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.
1,819
datasets available to search
ShareScore release 0.9.0
Dataset results
1,819 results for “Experimental data”
Data from: Experimental evidence for fundamental, and not realised, niche partitioning in a plant-herbivore community interaction network
Patterns of niche partitioning can result from local ecological interactions (e.g. interspecific competition) occurring within a contemporary time frame (realised niche partitioning). Alternatively they may represent the end-product of historical processes acting over long time frames (fundamental niche partitioning). Niche partitioning is often detected by analysing patterns of resource use within communities, but experiments are rarely conducted to test whether patterns of non-overlapping resource use reflect realised or fundamental niche partitioning. We studied a community of restio leafhoppers from the genus Cephalelus, and their host plants, the Restionaceae (restios). We used network and experimental approaches to determine whether network modularity (a measure of niche partitioning within local communities) reflects fundamental or realised niche partitioning. Using a weighted modularity index for two party networks (e.g. insect - plant) we determined whether the network of this community is modular (i.e. consists of groups of species interacting strongly, with weak interactions between groups). We also aimed to identify specific Cephalelus - restio modules (groups). Using knowledge of module membership to design experiments, we tested whether Cephalelus species from two different modules, C. uncinatus and C. pickeri, prefer and perform better on restios from their own modules versus restios from other modules. These experiments were performed under controlled conditions, eliminating the influences of competition and predation on host choices. The Cephalelus – restio community was modular, implying niche partitioning. Cephalelus also preferred and performed better on restios from their own modules in the absence of local contemporary factors. Most niche partitioning in the investigated Cephalelus community, is not caused by local interactions, and thus host use patterns represent fundamental niches. Our findings highlight the importance of understanding local community structure in the light of processes extrinsic to the local community context.
Data from: Experimental brood enlargement differentially influences the magnitude of the corticosterone stress response in closely related, co‐occurring songbirds
1. Rearing environments can shape offspring phenotype across taxa, yet little is known about how brood size influences hypothalamic-pituitary axis functioning, whether its expression trades off with growth, and the degree to which these relationships vary between species. 2. We evaluated how brood size influenced nestling physiological (glucocorticoids) and somatic traits (growth), and the extent to which these relationships differed between two closely related, sympatric songbirds when experiencing identical rearing environments. Specifically, we used a cross-fostering approach to alter brood size and create an experimental gradient of nestmate competition, and then tested whether experimentally manipulated brood sizes resulted in nestlings with altered concentrations of corticosterone and if corticosterone responses traded off with growth. 3. Nestlings of both species experienced elevated concentrations of baseline and stressor-induced corticosterone when raised in enlarged broods, relative to control and reduced broods, but neither measurement was found to trade off with growth or be linked to survival to fledging. 4. In contrast, we found divergence in the magnitude of the corticosterone stress response between species across all brood treatments, with greater stressor-induced corticosterone concentrations found in the Violet-green Swallow (Tachycineta thalassina) relative to the closely related Tree Swallow (T. bicolor). 5. Our study demonstrated that brood size can lead to changes in offspring corticosterone concentrations in swallows, and that nestlings of sympatric species, even those that are closely related and ecologically similar, can diverge in their corticosterone stress response when experiencing identical rearing conditions. 6. We conclude that corticosterone appears to play a key role for balancing energetic demands that arise in the face of nestmate competition in Tachycineta swallows, and that elevated concentrations of corticosterone may enhance offspring survival during challenging environmental conditions, such as when brood competition is strong.
Data from: Experimental manipulation reveals a trade-off between weapons and testes
Theory predicts a trade-off between sexually-selected weapons used to secure mates and post-copulatory traits used to maximize fertilization success. However, individuals that have a greater capacity to acquire resources from the environment may invest more in both pre- and post-copulatory traits, and trade-offs may not be readily apparent. Here, we manipulate the phenotype of developing individuals to examine allocation trade-offs between weapons and testes in Mictis profana (Hemiptera: Coreidae), a species where the hind legs are sexually selected weapons used in contests over access to females. We experimentally prevented males from developing weapons by inducing them to autotomize their hind legs before the final molt to adulthood. We compared trait expression in this group to males where autotomy was induced in the mid legs, which are presumably not under sexual selection to the same extent. We found males without weapons invested proportionally more in testes mass than those with their mid legs removed. Males that developed to adulthood without weapons did not differ from the mid leg removal group in other traits potentially under pre-copulatory sexual selection, other post-copulatory traits, or naturally selected traits. In addition, a sample of adult males from the same population in the wild revealed a positive correlation between investment in testes and weapons. Our study presents a critical contribution to a growing body of literature suggesting the allocation of resources to pre- and post-copulatory sexual traits is influenced by a resource allocation trade-off and that this trade-off may only be revealed with experimental manipulation.
Data from: Experimental defaunation of terrestrial mammalian herbivores alters tropical rain forest understory diversity
It has been suggested that tropical defaunation may unleash community-wide cascading effects, leading to reductions in plant diversity. However, experimental evidence establishing cause–effect relationships thereof is poor. Through a 5 year exclosure experiment, we tested the hypothesis that mammalian defaunation affects tree seedling/sapling community dynamics leading to reductions in understorey plant diversity. We established plot triplets (n = 25) representing three defaunation contexts: terrestrial-mammal exclosure (TE), medium/large mammal exclosure (PE) and open access controls (C). Seedlings/saplings 30–100 cm tall were marked and identified within each of these plots and re-censused three times to record survival and recruitment. In the periods 2010–2011 and 2011–2013, survival was greater in PE than in C plots and recruitment was higher in TE plots than in C plots. Overall, seedling density increased by 61% in TE plots and 23% in PE plots, whereas it decreased by 5% in C plots. Common species highly consumed by mammals (e.g. Brosimum alicastrum and Ampelocera hottlei) increased in their abundance in TE plots. Rarefaction curves showed that species diversity decreased in TE plots from 2008 to 2013, whereas it remained similar for C plots. Given the prevalence of tropical defaunation, we posit this is an anthropogenic effect threatening the maintenance of tropical forest diversity.
Data from: Exposure to predators does not lead to the evolution of larger brains in experimental populations of threespine stickleback
Natural selection is often invoked to explain differences in brain size among vertebrates. However, the particular agents of selection that shape brain size variation remain obscure. Recent studies suggest that predators may select for larger brains because increased cognitive and sensory abilities allow prey to better elude predators. Yet, there is little direct evidence that exposure to predators causes the evolution of larger brains in prey species. We experimentally tested this prediction by exposing families of 1000-2000 F2 hybrid benthic-limnetic threespine stickleback to predators under naturalistic conditions, along with matched controls. After two generations of selection, we found that fish from the predator addition treatment had significantly smaller brains (specifically smaller telencephalons and optic lobes) than fish from the control treatment. After an additional generation of selection, we reared experimental fish in a common environment and found that this difference in brain size was maintained in the offspring of fish from the predator addition treatment. Our results provide direct experimental evidence that (a) predators can indeed drive the evolution of brain size – but not in the fashion commonly expected and (b) that the tools of experimental evolution can be used to the study the evolution of the vertebrate brain.
Data from: Experimental manipulation suggests effect of polyandry but not mate familiarity on within-pair aggression in the social skink, Liopholis whitii
Long-term monogamy is a key characteristic of family living across animals. The evolutionary maintenance of long-term monogamy has been suggested to be facilitated by increased reproductive coordination as a result of mate familiarity, leading to increased reproductive success. However, such effects can be compromised if females mate outside the pair bond (e.g. female polyandry), introducing conflicts of interest between the male and female. Here, we experimentally test the effects of both mate familiarity and female polyandry on agonistic behaviour and reproduction in a family living lizard, Liopholis whitii. We found that mate familiarity did not decrease the level of aggression between pairs whereas reducing female polyandry did. However, we did not find an effect of either mate familiarity or female polyandry on female reproductive output. These results suggest that male behavioural responses to female polyandry may influence pair stability in Liopholis whitii, providing support for the growing appreciation of the multiple ways in which female polyandry can influence the stability of family living.
Data from: Experimental rewilding enhances grassland functional composition and pollinator habitat use
1. Semi-natural grasslands are rich in biodiversity and thus important habitats for conservation, yet subjected to rapid declines due to agricultural intensification or abandonment. Promoting a more diverse mammalian herbivore community, including large and megaherbivores, may result in positive cascade effects for biodiversity and ecosystem functioning. Therefore, reintroducing an ecologically functional substitute of an extinct large herbivore could mitigate current biodiversity declines and foster semi-natural grassland conservation. 2. To test this hypothesis, we set up a 3-year rewilding experiment where 12 feral horses were introduced in three 10-hectare enclosure replicates (four horses per enclosure). We used community-weighted mean plant functional traits to elucidate plant community changes induced by grazing through time. We additionally investigated the effects of the experimental treatment on insect pollinated plants and on pollinator habitat use. 3. The grassland community exerted a mixed tolerance/avoidance response to grazing. This resulted in plant functional compositional changes which favoured prostrate plant species with higher specific leaf area, characteristic of ruderal communities. 4. Plant species richness was higher in grazed compared to ungrazed areas. Butterfly and bumblebee habitat use, as well as feeding and resting activities were also higher in grazed areas. Moreover, the number of pollinators increased with plant species richness. 5. Synthesis and applications. This study demonstrates that to enhance the diversity of a given herbivore community with an ecologically functional substitute of extinct wild horses can have significant effects on the functional composition of grasslands, mitigate plant species declines, and boost pollinator habitat use. Thus, rewilding interventions with large herbivores may offset current biodiversity declines by maintaining important functional links between plants and pollinators in grassland ecosystems.
Data from: A 37-year experimental study of effects of structural alterations on a shrub community in the Mojave Desert, California
1. In 1977 an experiment was initiated in the Mojave Desert to investigate how shrub interactions affect structure in a community dominated by Ambrosia dumosa and Larrea tridentata. Here, as in much of the Mojave, Larrea were regularly distributed, Ambrosia occurred in aggregations, and the two were randomly distributed relative to each other. Pre-dawn xylem pressure potentials (PDXPPs) of single Ambrosia or Larrea in centers of 100m2 circular plots were monitored to assess effects of intraspecific, interspecific, and total removals of neighboring shrubs. Contrary to theory, results over the next two years indicated interspecific interference was more intense than intraspecific interference in both species. 2. These plots were maintained through 2014. Measurements of seedling recruitment from 1980 to 2014, and of PDXPP, aboveground biomass, and canopy senescence from 2003 to 2014 were conducted. 3. Recruitment of both species was substantial immediately after the removals, but declined to very low levels after 1983. Ambrosia recruited into all Ambrosia and Total-Removal plots, but Larrea recruited only into plots that contained mature Ambrosia. 4. PDXPPs of monitored shrubs continued to be enhanced in removal plots for at least 27 years, but this changed from most being due to interspecific removals in both species to intraspecific removals causing most enhancement in Ambrosia and inter- and intraspecific removals causing nearly equal enhancements in Larrea. 5. Aboveground biomasses of monitored shrubs of Ambrosia and Larrea were 2.1X and 2.8X larger in Total-Removal plots, 1.6X and 1.7X larger in intraspecific removal plots, respectively, and 1.1X larger in interspecific removal plots for both species than those in Control plots, indicating the absence of intraspecific interference had the dominant long-term effect. 6. Canopy senescence differed between Ambrosia and Larrea in extent, timing and effect of specific removal treatments; it was greatest for both species in Controls, averaging 75% and 34%, respectively. 7. Synthesis. Shrub interactions and their relations to community structure are mechanistically and spatially complex. Differences between short-term and long-term responses to removals reveal multi-tiered, temporally dynamic feedback loops between shrub interactions and community structure driven by demographics, species-specific root growth, resource competition, communications, and territoriality.
Data from: Small population size and low genomic diversity have no effect on fitness in experimental translocations of a wild fish
<p>Little empirical work in nature has quantified how wild populations with varying effective population sizes and genetic diversity perform when exposed to a gradient of ecologically important environmental conditions. To achieve this, juvenile brook trout from 12 isolated populations or closed metapopulations that differ substantially in population size and genetic diversity were transplanted to previously fishless ponds spanning a wide gradient of ecologically important variables. We evaluated the effect of genome-wide variation, effective population size (Ne), pond habitat, and initial body size on two fitness correlates (survival and growth). Genetic variables had little effect on either fitness correlate, which were determined primarily by habitat (pond temperature, depth, and pH) and initial body size. These results suggest that some vertebrate populations with low genomic diversity, low Ne and long-term isolation can represent important sources of variation and be capable of maintaining fitness in, and ultimately persisting and adapting to, changing environments. Our results also reinforce the paramount importance of improving available habitat and slowing habitat degradation for species conservation.</p>
Data from: Experimental exposure to trace metals affects plumage bacterial community in the feral pigeon
Bacteria are fundamental associates of animals, and recent studies have highlighted their major role in host behaviour, immunity or reproductive investment. Thus, any environmental factor modifying bacterial community may affect host fitness. In birds, trace metals emitted by anthropogenic activities accumulate onto the plumage where they may alter bacterial community and ultimately affect bird fitness. Although trace metals are current major environmental issues in urban habitats, their effects on feather bacterial community have never been investigated. Here, we supplemented feral pigeons Columba livia, an emblematic urban species, with zinc and/or lead in drinking and bath water. As expected, lead and zinc supplementations modified plumage bacterial community composition. Zinc decreased bacterial load, while lead decreased bacterial richness and the frequency of preening behaviour in birds, known to regulate feather bacteria. Our results demonstrate for the first time the effects of common urban trace metals on plumage bacterial community and shed light on one of the mechanisms by which trace metals can affect bird fitness. Further studies are now needed to investigate how this effect modulates avian life history traits known to depend on plumage bacterial community.
Data from: Experimental evidence for sex-specific plasticity in adult brain
Background: Plasticity in brain size and the size of different brain regions during early ontogeny is known from many vertebrate taxa, but less is known about plasticity in the brains of adults. In contrast to mammals and birds, most parts of a fish's brain continue to undergo neurogenesis throughout adulthood, making lifelong plasticity in brain size possible. We tested whether maturing adult three-spined sticklebacks (Gasterosteus aculeatus) reared in a stimulus-poor environment exhibited brain plasticity in response to environmental enrichment, and whether these responses were sex-specific, thus altering the degree of sexual size dimorphism in the brain. Results: Relative sizes of total brain and bulbus olfactorius showed sex-specific responses to treatment: males developed larger brains but smaller bulbi olfactorii than females in the enriched treatment. Hence, the degree of sexual size dimorphism (SSD) in relative brain size and the relative size of the bulbus olfactorius was found to be environment-dependent. Furthermore, the enriched treatment induced development of smaller tecta optica in both sexes. Conclusions: These results demonstrate that adult fish can alter the size of their brain (or brain regions) in response to environmental stimuli, and these responses can be sex-specific. Hence, the degree of SSD in brain size can be environment-dependent, and our results hint at the possibility of a large plastic component to SSD in stickleback brains. Apart from contributing to our understanding of the processes shaping and explaining variation in brain size and the size of different brain regions in the wild, the results show that provision of structural complexity in captive environments can influence brain development. Assuming that the observed plasticity influences fish behaviour, these findings may also have relevance for fish stocking, both for economical and conservational purposes.
Data from: Rapid evolutionary responses of life history traits to different experimentally-induced pollution in Caenorhabditis elegans
Background Anthropogenic disturbances can lead to intense selection pressures on traits and very rapid evolutionary changes. Evolutionary responses to environmental changes, in turn, reflect changes in the genetic structure of the traits, accompanied by a reduction of evolutionary potential of the populations under selection. Assessing the effects of pollutants on the evolutionary responses and on the genetic structure of populations is thus important to understanding the mechanisms that entail specialization to novel environmental conditions or resistance to novel stressors. Results Using an experimental evolution approach we exposed Caenorhabditis elegans populations to uranium, salt and alternating uranium-salt environments over 22 generations. We analyzed the changes in the average values of life history traits and the consequences at the demographic level in these populations. We also estimated the phenotypic and genetic (co)variance structure of these traits at different generations. Compared to populations in salt, populations in uranium showed a reduction of the stability of their traits structure and a higher capacity to respond by acclimation. However, the evolutionary responses of traits were generally lower for uranium than salt and the evolutionary responses in the alternating uranium-salt environment were between those of constant environments. Consequently, at the end of the experiment, the population rate of increase were higher in uranium than in salt and intermediate in the alternating environment. Conclusions Our multigenerational experiment confirmed that rapid adaptation to different polluted environments may involve different evolutionary responses resulting demographic consequences. These changes are partly explain by the effects of the pollutants on the genetic (co)variance structure of traits and the capacity of acclimation to novel conditions. Finally, our results in the alternating environment may confirm the selection of a generalist type in this environment.
Data from: How do foragers decide when to leave a patch? A test of alternative models under natural and experimental conditions
1. A forager's optimal patch-departure time can be predicted by the prescient marginal value theorem (pMVT), which assumes they have perfect knowledge of the environment, or by approaches such as Bayesian-updating and learning rules, which avoid this assumption by allowing foragers to use recent experiences to inform their decisions. 2. In understanding and predicting broader scale ecological patterns, individual-level mechanisms, such as patch-departure decisions, need to be fully elucidated. Unfortunately, there are few empirical studies that compare the performance of patch-departure models that assume perfect knowledge with those that do not, resulting in a limited understanding of how foragers decide when to leave a patch. 3. We tested the patch-departure rules predicted by fixed-rule, pMVT, Bayesian-updating and learning models against one another, using patch residency times recorded from 54 chacma baboons (Papio ursinus) across two groups in natural (n = 6,594 patch visits) and field-experimental (n = 8,569) conditions. 4. We found greater support in the experiment for the model based on Bayesian-updating rules, but greater support for the model based on the pMVT in natural foraging conditions. This suggests that foragers may place more importance on recent experiences in predictable environments, like our experiment, where these experiences provide more reliable information about future opportunities.5. Furthermore, the effect of a single recent foraging experience on patch residency times was uniformly weak across both conditions. This suggests that foragers' perception of their environment may incorporate many previous experiences, thus approximating the perfect knowledge assumed by the pMVT. Foragers may, therefore, optimise their patch-departure decisions in line with the pMVT through the adoption of rules similar to those predicted by Bayesian-updating.
Data from: Experimental small-scale flower patches increase species density but not abundance of small urban bees
1. Large flower plantings are often used to combat negative effects of habitat loss on pollinators, but whether these floral additions are effective at smaller scales remains unclear, particularly in urban settings. 2. To test the effectiveness of small-scale floral additions on enhancing urban bee populations, as well as their impact from one year to the next, different quantities of potted sweet alyssum (Lobularia maritima) flowers were placed across sites in Ann Arbor, Michigan for two consecutive years and the resulting Halictid bee visitors were monitored. 3. Overall we found the number of flowers added at the local level was significantly and positively correlated with small Halictid bee abundance and species density in an urban landscape. At smaller flower quantities dynamics were clearly linear, where incremental increases in number of flowers showed significant increases in bee abundance and species density. At larger quantities of floral additions, however, dynamics were nonlinear in that incremental increases in flower quantity had no effect on bee abundance and highly variable effects on bee species density. 4. When comparing the change in small Halictid bee abundance and species density from one year to the next, we found a significant increase in bee species density in the second year of small-scale floral additions, but no significant difference in bee abundance. 5. Synthesis and applications. Our results show that small flower plantings can have positive effects on small bee communities in urban systems even over a short period of time, and therefore confirm that encouraging citizens to plant flowers can be an effective conservation strategy for certain urban pollinator populations. In addition, our finding that smaller flower plantings may have higher impacts on small pollinators than larger plantings suggests resource managers interested in pollinator conservation should consider spreading multiple, smaller floral plantings across the urban landscape, rather than pooling all resources into one large flower patch.29-Nov-2017
Data from: An experimental evaluation of traits that influence the sexual behaviour of pollinators in sexually deceptive orchids
Pollination by sexual deception of male insects is perhaps one of the most remarkable cases of mimicry in the plant kingdom. However, understanding the influence of floral traits on pollinator behaviour in sexually deceptive orchids is challenging, due to the risk of confounding changes in floral odour when manipulating morphology. Here, we investigated the floral traits influencing the sexual response of male Zaspilothynnus nigripes (Tiphiidae) wasps, a pollinator of two distantly related sexually deceptive orchids with contrasting floral architecture, Caladenia pectinata and Drakaea livida. In D. livida the chemical sexual attractant is emitted from the labellum, while in C. pectinata it is produced from the distal sepal tips, allowing manipulative experiments. When controlling for visual cues there was no difference in long distance attraction, though the floral odour of D. livida induced copulation more frequently than that of C. pectinata. The role of colour in pollinator sexual attraction was equivocal, indicating that colour may not be a strong constraint on the initial evolution of sexual deception. The frequency of wasp visitors landing on C. pectinata decreased when the amount of floral odour was reduced, but attempted copulation rates were enhanced when the source of floral odour was associated with the labellum. These latter variables may represent axes of selection that operate across many sexually deceptive species. Nonetheless, the observed variation in floral traits suggests flexibility in how sexual deception can be achieved.
Data from: Head-to-head comparison of three experimental methods of quantifying competitive fitness in C. elegans
Organismal fitness is relevant in many contexts in biology. The most meaningful experimental measure of fitness is competitive fitness, when two or more entities (e.g., genotypes) are allowed to compete directly. In theory, competitive fitness is simple to measure: an experimental population is initiated with the different types in known proportions and allowed to evolve under experimental conditions to a predefined endpoint. In practice, there are several obstacles to obtaining robust estimates of competitive fitness in multicellular organisms, the most pervasive of which is simply the time it takes to count many individuals of different types from many replicate populations. Methods by which counting can be automated in high throughput are desirable, but for automated methods to be useful, the bias and technical variance associated with the method must be (a) known, and (b) sufficiently small relative to other sources of bias and variance to make the effort worthwhile. The nematode Caenorhabditis elegans is an important model organism, and the fitness effects of genotype and environmental conditions are often of interest. We report a comparison of three experimental methods of quantifying competitive fitness, in which wild-type strains are competed against GFP-marked competitors under standard laboratory conditions. Population samples were split into three replicates and counted (1) "by eye" from a saved image, (2) from the same image using CellProfiler image analysis software, and (3) with a large particle flow cytometer (a "worm sorter"). From 720 replicate samples, neither the frequency of wild-type worms nor the among-sample variance differed significantly between the three methods. CellProfiler and the worm sorter provide at least a tenfold increase in sample handling speed with little (if any) bias or increase in variance.
Data from: Stressful colors: corticosterone concentrations in a free-living songbird vary with the spectral composition of experimental illumination
Organisms have evolved under natural daily light/dark cycles for millions of years. These cycles have been disturbed as night-time darkness is increasingly replaced by artificial illumination. Investigating the physiological consequences of free-living organisms in artificially lit environments is crucial to determine whether nocturnal lighting disrupts circadian rhythms, changes behaviour, reduces fitness and ultimately affects population numbers. We make use of a unique, large-scale network of replicated field sites which were experimentally illuminated at night using lampposts emanating either red, green, white or no light to test effect on stress hormone concentrations (corticosterone) in a songbird, the great tit (Parus major). Adults nesting in white-light transects had higher corticosterone concentrations than in the other treatments. We also found a significant interaction between distance to the closest lamppost and treatment type: individuals in red light had higher corticosterone levels when they nested closer to the lamppost than individuals nesting farther away, a decline not observed in the green or dark treatment. Individuals with high corticosterone levels had fewer fledglings, irrespective of treatment. These results show that artificial light can induce changes in individual hormonal phenotype. As these effects vary considerably with light spectrum, it opens the possibility to mitigate these effects by selecting street lighting of specific spectra.
Data from: Contemporary evolution of plant growth rate following experimental removal of herbivores
Herbivores are credited with driving the evolutionary diversification of plant defensive strategies over macroevolutionary time. For this to be true, herbivores must also cause short-term evolution within plant populations, but few studies have experimentally tested this prediction. We addressed this gap using a long-term manipulative field experiment where exclosures protected 22 plant populations from natural rabbit herbivory for <1 to 26 years. We collected seeds of Rumex acetosa L. (Polygonaceae) from our plots and grew them in a common greenhouse environment to quantify evolved differences among populations in individual plant growth rate, tolerance to herbivory, competitive ability, and the concentration of secondary metabolites (tannins and oxalate) implicated in defense against herbivores. In 26 years without rabbit herbivory, plant growth rate decreased linearly by 30%. We argue that plant growth rate has evolved as a defense against intense rabbit herbivory. In contrast, we found no change in tolerance to herbivory or concentrations of secondary metabolites. We also found no change in competitive ability, suggesting that contemporary evolution may not feed back to alter ecological interactions within this plant community. Our results combined with those of other studies show that the evolution of gross morphological traits such as growth rate in response to herbivory may be common, which calls into question assumptions about some of the most popular theories of plant defense.
Data from: The effect of elevated CO2 on growth and competition in experimental phytoplankton communities
We report an experiment designed to identify the effect of elevated CO2 on species of phytoplankton in a simple laboratory system. Major taxa of phytoplankton differ in their ability to take up CO2, which might lead to predictable changes in the growth rate of species and thereby shifts in the composition of phytoplankton communities in response to rising CO2. Six species of phytoplankton belonging to three major taxa (cyanobacteria, diatoms and chlorophytes) were cultured in atmospheres whose CO2 concentration was gradually increased from ambient levels to 1000 parts per million over about 100 generations and then maintained for a further 200 generations at elevated CO2. The experimental design allowed us to trace a predictive sequence, from physiological features to the growth response of species to elevated CO2 in pure culture, from the growth response in pure culture to competitive ability in pairwise mixtures and from pairwise competitive ability to shifts in the relative abundance of species in the full community of all six species. CO2 altered the dynamics of growth in a fashion consistent with known differences among major taxa in their ability to take up and use CO2. This pure-culture response was partly successful in predicting the outcome of competition in pairwise mixtures, especially the enhanced competitive ability of chlorophytes relative to cyanobacteria, although generally statistical support was weak. The competitive response in pairwise mixtures was a good predictor of changes in competitive ability in the full community. Hence, there is a potential for forging a logical chain of inferences for predicting how phytoplankton communities will respond to elevated CO2. Clearly further extensive experiments will be required to validate this approach in the greater complexity found in diverse communities and environments of natural systems.
Data from: Biparental care is more than the sum of its parts: experimental evidence for synergistic effects on offspring fitness
Despite an extensive body of theoretical and empirical literature on biparental cooperation, it is still unclear whether offspring fare equally, better, or worse when receiving care by two parents versus a single parent. Some models predict that parents should withhold the amount of care they provide due to sexual conflict, thereby shifting as much of the workload as possible to their partner. This conflict should lead to offspring faring worse with two parents. Yet, other models predict that when parents care for their offspring together, their individual contributions can have synergistic (more than additive) effects on offspring fitness. Under this scenario, biparental cooperation should lead to offspring faring better with two parents. We address this fundamental question using a unique experimental design where we compared offspring fitness when the two parents worked together (biparental treatment) and when the two parents worked separately (uniparental treatment), while keeping constant the amount of resources and number of offspring per parent across treatments. This made it possible to directly compare the biparental treatment to the sum of the male and female contributions in the uniparental treatment. Our main finding was that offspring grew larger and were more likely to survive to adulthood when reared by both parents than a single parent. This is the first empirical evidence for a synergistic effect of biparental cooperation on offspring fitness and could provide novel insights into the conditions favouring the evolution of biparental cooperation.
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.