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.
3,101
datasets available to search
ShareScore release 0.9.0
Dataset results
3,101 results for “Historical”
FIGURE 11. A–D. Reteporella ilala n in Novel taxa of Cheilostomata Bryozoa discovered in the historical backlogs of the Iziko South African Museum
FIGURE 11. A–D. Reteporella ilala n. sp. A. Close-up of the orifice with beaded anter and suboral avicularium forming a pseudosinus (SAMC-A028986) (scale bar = 0.1 mm, magnified x200). B. Developing ooecium and different types of avicularia (SAMC-A029107) (scale bar = 0.2 mm, magnified x100). C. View of ovicelled zooid with ooecium covered by secondary calcification (SAMC-A029107) (scale bar = 0.2 mm, magnified x75). D. Close-up of ooecia covered by secondary calcification, except frontal fissure (SAMC-A029107) (scale bar = 0.1 mm, magnified x150). E–F. Triphyllozoon sp. (SAMC-A028905) E. View of trabeculae and autozooids (scale bar = 0.4 mm, magnified x35). F. Orifice and adventitious avicularia (scale bar = 0.2 mm, magnified x75).
FIGURE 9. A–F. Phidolopora chakra n in Novel taxa of Cheilostomata Bryozoa discovered in the historical backlogs of the Iziko South African Museum
FIGURE 9. A–F. Phidolopora chakra n. sp. (SAMC-A029097) A. Partial view of a colony fragment showing ovicelled zooids and fenestrulae (scale bar = 0.4 mm, magnified x50). B. Abfrontal view of a colony fragment showing conspicuous vibices and two types of adventitious avicularia (scale bar = 0.2 mm, magnified x75). C. Close-up of an ovicell and avicularia (scale bar = 0.1 mm, magnified x200). D. Close-up of the orifice with beaded anter and shallow sinus (scale bar = 0.05 mm, magnified x500). E. Developing ooecium (scale bar = 0.1 mm, magnified x200). F. Close-up of ovicells with median convexity and secondary calcification (scale bar = 0.1 mm, magnified x200).
FIGS. 1–9. Historical types. 1 in A revision of the Anthaxia (Haplanthaxia) dispar Kerremans species-group (Coleoptera: Buprestidae: Anthaxiini)
FIGS. 1–9. Historical types. 1—Anthaxia dispar Kerremans, 1898, holotype, female 7.1 mm; 2—A. hyperlasia Obenberger, 1928, holotype, female, 8.9 mm; 3—A. komareki Obenberger, 1931, holotype, male, 4.8 mm; 4—A. lasioptera Obenberger, 1915, holotype, female, 7.3 mm; 5—A. pilifrons Kerremans, 1898, holotype, male, 7.5 mm; 6—A. vulpes Théry, 1930, holotype, female, 7.2 mm, © MNHN; 7—Anthaxia (Haplathaxia) aethiopica sp. nov., holotype, male, 5.7 mm; 8—A. (H.) caerulea sp. nov., holotype, male, 8.6 mm; 9—A. (H.) dispar Kerremans, 1898, (RSA, Limpopo), male, 7.6 mm.
Reproductive success of the threatened San Clemente Bell's Sparrow in recovering habitats is similar to success in historical habitat
<p>The San Clemente Bell's Sparrow <i>Artemisiospiza belli clementeae</i> is a federally threatened subspecies endemic to San Clemente Island, California. Previous research suggested dependence on boxthorn (<i>Lycium californicum</i>) as breeding habitat and nesting substrate; however, this conclusion was based on data collected when introduced feral ungulates had severely degraded the soil and vegetation cover. Since removal of the ungulates, native vegetation has gradually increased and the San Clemente Bell's Sparrows have expanded into areas where habitat had been unsuitable. To explore how Bell's Sparrows use these areas, we examined reproductive metrics associated with habitat covariates gathered at 214 nest sites used by Bell's Sparrows from 2014 ̶ 2016. We found that nest success in boxthorn habitat, previously considered an essential habitat for Bell's Sparrow nesting, was similar to success in alternative habitat types. Our findings contradict previous conclusions that Bell's Sparrows were boxthorn-dependent. We believe this previously documented relationship was likely due to the lack of available alternative nesting habitat following years of feral ungulate degradation, and Bell's Sparrows now reproduce in multiple habitat types and throughout most of San Clemente Island. Furthermore, our findings illustrate the importance of long-term monitoring and corresponding adaptive management when monitoring species in changing and recovering landscapes.The San Clemente Bell's Sparrow <i>Artemisiospiza belli clementeae</i> is a federally threatened subspecies endemic to San Clemente Island, California. Previous research suggested dependence on boxthorn (<i>Lycium californicum)</i> as breeding habitat and nesting substrate; however, this conclusion was based on data collected when introduced feral ungulates had severely degraded the soil and vegetation cover. Since removal of the ungulates, native vegetation has gradually increased and the San Clemente Bell's Sparrows have expanded into areas where habitat had been unsuitable. To explore how Bell's Sparrows use these areas, we examined reproductive metrics associated with habitat covariates gathered at 214 nest sites used by Bell's Sparrows from 2014 ̶ 2016. We found that nest success in boxthorn habitat, previously considered an essential habitat for Bell's Sparrow nesting, was similar to success in alternative habitat types. Our findings contradict previous conclusions that Bell's Sparrows were boxthorn-dependent. We believe this previously documented relationship was likely due to the lack of available alternative nesting habitat following years of feral ungulate degradation, and Bell's Sparrows now reproduce in multiple habitat types and throughout most of San Clemente Island. Furthermore, our findings illustrate the importance of long-term monitoring and corresponding adaptive management when monitoring species in changing and recovering landscapes.</p>
CMIP5-historical dataset on Temperature and Precipitation
<p>CMIP5-historical dataset on Temperature and Precipitation</p>
Data from: Past distribution of epiphyllous liverworts in China: the usability of historical data
Epiphyllous liverworts form a special group of bryophytes that primarily grow on the leaves of understory vascular plants in tropical and subtropical evergreen broadleaf forests. Being sensitive to moisture and temperature changes, epiphyllous liverworts are often consider to be good indicators of climate change and forest degradation. However, they are a poorly collected and taxonomically complicated group, with an only partly identified distribution pattern. In this study, we built four models based on 24 environmental variables at four different spatial resolutions (i.e., 1 km, 5 km, 10 km, and 15 km) to predict the past distribution of epiphyllous liverworts in China, using Maxent model and 63 historical location records (i.e., presence-only data). Both area under the curve of the receiver operating characteristic (AUC) and true skill statistic (TSS) methods are used to assess the model performance. Results showed that the model with the predictors at a 15-km resolution achieved the highest predictive accuracy (AUC=0.946; TSS=0.880), although there was no statistically significant difference between the four models (p > 0.05). The most significant environmental variables included aridity, annual precipitation, precipitation of wettest month, precipitation of wettest quarter, precipitation of warmest quarter, annual mean NDVI, and minimum NDVI. The predicted suitable areas for epiphyllous liverworts were mainly located in the south of Yangtze River and seldom exceeds 35° N, which were consistent with the museum and herbarium records, as well as the historical records in scientific literatures. Our study further demonstrated the value of historical data to ecological and evolutionary studies.
Data from: Disentangling the Pelomedusa complex using type specimens and historical DNA (Testudines: Pelomedusidae)
Recent research has shown that the helmeted terrapin (Pelomedusa subrufa), a species that occurs throughout sub-Saharan Africa, in Madagascar and the southwestern Arabian Peninsula, consists of several deeply divergent genetic lineages. Here we examine all nominal taxa currently synonymized with Pelomedusa subrufa (Bonnaterre, 1789) and provide mitochondrial DNA sequences of type specimens or topotypic material for most taxa. Lectotypes are designated for Testudo galeata Schoepff, 1792, Pentonyx capensis Duméril & Bibron, 1835, Pelomedusa nigra Gray, 1863, Pelomedusa galeata var. disjuncta Vaillant & Grandidier, 1910, and Pelomedusa galeata damarensis Hewitt, 1935. For Pelomedusa gasconi Rochebrune, 1884, a taxon without preserved type material, a neotype is designated. Type material of Pentonix americana Cornalia, 1849, a nominal species without credible type locality, is lost and its identity remains questionable. Also the holotype of Pelomedusa galeata orangensis Hewitt, 1935 is lost, but its allocation to the only genetic lineage occurring in South Africa is unambiguous. Phylogenetic analyses of type sequences or topotypic material reveal that the remaining nominal taxa represent three of the nine previously identified lineages of Pelomedusa. Among these three lineages is the South African one. Type specimens of Pentonyx gehafie Rüppell, 1835 correspond to an additional distinct lineage. The present study provides a sound basis for a subsequent integrative taxonomic revision of the Pelomedusa complex.
Data from: Mauritius on fire: tracking historical human impacts on biodiversity loss
Fire was rare on Mauritius prior to human arrival (AD 1598); subsequently three phases of elevated fire activity occurred: c. 1630-1747, 1787-1833, and 1950-modern. Elevated fire frequency coincided with periods of high human impact evidenced from the historical record, and is linked to the extinction of island endemics.
Data from: Matrix correspondence tests on the DNA phylogeny of the Tenerife lacertid elucidate both historical causes and morphological adaptation
Previous studies using partial regression Mantel tests of matrix correspondence on within-island geographic variation in the color pattern of the Tenerife (Canary Islands) lacertid lizard (Gallotia galloti) support natural selection for different north--south climatically determined biotopes but do not support any historical cause. However, tests on the DNA phylogeny based primarily on population data from 57 localities on Tenerife support the hypothesis that there were populations on two putative precursor islands that have come into secondary contact and introgressed after these islands were joined to form Tenerife by the eruption of the Canadas edifice. Subsequent partial Mantel tests continue to support the hypothesis that color pattern is adapted to the climatic biotopes even when this phylogenetic information is taken into account by (1) testing for color pattern adaptation separately within each lineage and (2) testing for color pattern adaptation across the entire island while considering the molecular phylogenetic relationships as representing an alternative explanation. Selection has largely expunged any trace of the geological history from current morphological variation, and the introgression of these island populations after an estimated 0.7 million years of separation gives an insight into the relationships between allopatric divergence and reproductive isolation.
Data from: Return of the ghosts of dispersal past: historical spread and contemporary gene flow in the blue sea star Linckia laevigata
Marine animals inhabiting the Indian and Pacific oceans have some of the most extensive species ranges in the world, sometimes spanning over half the globe. These Indo-Pacific species present a challenge for study with both geographic scope and sampling density as limiting factors. Here, we augment and aggregate phylogeographic sampling of the iconic blue sea star, Linckia laevigata Linnaeus, 1758, and present one of the most geographically comprehensive genetic studies of any Indo-Pacific species to date, sequencing 392 base pairs of mitochondrial COI from 791 individuals from 38 locations spanning over 14,000 km. We first use a permutation based multiple-regression approach to simultaneously evaluate the relative influence of historical and contemporary gene flow together with putative barriers to dispersal. We then use a discrete diffusion model of phylogeography to infer the historical migration and colonization routes most likely used by L. laevigata across the Indo-Pacific. We show that estimates of genetic structure have a stronger correlation to geographic distances than to "oceanographic" distances from a biophysical model of larval dispersal, reminding us that population genetic estimates of gene flow and genetic structure are often shaped by historical processes. While the diffusion model was equivocal about the location of the mitochondrial most recent common ancestor (MRCA), we show that gene flow has generally proceeded in a step-wise manner across the Indian and Pacific oceans. We do not find support for previously described barriers at the Sunda Shelf and within Cenderwasih Bay. Rather, the strongest genetic disjunction is found to the east of Cenderwasih Bay along northern New Guinea. These results underscore the importance of comprehensive range-wide sampling in marine phylogeography.
Current climate overrides historical effects on species richness and range size of freshwater plants in Europe and North America
<p>1. The latitudinal diversity gradient (LDG) hypothesis suggests that species richness should be highest at low latitudes, whereas Rapoport's rule states that largest ranges ought to be found for species at high latitudes. However, there is no consensus over these patterns and their underlying drivers in the freshwater realm.</p> <p>2. We investigated species richness and mean range size of freshwater plants in 50 km × 50 km grid cells across Europe (40°N to 71°N) and North America (25°N to 78°N), supplemented with data based on 1° latitudinal bands for mean range size. We were especially interested to find out whether there are similarities and differences in these ecogeographical patterns and their underlying drivers between the continents due to their contrasting historical characteristics, spatial extent and topography. </p> <p>3. First, we used partial regression to reveal whether species richness and mean range size of freshwater plants have a linear or quadratic relationship with latitude. Second, we employed variation partitioning based on partial regression to model relationships between plant species richness and mean range size and four explanatory variable groups (i.e., environmental features, current climate, historical climate and geographical location). Third, we utilized boosted regression tree analysis to further investigate species richness and mean range size of freshwater plants in relation to a set of explanatory variables. </p> <p>4. Our results revealed that species richness showed relatively similar patterns in relation to latitude between the continents. Similarly, mean range size trends were alike in North America whether we used 50 km x 50 km grid cell data or 1° latitudinal bands. Instead, different patterns in mean range size emerged between the used data sets in Europe. For both of species richness and mean range size, current climate (with different individual predictor variables) was the main driver in both the continents, but historical effects had a small influence on the response variables.</p> <p>5. <i>Synthesis</i>. Our findings indicated that major ecogeographical rules can strongly vary for the same taxonomic group across broad scales between continents. It is also premature to rely solely on well-known terrestrial taxonomic groups when drawing generalizations about ecogeographical rules.</p>
Data from: The effect of historical legacy on adaptation: do closely related species respond to the environment in the same way?
The many documented examples of parallel and convergent evolution in similar environments are strong evidence for the role of natural selection in the evolution of trait variation. However, species may respond to selection in different ways; idiosyncrasies of their evolutionary history may affect how different species respond to the same selective pressure. To determine whether evolutionary history affects trait-environment associations in a recently diverged lineage, we investigated within-species trait-environment associations in the white proteas, a closely related monophyletic group. We first used MANOVAs to determine the relative importance of shared response to selection, evolutionary history, and unique responses to selection on trait variation. We found that on average, similar associations to the environment across species explained trait variation, but that the species had different mean trait values. We also detected species-specific associations of traits to the environmental gradients. To identify the traits associated uniquely to the environment we used a structural equation model. Our analysis showed that the species differed in how their traits were associated with each of the environmental variables. Further, in the cases of two root traits (root mass and root length:mass ratio), two species differed in the direction of their associations (e.g. populations in one species had heavier roots in warmer areas, and populations in the other species had lighter roots in warmer areas). Our study shows that even in a closely related group of species, evolutionary history may have an effect on both the size and direction of adaptations to the environment.
Data from: Which frugivory‐related traits facilitated historical long‐distance dispersal in the custard apple family (Annonaceae)?
Aim Long-distance dispersal has contributed to the disjunct biogeographical distribution of rain forest plants – something that has fascinated biogeographers since Humboldt's time. However, the dispersal 'agent' for these tropical plant lineages remains puzzling. Here, we investigate which frugivory-related traits may have facilitated past intercontinental long-distance dispersal in the custard apple family (Annonaceae), a major vertebrate-dispersed tropical plant family. We hypothesize that long-distance dispersal was associated with the evolution of traits related to dispersal by large-bodied mammals (e.g. large, dull-coloured, 'megafaunal' fruits) and strong-flying, ocean-crossing birds and bats (e.g. dehiscent, moniliform or cauliflorous fruits). Location Global Taxon Annonaceae Methods We used a fossil-calibrated phylogenetic framework to infer the biogeographic history of 234 Annonaceae species (10%, covering nearly all genera) in relation to the evolution of 15 frugivory-related traits, using maximum likelihood and Bayesian inferences. Furthermore, we used linear and generalized linear models and phylogenetic simulations to test whether ancestral fruit traits during intercontinental dispersal were different from those of other lineages not involved in long-distance dispersal. Results We inferred the ancestral Annonaceae fruits to be small with a single or few small seeds and a small number of fruitlets. These fruits were most probably apocarpous, indehiscent and/or moniliform (i.e. long beads of fruitlets). Furthermore, most of the long-distance dispersal events in Annonaceae occurred via the expanded tropical forests in the Early Cenozoic ('geodispersal'), and were significantly associated with large (c. 3 cm long), dull-coloured fruits, and short stipes. Additionally, long-distance dispersal was also facilitated by dehiscent, moniliform and non-cauliflorous fruits. Main conclusions We suggest that the evolution of frugivory-related traits associated with dispersal by frugivores that frequently move across large distances and/or barriers, such as large-bodied mammals and strong-flying birds, has contributed to the disjunct tropical biogeographical distribution of Annonaceae, and probably of tropical rain forest plants more generally.
Data from: Historical changes in northeastern US bee pollinators related to shared ecological traits
Pollinators such as bees are essential to the functioning of terrestrial ecosystems. However, despite concerns about a global pollinator crisis, long-term data on the status of bee species are limited. We present a long-term study of relative rates of change for an entire regional bee fauna in the northeastern United States, based on >30,000 museum records representing 438 species. Over a 140-y period, aggregate native species richness weakly decreased, but richness declines were significant only for the genus Bombus. Of 187 native species analyzed individually, only three declined steeply, all of these in the genus Bombus. However, there were large shifts in community composition, as indicated by 56% of species showing significant changes in relative abundance over time. Traits associated with a declining relative abundance include small dietary and phenological breadth and large body size. In addition, species with lower latitudinal range boundaries are increasing in relative abundance, a finding that may represent a response to climate change. We show that despite marked increases in human population density and large changes in anthropogenic land use, aggregate native species richness declines were modest outside of the genus Bombus. At the same time, we find that certain ecological traits are associated with declines in relative abundance. These results should help target conservation efforts focused on maintaining native bee abundance and diversity and therefore the important ecosystems services that they provide.
Data from: Contemporary and historic factors influence differently genetic differentiation and diversity in a tropical palm
Population genetics theory predicts loss in genetic variability because of drift and inbreeding in isolated plant populations; however, it has been argued that long-distance pollination and seed dispersal may be able to maintain gene flow, even in highly fragmented landscapes. We tested how historical effective population size, historical migration and contemporary landscape structure, such as forest cover, patch isolation and matrix resistance, affect genetic variability and differentiation of seedlings in a tropical palm (Euterpe edulis) in a human-modified rainforest. We sampled 16 sites within five landscapes in the Brazilian Atlantic forest and assessed genetic variability and differentiation using eight microsatellite loci. Using a model selection approach, none of the covariates explained the variation observed in inbreeding coefficients among populations. The variation in genetic diversity among sites was best explained by historical effective population size. Allelic richness was best explained by historical effective population size and matrix resistance, whereas genetic differentiation was explained by matrix resistance. Coalescence analysis revealed high historical migration between sites within landscapes and constant historical population sizes, showing that the genetic differentiation is most likely due to recent changes caused by habitat loss and fragmentation. Overall, recent landscape changes have a greater influence on among-population genetic variation than historical gene flow process. As immediate restoration actions in landscapes with low forest amount, the development of more permeable matrices to allow the movement of pollinators and seed dispersers may be an effective strategy to maintain microevolutionary processes.
Data from: Damming, lost connectivity and the historical role of anadromous fish in freshwater ecosystem dynamics
Recent research has demonstrated the important role that high-biomass species play in the transfer of energy and nutrients across habitat boundaries, as well as the ecosystem consequences of their loss. To contrast the historical and current biomass of historically abundant anadromous forage fish, we combined historical records of habitat loss from damming with contemporary freshwater productivity of alewives and diet data of freshwater predator fish. Significant declines in production occurred by 1850 in the northeastern United States, long before any direct abundance data were available, which would have had significant effects on freshwater prey resources for the numerous predators directly affected by the transfer of nutrients across the freshwater–marine nexus. Current freshwater systems operate at approximately 6.7% of historical capacity of anadromous alewife biomass and abundance. This provides an example of habitat-mediated changes in connectivity limiting nutrient flux and energy flow among populations and species that alter ecosystem function at multiple scales.
Data from: Of niche differentiation, dispersal ability and historical legacies: what drives woody community assembly in recent Mediterranean forests?
Community assembly rules have been extensively studied, but its association with regional environmental variation and land use history remains largely unexplored. Land use history might be especially important in Mediterranean forests, considering their historical deforestation and recent afforestation. Using forest inventories and historical (1956) and recent (2000) land cover maps, we explored the following hypotheses: 1) woody species assembly is driven by environmental factors, but also by historical landscape attributes; 2) recent forests exhibit lower woody species richness than pre-existing due to the existence of colonization credits; 3) these credits are modulated by species' life-forms and dispersal mechanisms. We examined the association of forest historical type (pre-existing versus recent) with total species richness and that of diverse life-forms and dispersal groups, also considering the effects of current environment and past landscape factors. When accounting for these effects, no significant differences in woody species richness were found between forest historical types except for vertebrate-dispersed species. Species richness of this group was affected by the interaction of forest historical type with distance to coast and rainfall: vertebrate-dispersed species richness increased with rainfall and distance to the coast in recent forests, while it was higher in dryer sites in pre-existing forests. In addition, forest historical types showed differences in woody species composition associated to diverse environmental and past landscape factors. In view of these results we can conclude that: 1) community assembly in terms of species richness is fast enough to exhaust most colonization credit in recent Mediterranean forests except for vertebrate-dispersed species; 2) for these species, colonization credit is affected by the interplay of forest history and a set of proxies of niche and landscape constraints of species dispersal and establishment; 3) woody species assemblage is mostly shaped by the species' ecological niches in these forests.
Data from: Multilocus genetic diversity and historical biogeography of the endemic wall lizard from Ibiza and Formentera, Podarcis pityusensis (Squamata: Lacertidae)
Two monophyletic sister species of wall lizards inhabit the two main groups of Balearic Islands: Podarcis lilfordi from islets and small islands around Mallorca and Menorca and Podarcis pityusensis from Ibiza, Formentera and associated islets. Genetic diversity within the endangered P. lilfordi has been well characterized, but P. pityusensis has not been studied in depth. Here, 2430 bp of mtDNA and 15 microsatellite loci were analysed from P. pityusensis populations from across its natural range. Two main genetic groupings were identified, although geographical structuring differed slightly between the mtDNA and the nuclear loci. In general, individuals from islets/islands adjacent to the main island of Ibiza were genetically distinct from those from Formentera and the associated Freus islands for both mtDNA and the nuclear loci. However, most individuals from the island of Ibiza were grouped with neighbouring islets/islands for nuclear loci, but with Formentera and Freus islands for the mitochondrial locus. A time-calibrated Bayesian tree was constructed for the principal mitochondrial lineages within the Balearics, using the multispecies coalescent model, and provided statistical support for divergence of the two main P. pityusensis lineages 0.111–0.295 Ma. This suggests a mid-late Pleistocene intraspecific divergence, compared with an early Pleistocene divergence in P. lilfordi, and postdates some major increases in sea level between 0.4 and 0.6 Ma, which may have flooded Formentera. The program IMa2 provided a posterior divergence time of 0.089–0.221 Ma, which was similar to the multispecies coalescent tree estimate. More significantly, it indicated low but asymmetric effective gene copy migration rates, with higher migration from Formentera to Ibiza populations. Our findings suggest that much of the present-day diversity may have originated from a late Pleistocene colonization of one island group from the other, followed by allopatric divergence of these populations. Subsequent gene flow between these insular groups seems likely to be explained by recent human introductions. Two evolutionary significant units can be defined for P. pityusensis but these units would need to exclude the populations that have been the subjects of recent admixture.
Data from: Microevolution in time and space: SNP analysis of historical DNA reveals dynamic signatures of selection in Atlantic cod
Little is known about how quickly natural populations adapt to changes in their environment and how temporal and spatial variation in selection pressures interact to shape patterns of genetic diversity. We here address these issues with a series of genome scans in four overfished populations of Atlantic cod (Gadus morhua) studied over an 80-year period. Screening of >1000 gene-associated single-nucleotide polymorphisms (SNPs) identified 77 loci that showed highly elevated levels of differentiation, likely as an effect of directional selection, in either time, space or both. Exploratory analysis suggested that temporal allele frequency shifts at certain loci may correlate with local temperature variation and with life history changes suggested to be fisheries induced. Interestingly, however, largely nonoverlapping sets of loci were temporal outliers in the different populations and outliers from the 1928 to 1960 period showed almost complete stability during later decades. The contrasting microevolutionary trajectories among populations resulted in sequential shifts in spatial outliers, with no locus maintaining elevated spatial differentiation throughout the study period. Simulations of migration coupled with observations of temporally stable spatial structure at neutral loci suggest that population replacement or gene flow alone could not explain all the observed allele frequency variation. Thus, the genetic changes are likely to at least partly be driven by highly dynamic temporally and spatially varying selection. These findings have important implications for our understanding of local adaptation and evolutionary potential in high gene flow organisms and underscore the need to carefully consider all dimensions of biocomplexity for evolutionarily sustainable management.
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.
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.