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11,506 results for “Dynamics”
Impact of Pleistocene eustatic fluctuations on evolutionary dynamics in Southeast Asian biodiversity hotspots
Pleistocene Climatic Fluctuations (PCF) are frequently highlighted as important evolutionary engines that triggered cycles of biome expansion and contraction. While there is ample evidence of the impact of PCF on biodiversity for continental biomes, the consequences in insular systems depend on the geology of the islands and the ecology of the taxa inhabiting them. The idiosyncratic aspects of insular systems are exemplified by the islands of the Sunda Shelf in Southeast Asia (Sundaland), where PCF-induced eustatic fluctuations had complex interactions with the geology of the region, resulting in high species diversity and endemism. Emergent land in Southeast Asia varied drastically with sea level fluctuations during the Pleistocene. Climate-induced fluctuations in sea level caused temporary connections between insular and continental biodiversity hotspots in Southeast Asia. These exposed lands likely had freshwater drainage systems that extended between modern islands: the Paleoriver Hypothesis. Built upon the assumption that aquatic organisms are among the most suitable models to trace ancient river boundaries and fluctuations of landmass coverage, the present study aims to examine the evolutionary consequences of PCF on the dispersal of freshwater biodiversity in Southeast Asia. Time-calibrated phylogenies of DNA-delimited species were inferred for six species-rich freshwater fish genera in Southeast Asia (Clarias, Channa, Glyptothorax, Hemirhamphodon, Dermogenys, Nomorhamphus). The results highlight rampant cryptic diversity and the temporal localization of most speciation events during the Pleistocene, with 88% of speciation events occurring during this period. Diversification analyses indicate that sea level-dependent diversification models poorly account for species proliferation patterns for all clades excepting Channa. Ancestral area estimations point to Borneo as the most likely origin for most lineages, with two waves of dispersal to Sumatra and Java during the last 5 Myrs. Speciation events are more frequently associated with boundaries of the paleoriver watersheds, with 60%, than islands boundaries, with 40%. In total, one-third of speciation events are inferred to have occured within paleorivers on a single island, suggesting that habitat heterogeneity and factors other than allopatry between islands substantially affected diversification of Sundaland fishes. Our results suggest that species proliferation in Sundaland is not wholly reliant on Pleistocene sea-level fluctuations isolating populations on different islands.
Data from: A test for rate-coupling of trophic and cranial evolutionary dynamics in New World bats
<p>Data supporting article Shi et al. 2021, Evolution: <a href="https://doi.org/10.1111/evo.14188">https://doi.org/10.1111/evo.14188</a></p> <p>Morphological evolution is often assumed to be causally related to underlying patterns of ecological trait evolution. However, few studies have directly tested whether evolutionary dynamics of and major shifts in ecological resource use are coupled with morphological shifts that may facilitate trophic innovation. Using diet and multivariate cranial (microCT) data, we tested whether rates of trophic and cranial evolution are coupled in the radiation of New World bats. <span>We developed a generalizable information-theoretic method for describing evolutionary rate heterogeneity across large candidate sets of multi-rate models of evolution, without relying on a single best-fitting model</span>. We found considerable variation in trophic evolutionary dynamics, in sharp contrast to a largely homogeneous cranial evolutionary process. This dichotomy is surprising given documented functional associations between overall skull morphology and trophic ecology. We suggest that assigning discrete trophic states may underestimate trophic generalism, and that this radiation could be characterized by generally labile crania that result in a homogeneous dynamic of overall high morphological rates. Overall, we discuss how trophic classification could substantively impact our interpretation of how these dynamics covary in adaptive radiations.</p>
Data from: Pollen limitation as a main driver of fruiting dynamics in oak populations
In many perennial wind-pollinated plants, the dynamics of seed production is commonly known to be highly fluctuating from year to year and synchronized among individuals within populations. The proximate causes of such seeding dynamics, called masting, are still poorly understood in oak species that are widespread in the northern hemisphere, and whose fruiting dynamics dramatically impacts forest regeneration and biodiversity. Combining long-term surveys of oak airborne pollen amount and acorn production over large-scale field networks in temperate areas, and a mechanistic modeling approach, we found that the pollen dynamics is the key driver of oak masting. Mechanisms at play involved both internal resource allocation to pollen production synchronized among trees and spring weather conditions affecting the amount of airborne pollen available for reproduction. The sensitivity of airborne pollen to weather conditions might make oak masting and its ecological consequences highly sensitive to climate change.
Data from: Contact zone dynamics during early stages of speciation in a chorus frog (Pseudacris crucifer)
Characterizing the genetic and behavioural consequences of contact between previously geographically isolated lineages provides insights into the mechanisms underlying diversification and ultimately speciation. The spring peeper (Pseudacris crucifer) is a widespread Nearctic chorus frog with six divergent mitochondrial DNA (mtDNA) lineages, many of which came into secondary contact during the Holocene. We examined genetics, morphology, advertisement calls and female preference for two lineages that began diverging in allopatry in the Pliocene and now overlap in southwestern Ontario, Canada. We found non-coincident clines in mtDNA and nuclear DNA, mirroring directionality of premating isolation barriers. We also found divergence in a range of traits between these two lineages, displacement in male call attributes and female preference for calls of their natal lineage in sympatry. Hybrids were morphologically distinct from both parental lineages, but hybrid male calls were acoustically intermediate. Female hybrids showed asymmetrical preference for Eastern male calls. These results considered together provide evidence of either unidirectional hybridization or selection against hybrids, potentially implying reproductive character displacement. Our work demonstrates the utility of integrated, multi-character approaches to understanding the processes of divergence and the nature of speciation.
Data from: Dissecting biodiversity in a global hotspot: uneven dynamics of immigration and diversification within the Cape Floristic Region of South Africa
Aim: Fragmented distributions should show immigration and diversification dynamics consistent with the predictions of island biogeography theory. We test whether this applies to the fragmented Cape fynbos vegetation. Location: Southern Africa, Cape Floristic Region (CFR) Taxon: Angiosperms, Restionaceae (restios) Methods: We used a large occurrence dataset and environmental layers to characterize an existing regionalization and the intervals between the regions ecologically and spatially. We extended the available phylogeny for restios and inferred their historical biogeography using models implemented in BioGeoBEARS. We then measured the relative contribution of immigration and in situ speciation to the species richness of each region within the CFR. We used standard statistical methods to test the predictions of the island biogeography theory. Results: The area and environmental heterogeneity of the seven regions of the CFR are positively correlated with in situ speciation rate. Furthermore, more isolated areas, and areas colonized more recently, have proportionally higher immigration rates, and more central and older areas proportionally higher in situ speciation rates. Main Conclusions: The variation in immigration and diversification dynamics among the regions within the CFR is extensive and consistent with the archipelago model of island biography theory. This dynamic may contribute significantly to the diversity of the Cape flora. Such a model could be generally useful for understanding the generation and maintenance of diversity in biodiversity hotspots, and may even scale up to explain continental biodiversity.
Data from: Litter conversion into detritivore faeces reshuffles the quality control over C and N dynamics during decomposition
1. In many terrestrial ecosystems, detritivorous soil organisms ingest large amounts of leaf litter returning most of it to the soil as faeces. Such conversion of leaf litter into faeces may stimulate decomposition by increasing the surface area available for microbial colonization. Yet, experimental support for either the outcome or the mechanism of these conversion effects is lacking. 2. Based on the hypothesis that the identity of plant species from which leaf litter is transformed into faeces has a critical role in how faeces decomposition proceeds, we collected faeces of the widely abundant millipede Glomeris marginata fed with leaf litter from seven distinct tree species. We compared the physical and chemical characteristics and the rates of carbon (C) and nitrogen (N) loss between litter and faeces. 3. We found that after 100 days of exposure under controlled conditions, C loss was on average higher in faeces (40%) than in litter (26.6%), with a significant increase for six out of the seven species. Concurrently, N dynamics switched from a net immobilisation (7.7%) in litter to a net release (14.6%) in faeces, with a significant increase for five out of the seven species. 4. Litter conversion into faeces generally homogenised differences in physical and chemical characteristics among species. Despite such homogenisation, variability in rates of faeces C and N loss among species was similar compared to leaf litter, but correlated with a different set of traits. Specifically, faecal pellet C loss was positively related to compaction (decreased specific area and increased density of faecal pellets), and both C and N loss from faecal pellets were positively related to fragmentation (increased specific area and perimeter of particles within faecal pellets). 5. We conclude that litter fragmentation and compaction into detritivore faecal pellets leads to substantially enhanced decomposition, with a particularly strong impact on N dynamics that changed from immobilisation to net release depending on litter species. Moreover, litter quality control on decomposition is reshuffled by litter conversion into faeces. In ecosystems with high detritivore abundance, this so far largely overlooked pathway of organic matter turnover may strongly affect ecosystem C and N cycling.
Data from: Surface-water dynamics and land use influence landscape connectivity across a major dryland region
Landscape connectivity is important for the long-term persistence of species inhabiting dryland freshwater ecosystems, with spatiotemporal surface-water dynamics (e.g., flooding) maintaining connectivity by both creating temporary habitats and providing transient opportunities for dispersal. Improving our understanding of how landscape connectivity varies with respect to surface-water dynamics and land use is an important step to maintaining biodiversity in dynamic dryland environments. Using a newly available validated Landsat TM and ETM+ surface-water time series, we modelled landscape connectivity between dynamic surface-water habitats within Australia's 1 million km2 semi-arid Murray Darling Basin across a 25-year period (1987 to 2011). We identified key habitats that serve as well-connected 'hubs', or 'stepping-stones' that allow long-distance movements through surface-water habitat networks. We compared distributions of these habitats for short- and long-distance dispersal species during dry, average and wet seasons, and across land-use types. The distribution of stepping-stones and hubs varied both spatially and temporally, with temporal changes driven by drought and flooding dynamics. Conservation areas and natural environments contained higher than expected proportions of both stepping-stones and hubs throughout the time series; however, highly modified agricultural landscapes increased in importance during wet seasons. Irrigated landscapes contained particularly high proportions of well-connected hubs for long-distance dispersers, but remained relatively disconnected for less vagile organisms. The habitats identified by our study may serve as ideal high-priority targets for land-use specific management aimed at maintaining or improving dispersal between surface-water habitats, potentially providing benefits to biodiversity beyond the immediate site scale. Our results also highlight the importance of accounting for the influence of spatial and temporal surface-water dynamics when studying landscape connectivity within highly variable dryland environments.
Data from: Time since disturbance affects colonization dynamics in a metapopulation
1. Disturbances are widespread in nature and can have substantial population-level consequences. Most empirical studies on the effects of disturbance track population recovery within habitat patches, but have an incomplete representation of the recolonization process. Additionally, recent metapopulation models represent post-disturbance colonization with a recovery state or time-lag for disturbed ("focal") patches, thus assuming that recolonization rates are uniform. 2. However, the availability of colonists in neighboring "source" patches can vary, especially in frequently-disturbed landscapes such as fire-managed forests that have a mosaic of patches that differ in successional state and undergo frequent local extinctions. To determine how time since disturbance in both focal and neighboring source patches might affect metapopulations, we studied the effects of time since fire (TSF) on abundances of a specialist palmetto beetle within and between fire management units in Apalachicola National Forest, Florida. 3. We measured beetle abundances at three distances from the shared edge of paired units, with units ranging from 0-64 months since fire and the difference in time since burning for a focal-source pair ranging from 3-58 months. 4. Soon after fire, beetle abundances within management units were highest near the unit edge, but this pattern changed with increasing TSF. Between paired units, the more recently-disturbed ("focal") unit's beetle abundance was positively related to source unit abundance, but the shape of this relationship differed based on focal unit TSF and the units' difference in time since burning. 5. Results suggest that both focal and source habitat history can influence recolonization of recently-disturbed patches and that these effects may persist over years. Thus, when predicting metapopulation dynamics, variation in habitat characteristics should be considered not only for patches receiving colonists, but for patches supplying colonists as well.
Data from: Male social plasticity influences transient dynamics of alternative mating systems in water striders
Animal mating systems are often studied with the goal of understanding why species, populations, or groups vary from one another in the system they display. Although these differences are often treated as basically stable, it is also known that these systems may shift over time (e.g. from one breeding season to the next). There has been some study of how ecological factors correlate with these changes; however, few, if any, studies have investigated how the phenotypic composition of a group governs the timing and probability of system transitions. Groups of stream water striders (Aquarius remegis) can demonstrate quick and flexible transitions in mating system dynamics, with many groups eventually transitioning to a system in which a single, large male monopolizes mating opportunities. We asked if variation in individual- and group-level traits associated with morphology and behavior (e.g. size of the largest individual, variance in activity behavioral types, and average social plasticity) could partially explain the variability in how rapidly groups make this transition, if they make it all. Our results show that the average social plasticity of males in a group has important effects on the emergence timing of mating systems dominated by a single male.
Data from: Flower phenology as a disruptor of the fruiting dynamics in temperate oak species
<ul> <li> <p class="western"><span>Many perennial plants display masting, <i>i.e.,</i> fruiting with strong interannual variations, irregular and synchronized between trees within the population. Here, we tested the hypothesis that the early flower phenology in temperate oak species promotes stochasticity into their fruiting dynamics, which could play a major role in tree reproductive success.</span></p> </li> <li> <p class="western"><span>From large field monitoring network, we compared the pollen phenology between temperate and Mediterranean oak species. Then, focusing on temperate oak species, we explored the influence of the weather around the time of bud-burst and flowering on seed production, and simulated with a mechanistic model the consequences an evolutionary shifting of flower phenology would have on fruiting dynamics.</span></p> </li> <li> <p><span>Temperate oak species release pollen earlier in the season than Mediterranean oak species. Such early flowering in temperate oak species results in pollen being often released during unfavorable weather conditions and resulting in frequent reproductive failure. If pollen release was delayed due to natural selection, fruiting dynamics would exhibit much reduced stochastic variation.</span></p> </li> <li> <p class="western"><span>We propose that early flower phenology might be adaptive by making mast-seeding years rare and unpredictable, which would greatly help controlling the dynamics of seed consumers.</span></p> </li> </ul>
Data from: Investigating the association between social interactions and personality states dynamics
The recent personality psychology literature has coined the name of personality states to refer to states having the same behavioural, affective and cognitive content (described by adjectives) as the corresponding trait, but for a shorter duration. The variability in personality states may be the reaction to specific characteristics of situations. The aim of our study is to investigate whether specific situational factors, that is, different configurations of face-to-face interactions, are predictors of variability of personality states in a work environment. The obtained results provide evidence that within-person variability in personality is associated with variation in face-to-face interactions. Interestingly, the effects differ by type and level of the personality states: adaptation effects for Agreeableness and Emotional Stability, whereby the personality states of an individual trigger similar states in other people interacting with them and complementarity effects for Openness to Experience, whereby the personality states of an individual trigger opposite states in other people interacting with them. Overall, these findings encourage further research to characterize face-to-face and social interactions in terms of their relevance to personality states.
Data from: Temporal population-genetic structure of eastern mosquitofish in a dynamic aquatic landscape
We analyzed the effect of periodic drying in the Florida Everglades on spatio-temporal population genetic structure of eastern mosquitofish (Gambusia holbrooki). Severe periodic drying events force individuals from disparate sources to mix in dry-season relatively deep-water refuges. In 1996 (a wet year) and 1999 (a dry year), we sampled mosquitofish at 20 dry-season refuges distributed in three water-management regions and characterized genetic variation for 10 allozyme and 3 microsatellite loci. In 1996, most of the ecosystem did not dry, while in 1999, many of our sampling locations were isolated by expanses of dried marsh surface. In 1996, most spatial genetic variation was attributed to heterogeneity within regions. In 1999, spatial genetic variation within regions was not significant. In both years, a small but significant amount of variation (less than 1% of the total variation) was partitioned among regions. Variance was consistently greater than zero among long-hydroperiod sites within a region, but not among short-hydroperiod sites within a region, where hydroperiod was measured as time since last marsh surface dry-down forcing fishes into local refuges. In 1996, all sites were in Hardy-Weinberg equilibrium. In 1999, we observed fewer heterozygotes than expected for most loci and sites suggesting a Wahlund effect arising from fish leaving areas that dried and mixing in deep-water refuges.
Data from: The role of predation and food limitation on claims for compensation, reindeer demography and population dynamics
1. A major challenge in biodiversity conservation is to facilitate viable populations of large apex predators in ecosystems where they were recently driven to ecological extinction due to resource conflict with humans. 2. Monetary compensation for losses of livestock due to predation is currently a key instrument to encourage human–carnivore coexistence. However, a lack of quantitative estimates of livestock losses due to predation leads to disagreement over the practise of compensation payments. This disagreement sustains the human–carnivore conflict. 3. The level of depredation on year-round, free-ranging, semi-domestic reindeer by large carnivores in Fennoscandia has been widely debated over several decades. In Norway, the reindeer herders claim that lynx and wolverine cause losses of tens of thousands of animals annually and cause negative population growth in herds. Conversely, previous research has suggested that monetary predator compensation can result in positive population growth in the husbandry, with cascading negative effects of high grazer densities on the biodiversity in tundra ecosystems. 4. We utilized a long-term, large-scale dataset to estimate the relative importance of lynx and wolverine predation and density-dependent and climatic food limitation on claims for losses, recruitment and population growth rates in Norwegian reindeer husbandry. 5. Claims of losses increased with increasing predator densities, but with no detectable effect on population growth rates. Density-dependent and climatic effects on claims of losses, recruitment and population growth rates, were much stronger than the effects of variation in lynx and wolverine densities. 6. Synthesis and applications. Our analysis provides a quantitative basis for predator compensation and estimation of the costs of reintroducing lynx and wolverine in areas with free-ranging semi-domestic reindeer. We outline a potential path for conflict management which involves adaptive monitoring programs, open access to data, herder involvement, and development of management strategy evaluation (MSE) models to disentangle complex responses including multiple stakeholders and individual harvester decisions.
Data from: Seasonal dynamics of spatial distribution and overlap between Northeast Arctic cod (Gadus morhua) and capelin (Mallotus villosus) in the Barents Sea
The trophic link between cod (Gadus sp.) and capelin (Mallotus sp.) is important in many panarctic ecosystems. Since the early 2000s, the Northeast Arctic cod stock (G. morhua) in the Barents Sea has increased greatly, and the sea has been exceptionally warm. Such changes have potentially large effects on species distributions and overlap, which in turn could affect the strength of species interactions. Due to its high latitude location, the Barents Sea has strong seasonal variation in physical conditions and interactions. To study drivers of variation in cod-capelin overlap, we use data from two annual surveys run in winter and in autumn of 2004-2015. We first model winter and autumn spatial distributions of mature and immature cod and capelin. We then calculate overlap from model predictions on a grid with similar spatial resolution as the survey data. Our approach allowed us to interpret changes in overlap as species-specific effects of stock size and temperature, while accounting for sampling variation due to sampling time and depth. We found that during winter both species expanded their distribution in response to increased stock sizes, but how strongly and where the expansion occurred varied. The effect of temperature on distributions varied in space, and differed for cod and capelin and for different components of the two species. The results for autumn were clearer and more consistent. Both species expanded their distribution areas as their stock sizes increased. A positive effect of temperature was found in the north-eastern Barents Sea, where temperatures were lowest at the start of the study. Overlap increased and shifted north-eastwards during the study period and remained high despite a decline in the capelin stock. The increased overlap during autumn could mainly be attributed to the shift in cod distribution with increased cod stock biomass.
Data from: Canopy soil greenhouse gas dynamics in response to indirect fertilization across an elevation gradient of tropical montane forests
Canopy soils can significantly contribute to aboveground labile biomass, especially in tropical montane forests. Whether they also contribute to the exchange of greenhouse gases is unknown. To examine the importance of canopy soils to tropical forest-soil greenhouse gas exchange, we quantified gas fluxes from canopy soil cores along an elevation gradient with 4 yr of nutrient addition to the forest floor. Canopy soil contributed 5–12 percent of combined (canopy + forest floor) soil CO2 emissions but CH4 and N2O fluxes were low. At 2000 m, phosphorus decreased CO2 emissions (>40%) and nitrogen slightly increased CH4 uptake and N2O emissions. Our results show that canopy soils may contribute significantly to combined soil greenhouse gas fluxes in montane regions with high accumulations of canopy soil. We also show that changes in fluxes could occur with chronic nutrient deposition.
Data from: Quantifying uncertainty due to fission-fusion dynamics as a component of social complexity
Groups of animals (including humans) may show flexible grouping patterns, in which temporary aggregations or subgroups come together and split, changing composition over short temporal scales, i.e. fission and fusion). A high degree of fission-fusion dynamics may constrain the regulation of social relationships, introducing uncertainty in interactions between group members. Here we use Shannon's entropy to quantify the predictability of subgroup composition for three species known to differ in the way their subgroups come together and split over time: spider monkeys (Ateles geoffroyi), chimpanzees (Pan troglodytes) and geladas (Theropithecus gelada). We formulate a random expectation of entropy that considers subgroup size variation and sample size, against which the observed entropy in subgroup composition can be compared. Using the theory of set partitioning, we also develop a method to estimate the number of subgroups that the group is likely to be divided into, based on the composition and size of single focal subgroups. Our results indicate that Shannon's entropy and the estimated number of subgroups present at a given time provide quantitative metrics of uncertainty in the social environment (within which social relationships must be regulated) for groups with different degrees of fission-fusion dynamics. These metrics also represent an indirect quantification of the cognitive challenges posed by socially dynamic environments. Overall, our novel methodological approach provides new insight for understanding the evolution of social complexity and the mechanisms to cope with the uncertainty that results from fission-fusion dynamics.
Data from: Integrated modeling predicts shifts in waterbird population dynamics under climate change
Climate change has been identified as one of the most important drivers of wildlife population dynamics. The in-depth knowledge of the complex relationships between climate and population sizes through density dependent demographic processes is important for understanding and predicting population shifts under climate change, which requires integrated population models (IPMs) that unify the analyses of demography and abundance data. In this study we developed an IPM based on Gaussian approximation to dynamic N-mixture models for large scale population data. We then analyzed four decades (1972-2013) of Mallard (Anas platyrhynchos) breeding population survey, band-recovery, and climate data covering a large spatial extent from North American prairies through boreal habitat to Alaska. We aimed to test the hypothesis that climate change will cause shifts in population dynamics if climatic effects on demographic parameters that have substantial contribution to population growth vary spatially. More specifically, we examined the spatial variation of climatic effects on density dependent population demography, identified the key demographic parameters that are influential to population growth, and forecasted population responses to climate change. Our results revealed that recruitment, which explained more variance of population growth than survival, was sensitive to the temporal variation of precipitation in the southern portion of the study area but not in the north. Survival, by contrast, was insensitive to climatic variation. We then forecasted a decrease in Mallard breeding population density in the south and an increase in the northwestern portion of the study area, indicating potential shifts in population dynamics under future climate change. Our results implied that different strategies need to be considered across regions to conserve waterfowl populations in the face of climate change. Our modelling approach can be adapted for other species and thus has wide application to understanding and predicting population dynamics in the presence of global change.
Data from: Using the Spatial Population Abundance Dynamics Engine for conservation management
1. An explicit spatial understanding of population dynamics is often critical for effective management of wild populations. Sophisticated approaches are available to simulate these dynamics, but are largely either spatially homogeneous or agent-based, and thus best suited to small spatial or temporal scales. These approaches also often ignore financial decisions crucial to choosing management approaches on the basis of cost-effectiveness. 2. We created a user-friendly and flexible modelling framework for simulating these population issues at large spatial scales – the Spatial Population Abundance Dynamics Engine (SPADE). SPADE is based on the STAR model (McMahon et al. 2010) and uses a reaction-diffusion approach to model population trajectories and a cost-benefit analysis technique to calculate optimal management strategies over long periods and across broad spatial scales. It expands on STAR by incorporating species interactions and multiple concurrent management strategies, and by allowing full user control of functional forms and parameters. 3. We used SPADE to simulate the eradication of feral domestic cats Felis catus on sub-Antarctic Marion Island (Bester et al. 2002) and compared modelled outputs to observed data. The parameters of the best-fitting model reflected the conditions of the management programme, and the model successfully simulated the observed movement of the cat population to the southern and eastern portion of the island under hunting pressure. We further demonstrated that none of the management strategies would likely have been successful within a reasonable timeframe if performed in isolation. 4. SPADE is applicable to a wide range of population management problems, and allows easy generation, modification and analysis of management scenarios. It is a useful tool for the planning, evaluation and optimisation of the management of wild populations, and can be used without specialised training.
Data from: Identification of source-sink dynamics in mountain lions of the Great Basin
Natural and anthropogenic boundaries have been shown to affect population dynamics and population structure for many species with movement patterns at the landscape level. Understanding population boundaries and movement rates in the field for species that are cryptic and occur at low densities is often extremely difficult and logistically prohibitive; however genetic techniques may offer insights that have previously been unattainable. We analyzed thirteen microsatellite loci for 739 mountain lions (Puma concolor) using muscle tissue samples from individuals in the Great Basin throughout Nevada and the eastern Sierra Nevada mountain range to test the hypothesis that heterogeneous hunting pressure results in source-sink dynamics at the landscape scale. We used a combination of non-spatial and spatial model-based Bayesian clustering methods to identify genetic populations. We then used a recently developed Bayesian multilocus genotyping method to estimate asymmetrical rates of contemporary movement between those sub-populations and to identify source and sink populations. We identified 2 populations at the highest level of genetic structuring with a total of 5 subpopulations in the Great Basin of Nevada and the eastern Sierra Nevada range. Our results suggest that source-sink dynamics occur at landscape scales for wide-ranging species, such as mountain lions, and that source populations may be those that are under relatively less hunting pressure and that occupy refugia.
Data from: Long-term dynamics of adaptation in asexual populations
Experimental studies of evolution have increased greatly in recent years, stimulated by the growing power of genomic tools. However, organismal fitness remains the ultimate metric for interpreting these experiments, and the dynamics of fitness remain poorly understood over long timescales. Here, we examine fitness trajectories for 12 Escherichia coli populations during 50,000 generations. Mean fitness appears to increase without bound, consistent with a power law. We also derive this power-law relation theoretically by incorporating clonal interference and diminishing-returns epistasis into a dynamical model of changes in mean fitness over time.
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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.