Find research datasets worth reusing
Search datasets from major research repositories and use ShareScore to quickly assess how well each record supports discovery, access, and reuse.
1,999
datasets available to search
ShareScore release 0.9.0
Dataset results
1,999 results for “Endangered”
Data from: Spatial and temporal patterns of neutral and adaptive genetic variation in the endangered African wild dog (Lycaon pictus)
Deciphering patterns of genetic variation within a species is essential for understanding population structure, local adaptation and differences in diversity between populations. Whilst neutrally evolving genetic markers can be used to elucidate demographic processes and genetic structure, they are not subject to selection and therefore are not informative about patterns of adaptive variation. As such, assessments of pertinent adaptive loci, such as the immunity genes of the Major Histocompatibility Complex (MHC), are increasingly being incorporated into genetic studies. In this study we combined neutral (microsatellite, mtDNA) and adaptive (MHC class II DLA-DRB1 locus) markers to elucidate the factors influencing patterns of genetic variation in the African wild dog (Lycaon pictus); an endangered canid that has suffered extensive declines in distribution and abundance. Our genetic analyses found all extant wild dog populations to be relatively small (Ne < 30). Furthermore, through coalescent modelling, we detected a genetic signature of a recent and substantial demographic decline, which correlates with human expansion, but contrasts with findings in some other African mammals. We found strong structure of wild dog populations, indicating the negative influence of extensive habitat fragmentation and loss of gene flow between habitat patches. Across populations we found that the spatial and temporal structure of microsatellite and MHC diversity were correlated, and strongly influenced by demographic stability and population size, indicating the effects of genetic drift in these small populations. Despite this correlation, we detected signatures of selection at the MHC, implying that selection has not been completely overwhelmed by genetic drift.
Data from: Endemic species may have complex histories: within-refugium phylogeography of an endangered Iberian vole
Glacial refugia protected and promoted biodiversity during the Pleistocene, not only at a broader scale, but also for many endemics that contracted and expanded their ranges within refugial areas. Understanding the evolutionary history of refugial endemics is especially important in the case of endangered species to recognise the origins of their genetic structure and thus produce better informed conservation practices. The Iberian Peninsula is an important European glacial refugium, rich in endemics of conservation concern, including small mammals, such as the Cabrera vole (Microtus cabrerae). This near-threatened rodent is characterised by an unusual suite of genetic, life history and ecological traits, being restricted to isolated geographic nuclei in fast-disappearing Mediterranean sub-humid herbaceous habitats. To reconstruct the evolutionary history of the Cabrera vole, we studied sequence variation at mitochondrial, autosomal and sex-linked loci, using invasive and noninvasive samples. Despite low overall mitochondrial and nuclear nucleotide diversities, we observed two main well-supported mitochondrial lineages, west and east. Phylogeographic modelling in the context of the Cabrera vole's detailed fossil record, supports a demographic scenario of isolation of two populations during the Last Glacial Maximum (LGM) from a single focus in the southern part of the Iberian Peninsula. In addition, our data suggests subsequent divergence within the east, and secondary contact and introgression of the expanding western population, during the late Holocene. This work emphasises that refugial endemics may have a phylogeographic history as rich as that of more widespread species, and conservation of such endemics includes the preservation of that genetic legacy.
Data from: The biogeography of introgression in the critically endangered African monkey Rungweceubs kipunji
In the four years since its original description, the taxonomy of the kipunji (Rungwecebus kipunji), a geographically restricted and critically endangered African monkey, has been the subject of much debate, and recent research suggesting that the first voucher specimen of Rungwecebus has baboon mitochondrial DNA has intensified the controversy. We show that Rungwecebus from a second region of Tanzania has a distinct mitochondrial haplotype that is basal to a clade containing all Papio species and the original Rungwecebus voucher, supporting the placement of Rungwecebus as the sister taxon of Papio and its status as a separate genus. We suggest that the Rungwecebus population in the Southern Highlands has experienced geographically localized mitochondrial DNA introgression from Papio, while the Ndundulu population retains the true Rungwecebus mitochondrial genome.
Data from: Detection of an endangered aquatic heteropteran using environmental DNA in a wetland ecosystem
The use of environmental DNA (eDNA) has recently been employed to evaluate the distribution of various aquatic macroorganisms. Although this technique has been applied to a broad range of taxa, from vertebrates to invertebrates, its application is limited for aquatic insects such as aquatic heteropterans. Nepa hoffmanni (Heteroptera: Nepidae) is a small (approx. 23 mm) aquatic heteropteran that inhabits wetlands, can be difficult to capture and is endangered in Japan. The molecular tool eDNA was used to evaluate the species distribution of N. hoffmanni in comparison to that determined using hand-capturing methods in two regions of Japan. The eDNA of N. hoffmanni was detected at nearly all sites (10 eDNA-detected sites out of 14 sites), including sites where N. hoffmanni was not captured by hand (five eDNA-detected sites out of six captured sites). Thus, this species-specific eDNA technique can be applied to detect small, sparsely distributed heteropterans in wetland ecosystems. In conclusion, eDNA could be a valuable technique for the detection of aquatic insects inhabiting wetland habitats, and could make a significant contribution to providing distribution data necessary to species conservation.
Data from: Population genetic and field ecological analyses return similar estimates of dispersal over space and time in an endangered amphibian
The explosive growth of empirical population genetics has seen a proliferation of analytical methods leading to a steady increase in our ability to accurately measure key population parameters, including genetic isolation, effective population size, and gene flow in natural systems. Assuming they yield similar results, population genetic methods offer an attractive complement to, or replacement of, traditional field ecological studies. However, empirical assessments of the concordance between direct field ecological and indirect population genetic studies of the same populations are uncommon in the literature. In this study, we investigate genetic isolation, rates of dispersal, and population sizes for the endangered California tiger salamander, Ambystoma californiense, across multiple breeding seasons in an intact vernal pool network. We then compare our molecular results to a previously published study based on multi-year, mark-recapture data from the same breeding sites. We found that field and genetic estimates of population size were only weakly correlated, but dispersal rates were remarkably congruent across studies and methods. In fact, dispersal probability functions derived from genetic data and traditional field ecological data were a significant match, suggesting that either method can be used effectively to assess population connectivity. These results provide one of the first explicit tests of the correspondence between landscape genetic and field ecological approaches to measuring functional population connectivity and suggest that even single-year genetic samples can return biologically meaningful estimates of natural dispersal and gene flow.
Data from: Historical population size change and differentiation of relict populations of the endangered giant kangaroo rat
From a conservation management perspective it is important to understand how genetic diversity is partitioned across a species' range, including (1) identification of evolutionarily distinct units versus those recently isolated through anthropogenic activities and (2) the relative genetic contributions among components of fragmented (meta)populations. To address these questions, we investigated the phylogeography and metapopulation structure among relict populations of the endangered giant kangaroo rat (Dipodomys ingens) in the highly altered San Joaquin Desert Ecosystem. This keystone species underwent a ~97% range reduction over the past century, resulting in a current range that is highly fragmented, with two dominant northern and southern populations occurring 150 km apart. We sequenced >800 bp of mitochondrial DNA and genotyped 17 nuclear microsatellites in >275 D. ingens to assess the evolutionary relationship of these populations as well as the genetic structure within the northern metapopulation. A Bayesian Skyline Plot indicated that the species experienced a demographic expansion toward the end of the Pleistocene, with a recent population decline. Northern and southern D. ingens split 1,857–13,443 years ago, prior to the massive conversion of the San Joaquin Valley to irrigated agriculture. We recommend that the northern and southern populations of D. ingens be re-classified as distinct population segments under the United States Endangered Species Act. We also observed population structure and asymmetrical migration within northern D. ingens where the Tumey Hills acted as a source contributing gene flow to all peripheral populations. This emphasized the importance of this location in the conservation of the metapopulation as a whole.
Data from: Genome sequence and population declines in the critically endangered greater bamboo lemur (Prolemur simus) and implications for conservation
Background: The greater bamboo lemur (Prolemur simus) is a member of the Family Lemuridae that is unique in their dependency on bamboo as a primary food source. This Critically Endangered species lives in small forest patches in eastern Madagascar, occupying a fraction of its historical range. Here we sequence the genome of the greater bamboo lemur for the first time, and provide genome resources for future studies of this species that can be applied across its distribution. Results: Following whole genome sequencing of five individuals we identified over 152,000 polymorphic single nucleotide variants (SNVs), and evaluated geographic structuring across nearly 19k SNVs. We characterized a stronger signal associated with a north-south divide than across elevations for our limited samples. We also evaluated the demographic history of this species, and infer a dramatic population crash. This species had the largest effective population size (estimated between ~900,000 to one million individuals) between approximately 60,000-90,000 years before present (ybp), during a time in which global climate change affected terrestrial mammals worldwide. We also note the single sample from the northern portion of the extant range had the largest effective population size around 35,000 ybp. Conclusions: From our whole genome sequencing we recovered an average genomic heterozygosity of 0.0037%, comparable to other lemurs. Our demographic history reconstructions recovered a probable climate-related decline (60-90,000 ybp), followed by a second population decrease following human colonization, which has reduced the species to a census size of approximately 1,000 individuals. The historical distribution was likely a vast portion of Madagascar, minimally estimated at 44,259 km2, while the contemporary distribution is only ~1,700 km2. The decline in effective population size of 89-99.9% corresponded to a vast range retraction. Conservation management of this species is crucial to retain genetic diversity across the remaining isolated populations.
Data from: Estimating effects of species interactions on populations of endangered species
Global change causes community composition to change considerably through time, with ever-new combinations of interacting species. To study the consequences of newly established species interactions, one available source of data could be observational surveys from biodiversity monitoring. However, approaches using observational data would need to account for niche differences between species and for imperfect detection of individuals. To estimate population sizes of interacting species, we extended N-mixture models that were developed to estimate true population sizes in single species. Simulations revealed that our model is able to disentangle direct effects of dominant on subordinate species from indirect effects of dominant species on detection probability of subordinate species. For illustration, we applied our model to data from a Swiss amphibian monitoring program and showed that sizes of expanding water frog populations were negatively related to population sizes of endangered yellow-bellied toads and common midwife toads and partly of natterjack toads. Unlike other studies that analyzed presence and absence of species, our model suggests that the spread of water frogs in Central Europe is one of the reasons for the decline of endangered toad species. Thus, studying population impacts of dominant species on population sizes of endangered species using data from biodiversity monitoring programs should help to inform conservation policy and to decide whether competing species should be subject to population management.
Data from: SNPs selected by information content outperform randomly selected microsatellite loci for delineating genetic identification and introgression in the endangered dark European honeybee (Apis mellifera mellifera)
The honeybee (Apis mellifera) has been threatened by multiple factors, including pests and pathogens, pesticides, and loss of locally adapted gene complexes due to replacement and introgression. In western Europe, the genetic integrity of the native A.m. mellifera (M-lineage) is endangered due to trading and intensive queen breeding with commercial subspecies of eastern European ancestry (C-lineage). Effective conservation actions require reliable molecular tools to identify purebred A.m. mellifera colonies. Microsatellites have been preferred for identification of A.m. mellifera stocks across conservation centers. However, owing to high-throughput, easy transferability between laboratories and low genotyping error, SNPs promise to become popular. Here, we compared the resolving power of a widely utilized microsatellite dataset to detect structure and introgression with that of different datasets that combine a variable number of SNPs selected for their information content and genomic proximity to the microsatellites. Contrary to every SNP dataset, microsatellites were unable to clearly separate the two European lineages in the PCA space. Mean introgression proportions were identical across the two marker types, although at the individual level microsatellites' performance was relatively poor at the upper range of introgression, a result reflected by their lower precision. Although mean accuracy was relatively high across datasets (>91%), microsatellites were the least accurate and the top-ranked informative 144 SNPs were the most accurate. Comparisons amongst the SNP datasets showed that those combining SNPs flanking microsatellites performed worst. Our results suggest that SNPs are more powerful for identification of A.m. mellifera colonies, especially when they are selected by information content.
Data from: Museum DNA reveals the demographic history of the endangered Seychelles warbler
The importance of evolutionary conservation – how understanding evolutionary forces can help guide conservation decisions – is widely recognized. However, the historical demography of many endangered species is unknown, despite the fact that this can have important implications for contemporary ecological processes and for extinction risk. Here, we reconstruct the population history of the Seychelles warbler (Acrocephalus sechellensis) – an ecological model species. By the 1960s, this species was on the brink of extinction, but its previous history is unknown. We used DNA samples from contemporary and museum specimens spanning 140 years to reconstruct bottleneck history. We found a 25% reduction in genetic diversity between museum and contemporary populations, and strong genetic structure. Simulations indicate that the Seychelles warbler was bottlenecked from a large population, with an ancestral Ne of several thousands falling to <50 within the last century. Such a rapid decline, due to anthropogenic factors, has important implications for extinction risk in the Seychelles warbler, and our results will inform conservation practices. Reconstructing the population history of this species also allows us to better understand patterns of genetic diversity, inbreeding and promiscuity in the contemporary populations. Our approaches can be applied across species to test ecological hypotheses and inform conservation.
Data from: Facultative parthenogenesis in a critically endangered wild vertebrate
Facultative parthenogenesis — the ability of sexually reproducing species to sometimes produce offspring asexually — is known from a wide range of ordinarily sexually reproducing vertebrates in captivity, including some birds, reptiles and sharks 1, 2 and 3. Despite this, free-living parthenogens have never been observed in any of these taxa in the wild, although two free-living snakes were recently discovered each gestating a single parthenogen — one copperhead (Agkistrodon contortrix) and one cottonmouth (Agkistrodon piscivorus). Vertebrate parthenogens are characterized as being of the homogametic sex (e.g., females in sharks, males in birds) and by having elevated homozygosity compared to their mother 1, 2 and 3, which may reduce their viability. Although it is unknown if either of the parthenogenetic snakes would have been carried to term or survived in the wild, facultative parthenogenesis might have adaptive significance. If this is true, it is reasonable to hypothesize that parthenogenesis would be found most often at low population density, when females risk reproductive failure because finding mates is difficult. Here, we document the first examples of viable parthenogens living in a normally sexually reproducing wild vertebrate, the smalltooth sawfish (Pristis pectinata). We also provide a simple approach to screen any microsatellite DNA database for parthenogens, which will enable hypothesis-driven research on the significance of vertebrate parthenogenesis in the wild.
Data from: A low-cost solution for documenting distribution and abundance of endangered marine fauna and impacts from fisheries
Fisheries bycatch is a widespread and serious issue that leads to declines of many important and threatened marine species. However, documenting the distribution, abundance, population trends and threats to sparse populations of marine species is often beyond the capacity of developing countries because such work is complex, time consuming and often extremely expensive. We have developed a flexible tool to document spatial distribution and population trends for dugongs and other marine species in the form of an interview questionnaire supported by a structured data upload sheet and a comprehensive project manual. Recognising the effort invested in getting interviewers to remote locations, the questionnaire is comprehensive, but low cost. The questionnaire has already been deployed in 18 countries across the Indo-Pacific region. Project teams spent an average of USD 5,000 per country and obtained large data sets on dugong distribution, trends, catch and bycatch, and threat overlaps. Findings indicated that >50% of respondents had never seen dugongs and that 20% had seen a single dugong in their lifetimes despite living and fishing in areas of known or suspected dugong habitat, suggesting that dugongs occured in low numbers. Only 3% of respondents had seen mother and calf pairs, indicative of low reproductive output. Dugong hunting was still common in several countries. Gillnets and hook and line were the most common fishing gears, with the greatest mortality caused by gillnets. The questionnaire has also been used to study manatees in the Caribbean, coastal cetaceans along the eastern Gulf of Thailand and western Peninsular Malaysia, and river dolphins in Peru. This questionnaire is a powerful tool for studying distribution and relative abundance for marine species and fishery pressures, and determining potential conservation hotspot areas. We provide the questionnaire and supporting documents for open-access use by the scientific and conservation communities.
Data from: Utility of island populations in reintroduction programs—relationships between Arabian gazelles (Gazella arabica) from the Farasan Archipelago and endangered mainland populations
Understanding local adaptation and population differentiation is vital to the success of reintroduction initiatives. Like other mammals living on islands, Arabian gazelles (G. arabica) show reduced body size on the Farasan archipelago, which we corroborated in this study through morphometric analyses of skulls. In light of the steep population decline on the Arabian Peninsula—but stable population development on the archipelago—we tested the potential suitability of Farasan gazelles as a source for reintroductions on the mainland. We, therefore, investigated genetic differentiation between Farasan and mainland populations using eleven nuclear microsatellite loci and detected a distinct genetic cluster exclusively present on the archipelago, which we inferred to be separated from the mainland cluster for less than 2,000 years. About 30% of sampled individuals from Farasan Islands showed assignment to a mainland cluster with signs of ongoing introgression. Analyses using the Isolation-with-Migration model confirmed recent (probably human-induced) bidirectional exchange of gazelles between mainland and island populations. Hence, the surprisingly uniform island dwarfism most likely reflects phenotypic plasticity, i.e., altered morphology as a direct consequence of harsh environmental conditions and resource limitation on the archipelago. Should a further decline of Arabian gazelles on the mainland necessitate restocking in the future, Farasan gazelles may thus become an additional source for captive breeding programs.
Data from: Markov switching autoregressive models for interpreting vertical movement data with application to an endangered marine apex predator
1.Time series of animal movement obtained from bio-loggers are becoming widely used across all taxa. These data are nowadays of high quality, combining high resolution with precision, as the tags are able to collect for longer times and store larger quantities of data. Due to their nature, high-frequency data sequences often pose non-trivial problems in time series analysis: non-linearity, non-Normality, non-stationarity, and long memory. These issues can be tackled by modelling the data sequence as a realization of a stochastic regime switching process. 2. We suggest a novel Markov switching autoregressive model where the hidden Markov chain is non-homogeneous, with time-varying transition probabilities, whose dynamics depend on the dynamics of some contemporary categorical covariates. 3. To illustrate the use of the method, we apply it to the depth profiles of four individuals of flapper skate (Dipturus cf. intermedia) in order to identify swimming behaviours. Individual time series were obtained from data storage tags that recorded pressure every two minutes. The environmental covariates used were lunar phase (a proxy for the spring-neap tidal cycle), lunar cycle, and diel cycle. For all individuals two states (or regimes) were always selected (the autoregressive order was either three or four), representing different regimes of animal activity, i.e., state 1 for resting or horizontal swimming or slow vertical movement; state 2 for fast ascending and descending. The cycle of the four lunar phases was the only environmental covariate that explained the hidden state dynamics in all individuals, whereas lunar cycle was selected for two individuals and diel cycle for one only. 4. The method is an efficient approach to fit one-dimensional tag data using categorical environmental covariates, and to classify the observations into a small number of states representing individual behaviours of tagged individuals.
Data from: Genetic evidence of a population bottleneck and inbreeding in the endangered New Zealand sea lion, Phocarctos hookeri
The New Zealand sea lion (NZSL) is of high conservation concern due to its limited distribution and its declining population size. Historically it occupied most of coastal New Zealand, but is now restricted to a few coastal sites in southern mainland New Zealand and the sub-Antarctic Islands. NZSLs have experienced a recent reduction in population size due to sealing in the 1900s, which is expected to have resulted in increased inbreeding and a loss of genetic variation, potentially reducing the evolutionary capacity of the species and negatively impacting on its long-term prospects for survival. We used 17 microsatellite loci, previously shown to have cross-species applications in pinnipeds, to determine locus- and population-specific statistics for 1205 NZSLs from seven consecutive breeding seasons. We show that the NZSL population has a moderate level of genetic diversity in comparison to other pinnipeds. We provide genetic evidence for a population reduction, likely caused by historical sealing, and a measure of allele sharing/parental relatedness (internal relatedness, IR) that is suggestive of increased inbreeding in pups that died during recent epizootic episodes. We hypothesise that population bottlenecks and non-random mating have impacted on the population genetic architecture of NZSLs, affecting its population recovery.
Targeted conservation genetics of the endangered chimpanzee
<p>Populations of the common chimpanzee (<i>Pan troglodytes</i>) are in an impending risk of going extinct in the wild as a consequence of damaging anthropogenic impact on their natural habitat and illegal pet and bushmeat trade. Conservation management programmes for the chimpanzee have been established outside their natural range (<i>ex situ</i>), and chimpanzees from these programmes could potentially be used to supplement future conservation initiatives in the wild (<i>in situ</i>). However, these programmes have often suffered from inadequate information about the geographical origin and subspecies ancestry of the founders. Here, we present a newly designed capture array with 60 000 ancestry informative markers used to infer ancestry of individual chimpanzees in <i>ex situ</i> populations and determine geographical origin of confiscated sanctuary individuals. From a test panel of 167 chimpanzees with unknown origins or subspecies labels, we identify 90 suitable non-admixed individuals in the European Association of Zoos and Aquaria (EAZA) <i>Ex situ</i> Programme (EEP). Equally important, another 46 individuals have been identified with admixed subspecies ancestries, which therefore over time, should be naturally phased out of the breeding populations. With potential for future re-introduction to the wild, we determine the geographical origin of 31 individuals that were confiscated from the illegal trade and demonstrate the promises of using non-invasive sampling in future conservation action plans. Collectively, our genomic approach provides an exemplar for <i>ex situ </i>management of endangered species and offers an efficient tool in future <i>in situ </i>efforts to combat the illegal wildlife trade.</p>
Data from: Evidence of opposing fitness effects of parental heterozygosity and relatedness in a critically endangered marine turtle?
How individual genetic variability relates to fitness is important in understanding evolution and the processes affecting populations of conservation concern. Heterozygosity-fitness correlations (HFCs) have been widely used to study this link in wild populations, where key parameters that affect both variability and fitness, such as inbreeding, can be difficult to measure. We used estimates of parental heterozygosity and genetic similarity ('relatedness') derived from 32 microsatellite markers to explore the relationship between genetic variability and fitness in a population of the critically endangered hawksbill turtle, Eretmochelys imbricata. We found no effect of maternal MLH (multilocus heterozygosity) on clutch size or egg success rate, and no single-locus effects. However, we found effects of paternal MLH and parental relatedness on egg success rate that interacted in a way that may result in both positive and negative effects of genetic variability. Multicollinearity in these tests was within safe limits, and null simulations suggested the effect was not an artefact of using paternal genotypes reconstructed from large samples of offspring. Our results could imply a tension between inbreeding and outbreeding depression in this system, which is biologically feasible in turtles: female-biased natal philopatry may elevate inbreeding risk and local adaptation, and both processes may be disrupted by male-biased dispersal. Although this conclusion should be treated with caution due to a lack of significant identity disequilibrium, our study shows the importance of considering both positive and negative effects when assessing how variation in genetic variability affects fitness in wild systems.
Data from: Genetic diversity and population history of the endangered killifish Aphanius baeticus
The secondary freshwater fish fauna of the western-Iberian Peninsula basin is primarily restricted to local coastal streams, and man-made salt evaporation ponds, etc., which are susceptible to periodical flood and drought events. Despite its uniqueness in ecological adaptation to high saltwater tolerance, very little is known about this fauna's population dynamics and evolutionary history. The killifish, Aphanius baeticus (Cyprinodontidae) is an endemic species restricted to river basins on Spain's southern Atlantic coastline, considered as "Endangered." In this study, the genetic structure, diversity and historical demography of A. baeticus were analyzed using mitochondrial (cytochrome b, N = 131) and nuclear (4 out of 19 microsatellites tested, N = 288) markers across its distribution range. The phylogenetic and networking reconstruction revealed subtle phylogeographic structuring. A scattered expansion at the beginning of the interglacial periods, coupled with posterior events of extinction and colonization caused by periodical cycles of flooding, could explain the absence of well-defined phylogenetic relationships among populations. Moreover, very low genetic diversity values and a weak population differentiation were detected. We proposed that dispersals allowed by periodic floods connecting river drainages may have promoted a wide genetic exchange among populations and could have contributed to the current genetic relatedness of these populations.
Genomics confirms surprising ecological divergence and isolation in an endangered butterfly
<p>Phylogeographic patterns in phytophagous organisms are often contextualized in light of geographic isolation and ecological (host, habitat) specialization. However, assessing the relative impact of these phenomena is not straightforward, even in areas where phylogeography is well-studied, such as the California Floristic Province. Here, we use genome-wide markers to elucidate population genomic and phylgeographic patterns for a group of monophytophagous butterflies in southern California. This group is of high conservation interest because it includes the El Segundo blue, <i>Euphilotes battoides allyni</i>,<i> </i>one of the first insects listed under the U.S. Endangered Species Act, and a newly discovered population putatively assigned to <i>E. b. allyni</i>. Despite using the same unique host and coastal habitat, our results indicate that the newly discovered populations are not <i>E. b. allyni</i> and are more closely related to geographically proximate populations of the <i>E. battoides</i> group using a different habitat host. Aside from <i>E. b. allyni</i> and the newly discovered populations, the rest of the group shows only fine-scale structure and apparently maintains genetic connectivity throughout southern California, across a vast range of habitats and climates, and on multiple hosts. Thus, habitat and host specialization did not elicit genetic isolation in neighboring populations suggesting that: 1) other phenomena are needed to explain the remarkable and idiosyncratic divergence of these highly restricted, proximate, taxa, and 2) fine-scale genomic markers suggest broader implications for understanding the mechanisms of speciation and reinvestigation of phylogeographic patterns in regions like the California Floristic Province.</p>
Data from: AFLP diversity and spatial structure of Calycophyllum candidissimum (Rubiaceae), a dominant tree species of Nicaragua's critically endangered seasonally dry forest
The Central American seasonally dry tropical (SDT) forest biome is one of the worlds' most endangered ecosystems, yet little is known about the genetic consequences of its recent fragmentation. A prominent constituent of this biome is Calycophyllum candidissimum, an insect-pollinated and wind-dispersed canopy tree of high socio-economic importance, particularly in Nicaragua. Here, we surveyed amplified fragment length polymorphisms across 13 populations of this species in Nicaragua to elucidate the relative roles of contemporary vs historical factors in shaping its genetic variation. Genetic diversity was low in all investigated populations (mean HE=0.125), and negatively correlated with latitude. Overall population differentiation was moderate (ΦST=0.109, P<0.001), and Bayesian analysis of population structure revealed two major latitudinal clusters (I: 'Pacific North'+'Central Highland'; II: 'Pacific South'), along with a genetic cline between I and II. Population-based cluster analyses indicated a strong pattern of 'isolation by distance' as confirmed by Mantel's test. Our results suggest that (1) the low genetic diversity of these populations reflects biogeographic/population history (colonisation from South America, Pleistocene range contractions) rather than recent human impact; whereas (2) the underlying process of their isolation by distance pattern, which is best explained by 'isolation by dispersal limitation', implies contemporary gene flow between neighbouring populations as likely facilitated by the species' efficient seed dispersal capacity. Overall, these results underscore that even tree species from highly decimated forest regions may be genetically resilient to habitat fragmentation due to species-typical dispersal characteristics, the necessity of broad-scale measures for their conservation notwithstanding.
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.