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9,097 results for “wild”
Data from: The relevance of gene flow with wild relatives in understanding the domestication process
<p><span><span><span>The widespread use of genomic tools has allowed for a deeper understanding of the genetics and the evolutionary dynamics of domestication. Recent studies have suggested that multiple domestications and introgression are more common than previously thought. However, the ability to correctly infer the domestication process depends on having an adequate representation of wild relatives. Cultivated maize (<i>Zea mays</i> spp. <i>mays</i>) is one of the most important crops in the world, with a long and a relatively well documented history of domestication. The current consensus points towards a single domestication event from teosinte <i>Zea mays</i> spp. <i>parviglumis</i> from the Balsas Basin in Southwest central Mexico. However, the underlying diversity of teosintes from lowlands <i>Z. mays</i> spp<i>. parviglumis</i> and highlands <i>Zea mays</i> spp. <i>mexicana</i>) was not taken into account in early studies. We used 32,739 SNPs obtained from 29 teosinte populations and 43 maize landraces to explore the relationship between wild and cultivated members of <i>Zea.</i> We then inferred levels of gene flow among teosinte populations and maize, the degree of population structure of <i>Zea mays</i> subspecies, and potential domestication location of maize. We confirmed a strong geographic structure within <i>Z. mays </i>spp. <i>parviglumis</i> and documented multiple gene flow events with other members of the genus, including an event between <i>Z. mays</i> spp. <i>mexicana </i>and maize. Our results suggest that the likely ancestor of maize may have been domesticated not in the Balsas Basin as previously thought, but in Jalisco or in the Pacific coast, and that different populations of the teosinte subspecies have contributed to modern maize's gene pool. Our results points towards a long period of domestication marked by gene flow with wild relatives, making domestication a long and ongoing process. </span></span></span></p>
Multigenerational exposure to elevated temperatures leads to a reduction in standard metabolic rate in the wild
<ol> <li>In light of global climate change, there is a pressing need to understand and predict the capacity of populations to respond to rising temperatures. Metabolic rate is a key trait that is likely to influence the ability to cope with climate change. Yet, empirical and theoretical work on metabolic rate responses to temperature changes has so far produced mixed results and conflicting predictions.</li> <li>Our study addresses this issue using a novel approach of comparing fish populations in geothermally warmed lakes and adjacent ambient-temperature lakes in Iceland. This unique 'natural experiment' provides repeated and independent examples of populations experiencing contrasting thermal environments for many generations over a small geographic scale, thereby avoiding the confounding factors associated with latitudinal or elevational comparisons. Using Icelandic sticklebacks from three warm and three cold habitats, we measured individual metabolic rates across a range of acclimation temperatures to obtain reaction norms for each population.</li> <li>We found a general pattern for a lower standard metabolic rate in sticklebacks from warm habitats when measured at a common temperature, as predicted by Krogh's rule. Metabolic rate differences between warm- and cold-habitat sticklebacks were more pronounced at more extreme acclimation temperatures, suggesting the release of cryptic genetic variation upon exposure to novel conditions, which can reveal hidden evolutionary potential. We also found a stronger divergence in metabolic rate between thermal habitats in allopatry than sympatry, indicating that gene flow may constrain physiological adaptation when dispersal between warm and cold habitats is possible.</li> <li>In sum, our study suggests that fish may diverge toward a lower standard metabolic rate in a warming world, but this might depend on connectivity and gene flow between different thermal habitats.</li> </ol>
Data from: Immune stability predicts tuberculosis infection risk in a wild mammal
Immunity is one of the most variable phenotypic traits in animals; however, some individuals may show less fluctuation in immune traits, resulting in stable patterns of immune variation over time. It is currently unknown whether immune variation has consequences for infectious disease risk. In this study, we identified moderately stable immune traits in wild African buffalo and asked whether the stability of these traits affected bovine tuberculosis (TB) infection risk. We found that adaptive immune traits such as the level of IFN-γ released after white blood cell stimulation, the number of circulating lymphocytes, and the level of antibodies against bovine adenovirus-3 were moderately repeatable (i.e. stable) over time, whereas parameters related to innate immunity either had low repeatability (circulating eosinophil numbers) or were not repeatable (e.g. neutrophil numbers, plasma bacteria killing capacity). Intriguingly, individuals with more repeatable IFN-γ and lymphocyte levels were at a significantly higher risk of acquiring TB infection. In stark contrast, average IFN-γ and lymphocyte levels were poor predictors of TB risk, indicating that immune variability rather than absolute response level better captured variation in disease susceptibility. This work highlights the important and under-appreciated role of immune variability as a predictor of infection risk.
Data from: Predictable adaptive trajectories of sexual coloration in the wild: evidence from replicate experimental guppy populations
The question of whether populations evolve predictably and consistently under similar selective regimes is fundamental to understanding how adaptation proceeds in the wild. We address this question with a replicated evolution experiment focused upon male sexual coloration in guppies (Poecilia reticulata). Fish were transplanted from a single high predation population in the Guanapo River to four replicate, guppy‐free low predation headwater streams. Two streams had their canopies thinned to adjust the setting under which male coloration is displayed and perceived. We assessed evolutionary divergence using second‐generation lab‐bred offspring of fish sampled four to six years following translocation. A prior experiment of the same design, performed in an adjacent drainage, resulted in the evolution of more extensive orange, black and iridescent markings. We however found evidence for expansion only in structural coloration (iridescent blue/green), no change in orange, and a reduction in black. This response amplifies earlier findings for Guanapo fish, revealing that trajectories of color elaboration differ among drainages. We also found that color phenotypes evolved more greatly at the thinned‐canopy sites. Our findings support the predictability of sexual trait evolution in the wild, and underscore the importance of signaling conditions and ornamental starting points in shaping adaptive trajectories.
Ecological patterns of root nodule diversity in cultivated and wild rooibos populations: a community prediction approach
<p>There is interest in understanding the factors behind the biogeography of root-associated bacteria due to the joint effects that plant host, climate, and soil conditions can have on bacterial diversity. For legume crops with remaining wild populations, this is of even more importance, because the effects of cropping on undisturbed root-associated bacterial communities can be addressed. Here, we used a community prediction approach to describe the diversity of the root nodule bacterial communities of rooibos (<i>Aspalathus linearis</i>), an endemic legume crop from South Africa. The goal was to reveal whether patterns of root nodule community composition in paired cultivated and wild rooibos populations could be related to geographical distance, plant traits, and plant population type (i.e. cultivated or uncultivated). We identified a core of dominant and widespread <i>Mesorhizobium</i> ZOTUs that each defined one of 4 different root nodule community classes. Rooibos cultivation impacted root nodule bacterial diversity at regional and local scales, while the geographical origin of the root nodule communities was the strongest predictor of root nodule community structure. Beyond impacts of cultivation on root nodule bacterial diversity, this study suggests a mixture of dispersal limitation and ecological drift regionally, and selection by different plant populations locally, define the biogeography of rooibos root nodule bacterial communities. </p>
Data from: The genomic landscape of rapid repeated evolutionary adaptation to toxic pollution in wild fish
Atlantic killifish populations have rapidly adapted to normally lethal levels of pollution in four urban estuaries. Through analysis of 384 whole killifish genome sequences and comparative transcriptomics in four pairs of sensitive and tolerant populations, we identify the aryl hydrocarbon receptor–based signaling pathway as a shared target of selection. This suggests evolutionary constraint on adaptive solutions to complex toxicant mixtures at each site. However, distinct molecular variants apparently contribute to adaptive pathway modification among tolerant populations. Selection also targets other toxicity-mediating genes and genes of connected signaling pathways; this indicates complex tolerance phenotypes and potentially compensatory adaptations. Molecular changes are consistent with selection on standing genetic variation. In killifish, high nucleotide diversity has likely been a crucial substrate for selective sweeps to propel rapid adaptation.
Data from: Context-dependent costs and benefits of tuberculosis resistance traits in a wild mammalian host
Disease acts as a powerful driver of evolution in natural host populations, yet individuals in a population often vary in their susceptibility to infection. Energetic trade-offs between immune and reproductive investment lead to the evolution of distinct life-history strategies, driven by the relative fitness costs and benefits of resisting infection. However, examples quantifying the cost of resistance outside of the laboratory are rare. Here, we observe two distinct forms of resistance to bovine tuberculosis (bTB), an important zoonotic pathogen, in a free-ranging African buffalo (Syncerus caffer) population. We characterize these phenotypes as 'infection resistance', in which hosts delay or prevent infection, and 'proliferation resistance', in which the host limits the spread of lesions caused by the pathogen after infection has occurred. We found weak evidence that infection resistance to bTB may be heritable in this buffalo population (h2=0.10) and comes at the cost of reduced body condition and marginally reduced survival once infected, but also associates with an overall higher reproductive rate. Infection resistant animals thus appear to follow a 'fast' pace of life syndrome, in that they reproduce more quickly but die upon infection. In contrast, proliferation resistance had no apparent costs and was associated with measures of positive host health- such as having a higher body condition and reproductive rate. This study quantifies striking phenotypic variation in pathogen resistance and provides evidence for a link between life history variation and a disease resistance trait in a wild mammalian host population.
African wild dog dispersal and implications for management
Successful conservation of species that roam and disperse over large areas requires detailed understanding of their movement patterns and connectivity between subpopulations. But empirical information on movement, space use, and connectivity is lacking for many species, and data acquisition is often hindered when study animals cross international borders. The African wild dog (Lycaon pictus) exemplifies such species that require vast undisturbed areas to support viable, self‐sustaining populations. To study wild dog dispersal and investigate potential barriers to movements and causes of mortality during dispersal, between 2016 and 2019 we followed the fate of 16 dispersing coalitions (i.e., same‐sex group of ≥1 dispersing African wild dogs) in northern Botswana through global positioning system (GPS)‐satellite telemetry. Dispersing wild dogs covered ≤54 km in 24 hours and traveled 150 km to Namibia and 360km to Zimbabwe within 10 days. Wild dogs were little hindered in their movements by natural landscape features, whereas medium to densely human‐populated landscapes represented obstacles to dispersal. Human‐caused mortality was responsible for >90% of the recorded deaths. Our results suggest that a holistic approach to the management and conservation of highly mobile species is necessary to develop effective research and evidence‐based conservation programs across transfrontier protected areas, including the need for coordinated research efforts through collaboration between national and international conservation authorities.
Impacts of environmental heterogeneity on natural selection in a wild bird population
<p>Natural selection has been studied for several decades, resulting in the computation of thousands of selection estimates. Although the importance of environmental conditions on selection has often been suggested, published estimates rarely take into account the effects of environmental heterogeneity on selection patterns. Here, we estimated linear and non‐linear viability selection gradients on morphological traits of 12 days‐old nestlings in a wild population of tree swallows (<i>Tachycineta bicolor</i>) across a large‐scale heterogeneous study system in southern Québec, Canada. We assessed the environmental drivers of nestling survival and evaluated their effects on strength and direction of selection gradients. Separate analyses of environmental variables showed that high temperatures and heavy rainfall caused stronger positive linear selection on morphological traits. Weaker linear selection was also measured in more extensively cultivated areas. Both strength and shape of non‐linear quadratic and correlational components of selection were modified by environmental variables. Considering all environmental variables revealed that precipitation since hatching affected patterns of linear selection on traits, while temperatures since hatching shaped nonlinear selection patterns. Our study underlines the importance of quantifying linear and non‐linear natural selection under various environmental conditions and how the evolutionary response of traits may be affected by ongoing human‐induced environmental changes.</p>
Data from: Seasonal food scarcity prompts long-distance foraging by a wild social bee
Foraging is an essential process for mobile animals and its optimization serves as a foundational theory in ecology and evolution; however, drivers of foraging are rarely investigated across landscapes and seasons. Using a common bumble bee species from the Western US (Bombus vosnesenskii), we ask if seasonal decreases in food resources prompt changes in foraging behavior and space use. We employ a unique integration of population genetic tools and spatially-explicit foraging models to estimate foraging distances and rates of patch visitation for wild bumble bee colonies across three study regions and two seasons. By mapping the locations of 669 wild-caught individual foragers, we find substantial variation in colony-level foraging distances, often exhibiting a 60-fold difference within a study region. Our analysis of visitation rates indicates that foragers display a preference for high-cover destination patches and forage significantly further for these patches, but only in the summer, when landscape-level resources are low. Overall, these results indicate that an increasing proportion of long-distance foraging bouts take place in the summer. As pollinators, the foraging dynamics of wild bees are of urgent concern given the potential impacts of global change on their movement and services. The behavioral shift towards long-distance foraging with seasonal declines in food resources suggests a novel phenologically-directed approach to landscape-level pollinator conservation and increased evaluation of late-season floral resources.
Wild chimpanzees exhibit human-like aging of glucocorticoid regulation
<p><span>Cortisol, a key product of the stress response, has critical influences on degenerative aging in humans. In turn, cortisol production is affected by senescence of the hypothalamic-pituitary-adrenal (HPA) axis, leading to progressive dysregulation and increased cortisol exposure. These processes have been studied extensively in industrialized settings, but few comparative data are available from humans and closely-related species living in natural environments, where stressors are very different. Here, we examine age-related changes in urinary cortisol in a 20-year longitudinal study of wild chimpanzees (N = 59 adults) in the Kanyawara community of Kibale National Park, Uganda. We tested for three key features of HPA aging identified in many human studies: increased average levels, a blunted diurnal rhythm, and enhanced response to stressors. Using linear mixed models, we found that aging was associated with a blunting of the diurnal rhythm and a significant linear increase in cortisol, even after controlling for changes in dominance rank. These effects did not differ by sex. Aging did not increase sensitivity to energetic stress or social status. Female chimpanzees experienced their highest levels of cortisol during cycling (versus lactation), and this effect increased with age. Male chimpanzees experienced their highest levels when exposed to sexually-attractive females, but this effect was diminished by age. Our results indicate that chimpanzees share some key features of HPA aging with humans. These findings suggest that impairments of HPA regulation are intrinsic to the aging process in hominids and are neither side effects of extended human lifespan nor of atypical environments.</span></p>
Data from: Plasticity of plant defense and its evolutionary implications in wild populations of Boechera stricta
Phenotypic plasticity is thought to impact evolutionary trajectories by shifting trait values in a direction that is either favored by natural selection ("adaptive plasticity") or disfavored ("nonadaptive" plasticity). However, it is unclear how commonly each of these types of plasticity occurs in natural populations. To answer this question, we measured glucosinolate defensive chemistry and reproductive fitness in over 1,500 individuals of the wild perennial mustard Boechera stricta, planted in four common gardens across central Idaho, USA. Glucosinolate profiles—including total glucosinolate concentration as well as the relative abundances and overall diversity of different compounds—were strongly plastic both among habitats and within habitats. Patterns of glucosinolate plasticity varied greatly among genotypes. Plasticity among sites was predicted to affect fitness in 27.1% of cases; more often than expected by chance, glucosinolate plasticity increased rather than decreased relative fitness. In contrast, we found no evidence for within-habitat selection on glucosinolate reaction norm slopes (i.e., plasticity along a continuous environmental gradient). Together, our results indicate that glucosinolate plasticity may improve the ability of B. stricta populations to persist after migration to new habitats.
Data from: Methylation of avpr1a in the cortex of wild prairie voles: effects of CpG position and polymorphism
DNA methylation can cause stable changes in neuronal gene expression, but we know little about its role in individual differences in the wild. In this study, we focus on the vasopressin 1a receptor (avpr1a), a gene extensively implicated in vertebrate social behaviour, and explore natural variation in DNA methylation, genetic polymorphism and neuronal gene expression among 30 wild prairie voles (Microtus ochrogaster). Examination of CpG density across 8 kb of the locus revealed two distinct CpG islands overlapping promoter and first exon, characterized by few CpG polymorphisms. We used a targeted bisulfite sequencing approach to measure DNA methylation across approximately 3 kb of avpr1a in the retrosplenial cortex, a brain region implicated in male space use and sexual fidelity. We find dramatic variation in methylation across the avrp1a locus, with pronounced diversity near the exon–intron boundary and in a genetically variable putative enhancer within the intron. Among our wild voles, differences in cortical avpr1a expression correlate with DNA methylation in this putative enhancer, but not with the methylation status of the promoter. We also find an unusually high number of polymorphic CpG sites (polyCpGs) in this focal enhancer. One polyCpG within this enhancer (polyCpG 2170) may drive variation in expression either by disrupting transcription factor binding motifs or by changing local DNA methylation and chromatin silencing. Our results contradict some assumptions made within behavioural epigenetics, but are remarkably concordant with genome-wide studies of gene regulation.
Data from: Highly diversified crop-livestock farming systems reshape wild bird communities
<p>Agricultural intensification is a leading threat to bird conservation. Highly diversified farming systems that integrate livestock and crop production might promote a diversity of habitats useful to native birds foraging across otherwise-simplified landscapes. At the same time, these features might be attractive to non-native birds linked to a broad range of disservices to both crop and livestock production. We evaluated the influence of crop-livestock integration on wild bird richness and density along a north-south transect spanning the U.S. west coast. We surveyed birds on 52 farms that grew primarily mixed vegetables and fruits alone or integrated livestock into production. Crop-livestock systems harbored higher native bird density and richness relative to crop only farms, a benefit more pronounced on farms embedded in non-natural landscapes. Crop-livestock systems bolstered native insectivores linked to the suppression of agricultural pest insects but did not bolster native granivores that may be more likely to damage crops. Crop-livestock systems also significantly increased the density of non-native birds, primarily European starlings (<i>Sturnus vulgaris</i>) and house sparrows (<i>Passer domesticus</i>) that may compete with native birds for resources. Models supported a small, positive correlation between non-native density and overall native bird density as well as between non-native density and native granivore density.<a name="_Hlk19446924">Relative to crop-only farms, on average crop-livestock systems exhibited 1.5 times higher patch richness, 2.4 times higher density of farm structures, 7.3 times smaller field sizes, 2.4 times greater integration of woody crops, and 5.3 times greater integration of pasture/hay habitat on farm.</a> Wild birds may have responded to this habitat diversity and/or associated food resources. Individual farm factors had significantly lower predictive power than farming system alone (ΔCIC = 80.2), suggesting crop-livestock systems may impact wild birds through a suite of factors that change with system conversion. Collectively, our findings suggest that farms that integrate livestock and crop production can attract robust native bird communities, especially within landscapes devoted to intensified food production. However, additional work is needed to demonstrate persistent farm bird communities through time, eco-physiological benefits to birds foraging on these farms, and net effects of both native and non-native wild birds in agroecosystems. </p>
Data from: Transmission pathways and spillover of an erythrocytic bacterial pathogen from domestic cats to wild felids
Many pathogens infect multiple hosts, and spillover from domestic to wild species poses a significant risk for spread of diseases that threaten wildlife and humans. Documentation of cross-species transmission, and unravelling the mechanisms that drive it, remains a challenge. Focusing on co-occurring domestic and wild felids, we evaluate possible transmission mechanisms and evidence of spillover of 'Candidatus Mycoplasma haemominutum' (CMhm), an erythrocytic bacterial parasite of cats. We examine transmission and possibility of spillover by analysing CMhm prevalence, modeling possible transmission pathways, deducing genotypes of CMhm pathogens infecting felid hosts based on sequences of the bacterial 16S rRNA gene, and conducting phylogenetic analyses with ancestral state reconstruction to identify likely cross-species transmission events. Model selection analyses suggest both indirect (i.e., spread via vectors) and direct (i.e., via inter-specific predation) pathways may play a role in CMhm transmission. Phylogenetic analyses indicate that transmission of CMhm appears to predominate within host species, with occasional spillover, at unknown frequency, between species. These analyses are consistent with transmission by predation of smaller cats by larger species, with subsequent within-species persistence after spillover. Our results implicate domestic cats as a source of global dispersal and spillover to wild felids via predation. We contribute to the emerging documentation of predation as a common means of pathogen spillover from domestic to wild cats, including pathogens of global conservation significance. These findings suggest risks for top predators as bioaccumulators of pathogens from subordinate species.
Data from: Maternal oxidative stress and reproduction: testing the constraint, cost and shielding hypotheses in a wild mammal
1. Oxidative stress has been proposed as a central causal mechanism underlying the life history trade-off between current and future reproduction and survival in wild animals. 2. Whereas mixed evidence suggests that maternal oxidative stress may act both as a constraint and a cost to reproduction, some studies have reported a lack of association between reproduction and maternal oxidative stress. 3. The oxidative shielding hypothesis offers an alternative explanation, suggesting that mothers may pre-emptively mitigate the oxidative costs of reproduction by increasing antioxidant defences prior to reproduction. 4. We tested the oxidative constraint, cost, and shielding hypotheses using a longitudinal field study of oxidative stress levels in a species that breeds using daily energy income, the Columbian ground squirrel (Urocitellus columbianus). 5. Elevated maternal oxidative damage prior to reproduction was associated with higher maternal investment in litter mass at birth, but not at weaning. 6. Breeding females increased their antioxidant capacity and decreased their oxidative damage from birth to lactation compared to non-breeding females measured at the same time periods. However, lower maternal oxidative stress during lactation was not associated with higher offspring survival or mass growth over this period. 7. Our results provide little evidence for maternal oxidative stress acting as a constraint on, or cost to, reproduction in Columbian ground squirrels, but partially support the idea that oxidative shielding occurred to buffer potential oxidative costs of reproduction.
Listening and watching: do camera traps or acoustic sensors more efficiently detect wild chimpanzees in an open habitat?
<p>1. With one million animal species at risk of extinction, there is an urgent need to regularly monitor threatened species. However, in practice this is challenging, especially with wide-ranging, elusive and cryptic species or those that occur at low density.<br> 2. Here we compare two non-invasive methods, passive acoustic monitoring (n=12) and camera trapping (n=53), to detect chimpanzees (Pan troglodytes) in a savanna-woodland mosaic habitat at the Issa Valley, Tanzania. With occupancy modelling we evaluate the efficacy of each method, using the estimated number of sampling days needed to establish chimpanzee absence with 95% probability, as our measure of efficacy.<br> 3. Passive acoustic monitoring was more efficient than camera trapping in detecting wild chimpanzees. Detectability varied over seasons, likely due to social and ecological factors that influence party size and vocalization rate. The acoustic method can infer chimpanzee absence with less than ten days of recordings in the field during the late dry season, the period of highest detectability, which was five times faster than the visual method.<br> 4. Synthesis and applications: Despite some technical limitations, we demonstrate that passive acoustic monitoring is a powerful tool for species monitoring. Its applicability in evaluating presence/absence, especially but not exclusively for loud call species, such as cetaceans, elephants, gibbons or chimpanzees provides a more efficient way of monitoring populations and inform conservation plans to mediate species-loss.</p>
Data from: Ovarian cycling and reproductive state shape the vaginal microbiota in wild baboons
Background: The vaginal microbiome is an important site of bacterial-mammalian symbiosis. This symbiosis is currently best characterized for humans, where lactobacilli dominate the microbial community and may help defend women against infectious disease. However, lactobacilli do not dominate the vaginal microbiota of any other mammal studied to date, raising key questions about the forces that shape the vaginal microbiome in non-human mammals. Results: We used Illumina sequencing of the bacterial 16S rRNA gene to investigate variation in the taxonomic composition of the vaginal microbiota in 48 baboons (Papio cynocephalus), members of a well-studied wild population in Kenya. Similar to prior studies, we found that the baboon vaginal microbiota was not dominated by lactobacilli. Despite this difference, and similar to humans, reproductive state was the dominant predictor of baboon vaginal microbiota, with pregnancy, postpartum amenorrhea, and ovarian cycling explaining 18% of the variance in community composition. Furthermore, among cycling females, a striking 39% of variance in community composition was explained by ovarian cycle phase, with an especially distinctive microbial community around ovulation. Peri-ovulatory females exhibited the highest relative abundance of lactic acid-producing bacteria compared to any other phase, with a mean relative abundance of 44%. To a lesser extent, sexual behavior, especially a history of shared sexual partners, also predicted vaginal microbial similarity between baboons. Conclusions: Despite striking differences in their dominant microbes, both human and baboon vaginal microbiota exhibit profound changes in composition in response to reproductive state, ovarian cycle phase, and sexual behavior. We found major shifts in composition during ovulation, which may have implications for disease risk and conception success. These findings highlight the need for future studies to account for fine-scale differences in reproductive state, particularly differences between the various phases of the ovarian cycle. Overall, our work contributes to an emerging understanding of the forces that explain intra- and inter-individual variation in the mammalian vaginal microbiome, with particular emphasis on its role in host health and disease risk.
Assessing changes in genomic divergence following a century of human mediated secondary contact among wild and captive-bred ducks
<p>Along with manipulating habitat, the direct release of domesticated individuals into the wild is a practice used world-wide to augment wildlife populations. We test between possible outcomes of human-mediated secondary contact using genomic techniques at both historical and contemporary time scales for two iconic duck species. First, we sequence several thousand ddRAD-seq loci for contemporary mallards (<i>Anas platyrhynchos</i>) throughout North America, and two domestic mallard-types (i.e., known game-farm mallards and feral Khaki Campbell's). We show that North American mallards may well be becoming a hybrid swarm due to interbreeding with domesticated game-farm mallards released for hunting. Next, to attain a historical perspective, we applied a bait-capture array targeting thousands of loci in century-old (1842-1915) and contemporary (2009-2010) mallard and American black duck (<i>A. rubripes</i>) specimens. We conclude that American black ducks and mallards have always been closely related, with a divergence time of ~600,000 years before present, and likely evolved through prolonged isolation followed by limited bouts of gene flow (i.e., secondary contact). They continue to maintain genetic separation, a finding that overturns decades of prior research and speculation suggesting the genetic extinction of the American black duck due to contemporary interbreeding with mallards. Thus, despite having high rates of hybridization, actual gene flow is limited between mallards and American black ducks. Conversely, our historical and contemporary data confirm that the intensive stocking of game-farm mallards during the last ~100 years has fundamentally changed the genetic integrity of North America's wild mallard population, especially in the east. It thus becomes of great interest to ask whether the iconic North American mallard is declining in the wild due to introgression of maladaptive traits from domesticated forms. Moreover, we hypothesize that differential gene flow from domestic game-farm mallards into the wild mallard population may explain the overall temporal increase in differentiation between wild black ducks and mallards, as well as the uncoupling of genetic diversity and effective population size estimates across time in our results. Finally, our findings highlight how genomic methods can recover complex population histories by capturing DNA preserved in traditional museum specimens.</p>
Data from: Genotyping by sequencing and genome–environment associations in wild common bean predict widespread divergent adaptation to drought
Drought will reduce global crop production by >10% in 2050 substantially worsening global malnutrition. Breeding for resistance to drought will require accessing crop genetic diversity found in the wild accessions from the driest high stress ecosystems. Genome–environment associations in crop wild relatives reveal natural adaptation, and therefore can be used to identify adaptive variation. We explored this approach in the food crop Phaseolus vulgaris L., characterizing 86 geo-referenced wild accessions using Genotyping by Sequencing (GBS) to discover single-nucleotide-polymorphisms (SNPs). The wild beans represented Mesoamerica, Guatemala, Colombia, Ecuador/Northern Peru and Andean groupings. We found high polymorphism with a total of 22,845 SNPs across the 86 accessions loci that confirmed genetic relationships for the groups. As a second objective, we quantified allelic associations with a bioclimatic-based drought index using 10 different statistical models that accounted for population structure. Based on the optimum model, 115 SNPs in 90 regions, widespread in all 11 common bean chromosomes, were associated with the bioclimatic-based drought index. A gene coding for an Ankyrin repeat-containing protein and a phototropic-responsive NPH3 gene were identified as potential candidates. Genomic windows of 1Mb containing associated SNPs had more positive Tajima's D scores than windows without associated markers. This indicates that adaptation to drought, as estimated by bioclimatic variables, has been under natural divergent selection, suggesting that drought tolerance may be favorable under dry conditions but harmful in humid conditions. Our work exemplifies that genomic signatures of adaptation are useful for germplasm characterization, potentially enhancing future marker-assisted selection and crop improvement.
ScienceDex guides
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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.