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.
61
datasets available to search
ShareScore release 0.9.0
Dataset results
61 results for “range margin”
Data from: Adaptive divergence at the margin of an invaded range
Invasive plant species threaten biological communities globally. However, relatively little is known about how evolutionary processes vary over the course of an invasion. To evaluate the importance of historical and adaptive drivers of range expansion, we compare the performance of North American populations of invasive Lonicera japonica from areas established 100-150 years ago, now the southern core of the range, to populations from the northern range margin, established within the last 65 years. Growth and survival of individuals from 17 core and 14 margin populations were compared in common gardens at both regions. After three years, margin plants were larger than core plants regardless of planting region, with 34% more branches and 36% greater biomass. Growth rate was directly related to survival, and margin plants also had 30% greater survival than core plants across both regions. Larger size of individuals from margin populations suggests either that the shorter growing period at the northern margin has selected for more rapid growth or that range expansion has selected for plants with a greater colonizing ability, including rapid establishment and growth. Because this evolution has resulted in enhanced survival and increased growth rate it may drive spread, increasing the likelihood of further invasion.
Flight capacity increases then declines from the core to the margins of an invasive species' range
<p>Individuals that disperse farther than other individuals are more likely to be on the frontlines of spreading populations and may be more likely to mate with one another as a consequence of their spatial proximity. Over generations, this process—known as spatial sorting—can produce patterns of increasing dispersal ability from a population's core towards the spreading front. By contrast, when the spread of a population is limited by the availability of suitable habitat, theory predicts that range boundaries can select against more dispersive phenotypes and produce patterns of decreasing dispersal capacity towards population margins. In a common garden study of invasive kudzu bugs (<i>Megacopta cribraria</i>)—which are limited by the availability of hostplants in their southern and western margins—I show that midrange individuals fly 49% farther than individuals in the core and 37% farther than individuals at margins. This result highlights that other processes, such as maternal effects or selection at range boundaries, may create more complicated patterns of dispersal ability across landscapes than predicted by models of spatial sorting alone.</p>
Data from: Spatiotemporal SNP analysis reveals pronounced biocomplexity at the northern range margin of Atlantic cod Gadus morhua
Accurate prediction of species distribution shifts in the face of climate change requires a sound understanding of population diversity and local adaptations. Previous modeling has suggested that global warming will lead to increased abundance of Atlantic cod (Gadus morhua) in the ocean around Greenland, but the dynamics of earlier abundance fluctuations are not well understood. We applied a retrospective spatiotemporal population genomics approach to examine the temporal stability of cod population structure in this region and to search for signatures of divergent selection over a 78-year period spanning major demographic changes. Analyzing >900 gene-associated single nucleotide polymorphisms in 847 individuals, we identified four genetically distinct groups that exhibited varying spatial distributions with considerable overlap and mixture. The genetic composition had remained stable over decades at some spawning grounds, whereas complete population replacement was evident at others. Observations of elevated differentiation in certain genomic regions are consistent with adaptive divergence between the groups, indicating that they may respond differently to environmental variation. Significantly increased temporal changes at a subset of loci also suggest that adaptation may be ongoing. These findings illustrate the power of spatiotemporal population genomics for revealing biocomplexity in both space and time and for informing future fisheries management and conservation efforts.
Data from: Effects of the landscape on boreal toad gene flow: does the pattern-process relationship hold true across distinct landscapes at the northern range margin?
Understanding the impact of natural and anthropogenic landscape features on population connectivity is a major goal in evolutionary ecology and conservation. Discovery of dispersal barriers is important for predicting population responses to landscape and environmental changes, particularly for populations at geographic range margins. We used a landscape genetics approach to quantify the effects of landscape features on gene flow and connectivity of boreal toad (Bufo boreas) populations from two distinct landscapes in Southeast Alaska (Admiralty Island, ANM, and the Chilkat River Valley, CRV). We used two common methodologies for calculating resistance distances in landscape genetics studies (resistance based on least-cost paths and circuit theory). We found a strong effect of saltwater on genetic distance of CRV populations, but no landscape effects were found for the ANM populations. Our discordant results show the importance of examining multiple landscapes that differ in the variability of their features, in order to maximize detectability of underlying processes and allow results to be broadly applicable across regions. Saltwater serves as a physiological barrier to boreal toad gene flow and affects populations on a small geographic scale, yet there appear to be few other barriers to toad dispersal in this intact northern region.
Data from: Effects of contemporary shifts of range margins on patterns of genetic structure and mating system in two coastal plant species
Species' geographical ranges are often restricted due to niche limitation resulting in geographical isolation and reduced population size at range margins. Under the 'abundant center' paradigm, static marginal populations are thus expected to show higher genetic differentiation and lower genetic diversity than core populations. Low mate availability may also drive shifts towards higher propensity for selfing in geographically marginal populations. However, these predictions remain to be validated for contemporary range shifts occurring under current environmental change. This study is devoted to bridging this gap and assesses the spatial patterns of genetic structure and mating system across the geographical range of two coastal plant species characterized by contrasting contemporary range dynamics: the receding myrmecochorous Dune pansy (Viola tricolor subsp. curtisii) and the widespread expanding hydrochorous Rock samphire (Crithmum maritimum) Both species exhibited high propensity for selfing, with indications of inbreeding depression acting at early life stages. In Dune pansy, a biogeographical break was observed between core and marginal populations, with trailing-edge populations showing higher levels of genetic differentiation, reduced genetic diversity and higher levels of selfing estimated through progeny arrays. In contrast, genetic structuring was weak in Rock samphire and no clear spatial trends were observed in genetic diversity nor in mating system, likely the result of efficient long-distance seed dispersal by sea-surface currents. Our study highlights that key species differences in life-history traits related to dispersal and/or mate limitation modify the expectations of genetic diversity loss and mating system shift in contemporary range-expanding populations, as compared to historical core populations.
Data from: Partial support for the central–marginal hypothesis within a population: reduced genetic diversity but not increased differentiation at the range edge of an island endemic bird
Large-scale population comparisons have contributed to our understanding of the evolution of geographic range limits and species boundaries, as well as the conservation value of populations at range margins. The central–marginal hypothesis (CMH) predicts a decline in genetic diversity and an increase in genetic differentiation toward the periphery of species' ranges due to spatial variation in genetic drift and gene flow. Empirical studies on a diverse array of taxa have demonstrated support for the CMH. However, nearly all such studies come from widely distributed species, and have not considered if the same processes can be scaled down to single populations. Here, we test the CMH on a species composed of a single population: the Island Scrub-Jay (Aphelocoma insularis), endemic to a 250 km2 island. We examined microsatellite data from a quarter of the total population and found that homozygosity increased toward the island's periphery. However, peripheral portions of the island did not exhibit higher genetic differentiation. Simulations revealed that highly localized dispersal and small total population size, but not spatial variation in population density, were critical for generating fine-scale variation in homozygosity. Collectively, these results demonstrate that microevolutionary processes driving spatial variation in genetic diversity among populations can also be important for generating spatial variation in genetic diversity within populations.
FIGURE 34 in Description, host range and distribution of a new Macrodiplosis species (Diptera: Cecidomyiidae) that induces leaf-margin fold galls on deciduous Quercus (Fagaceae) with comparative notes on Palaearctic congeners
FIGURE 34. Strict consensus of 197 equally parsimonious trees (tree length 423, consistency index = 0.6, retention index = 0.90, rescaled consistency index = 0.54) for Macrodiplosis spp. based on 658bp of the COI gene. Bootstrap values are indicated for nodes with more than 50% support.
FIGURES 22–25. Macrodiplosis pustularis. 22. Male flagellomere V. 23. Male terminalia, dorsal. 24. Female flagellomere VII. 25 in Description, host range and distribution of a new Macrodiplosis species (Diptera: Cecidomyiidae) that induces leaf-margin fold galls on deciduous Quercus (Fagaceae) with comparative notes on Palaearctic congeners
FIGURES 22–25. Macrodiplosis pustularis. 22. Male flagellomere V. 23. Male terminalia, dorsal. 24. Female flagellomere VII. 25. Ovipositor, lateral. Scale bars: 0.1 mm.
FIGURES 14–21 in Description, host range and distribution of a new Macrodiplosis species (Diptera: Cecidomyiidae) that induces leaf-margin fold galls on deciduous Quercus (Fagaceae) with comparative notes on Palaearctic congeners
FIGURES 14–21. Larva and pupa of M. selenis sp. n. 14. Larval head and mesothorax, dorsal, circles indicate dorsal papillae. 15. Larval sternal spatula. 16. Prothorax showing sternal spatula, ventral. 17. A part of larval sternal spatula and lateral papillae on prothorax, circles indicate two papillae in each cluster with minute seta. 18. Larval abdominal tergites II and III, circles indicate dorsal papillae. 19. Larval terminal segment, dorsal, large circles indicate four setose terminal papillae, small circles indicate the corniform papillae. 20. Same, ventral). 21. Pupal head (ventral). Abbreviations: ba, base of antennae. cs, cephalic seta. ps, prothoracic spiracle. Scale bars: 0.1 mm.
FIGURES 29–33. Macrodiplosis roboris. 29. Larval sternal spatula. 30 in Description, host range and distribution of a new Macrodiplosis species (Diptera: Cecidomyiidae) that induces leaf-margin fold galls on deciduous Quercus (Fagaceae) with comparative notes on Palaearctic congeners
FIGURES 29–33. Macrodiplosis roboris. 29. Larval sternal spatula. 30. Larval head and prothorax, ventral. 31. A part of sternal spatula (sp) and lateral papillae (in circles). 32. Larval terminal segment, dorsal. 33. Same, ventral. Scale bars: 0.1 mm.
FIGURES 9–13 in Description, host range and distribution of a new Macrodiplosis species (Diptera: Cecidomyiidae) that induces leaf-margin fold galls on deciduous Quercus (Fagaceae) with comparative notes on Palaearctic congeners
FIGURES 9–13. Macrodiplosis selenis sp. n. 9. Male flagellomere V. 10. Male terminalia, dorsal. 11. Female head, anterior. 12. Female flagellomere VII. 13. Ovipositor, lateral. Scale bars: 0.1 mm.
FIGURES 26–28 in Description, host range and distribution of a new Macrodiplosis species (Diptera: Cecidomyiidae) that induces leaf-margin fold galls on deciduous Quercus (Fagaceae) with comparative notes on Palaearctic congeners
FIGURES 26–28. Larva and pupa of M. pustularis. 26. Larval sternal spatula (after Möhn 1955). 27. Pupal prothoracic spiracle. 28. Portion of the pupal frontal area and the base of antennal sheath, ventral. Abbreviations: ba, base of antennae. cs, cephalic seta. Scale bars: 0.1 mm.
FIGURES 5–8 in Description, host range and distribution of a new Macrodiplosis species (Diptera: Cecidomyiidae) that induces leaf-margin fold galls on deciduous Quercus (Fagaceae) with comparative notes on Palaearctic congeners
FIGURES 5–8. Leaf galls induced by Macrodiplosis spp. on different Quercus species and in different localities. 5. M. roboris on Q. robur in Surrey, UK. 6. Macrodiplosis sp. 2. on Q. mongolica in Hokkaido, Japan. 7. M. pustularis on Q. robur in Surrey, UK. 8. Macrodiplosis sp. on Q. falcata in Maryland, USA. Scale bars: 5 mm.
Subspecies and Distribution. T.n.napuF.Cuvier,1822—SMyanmar,Thai/MalayPeninsula,islandsoffWMalayPeninsula(Langkawi&Pangkor),Borneo,SSumatra,BangkaI,islandsoffBorneo(Laut&Serasan). T.n.bangue:Chasen&Kloss,1931—BanggiIandBalembanganI,offNBorneo. T.n.bunguranensisMiller,1901—NatunaIs(=Bunguran),oftWBorneo. T.n.neubronneriSody,1931—NSumatra. T.n.nmiasisLyon,1916—NiasI,offWSumatra. T.n.rufulusMiller,1900—TiomanI,offEMalayPeninsula,RiauandLinggaArchipelagos. T. n. terutus Thomas & Wroughton, 1909 — Terutau I, off W Malay Peninsula. The species was recently reconfirmed for Singapore. Maps that include Vietnam, Cambodia, and Laos in the distribution range are based on the earlier assumption that 7. versicolor was a subspecies of 1. napu. Subsequent studies have indicated that 7. versicolor is a distinct species, and that the range of 1. napu therefore does not extend into Cambodia, Laos, and Vietnam. The northern limit on the Thai-Malay peninsula is not well defined. Specimens of 1. napu have been collected from as far north as Bankachon in southern Myanmar (10° 08" N), but despite fairly intensive camera-trapping in Kui Buri National Park, Thailand (12° N), 7. napu has not been photographed there. At the northern margin ofits range, it is generally rare. It has been reported, for example, that during the flooding of the Chiew Larn Reservoir (Surat Thani Province; about 9° N, 98° 45' E), only six 7. napu were rescued compared with 172 71. kanchil. This area is the transition zone from wetter evergreen forest to drier deciduous types, and it might be that 7° napu is not well adapted to the drier forest types towards the northern limit ofits range. There are unconfirmed reports of the species on Java, where it may have been confused with one of the two color morphs of 7. javanicus. As explained in the Taxonomy section, the subspecific status of the populations of several islands remains unclear. in Tragulidae
Subspecies and Distribution. T.n.napuF.Cuvier,1822—SMyanmar,Thai/MalayPeninsula,islandsoffWMalayPeninsula(Langkawi&Pangkor),Borneo,SSumatra,BangkaI,islandsoffBorneo(Laut&Serasan). T.n.bangue:Chasen&Kloss,1931—BanggiIandBalembanganI,offNBorneo. T.n.bunguranensisMiller,1901—NatunaIs(=Bunguran),oftWBorneo. T.n.neubronneriSody,1931—NSumatra. T.n.nmiasisLyon,1916—NiasI,offWSumatra. T.n.rufulusMiller,1900—TiomanI,offEMalayPeninsula,RiauandLinggaArchipelagos. T. n. terutus Thomas & Wroughton, 1909 — Terutau I, off W Malay Peninsula. The species was recently reconfirmed for Singapore. Maps that include Vietnam, Cambodia, and Laos in the distribution range are based on the earlier assumption that 7. versicolor was a subspecies of 1. napu. Subsequent studies have indicated that 7. versicolor is a distinct species, and that the range of 1. napu therefore does not extend into Cambodia, Laos, and Vietnam. The northern limit on the Thai-Malay peninsula is not well defined. Specimens of 1. napu have been collected from as far north as Bankachon in southern Myanmar (10° 08" N), but despite fairly intensive camera-trapping in Kui Buri National Park, Thailand (12° N), 7. napu has not been photographed there. At the northern margin ofits range, it is generally rare. It has been reported, for example, that during the flooding of the Chiew Larn Reservoir (Surat Thani Province; about 9° N, 98° 45' E), only six 7. napu were rescued compared with 172 71. kanchil. This area is the transition zone from wetter evergreen forest to drier deciduous types, and it might be that 7° napu is not well adapted to the drier forest types towards the northern limit ofits range. There are unconfirmed reports of the species on Java, where it may have been confused with one of the two color morphs of 7. javanicus. As explained in the Taxonomy section, the subspecific status of the populations of several islands remains unclear.
Data from: Genome-wide assessment of kokanee salmon stock diversity, population history and hatchery representation at the northern range margin
<p>Freshwater fisheries represent important natural resources, yet a vast majority are threatened by anthropogenic stressors. Accurate baseline information on stock diversity, population history and hatchery representation are required for implementing effective conservation and management strategies for mitigating declines. Genetic tools have played key roles for informing fisheries management, including for kokanee, the freshwater resident form of sockeye salmon (<i>Oncorhynchus nerka</i>), particularly in the southern portion of its North American range. Here, we investigated stock diversity, population history and hatchery representation of kokanee at the northern extent of its range in Canada in Kluane National Park and Reserve (KNPR) in the Yukon that underwent a 12-year population crash followed by a rapid increase in numbers. Using restriction-site associated DNA sequencing, we genotyped individuals at 11,442 single nucleotide polymorphisms (SNPs) that were sampled from putative reproductive ecotypes spawning on the shore of Sockeye Lake (n=26), within Sockeye Creek (n=20) or near an outlet in between (n=2), as well as broodstock from the Whitehorse Rapids Hatchery (n=29). We found no evidence of wild stock diversity or ecotype differentiation based on neutral SNPs nor outlier loci. Within-population genetic diversity and effective population size were substantially higher in the wild population relative to the hatchery and significant differentiation was detected, suggesting the hatchery population was not representative of wild stock diversity. Overall, our results suggest that separate management of kokanee in KNPR based on ecotype is not warranted at this time and that supplementation with the existing hatchery stock is not appropriate.</p>
Subspecies and Distribution. P. l. longimembris Coues, 1875 — SW USA (Mojave Desert and Transverse Ranges, SW California). P. l. aestivus Huey, 1928 — NW Mexico (W base Sierra Juarez to Valle de la Trinidad, N Baja California). P.l. arizonensis Goldman, 1931 — SW USA (SC Utah and NC Arizona to SE Nevada). P. l.bangsi Mearns, 1898 — SW USA (W Colorado Desert of S California). P. l. bombycinus Osgood, 1907 — SW USA and NW Mexico (lower Colorado River Valley of SE California, SW Arizona, NE Baja California, and NW Sonora). P. l. brevinasus Osgood, 1900 — SW USA (arid coastal basins of SW California). P. l. gulosus Hall, 1941 — W USA (along the W margin of former Pleistocene Lake Bonneville in the Great Basin of E Nevada and W Utah). P. l. internationalis Huey, 1939 — SW USA and NW Mexico (SC California and adjacent NC Baja California). P. l. kinoensis Huey, 1935 — NW Mexico (disjunct and geographically restricted population along Bahia Kino, W Sonora), but may be extinct. P. l. nevadensis Merriam, 1894 — W USA (Great Basin of SE Oregon, NE California, and NC Nevada). P. l. pacificus Mearns, 1898 — SW USA (coastal plains of SW California to the USA-Mexico border). P. I. panamintinus Merriam, 1894 — SW USA (Great Basin of W Nevada and SE California). P. l. pimensis Huey, 1937 — SW USA (disjunct distribution in SC Arizona). P. l. salinensis Bole, 1937 — SW USA (restricted distribution in the Salinas Valley of SE California). P. l. tularensis Richardson, 1937 — SW USA (restricted distribution in the upper valley of the Kern River, SC California). P. l. venustus Huey, 1930 — NW Mexico (known only from the type locality of San Agustin, NC Baja California). in Heteromyidae
Subspecies and Distribution. P. l. longimembris Coues, 1875 — SW USA (Mojave Desert and Transverse Ranges, SW California). P. l. aestivus Huey, 1928 — NW Mexico (W base Sierra Juarez to Valle de la Trinidad, N Baja California). P.l. arizonensis Goldman, 1931 — SW USA (SC Utah and NC Arizona to SE Nevada). P. l.bangsi Mearns, 1898 — SW USA (W Colorado Desert of S California). P. l. bombycinus Osgood, 1907 — SW USA and NW Mexico (lower Colorado River Valley of SE California, SW Arizona, NE Baja California, and NW Sonora). P. l. brevinasus Osgood, 1900 — SW USA (arid coastal basins of SW California). P. l. gulosus Hall, 1941 — W USA (along the W margin of former Pleistocene Lake Bonneville in the Great Basin of E Nevada and W Utah). P. l. internationalis Huey, 1939 — SW USA and NW Mexico (SC California and adjacent NC Baja California). P. l. kinoensis Huey, 1935 — NW Mexico (disjunct and geographically restricted population along Bahia Kino, W Sonora), but may be extinct. P. l. nevadensis Merriam, 1894 — W USA (Great Basin of SE Oregon, NE California, and NC Nevada). P. l. pacificus Mearns, 1898 — SW USA (coastal plains of SW California to the USA-Mexico border). P. I. panamintinus Merriam, 1894 — SW USA (Great Basin of W Nevada and SE California). P. l. pimensis Huey, 1937 — SW USA (disjunct distribution in SC Arizona). P. l. salinensis Bole, 1937 — SW USA (restricted distribution in the Salinas Valley of SE California). P. l. tularensis Richardson, 1937 — SW USA (restricted distribution in the upper valley of the Kern River, SC California). P. l. venustus Huey, 1930 — NW Mexico (known only from the type locality of San Agustin, NC Baja California).
Data from: Mycorrhizal interactions do not influence plant-herbivore interactions in populations of Clarkia xantiana ssp. xantiana spanning from center to margin of the geographic range
Open the record for dataset details and reuse information.
Data from: Partial support for the central–marginal hypothesis within a population: reduced genetic diversity but not increased differentiation at the range edge of an island endemic bird
Open the record for dataset details and reuse information.
Data from: Effects of contemporary shifts of range margins on patterns of genetic structure and mating system in two coastal plant species
Open the record for dataset details and reuse information.
Data from: Landscape resistance and habitat combine to provide an optimal model of genetic structure and connectivity at the range margin of a small mammal
Open the record for dataset details and reuse information.
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.