypoxia arrests embryonic development. We demonstrate that hypoxia can maintain developmental arrest after oviposition and that subsequent exposure of arrested embryos to normoxia triggers resumption of their development. We discovered remarkably low oxygen partial pressure in the oviducts of gravid turtles and found that secretions produced by the oviduct retard oxygen diffusion. Our results suggest that an extremely hypoxic environment in the oviduct arrests embryonic development and may constrain the evolution of viviparity in turtles, with the reduced diffusive capacity of oviducal secretions possibly creating or contributing to this hypoxia. We anticipate that these findings will allow us to better understand the mechanisms underlying the evolutionary transition between reproductive modes.
Data from: Too constrained to converse: the effect of financial constraints on word-of-mouth
Existing research demonstrates that financial constraints are widespread and influence consumer attention, preference, choice, and consumption in a variety of ways. Despite the growing knowledge of how financial constraints affect the consumer decision making process, less is known about its impact on post-purchase behavior. This work examines whether financial constraints impact an important post-purchase behavior—word-of-mouth—and in what direction. Seven studies show that financial constraints reduce purchase-related word-of-mouth. This effect emerges across consumers' reported frequencies of discussing their purchases with friends and family, as well as their intentions, desires, and real decisions to engage in online word-of-mouth. This effect is explained by reduced anticipated pleasure of engaging in purchase-related word-of-mouth, which results from financially constrained consumers' belief that rehearsing their monetary expenditures will reinforce negative feelings about their limited financial situation. This effect cannot be similarly explained by other accounts such as impression management or the desire to hoard informational resources. Further, the authors show that the reduction in anticipated pleasure from word-of-mouth is specific to sharing about one's monetary expenditures. Thus, financial constraints reduce purchase-related word-of-mouth, but they do not universally decrease one's propensity to share.
Data from: Logical validation and evaluation of practical feasibility for the SCRuM (School Clinical Rugby Measure) test battery developed for young adolescent rugby players in a resource-constrained environment
There is a growing impetus towards usage of test batteries in talent identification (TID) programmes in rugby. Consequently, there are many test batteries in existence profiling anthropometric, physiological characteristics and rugby-specific skills. There is no consensus in the literature on the constituent variables and corresponding tests required to inform TID programs. Following development of a new test battery called the SCRuM (School Clinical Rugby Measure), this study aimed at establishing face, logical validity and practical feasibility of included tests. The test battery, initially comprised of 23 items, had its face and logical validity evaluated by five (5) adolescent rugby coaches and 20 rugby experts, respectively. Logical validation was conducted in two questionnaire-based rounds with Content Validity Index (I-CVI) calculated for each variable. Subsequently, a cross-sectional study targeting 30 local rugby coaches was conducted to determine the perceived practical feasibility of each test item. The results showed excellent I-CVI (>0.78) for 17 variables (speed, weight, height and skin fold measures, repeated high-intensity exercise performance ability, prolonged high-intensity intermittent running ability, change of direction speed, anaerobic capacity, lower-and upper body muscular power and strength, muscular flexibility, reactive agility, passing for accuracy, tackling proficiency, and catching). However, three tests, namely, Reactive Agility, One Repetition Maximum Back Squat and One Repetition Maximum Bench Press had low test-feasibility indices (T-FI< 35) suggesting practicality concerns with implementation in the Zimbabwean context. Thus, these findings suggest the need for substitution or development of new practically feasible tests for upper-and lower body muscular strength and reactive agility.
Data from: Rate of evolutionary change in cranial morphology of the marsupial genus Monodelphis is constrained by the availability of additive genetic variation
We tested the hypothesis that the rate of marsupial cranial evolution is dependent on the distribution of genetic variation in multivariate space. To do so, we carried out a genetic analysis of cranial morphological variation in laboratory strains of Monodelphis domestica and used estimates of genetic covariation to analyze the morphological diversification of the Monodelphis brevicaudata species group. We found that within-species genetic variation is concentrated in only a few axes of the morphospace and that this strong genetic covariation influenced the rate of morphological diversification of the brevicaudata group, with between-species divergence occurring fastest when occurring along the genetic line of least resistance. Accounting for the geometric distribution of genetic variation also increased our ability to detect the selective regimen underlying species diversification, with several instances of selection only being detected when genetic covariances were taken into account. Therefore, this work directly links patterns of genetic covariation among traits to macroevolutionary patterns of morphological divergence. Our findings also suggest that the limited distribution of Monodelphis species in morphospace is the result of a complex interplay between the limited dimensionality of available genetic variation and strong stabilizing selection along two major axes of genetic variation.
Data from: Food limitation constrains host immune responses to nematode infections
Trade-offs in the allocation of finite-energy resources among immunological defences and other physiological processes are believed to influence infection risk and disease severity in food-limited wildlife populations. However, this prediction has received little experimental investigation. Here we test the hypothesis that food limitation impairs the ability of wild field voles (Microtus agrestis) to mount an immune response against parasite infections. We conducted a replicated experiment on vole populations maintained in large outdoor enclosures during boreal winter, using food supplementation and anthelmintic treatment of intestinal nematodes. Innate immune responses against intestinal parasite infections were compared between food-supplemented and non-supplemented voles. Voles with high food availability mounted stronger immune responses against intestinal nematode infections than food-limited voles. No food effects were seen in immune responses to intracellular coccidian parasites, possibly owing to their ability to avoid activation of innate immune pathways. Our findings demonstrate that food availability constrains vole immune responses against nematode infections, and support the concept that spatio-temporal heterogeneity in food availability creates variation in infectious disease susceptibility.
Data from: The evolution of novel host use is unlikely to be constrained by tradeoffs or a lack of genetic variation
The genetic and ecological factors that shape the evolution of animal diets remain poorly understood. For herbivorous insects, the expectation has been that trade-offs exist, such that adaptation to one host plant reduces performance on other potential hosts. We investigated the genetic architecture of alternative host use by rearing individual Lycaeides melissa butterflies from two wild populations in a crossed design on two hosts (one native and one introduced) and analysing the genetic basis of differences in performance using genomic approaches. Survival during the experiment was highest when butterfly larvae were reared on their natal host plant, consistent with local adaptation. However, cross-host correlations in performance among families (within populations) were not different from zero. We found that L. melissa populations possess genetic variation for larval performance and variation in performance had a polygenic basis. We documented very few genetic variants with trade-offs that would inherently constrain diet breadth by preventing the optimization of performance across hosts. Instead, most genetic variants that affected performance on one host had little to no effect on the other host. In total, these results suggest that genetic trade-offs are not the primary cause of dietary specialization in L. melissa butterflies.
Niche partitioning within a population of seasnakes is constrained by ambient thermal homogeneity and small prey size
<p>In many populations of terrestrial snakes, an individual's phenotype (e.g. body size, sex, colour) affects its habitat use. One cause for that link is gape-limitation, which can result in larger snakes eating prey that are found in different habitats. A second factor involves thermoregulatory opportunities, whereby individuals select habitats based upon thermal conditions. These ideas predict minimal intraspecific variation in habitat use in a species that eats small prey and lives in a thermally uniform habitat – such as the seasnake <i>Emydocephalus annulatus</i>, that feeds on tiny fish eggs and lives in inshore coral-reefs. To test that prediction, we gathered data on water depths and substrate attributes for 1475 sightings of 128 free-ranging <i>E. annulatus</i> in a bay near Noumea, New Caledonia. Habitat selection varied among individuals, but with a preference for coral-dominated substrates. A snake's body size and reproductive state affected its detectability in deep water, but overall habitat use was not linked to snake body size, colour morph, sex, or pregnancy. A lack of ontogenetic shifts in habitat use allows extreme philopatry in <i>E. annulatus</i>, thereby reducing gene flow among populations and potentially, delaying recolonization after local extirpation events.</p>
Data from: The tree balance signature of mass extinction is erased by continued evolution in clades of constrained size with trait-dependent speciation
The kind and duration of phylogenetic topological "signatures" left in the wake of macroevolutionary events remain poorly understood. To this end, we examined a broad range of simulated phylogenies generated using trait-biased, heritable speciation probabilities and mass extinction that could be either random or selective on trait value, but also using background extinction and diversity-dependence to constrain clade sizes. In keeping with prior results, random mass extinction increased imbalance of clades that recovered to pre-extinction size, but was a relatively weak effect. Mass extinction that was selective on trait values tended to produce clades of similar or greater balance compared to random extinction or controls. Allowing evolution to continue past the point of clade-size recovery resulted in erosion and eventual erasure of this signal, with all treatments converging on similar values of imbalance, except for very intense extinction regimes targeted at taxa with high speciation rates. Return to a more balanced state with extended post-extinction evolution was also associated with loss of the previous phylogenetic root in most treatments. These results further demonstrate that while a mass extinction event can produce a recognizable phylogenetic signal, its effects become increasingly obscured the further an evolving clade gets from that event, with any sharp imbalance due to unrelated evolutionary factors.
Data from: Constraining the role of early land plants in Early Palaeozoic weathering and global cooling
How the colonization of terrestrial environments by early land plants over 400 Ma influenced rock weathering, the biogeochemical cycling of carbon and phosphorus, and climate in the Palaeozoic is uncertain. Here we show experimentally that mineral weathering by liverworts—an extant lineage of early land plants—partnering arbuscular mycorrhizal (AM) fungi, like those in 410 Ma-old early land plant fossils, amplified calcium weathering from basalt grains threefold to sevenfold, relative to plant-free controls. Phosphate weathering by mycorrhizal liverworts was amplified 9–13-fold over plant-free controls, compared with fivefold to sevenfold amplification by liverworts lacking fungal symbionts. Etching and trenching of phyllosilicate minerals increased with AM fungal network size and atmospheric CO2 concentration. Integration of grain-scale weathering rates over the depths of liverwort rhizoids and mycelia (0.1 m), or tree roots and mycelia (0.75 m), indicate early land plants with shallow anchorage systems were probably at least 10-fold less effective at enhancing the total weathering flux than later-evolving trees. This work challenges the suggestion that early land plants significantly enhanced total weathering and land-to-ocean fluxes of calcium and phosphorus, which have been proposed as a trigger for transient dramatic atmospheric CO2 sequestration and glaciations in the Ordovician.
Data from: Synergism and antagonism of proximate mechanisms enable and constrain the response to simultaneous selection on body size and development time: an empirical test using experimental evolution
Natural selection acts on multiple traits simultaneously. How mechanisms underlying such traits enable or constrain their response to simultaneous selection is poorly understood. We show how antagonism and synergism among three traits at the developmental level enable or constrain evolutionary change in response to simultaneous selection on two focal traits at the phenotypic level. After 10 generations of 25% simultaneous directional selection on all four combinations of body size and development time in Manduca sexta (Sphingidae), the changes in the three developmental traits predict 93% of the response of development time and 100% of the response of body size. When the two focal traits were under synergistic selection, the response to simultaneous selection was enabled by juvenile hormone and ecdysteroids and constrained by growth rate. When the two focal traits were under antagonistic selection, the response to selection was due primarily to change in growth rate and constrained by the two hormonal traits. The approach used here reduces the complexity of the developmental and endocrine mechanisms to three proxy traits. This generates explicit predictions for the evolutionary response to selection that are based on biologically informed mechanisms. This approach has broad applicability to a diverse range of taxa, including algae, plants, amphibians, mammals, and insects.
Data from: A well-constrained estimate for the timing of the salmonid whole genome duplication reveals major decoupling from species diversification
Whole genome duplication (WGD) is often considered to be mechanistically associated with species diversification. Such ideas have been anecdotally attached to a WGD at the stem of the salmonid fish family, but remain untested. Here, we characterized an extensive set of gene paralogues retained from the salmonid WGD, in species covering the major lineages (subfamilies Salmoninae, Thymallinae and Coregoninae). By combining the data in calibrated relaxed molecular clock analyses, we provide the first well-constrained and direct estimate for the timing of the salmonid WGD. Our results suggest that the event occurred no later in time than 88 Ma and that 40–50 Myr passed subsequently until the subfamilies diverged. We also recovered a Thymallinae–Coregoninae sister relationship with maximal support. Comparative phylogenetic tests demonstrated that salmonid diversification patterns are closely allied in time with the continuous climatic cooling that followed the Eocene–Oligocene transition, with the highest diversification rates coinciding with recent ice ages. Further tests revealed considerably higher speciation rates in lineages that evolved anadromy—the physiological capacity to migrate between fresh and seawater—than in sister groups that retained the ancestral state of freshwater residency. Anadromy, which probably evolved in response to climatic cooling, is an established catalyst of genetic isolation, particularly during environmental perturbations (for example, glaciation cycles). We thus conclude that climate-linked ecophysiological factors, rather than WGD, were the primary drivers of salmonid diversification.
Data from: A question of time: the land snail Murella muralis (Gastropoda: Pulmonata) reveals constrains to past ecological speciation
The lively debate about speciation currently focuses on the relative importance of factors driving population differentiation. While many studies are increasingly producing results on the importance of selection, little is known about the interaction between drift and selection. Moreover there is still little knowledge on the spatial-temporal scales at which speciation occurs, i.e. arrangement of habitat patches, abruptness of habitat transitions, climate and habitat changes interacting with selective forces. To investigate these questions, we quantified variation on a fine geographical scale analysing morphological (shell) and genetic datasets coupled with environmental data in the land snail Murella muralis, endemic to the Mediterranean island of Sicily. Analysis of a fragment of the mitochondrial DNA Cytochrome Oxidase I gene (COI) and eight nuclear microsatellite loci showed that genetic variation is highly structured at a very fine spatial scale by local palaeogeographical events and historical population dynamics. Molecular clock estimates, calibrated here specifically for Tyrrhenian land snails, provided a framework of palaeogeographical events responsible for the observed geographical variations and migration routes. Finally, we showed for the first time well documented lines of evidences of selection in the past, which explains divergence of land snail shell shapes. We suggest that time and palaeogeographical history acted as constraints in the progress along the ecological speciation continuum. Our study shows that testing for correlation among palaeogeography, morphology and genetic data on a fine geographical scale provides information fundamental for a detailed understanding of ecological speciation processes.
Data from: Genetic regulatory network motifs constrain adaptation through curvature in the landscape of mutational (co)variance
Systems biology is accumulating a wealth of understanding about the structure of genetic regulatory networks, leading to a more complete picture of the complex genotype-phenotype relationship. However, models of multivariate phenotypic evolution based on quantitative genetics have largely not incorporated a network-based view of genetic variation. Here we model a set of two-node, two-phenotype genetic network motifs, covering a full range of regulatory interactions. We find that network interactions result in different patterns of mutational (co)variance at the phenotypic level (the M-matrix), not only across network motifs but also across phenotypic space within single motifs. This effect is due almost entirely to mutational input of additive genetic (co)variance. Variation in M has the effect of stretching and bending phenotypic space with respect to evolvability, analogous to the curvature of space-time under general relativity, and similar mathematical tools may apply in each case. We explored the consequences of curvature in mutational variation by simulating adaptation under divergent selection with gene flow. Both standing genetic variation (the G-matrix) and rate of adaptation are constrained by M, so that G and adaptive trajectories are curved across phenotypic space. Under weak selection the phenotypic mean at migration-selection balance also depends on M.
Data from: Constrained evolution of the sex comb in Drosophila simulans
Male fitness is dependent on sexual traits that influence mate acquisition (pre-copulatory sexual selection) and paternity (post-copulatory sexual selection), and while many studies have documented the form of selection in one or the other of these arenas, fewer have done it for both. Nonetheless, it appears that the dominant form of sexual selection is directional, although theoretically, populations should converge on peaks in the fitness surface, where selection is stabilizing. Many factors, however, can prevent populations from reaching adaptive peaks. Genetic constraints can be important if they prevent the development of highest fitness phenotypes, as can the direction of selection if it reverses across episodes of selection. In this study, we examine the evidence that these processes influence the evolution of the multivariate sex comb morphology of male Drosophila simulans. To do this, we conduct a quantitative genetic study together with a multivariate selection analysis to infer how the genetic architecture and selection interact. We find abundant genetic variance and covariance in elements of the sex comb. However, there was little evidence for directional selection in either arena. Significant nonlinear selection was detected prior to copulation when males were mated to non-virgin females, and post-copulation during sperm offence (again with males mated to non-virgins). Thus contrary to our predictions, the evolution of the D. simulans sex comb is limited neither by genetic constraints nor by antagonistic selection between pre- and post-copulatory arenas, but nonlinear selection on the multivariate phenotype may prevent sex combs from evolving to reach some fitness maximising optima.
Data from: Spatial distribution of nests constrains the strength of sexual selection in a warbler
In socially monogamous species, extra-pair paternity may increase the strength of inter-sexual selection by allowing males with preferred phenotypes to monopolize matings. Several studies have found relationships between male signals and extra-pair mating, but many others fail to explain variation in extra-pair mating success. A greater appreciation for the role that ecological contingencies play in structuring behavioral processes may help to reconcile contradictory results. We studied extra-pair mating in a spatial context in the common yellowthroat (Geothlypis trichas), a territorial wood warbler. Over the course of six years, we observed 158 breeding attempts by 99 males, resulting in a total of 369 nests and 520 sampled nestlings. The spatial distribution of territories varied greatly, with males having between 0 and 10 close neighbors and between 3 and 39 neighboring nestlings close enough to represent extra-pair siring opportunities. Both within-pair and extra-pair reproductive success increased with breeding density, but the opportunity for sexual selection and strength of selection varied with density. Total variance in reproductive success was highest at low density and was mostly explained by variation in within-pair success. In contrast, at high density, both within-pair and extra-pair success contributed substantially to variance in reproductive success. The relationships between plumage and extra-pair mating also varied by density; plumage was under strong sexual selection via extra-pair mating success at high density but no selection was detected at low density. Thus, ecological factors that structure social interactions can drive patterns of sexual selection by facilitating or constraining the expression of mating preferences.
Data from: Complexity increases predictability in allometrically constrained food webs
All ecosystems are subjected to chronic disturbances, such as harvest, pollution, and climate change. The capacity to forecast how species respond to such press perturbations is limited by our imprecise knowledge of pairwise species interaction strengths and the many direct and indirect pathways along which perturbations can propagate between species. Network complexity (size and connectance) has thereby been seen to limit the predictability of ecological systems. Here we demonstrate a counteracting mechanism in which the influence of indirect effects declines with increasing network complexity when species interactions are governed by universal allometric constraints. With these constraints, network size and connectance interact to produce a skewed distribution of interaction strengths whose skew becomes more pronounced with increasing complexity. Together, the increased prevalence of weak interactions and the increased relative strength and rarity of strong interactions in complex networks limit disturbance propagation and preserve the qualitative predictability of net effects even when pairwise interaction strengths exhibit substantial variation or uncertainty.
Data from: The path to re-evolve cooperation is constrained in Pseudomonas aeruginosa
Background. A common form of cooperation in bacteria is based on the secretion of beneficial metabolites, shareable as public good among cells within a group. Because cooperation can be exploited by "cheating" mutants, which contribute less or nothing to the public good, there has been great interest in understanding the conditions required for cooperation to remain evolutionarily stable. In contrast, much less is known about whether cheats, once fixed in the population, are able to revert back to cooperation when conditions change. Here, we tackle this question by subjecting experimentally evolved cheats of Pseudomonas aeruginosa, partly deficient for the production of the iron-scavenging public good pyoverdine, to conditions previously shown to favor cooperation. Results. Following approximately 200 generations of experimental evolution, we screened 720 evolved clones for changes in their pyoverdine production levels. We found no evidence for the re-evolution of full cooperation, even in environments with increased spatial structure, and reduced costs of public good production - two conditions that have previously been shown to maintain cooperation. In contrast, we observed selection for complete abolishment of pyoverdine production. The patterns of complete trait degradation were likely driven by "cheating on cheats" in unstructured, iron-limited environments where pyoverdine is important for growth, and selection against a maladaptive trait in iron-rich environments where pyoverdine is superfluous. Conclusions. Our study shows that the path to re-evolve public-goods cooperation can be constrained. While a limitation of the number of mutational targets potentially leading to reversion might be one reason for the observed pattern, an alternative explanation is that the selective conditions required for revertants to spread from rare are much more stringent than those needed to maintain cooperation.
Constrained shortest path instance dataset
<p>The dataset used in the experimental evaluation in the paper "Paths, Proofs, and Perfection: Developing a Human-Interpretable Proof System for Constrained Shortest Paths" submitted to AAAI-24.</p>
Supplement to: Absolute age and temperature of belemnite rostra: constrains on the Early Cretaceous cooling event.
Open the record for dataset details and reuse information.
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.