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.
8,729
datasets available to search
ShareScore release 0.9.0
Dataset results
8,729 results for “Ranges”
Rapid adaptive evolution of the diapause program during range expansion of an invasive mosquito
<p>In temperate climates, the recurring seasonal exigencies of winter represent a fundamental physiological challenge for a wide range of organisms. In response, many temperate insects enter diapause, an alternative developmental program, including developmental arrest, that allows organisms to synchronize their life cycle with seasonal environmental variation. Geographic variation in diapause phenology contributing to local climatic adaptation is well documented. However, few studies have examined how the rapid evolution of a suite of traits expressed across the diapause program may contribute to climatic adaptation on a contemporary timescale. Here, we investigate the evolution of the diapause program over the past 35 years by leveraging a "natural experiment" presented by the recent invasion of the Asian tiger mosquito, <i>Aedes albopictus,</i> across the eastern United States. We sampled populations<i> </i>from two distinct climatic regions separated by six degrees of latitude (~700 km). Using common-garden experiments, we identified regional genetic divergence in diapause-associated cold tolerance, diapause duration, and post-diapause starvation tolerance. We also found regional divergence in non-diapause thermal performance. In contrast, we observed minimal regional divergence in non-diapause larval growth traits and at neutral molecular marker loci. Our results demonstrate rapid evolution of the diapause program and imply strong selection caused by differences in winter conditions.</p>
Data from: Habitat loss in the restricted range of the endemic Ghanaian cichlid Limbochromis robertsi
<p>Remote sensing has become an integral and invaluable tool to inform biodiversity conservation and monitoring of habitat degradation and restoration over time. Despite the disproportionately high levels of biodiversity loss in freshwater ecosystems worldwide, ichthyofauna are commonly overlooked in favor of other keystone species. Freshwater fish, as indicators of overall aquatic ecosystem health can also be indicators of larger scale problems within an ecosystem. As a case study with multi-temporal, multi-resolution satellite imagery, we examined deforestation and forest fragmentation around the Atewa Forest Reserve, Ghana. Within small creeks, <i>Limbochromis robertsi</i>, a unique freshwater cichlid with an extremely limited distribution range can be found. Historically, the land cover in the area has undergone substantial deforestation for agriculture and artisanal small-scale mining. In the 1389 km<sup>2</sup> study area we found deforestation accelerated along with increased forest fragmentation in the 2014 – 2017 period (167.4 km<sup>2</sup> of deforestation) with the majority of the forest loss along the river and creek banks due to small-scale mining operations and increased agriculture. Field visits indicated a decrease in the total <i>L. robertsi</i> population by approximately 90% from the early 1990s to 2018. Its<i> </i>distribution has been reduced to higher elevations by anthropogenic habitat barriers at low elevations and the presence of predatory species. Loss of Riparian forest through land use and cover change to mining and agriculture contributes to the habitat degradation for these endemic species. The fine spatial and temporal scale studies required to assess habitat characteristics is not captured by global or continental scale datasets.</p>
Data from: Influence of paleolithic range contraction, admixture and long-distance dispersal on genetic gradients of modern humans in Asia
<p>Cavalli-Sforza and coauthors originally explored the genetic variation of modern humans throughout the world and observed an overall east-west genetic gradient in Asia. However, the specific environmental and population genetics processes causing this gradient were not formally investigated and promoted discussion in recent studies. Here we studied the influence of diverse environmental and population genetics processes on Asian genetic gradients and identified which could have produced the observed gradient. To do so, we performed extensive spatially-explicit computer simulations of genetic data under the following scenarios: (<i>i</i>) variable levels of admixture between Paleolithic and Neolithic populations, (<i>ii</i>) migration through long-distance dispersal (LDD), (<i>iii</i>) Paleolithic range contraction induced by the last glacial maximum (LGM) and, (<i>iv</i>) Neolithic range expansions from one or two geographic origins (the Fertile Crescent and the Yangzi and Yellow River Basins). Next, we estimated genetic gradients from the simulated data and we found that they were sensible to the analyzed processes, especially to the range contraction induced by LGM and to the number of Neolithic expansions. Some scenarios were compatible with the observed east-west genetic gradient, such as the Paleolithic expansion with a range contraction induced by the LGM or two Neolithic range expansions from both the east and the west. In general, LDD increased the variance of genetic gradients among simulations. We interpreted the obtained gradients as a consequence of both <i>allele surfing</i> caused by range expansions and isolation by distance along the vast east-west geographic axis of this continent.</p>
Data from: Candidate gene SNP variation in floodplain populations of pedunculate oak (Quercus robur L.) near the species' southern range margin: weak differentiation yet distinct associations with water availability
<p>Populations residing near species' low-latitude range margins (LLM) often occur in warmer and drier environments than those in the core range. Thus, their genetic composition could be shaped by climatic drivers that differ from those occurring at higher latitudes, resulting in potentially adaptive variants of conservation value. Such variants could facilitate the adaptation of populations from other portions of the geographic range to similar future conditions anticipated under ongoing climate change. However, very few studies have assessed standing genetic variation at potentially adaptive loci in natural LLM populations. We investigated standing genetic variation at SNPs located within 117 candidate genes and its links to putative climatic selection pressures across 19 pedunculate oak (Quercus robur L.) populations distributed along a regional climatic gradient near the species' southern range margin in southeastern Europe. These populations are restricted to floodplain forests along large lowland rivers, whose hydric regime is undergoing significant shifts under modern rapid climate change. The populations showed very weak geographic structure, suggesting extensive genetic connectivity and gene flow or shared ancestry. We identified eight (6.2%) positive FST-outlier loci, and genotype-environment association analyses revealed consistent associations between SNP allele frequencies and several climatic variables linked to water availability. A total of 61 associations involving 37 SNPs (28.5%) from 35 annotated genes provided important insights into putative functional mechanisms in our system. Our findings provide empirical support for the role of LLM populations as sources of potentially adaptive variation that could enhance species' resilience to climate change-related pressures.</p>
Massively parallel coherent laser ranging using soliton microcomb
<p>Available data for "Massively parallel coherent laser ranging using soliton microcomb", published in Nature 561, 164-170 on May 14th. </p> <p>DOI of original paper: https://doi.org/10.1038/s41586-020-2239-3</p> <p>URL of original paper: <a href="https://www.nature.com/articles/s41586-020-2239-3">https://www.nature.com/articles/s41586-020-2239-3</a></p> <p><br> Execution tested with Matlab 2019a or newer on Windows. Unzip folder to access files.</p> <p>For Figures and extended data Figures execute "Figure*.m" and "ExtDataFigure*.mat" files in corresponding subfolders.<br> Contact johann.riemensberger@epfl.ch or johann.riemensberger@gmail.com if problems with matlab code arise. <br> All matlab code remains under copyright by the authors: Johann Riemensberger and Wenle Weng and is provided solely to be used to reproduce the figures of the aforementioned paper.</p> <p>Raw data for the figures is stored in folder .\Data, preprocessed data is stored in folder .\ProcessedData. GDS file of Si3N4 photonic damascene waveguide resonators is stored in folder: GDS_design. </p>
Data from: Tradeoffs with growth limit host range in complex life cycle helminths
Parasitic worms with complex life cycles have several developmental stages, with each stage creating opportunities to infect additional host species. Using a dataset for 973 species of trophically transmitted acanthocephalans, cestodes, and nematodes, we confirmed that worms with longer life cycles (i.e. more successive hosts) infect a greater diversity of host species and taxa (after controlling for study effort). Generalism at the stage level was highest for 'middle' life stages, the second and third intermediate hosts of long life cycles. By simulating life cycles in real food webs, we found that middle stages had more potential host species to infect, suggesting that opportunity constrains generalism. However, parasites usually infected fewer host species than expected from simulated cycles, suggesting generalism also has costs. There was no tradeoff in generalism from one stage to the next, but worms spent less time growing and developing in stages where they infected more taxonomically diverse hosts. Our results demonstrate that life cycle complexity favors high generalism, and host use across life stages is determined by both ecological opportunity and life history tradeoffs.
Data from: The contribution of hybridization to range‐wide population genetic structure in a Pacific coastal dune plant
<p>Premise of the study: Interspecific hybridization can cause genetic structure across species ranges if the mating system and degree of sympatry/parapatry with close relatives varies geographically. The coastal dune endemic <em>Camissoniopsis cheiranthifolia</em> (Onagraceae) exhibits genetic subdivisions across its range, some of which are associated with shifts in mating system from outcrossing to selfing, while others are not. For instance, strong differentiation between large-flowered, self-incompatible (LF-SI) and large-flowered, self-compatible (LF-SC) populations occurs without much reduction in outcrossing or obvious barriers to gene flow. We hypothesized that LF-SI diverged from LF-SC via hybridization with the predominantly inland SI sister species <em>C. bistort</em>a.</p> <p>Methods: We analyzed spatial proximity using 1460 herbarium records, and genetic variation at 12 microsatellites assayed for 805 and 404 individuals from 32 <em>C. cheiranthifolia</em> and 18 <em>C. bistorta</em> populations, respectively. We also assayed nine chloroplast microsatellites for 124 and 111 individuals from 27 and 19 populations, respectively. </p> <p>Key results: Closer parapatry was associated with unexpectedly high genetic continuity between LF-SI <em>C. cheiranthifolia</em> and <em>C. bistorta</em>. LF-SI genotypes clustered with <em>C. bistorta</em> exclusive of other <em>C. cheiranthifolia</em> genotypes. Similarly, pairwise FST among SI <em>C. cheiranthifolia</em> and <em>C. bistorta</em>, adjusted for geographic proximity, was not higher between heterospecific than conspecific populations. </p> <p>Conclusions: The lack of genetic differentiation between LF-SI <em>C. cheiranthifolia</em> and <em>C. bistorta</em> populations, even those located away from the zone of parapatry, suggests that LF-SI <em>C. cheiranthifolia</em> instead of hybridizing with <em>C. bistorta</em> is rather an ecotype of <em>C. bistorta</em> that has adapted to coastal dune habitat independent of other lineages in <em>C. cheiranthifolia</em> proper.</p>
Data from: Expressed mutational load increases towards the edge of a species' geographic range
There is no general explanation for why species have restricted geographic distributions. One hypothesis posits that range expansion or increasing scarcity of suitable habitat result in accumulation of mutational load due to enhanced genetic drift, which constrains population performance towards range limits and further expansion. We tested this hypothesis in the North American plant, Arabidopsis lyrata. We experimentally assessed mutational load by crossing plants of 20 populations from across the entire species range and by raising the offspring of within- and between-population crosses at five common garden sites within and beyond the range. Offspring performance was tracked over three growing seasons. The heterosis effect, depicting expressed mutational load, was increased in populations with heightened genomic estimates of load, longer expansion distance or long-term isolation, and a selfing mating system. The decline in performance of within-population crosses amounted to 80%. Mutation accumulation due to past range expansion and long-term isolation of populations in the area of range margins is therefore a strong determinant of population-mean performance, and the magnitude of effect may be sufficient to cause range limits.
Data from: Population genomic diversity and structure at the discontinuous southern range of the Great Gray Owl in North America
<p>Species' distributions are often discontinuous near the edge of the range where the environment may be more variable than the core of the range. Range discontinuity can reduce or cut off gene flow to small peripheral populations and lead to genetic drift and subsequent loss of genetic diversity. The southern extent of the Great Gray Owl ( Strixnebulosa) range in North America is discontinuous, unlike their northern core range across the boreal forests. We sampled owls from five different locations on the periphery of the range across the western US (Wyoming, Idaho, California, northern Oregon, and southern Oregon) to investigate genetic population structure and genetic diversity. Using a reduced-representation genomic sequencing approach to genotype 123 individuals at 4,817 single nucleotide polymorphic loci, we identified four genetically differentiated populations: California, southern Oregon, northern Oregon, and Wyoming and Idaho grouped together as a single Rocky Mountain population. The four genetically differentiated populations of Great Gray Owls identified in this study display high differentiation and low genetic variation, which is suggestive of long-term isolation and lack of connectivity, potentially caused by range discontinuity. The populations that lack habitat connectivity to the rest of the breeding range (i.e. those in California and Oregon) had lower genetic diversity than the Rocky Mountain population that is connected to the core of the range. These factors and other risks (such as disease and human-caused mortality) heighten susceptibility of these range-edge populations to future habitat and climate changes, genetic diversity erosion, and potential extinction vortex. For these reasons, protecting and monitoring this species on the southern edge of their range is vital.</p>
Personality driven life-history trade-offs differ in two sub-populations of free ranging predators
<p>1) Consistent individual differences in behaviour (i.e. personality) can be explained in an evolutionary context if they are favoured by life-history trade-offs as conceptualized in the pace-of-life syndrome (POLS) hypothesis. Theory predicts that faster growing individuals suffer higher mortality and that this trade-off is mediated through exploration/risk-taking personality, but empirical support for this remains limited and ambiguous. Equivocal support to the POLS hypothesis suggests that the link between life-history and personality may only emerge under certain circumstances. Understanding personality driven trade-offs would be facilitated by long-term studies in wild populations experiencing different ecological conditions.</p> <p>2) Here, we tested whether personality measured in semi-captivity was associated with a growth-mortality trade-off via risk-taking in the wild in two sub-populations of juvenile lemon sharks (Negaprion brevirostris) known to differ in their predator abundance. We expected stronger personality driven trade-offs in the predator-rich environment as compared to the predator-poor environment.</p> <p>3) Sharks were captured yearly from 1995 onwards allowing us to obtain long-term data on growth and apparent survival in each sub-population. We then used a novel open-field assay to test sharks for exploration personality yearly from 2012 to 2017. A subset of the tested sharks was monitored in the field using telemetry to document risk-taking behaviours. We tested (i) if fast explorers in captivity took more risks and grew faster in the wild and (ii) if natural selection acted against more explorative, faster growing sharks.</p> <p>4) In the sub-population with fewer predators, more explorative sharks in captivity took more risks in the wild and grew faster. In turn, larger, fast-growing sharks had lower apparent survival. In the predator-rich sub-population, despite finding selection on fast growth, we found no link between exploration personality and the growth-mortality trade-off.</p> <p>5) Our study demonstrates that the association between personality and life-history is favoured in some ecological contexts but not in others. We identify predator and resource abundance as two main potential drivers of the personality mediated trade-off and emphasize that future work on the POLS hypothesis would benefit from an approach integrating behaviour and life-history across ecological conditions.</p>
Data from: Hurricanes overcome migration lag and shape intraspecific genetic variation beyond a poleward mangrove range limit
<p>Expansion of many tree species lags behind climate-change projections. Extreme storms can rapidly overcome this lag, especially for coastal species, but how will storm-driven expansion shape intraspecific genetic variation? Do storms provide recruits only from the nearest sources, or from more distant sources? Answers to these questions have ecological and evolutionary implications, but empirical evidence is absent from the literature. Hurricane Irma provided an opportunity to address this knowledge gap at the northern range limit of the neotropical black mangrove (<i>Avicennia germinans</i>) on the Atlantic coast of Florida, USA. We observed massive post-hurricane increases in beach-stranded <i>A. germinans</i> propagules at, and past, this species' present-day range margin when compared to a previously-surveyed, non-hurricane year. Yet, propagule dispersal does not guarantee subsequent establishment and reproductive success (i.e., effective dispersal). We also evaluated prior effective dispersal along this coastline with isolated <i>A. germinans</i> trees identified beyond the most northern established population. We used 12 nuclear microsatellite loci to genotype hurricane-driven drift propagules from nine sites (n = 896 propagules) and isolated trees from four sites (n = 10 trees), determined their sources of origin, and estimated dispersal distances. Almost all drift propagules and all isolated trees came from the nearest sources. This research suggests that hurricanes are a prerequisite for poleward range expansion of a coastal tree species and that storms can shape the expanding gene pool by providing almost exclusively range-margin genotypes. These insights and empirical estimates of hurricane-driven dispersal distances should improve our ability to forecast distributional shifts of coastal species.</p>
Data from: The evolution of parasite host range in heterogeneous host populations
<p>Theory on the evolution of niche width argues that resource heterogeneity selects for niche breadth. For parasites, this theory predicts that parasite populations will evolve, or maintain, broader host ranges when selected in genetically diverse host populations relative to homogeneous host populations. To test this prediction, we selected the bacterial parasite Serratia marcescens to kill Caenorhabditis elegans in populations that were genetically heterogeneous (50% mix of two experimental genotypes) or homogeneous (100% of either genotype). After 20 rounds of selection, we compared the host range of selected parasites by measuring parasite fitness (i.e. virulence, the selected fitness trait) on the two focal host genotypes and on a novel host genotype. As predicted, heterogeneous host populations selected for parasites with a broader host range: these parasite populations gained or maintained virulence on all host genotypes. This result contrasted with selection in homogeneous populations of one host genotype. Here, host range contracted, with parasite populations gaining virulence on the focal host genotype and losing virulence on the novel host genotype. This pattern was not, however, repeated with selection in homogeneous populations of the second host genotype: these parasite populations did not gain virulence on the focal host genotype, nor did they lose virulence on the novel host genotype. Our results indicate that host heterogeneity can maintain broader host ranges in parasite populations. Individual host genotypes, however, vary in the degree to which they select for specialization in parasite populations.</p>
Data from: A resurrection study reveals limited evolution of thermal performance in response to recent climate change across the geographic range of the scarlet monkeyflower
<p>Evolutionary rescue can prevent populations from declining under climate change, and should be more likely at high-latitude, "leading" edges of species' ranges due to greater temperature anomalies and gene flow from warm-adapted populations. Using a resurrection study with seeds collected before and after a seven-year period of record warming, we tested for thermal adaptation in the scarlet monkeyflower <i>Mimulus</i> <i>cardinalis</i>. We grew ancestors and descendants from northern-edge, central, and southern-edge populations across eight temperatures. Despite recent climate anomalies, populations showed limited evolution of thermal performance curves. However, one southern population evolved a narrower thermal performance breadth by 1.31 °C, which matches the direction and magnitude of the average decrease in seasonality experienced. Consistent with the climate variability hypothesis, thermal performance breadth increased with temperature seasonality across the species' geographic range. Inconsistent with performance trade-offs between low and high temperatures across populations, we did not detect a positive relationship between thermal optimum and mean temperature. These findings fail to support the hypothesis that evolutionary response to climate change is greatest at the leading edge, and suggest that the evolution of thermal performance is unlikely to rescue most populations from the detrimental effects of rapidly changing climate.</p>
Range-extending tropical herbivores increase diversity, intensity and extent of herbivory functions in temperate marine ecosystems
1. Climate change is modifying species distributions around the world, forcing some species poleward, where they can alter trophic interactions. Many tropical herbivorous fishes have successfully expanded their ranges into temperate ecosystems, and while it is clear they drive increases in herbivory rates in specific localities, little is known about how they might affect the diversity of herbivory functions across large spatial scales, considering their interaction with assemblages of native herbivores in temperate habitats. 2. We assessed the spatial overlap and habitat associations of native temperate and range-expanding tropical herbivorous fishes in six sub-regions of south-western Australia to determine how incursions of tropical species may have affected the diversity, redundancy (index of uniqueness) and the 'spatial extent' (addition of functions in new areas) and 'intensity' (increasing density of functional groups) of specific herbivory functions in recipient ecosystems. 3. Tropical herbivores were more abundant in temperate ecosystems, forming schools from 40 (parrotfish) to 200 (rabbitfish) individuals strongly associated with seagrass meadows and reefs with high cover of turf algae. Overlap with temperate herbivores was highest in the northern sub-regions, forming unique assemblages, with no apparent species displacements. The addition of tropical species increased functional diversity and uniqueness (the complement of redundancy), introducing novel herbivory functions to many locations. Seagrass browsing increased in spatial extent (27%) and intensity (15 x), while seaweed browsing and grazing increased in intensity by up to 2.5 x in regions with high abundances of tropical herbivores. 4. Our results suggest that the diversity, intensity and spatial extent of different herbivory functions can change as tropical species with different habitat affinities, behaviors and diets shift their distributions poleward. Changes in functional redundancy are likely to be heterogeneous in space and might not increase initially because the diversity of herbivory functions is relatively low in some temperate marine ecosystems. However, there is the potential for greater redundancy as further tropical species arrive, their abundances increase and the spatial and functional overlap of communities rises.
Data from: Nitrogen enrichment accelerates mangrove range expansion in the temperate-tropical ecotone
Climate change and nutrient enrichment are two phenomena impacting coastal ecosystems. In coastal wetlands, mangroves in temperate-tropical ecotones are encroaching on adjacent saltmarshes, a pattern that is primarily attributed to warmer winter temperatures. Climate change is also expected to increase the vulnerability of coastal wetlands to eutrophication, and increases in nutrient availability may further mediate the rate of mangrove expansion. We investigated the consequences of nutrient enrichment on coastal wetlands in the mangrove-saltmarsh ecotone near the temperate edge of mangrove distribution along the northeast coast of Florida. We tested the hypothesis that nutrient enrichment enhances the ongoing, climate-driven expansion of mangroves into areas historically dominated by saltmarshes by increasing mangrove growth and cover, allowing them to outcompete and overgrow adjacent saltmarsh plants. We manipulated nitrogen (N) and phosphorus (P) availability and measured the effects on growth, cover, diversity, leaf traits and nutrient dynamics of Avicennia germinans. We found that A. germinans shrubs growing in the saltmarsh-mangrove ecotone in northern Florida grew taller, increased their canopies, and had higher reproductive output when enriched with N compared to control plants and P-enriched plants. Nutrient enrichment did not alter Sarcocornia perennis growth, and increased Batis maritima height but did not alter density or biomass. Nitrogen addition caused an increase in A. germinans cover and decreases in B. maritima cover and Simpson's index of diversity, suggesting that N enrichment, an ongoing phenomenon, can hasten the invasion of mangroves into saltmarshes by favoring mangrove growth and reproduction without significantly enhancing saltmarsh plant growth.
High genomic diversity in the bank vole at the northern apex of a range expansion: the role of multiple colonizations and end-glacial refugia
<p>The history of repeated northern glacial cycling and southern climatic stability has long dominated explanations for how genetic diversity is distributed within temperate species in Eurasia and North America. However, growing evidence indicates the importance of cryptic refugia for northern colonization dynamics. An excellent geographic region to assess this is Fennoscandia, where recolonization at the end of the last glaciation was restricted to specific routes and temporal windows. We used genomic data to analyze genetic diversity and colonization history of the bank vole (<i>Myodes glareolus</i>) throughout Europe (> 800 samples) with Fennoscandia as the northern apex. We inferred that bank voles colonized Fennoscandia multiple times by two different routes; with three separate colonizations via a southern land-bridge route deriving from a 'Carpathian' glacial refugium and one via a north-eastern route from an 'Eastern' glacial refugium near the Ural Mts. Clustering of genome-wide SNPs revealed tremendous diversity in Fennoscandia, with eight genomic clusters: three of Carpathian origin and five Eastern. Time estimates revealed that the first of the Carpathian colonizations occurred before the Younger Dryas (YD), meaning that the first colonists survived the YD in Fennoscandia. Results also indicated that introgression between bank and northern red-backed voles (<i>Myodes rutilus</i>) took place in Fennoscandia just after end-glacial colonization. Therefore, multiple colonizations from the same and different cryptic refugia, temporal and spatial separations and interspecific introgression have shaped bank vole genetic variability in Fennoscandia. Together, these processes drive high genetic diversity at the apex of the northern expansion in this model species.</p>
ISSR analysis of Tulipa suaveolens (Liliaceae) populations in the European part of the species range
<p>Tulipa suaveolens Roth is a decorative bulbous, polycarpic species in the Liliaceae family. Currently, the species populations are declining due to the degradation of natural steppes. In the present article, we evaluated the genetic diversity of 216 specimens from 22 natural T. suaveolens localities in the European part of the species range using 10 inter simple sequence repeat (ISSR) markers. The polymerase chain reaction (PCR) yielded 250 unambiguous and reproducible polymorphic bands with a mean polymorphism information content (PIC) value of 0.27. Neither the principal component analysis nor the clustering method split the dataset. However, the Bayesian model-based STRUCTURE analysis detected two genetic clusters of T. suaveolens. The analysis of the biogeographical distributional pattern of the revealed genetic groups confirmed our hypothesis that the evolution and distribution of T. suaveolens were likely affected by the Early Khvalynian transgression of the Caspian Sea and the following Enotayevsk regression. Furthermore, this hypothesis was supported by the results of the NEW HYBRIDS analysis identifying the specimens from the populations located outside the Early Khvalynian flooding limit as pure parents, while the specimens of the populations within the flooding limit were classified as backcrosses and second generation hybrids.</p>
Inbreeding and disease avoidance in a free‐ranging koala population
<p>Habitat destruction and fragmentation are increasing globally, forcing surviving species into small, isolated populations. Isolated populations typically experience heightened inbreeding risk, and associated inbreeding depression and population decline; although individuals in these populations may mitigate these risks through inbreeding avoidance strategies. For koalas, as dietary specialists already under threat in the northern parts of their range, increased habitat fragmentation and associated inbreeding costs are of great conservation concern. Koalas are known to display passive inbreeding avoidance through sex-biased dispersal, although population isolation will reduce dispersal pathways. We tested whether free-ranging koalas display active inbreeding avoidance behaviours. We used VHF tracking data, parentage reconstruction, and veterinary examination results to test whether female koalas make mate choices based on [1] relatedness, and [2] chlamydial disease in available mates. We found no evidence that female koalas based their mate choice on the relative relatedness of available mates. In fact, as the relatedness of potential mates increases, so did inbreeding events. We also found no evidence that female koalas based their mate choice on the chlamydial disease status of available mates. The absence of active inbreeding avoidance mechanisms in koalas is concerning from a conservation perspective, as small, isolated populations may be at even higher risk of inbreeding depression than expected. At-risk koala populations may require urgent conservation interventions to augment gene flow and reduce inbreeding risks. Similarly, if koalas are not avoiding mating with individuals with chlamydial disease, populations may be at higher risk from disease than anticipated, further impacting population viability.</p>
Data from: Barrier bednets target malaria vectors and expand the range of usable insecticides
<p>Transmission of <i>Plasmodium falciparum </i>malaria parasites occurs when nocturnal <i>Anopheles </i>mosquito vectors feed on human blood. In Africa, where malaria burden is greatest, bednets treated with pyrethroid insecticide were highly effective in preventing mosquito bites and reducing transmission, and essential to achieving unprecedented reductions in malaria until 2015. Since then, progress has stalled and with insecticidal bednets losing efficacy against pyrethroid-resistant <i>Anopheles</i> vectors, methods that restore performance are urgently needed to eliminate any risk of malaria returning to the levels seen prior to their widespread use throughout sub-Saharan Africa. Here we show that the primary malaria vector <i>Anopheles gambiae</i> is targeted and killed by small insecticidal net barriers positioned above a standard bednet, in a spatial region of high mosquito activity but zero contact with sleepers, opening the way for deploying many more insecticides on bednets than currently possible. Tested against wild pyrethroid-resistant <i>Anopheles gambiae </i>in Burkina Faso, pyrethroid bednets with organophosphate barriers achieved significantly higher killing rates than bednets alone. Treated barriers on untreated bednets were equally effective, without significant loss of personal protection. Mathematical modelling of transmission dynamics predicted reductions in clinical malaria incidence with barrier bednets that exceeded those of 'next-generation' nets recommended by WHO against resistant vectors. Mathematical models of mosquito-barrier interactions identified alternative barrier designs to increase performance. Barrier bednets that overcome insecticide resistance are feasible using existing insecticides and production technology, and early implementation of affordable vector control tools is a realistic prospect.</p>
Data from: Integrating population genetics to define conservation units from the core to the edge of Rhinolophus ferrumequinum western range
The greater horseshoe bat (<i>Rhinolophus ferrumequinum</i>) is among the most widespread bat species in Europe but it has experienced severe declines, especially in Northern Europe. This species is listed Near Threatened in the European IUCN Red List of Threatened Animals and it is considered to be highly sensitive to human activities and particularly to habitat fragmentation. Therefore, understanding the population boundaries and demographic history of populations of this species is of primary importance to assess relevant conservation strategies. In this study, we used 17 microsatellite markers to assess the genetic diversity, the genetic structure and the demographic history of <i>R. ferrumequinum</i> colonies in the western part of its distribution. We identified one large population showing high levels of genetic diversity and large population size. Lower estimates were found in England and northern France. Analyses of clustering and isolation by distance suggested that the Channel and the Mediterranean seas could impede <i>R. ferrumequinum</i> gene flow. These results provide important information to improve the delineation of <i>R. ferrumequinum</i> management units. We suggest that a large management unit corresponding to the population ranging from Spanish Basque country to northern France must be considered. Particular attention should be given to mating territories as they seem to play a key role in maintaining the high levels of genetic mixing between colonies. Smaller management units corresponding to English and northern France colonies must also be implemented. These insular or peripheral colonies could be at higher risk of extinction in a near future.
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.