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1,245 results for “hypothesis”
Data from: Exaggerated sexual swellings and male mate choice in primates: testing the reliable indicator hypothesis in the Amboseli baboons
The paradigm of competitive males vying to influence female mate choice has been repeatedly upheld, but, increasingly, studies also report competitive females and choosy males. One female trait that is commonly proposed to influence male mate choice is the exaggerated sexual swelling displayed by females of many Old World primate species. The reliable indicator hypothesis posits that females use the exaggerated swellings to compete for access to mates, and that the swellings advertise variation in female fitness. We tested the two main predictions of this hypothesis in a wild population of baboons (Papio cynocephalus). First, we examined the effect of swelling size on the probability of mate guarding ('consortship') by the highest-ranking male and the behaviour of those males that trailed consortships ('follower males'). Second, we asked whether a female's swelling size predicted several fitness measures. We found that high-ranking males did not prefer females with larger swellings (when controlling for cycle number and conception) and that females with larger swellings did not have higher reproductive success. Our study, the only complete test of the reliable indicator hypothesis in a primate population, rejects the idea that female baboons compete for mates by advertising heritable fitness differences. Furthermore, we found unambiguous evidence that males biased their mating decisions in favour of females who had experienced more sexual cycles since their most recent pregnancy. Thus, rather than tracking the potential differences in fitness between females, male baboons appear to track and target the potential for a given reproductive opportunity to result in fertilization.
Data from: Acoustic emissions of Sorex unguiculatus (Mammalia: Soricidae): assessing the echo-based orientation hypothesis
Shrew species have been proposed to utilize an echo-based orientation system to obtain additional acoustic information while surveying their environments. This system has been supported by changes in vocal emission rates when shrews encounter different habitats of varying complexity, although detailed acoustic features in this system have not been reported. In this study, behavioral experiments were conducted using the long-clawed shrew (Sorex unguiculatus) to assess this orientation system. Three experimental conditions were set, two of which contained obstacles. Short-click, noisy, and different types of tonal calls in the audible-to-ultrasonic frequency range were recorded under all experimental conditions. The results indicated that shrews emit calls more frequently when they are facing obstacles or exploring the experimental environment. Shrews emitted clicks and several different types of tonal calls while exploring, and modified the use of different types of calls for varying behavior. Furthermore, shrews modified the dominant frequency and duration of squeak calls for different types of obstacles, i.e., plants and acrylic barriers. The vocalizations emitted at short interpulse intervals could not be observed when shrews approached these obstacles. These results are consistent with the echo-based orientation hypothesis according to which shrews use a simple echo-orientation system to obtain information from their surrounding environments, although further studies are needed to confirm this hypothesis.
Data from: Revisiting the relative growth rate hypothesis for gymnosperm and angiosperm species co‐occurrence
Premise of the study: It is unclear to what extent the co-occurrence of angiosperm and gymnosperm species in some marginal ecosystems is explained by reduced growth in angiosperms due to carbon (C) limitation, and by high stress tolerance in gymnosperms associated with lack of vessels and resource conservation. Methods: We examined growth patterns and traits associated with C balance in four evergreen angiosperm species (including one vesselless species, Drimys winteri) and three gymnosperm tree species of a cold-temperate rainforest in southern Chile. We measured the mean basal area increment for the first 50 (BAI50) and the last 10 years (BAI10), wood density, leaf lifespan, and non-structural carbohydrate (NSC) concentrations in different organs. Key results: BAI50 was 6-fold higher in angiosperms than in gymnosperms, and c. 4-fold higher in Drimys than in the fastest growing gymnosperm. BAI10 and aboveground NSC concentrations were significantly higher and leaf lifespan lower in angiosperms than in gymnosperms; these differences though were largely driven by the slow growth and low NSC concentrations of the Cupressaceae species (Pilgerodendron uviferum), while the two Podocarpaceae showed similar BAI10 and NSC concentrations to angiosperms. In angiosperms, NSC and starch concentrations were generally higher in species with lower BAI10, indicating no severe C limitation. Conclusions: The co-occurrence of angiosperms and gymnosperms in cold-temperate rainforests of southern Chile is not explained by growth disadvantages and C limitation in angiosperms. High leaf longevity, but not lack of vessels, appeared to favor resource conservation and C balance in some gymnosperms (Podocarpaceae). In compliance with data protection regulations, please contact the publication office if you would like to have your personal information removed from the database.
Data from: Does the niche-breadth or trade-off hypothesis explain the abundance-occupancy relationship in avian haemosporidia?
Two hypotheses have been proposed to explain the abundance-occupancy relationship (AOR) in parasites. The niche-breadth hypothesis suggests that host generalists are more abundant and efficient at colonizing different host communities than specialists. The trade-off hypothesis argues that host specialists achieve high density across their hosts' ranges, whereas generalists incur the high cost of adaptation to diverse immuno-defense systems. We tested these hypotheses using 386 haemosporidian cytochrome-b lineages (1894 sequences) recovered from 2318 birds of 103 species sampled in NW Africa, NW Iberia, W Greater Caucasus, and Transcaucasia. The number of regions occupied by lineages was associated with their frequency suggesting the presence of AOR in avian Haemosporidia. However, neither hypothesis provided a better explanation for the AOR. Although, the host-generalist Plasmodium SGS1 was over 3 times more abundant than other widespread lineages, both host specialists and generalists were successful in colonizing all study regions and achieved overall high prevalence.
Data from: Testing the prey-trap hypothesis at two wildlife conservancies in Kenya
Protecting an endangered and highly poached species can conflict with providing an open and ecologically connected landscape for coexisting species. In Kenya, about half of the black rhino (Diceros bicornis) live in electrically fenced private conservancies. Purpose-built fence-gaps permit some landscape connectivity for elephant while restricting rhino from escaping. We monitored the usage patterns at these gaps by motion-triggered cameras and found high traffic volumes and predictable patterns of prey movement. The prey-trap hypothesis (PTH) proposes that predators exploit this predictable prey movement. We tested the PTH at two semi-porous reserves using two different methods: a spatial analysis and a temporal analysis. Using spatial analysis, we mapped the location of predation events with GPS and looked for concentration of kill sites near the gaps as well as conducting clustering and hot spot analysis to determine areas of statistically significant predation clustering. Using temporal analysis, we examined the time lapse between the passage of prey and predator and searched for evidence of active prey seeking and/or predator avoidance. We found no support for the PTH and conclude that the design of the fence-gaps is well suited to promoting connectivity in these types of conservancies.
Data from: The Achilles' heel hypothesis: misinformed keystone individuals impair collective learning and reduce group success
Many animal societies rely on highly influential keystone individuals for proper functioning. When information quality is important for group success, such keystone individuals have the potential to diminish group performance if they possess inaccurate information. Here we test whether information quality (accurate or inaccurate) influences collective outcomes when keystone individuals are the first to acquire it. We trained keystone or generic individuals to attack or avoid novel stimuli and implanted these seed individuals within groups of naïve colony-mates. We subsequently tracked how quickly groups learned about their environment in situations that matched (accurate information) or mismatched (inaccurate information) the training of the seed individual. We found that colonies with just one accurately informed individual were quicker to learn to attack a novel prey stimulus than colonies with no informed individuals. However, this effect was no more pronounced when the informed individual was a keystone individual. In contrast, keystones with inaccurate information had larger effects than generic individuals with identical information: groups containing keystones with inaccurate information took longer to learn to attack/avoid prey/predator stimuli and gained less weight than groups harboring generic individuals with identical information. Our results convey that misinformed keystone individuals can become points of vulnerability for their societies.
Data from: Genomic tests of the species-pump hypothesis: recent island connectivity cycles drive population divergence but not speciation in Caribbean crickets across the Virgin Islands
Harnessing the power of genomic scans, we test the debated 'species pump' hypothesis that implicates repeated cycles of island connectivity and isolation as drivers of divergence. This question has gone understudied given the limited resolution of past molecular markers for studying such dynamic phenomena. With an average of 32000 SNPs from the genome of 136 individuals from ten populations of a Caribbean flightless ground cricket species (Amphiacusta sanctaecrucis) and a complementary set of statistical approaches, we infer a stepping-stone colonization model and high levels of genetic differentiation across the Virgin Islands, which have been periodically inter-connected until 8 ka. Estimates of divergence times from models based on the site frequency spectrum coincide with a period of repeated connection and fragmentation of the islands at 75–130 ka. These results are consistent with a role of island connectivity cycles in promoting genomic divergence and indicate that the genetic distinctiveness of island populations has persisted despite subsequent and extended interisland connections identified from bathymetric data. We discuss these findings in the broader context of Caribbean biogeography, and more specifically why high levels of genomic divergence across the Virgin Islands associated with repeated connectivity cycles do not actually translate into species diversification.
Data from: The Rapoport effect and the climatic variability hypothesis in Early Jurassic ammonites
The increase of species range size towards high latitudes, known as the Rapoport's rule, remains one of the most debated and poorly understood macroecological patterns. Numerous studies have challenged both its universality and the main mechanism originally proposed to explain it, i.e. the climatic variability hypothesis. Here we study this pattern on a group of fossil marine organisms: the early Pliensbachian ammonites of the western Tethys. We further take into account the influence of the marked provincialism prevailing at that time, with a Mediterranean province (MED) and a Northwest European province (NWE) located on each side of a latitudinally-oriented palaeobiogeographic barrier. We find that only species from the NWE province display a Rapoport effect, whereas species from the more tropical MED province show a boundary effect and have larger range sizes in average. This dual pattern can be explained by an alternative climatic variability hypothesis that better captures latitudinal seasonal variations and outlines the influence of the intertropical zone, characterized by stable and homogeneous climate that allows species to disperse over very large areas, regardless of their thermal tolerance. Accordingly, the NWE province probably displayed a gradient of seasonal climatic variations which caused the emergence of a Rapoport effect, whereas the MED province was probably located in the intertropical zone where no gradient in species range size is expected. Our multi-scale approach further shows that the Rapoport effect is scale dependent and may be labile through time. This probably explains the conflicting results of previous studies carried out at various spatio-temporal scales.
Data from: LiDAR-derived canopy structure supports the more-individuals hypothesis for arthropod diversity in temperate forests
Despite considerable progress in the ability to measure the complex 3-D structure of forests with the improvement of remote-sensing techniques, our mechanistic understanding of how biodiversity is linked to canopy structure is still limited. Here we tested whether the increase in arthropod abundance and richness in beech forest canopies with increasing canopy complexity supports the more-individuals hypothesis or the habitat-heterogeneity hypothesis. We used fogging to collect arthropod samples from 80 standardized plots from canopies of single- to multi-layered mature montane European beech stands. Tree height and an independent measure of vertical heterogeneity — the vertical distribution ratio — on each arthropod sampling plot were derived from high-resolution full-waveform airborne laser scanning data. Mixed-model path analysis based on almost 20,000 specimens of 762 species from 11 orders provided support for the more-individuals hypothesis, with higher arthropod abundance but not higher species richness in stands with a more equal vertical distribution of plant biomass. By contrast, we found no support for the habitat-heterogeneity hypothesis. The increase in the number of individuals with increasing vertical distribution of biomass might be caused either by increasing leaf area, as indicated by higher space filling and productivity in multi-layered stands, or by higher persistence of arthropod populations owing to better shelter, reduced competition and more refuges under harsh conditions, or by both. High-resolution airborne laser scanning, with its ability to penetrate dense canopies under leaf-on conditions, has proved suitable for measuring vertical structures as a predictor for canopy diversity. Expanding combinations of remote-sensing and canopy-biodiversity data opens many avenues for improving our understanding of the link between diversity and forest structures.
Data from: Geographic variation of life-history traits in the sand lizard, Lacerta agilis: testing Darwin's fecundity-advantage hypothesis
The fecundity-advantage-hypothesis (FAH) explains larger female size relative to male size as a correlated response to fecundity selection. We explored FAH by investigating geographic variation in female reproductive output and its relation to sexual size dimorphism (SSD) in Lacerta agilis, an oviparous lizard occupying a major part of temperate Eurasia. We analysed how sex-specific body size and SSD are associated with two putative indicators of fecundity selection intensity (clutch size and the slope of the clutch size-female size relationship), and with two climatic variables throughout the species range and across two widespread evolutionary lineages. Variation within the lineages provides no support for FAH. In contrast, the divergence between the lineages is in line with FAH: the lineage with consistently female-biased SSD (L. a. agilis) exhibits higher clutch size and steeper fecundity slope than the lineage with an inconsistent and variable SSD (L. a. exigua). L. a. agilis shows lower offspring size (egg mass, hatchling mass) and higher clutch mass relative to female mass than L. a. exigua, i.e. both possible ways to enhance offspring number are exerted. As the SSD difference is due to male size (smaller males in L. a. agilis), fecundity selection favouring larger females, together with viability selection for smaller size in both sexes, would explain the female-biased SSD and reproductive characteristics of L. a. agilis. The pattern of intraspecific life-history divergence in L.agilis is strikingly similar to that between oviparous and viviparous populations of a related species Zootoca vivipara. Evolutionary implications of this parallelism are discussed.
Data from: A test of the invasive pathogen hypothesis of bumble bee decline in North America
Emergent fungal diseases are critical factors in global biodiversity declines. The fungal pathogen Nosema bombi was recently found to be widespread in declining species of North American bumble bees (Bombus), with circumstantial evidence suggesting an exotic introduction from Europe. This interpretation has been hampered by a lack of knowledge of global genetic variation, geographic origin, and changing prevalence patterns of N. bombi in declining North American populations. Thus, the temporal and spatial emergence of N. bombi and its potential role in bumble bee decline remain speculative. We analyze Nosema prevalence and genetic variation in the United States and Europe from 1980, before an alleged introduction in the early 1990s, to 2011, extracting Nosema DNA from Bombus natural history collection specimens from across this time period. Nosema bombi prevalence increased significantly from low detectable frequency in the 1980s to significantly higher frequency in the mid- to late-1990s, corresponding to a period of reported massive infectious outbreak of N. bombi in commercial bumble bee rearing stocks in North America. Despite the increased frequency, we find no conclusive evidence of an exotic N. bombi origin based on genetic analysis of global Nosema populations; the widespread Nosema strain found currently in declining United States bumble bees was present in the United States before commercial colony trade. Notably, the US N. bombi is not detectably different from that found predominantly throughout Western Europe, with both regions characterized by low genetic diversity compared with high levels of diversity found in Asia, where commercial bee breeding activities are low or nonexistent.
Data from: A global test of the cold-climate hypothesis for the evolution of viviparity of squamate reptiles
Aim The evolution of viviparity in squamate reptiles has attracted considerable scientific attention since the beginning of last century. The cold climate hypothesis posits that cold regions favor viviparity (and therefore the incidence of viviparous squamates is increased in these regions) because viviparous females can use thermoregulatory behavior to shorten embryonic developmental time and to reduce exposure of embryos to stressful temperatures. However, a rigorous global-scale test of the impact of viviparity on the developmental time and viability of embryos is still absent. Recently developed biophysical models and climate databases enable us to conduct a mechanistic test of this hypothesis. Location Global Time period Summer Major taxa studied Squamata Methods We integrated global climate data, a biophysical model, and developmental functions to quantify the effects of temperature on embryo developmental time, developmental viability, and energy consumption of oviparous versus viviparous embryos. To examine the accuracy of our predictions, we calculated the percentage of squamate reptiles that were viviparous in each region and assessed developmental temperature of gravid females, latitude and elevation as predictors for the percentage of squamate reptiles. Results Compared with oviparous embryos, viviparous embryos develop faster in cold regions, and experience similar embryonic developmental viability. Across most latitudes and elevations, the total energetic cost of development is lower for viviparous embryos than for oviparous embryos. Cold regions contain a higher proportion of viviparous species than do hot regions. By comparing the distribution pattern of viviparity and temperature effects on embryonic development, we found that shortened development time provided the strongest benefit of viviparity. Main conclusions Our global and biophysical model based comparison generally supports the cold climate hypothesis. Moreover, viviparity in cold climates appears beneficial primarily by shortening developmental time.
Data from: Comparative support for the expensive tissue hypothesis: big brains are correlated with smaller gut and greater parental investment in Lake Tanganyika cichlids
The brain is one of the most energetically expensive organs in the vertebrate body. Consequently, the energetic requirements of encephalization are suggested to impose considerable constraints on brain size evolution. Three main hypotheses concerning how energetic constraints might affect brain evolution predict covariation between brain investment and i) investment into other costly tissues, ii) overall metabolic rate, and iii) reproductive investment. To date, these hypotheses have mainly been tested in homeothermic animals and the existing data are inconclusive. However, there are good reasons to believe that energetic limitations might play a role in large-scale patterns of brain size evolution also in ectothermic vertebrates. Here we test these hypotheses in a group of ectothermic vertebrates, the Lake Tanganyika cichlid fishes. After controlling for the effect of shared ancestry and confounding ecological variables, we find a negative association between brain size and gut size. Furthermore, we find that the evolution of a larger brain is accompanied by increased reproductive investment into egg size and parental care. Our results indicate that the energetic costs of encephalization may be an important general factor involved in the evolution of brain size also in ectothermic vertebrates.
Data from: Testing the hypothesis of loss of defences on islands across a wide latitudinal gradient of Periploca laevigata populations
PREMISE OF THE STUDY: We tested a hypothesis that predicts loss of chemical defences on island plant populations (LCDIH) as an evolutionary response to limited herbivore pressures. METHODS: Using a common garden approach, we grew 16 populations (N = 286 seedlings) of Periploca laevigata, a Mediterranean shrub for which previous studies suggested tannin-mediated responses to animal browsing. Our experimental setting represented a wide latitudinal gradient (37-15ºN) encompassing three island systems, virtually free of large herbivores, and three mainland areas. Putative chemical defences were estimated from tannin-protein precipitation assays, and inducible responses in growth and chemical traits were assessed between seasons and by subjecting plants to a pruning treatment. KEY RESULTS: We failed to find support for the LCDIH, since island populations (Canary Islands, Cape Verde) displayed increasingly higher constitutive levels of tannins at lower latitudes. Seasonality, but not experimental pruning, induced variation in levels of tannins in a consistent pattern across populations. Thus, net differences in leaf tannin concentration remained similar among geographical areas regardless of the factor considered, with latitude being the best explanatory factor for this trait over seasonal growth patterns. CONCLUSIONS: Geographical variation in total tannin pools appears to be mediated by factors other than herbivore pressure in P. laevigata. We hypothesize that abiotic correlates of latitude not considered in our study have promoted high constitutive levels of leaf tannins across Macaronesian populations, which ultimately may explain the pattern of seasonal variation and latitudinal increase from Mediterranean to subtropical Cape Verde populations. In compliance with data protection regulations, please contact the publication office if you would like to have your personal information removed from the database.
Data from: Males migrate farther than females in a differential migrant: an examination of the fasting endurance hypothesis
Patterns of migration including connectivity between breeding and non-breeding populations and intraspecific variation in the distance travelled are important to study because they can affect individual fitness and population dynamics. Using data from 182 band recoveries across North America and 17 light-level geolocators, we examined the migration patterns of the northern flicker (Colaptes auratus), a migratory woodpecker. This species is unusual among birds because males invest more in parental care than females. Breeding latitude was positively correlated to migration distance because populations in the north appeared to travel farther distances than southern populations to find wintering locations with little snow cover. Connectivity was strong for populations west and east of the Continental Divide. Contrary to the three main hypotheses for intraspecific variation in migration distance, females wintered, on average, farther north than males, although there was overlap throughout their non-breeding range. This pattern contradicts those of other species found to date and is most consistent with the fasting endurance hypothesis if investment in parental care depletes the energy reserves of male flickers more than females. We thus propose a new factor, parental effort, which may influence optimal wintering areas and migration strategies within birds, and encourage future experimental studies to test the relationship between parental care roles and migration strategies of the sexes.
Data from: Infection dynamics in coexisting sexual and asexual host populations: support for the Red Queen hypothesis
The persistence of sexual reproduction is a classic problem in evolutionary biology. The problem stems from the fact that, all else equal, asexual lineages should rapidly replace coexisting sexual individuals due to the cost of producing males in sexual populations. One possible countervailing advantage to sexual reproduction is that, on average, outcrossed offspring are more resistant than common clones to coevolving parasites, as predicted under the Red Queen hypothesis. In the present study, we evaluated the prevalence of infection by a sterilizing trematode (Microphallus sp.) in a natural population of freshwater snails that was composed of both sexual and asexual individuals (Potamopyrgus antipodarum). More specifically, we compared the frequency of infection in sexual and asexual individuals over a five-year period at four sites at a natural glacial lake (Lake Alexandrina, South Island, New Zealand). We found that at most sites and over most years, the sexual population was less infected than the coexisting asexual population. Moreover, the frequency of uninfected sexual females was periodically greater than two times the frequency of uninfected asexual females. These results give clear support for a fluctuating parasite-mediated advantage to sexual reproduction in a natural population.
Data from: Testing the Distraction Hypothesis: do extrafloral nectaries reduce ant‐pollinator conflict?
1. Ant guards protect plants from herbivores, but can also hinder pollination by damaging reproductive structures and/or repelling pollinators. Natural selection should favour the evolution of plant traits that deter ants from visiting flowers during anthesis, without waiving their defensive services. The Distraction Hypothesis posits that rewarding ants with extrafloral nectar could reduce their visitation of flowers, reducing ant-pollinator conflict while retaining protection of other structures. 2. We characterised the proportion of flowers occupied by ants and the number of ants per flower in a Mexican ant-plant, Turnera velutina. We clogged extrafloral nectaries on field plants and observed the effects on patrolling ants, pollinators and ants inside flowers, and quantified the effects on plant fitness. Based on the Distraction Hypothesis we predicted that preventing extrafloral nectar secretion should result in fewer ants active at extrafloral nectaries, more ants inside flowers and a higher proportion of flowers occupied by ants, leading to ant-pollinator conflict, with reduced pollinator visitation and reduced plant fitness. 3. Overall ant activity inside flowers was low. Preventing extrafloral nectar secretion through clogging reduced the number of ants patrolling extrafloral nectaries, significantly increased the proportion of flowers occupied by ants from 6.1% to 9.7%, and reduced plant reproductive output through a 12% increase in the probability of fruit abortion. No change in the numbers of ants or pollinators inside flowers was observed. This is the first support for the Distraction Hypothesis obtained under field conditions, showing ecological and plant fitness benefits of the distracting function of extrafloral nectar during anthesis. 4. Synthesis: Our study provides the first field experimental support for the Distraction Hypothesis, suggesting that extrafloral nectaries located close to flowers may bribe ants away from reproductive structures during the crucial pollination period, reducing the probability of ant-occupation of flowers, reducing ant-pollinator conflict, and increasing plant reproductive success.
Data from: A test of the eavesdropping avoidance hypothesis as an explanation for the structure of low amplitude aggressive signals in the song sparrow
Low amplitude signals function in private exchanges of information between signalers and nearby receivers. The eavesdropping avoidance hypothesis proposes that selection favors quiet threat signals in order to avoid the costs of eavesdroppers. If true, then selection should favor other acoustic traits in addition to low amplitude that lead to quiet signals transmitting less effectively through the environment compared to broadcast signals. The "warbled" soft songs of male song sparrows differ from "crystallized" soft songs and from broadcast songs in a number of acoustic traits, suggesting that these songs may transmit less effectively. We tested this prediction in a field experiment by playing broadcast songs, crystallized soft songs, and warbled soft songs through a loudspeaker at the same amplitude and recording the propagated songs at five distances, at two heights, and in two different habitat types. Counter to our prediction, we found no evidence that either form of soft song transmits differently than broadcast song when all were played loudly. If anything, soft songs transmitted more effectively when all songs were played quietly. Our results do not support one prediction made by the eavesdropping avoidance hypothesis, although the possibility remains that reduced amplitude alone is sufficient to reduce eavesdropping. The question of why warbled soft song differs in acoustic structure remains unresolved.
Data from: Polyandrous females provide sons with more competitive sperm: support for the sexy-sperm hypothesis in the rattlebox moth (Utetheisa ornatrix)
Given the costs of multiple-mating, why has female polyandry evolved? Utetheisa ornatrix moths are well-suited for studying multiple mating in females because females are highly polyandrous over their lifespan, with each male mate transferring a substantial spermatophore with both genetic and non-genetic material. The accumulation of resources might explain the prevalence of polyandry in this species, but another, not mutually-exclusive, possibility is that females mate multiply to increase the probability that their sons will inherit more-competitive sperm. This latter "sexy-sperm" hypothesis posits that female multiple mating and male sperm competitiveness co-evolve via a Fisherian runaway process. We tested the sexy-sperm hypothesis by using competitive double matings to compare the sperm competition success of sons of polyandrous versus monandrous females. In accordance with sexy-sperm theory, we found that in 511 offspring across 17 families, the male whose polyandrous mother mated once with each of three different males sired significantly more of all total offspring (81%) than did the male whose monandrous mother was mated thrice to a single male. Interestingly, sons of polyandrous mothers had a significantly biased sex ratio of their brood toward sons, also in support of the hypothesis.
Data from: Integrative taxonomy refutes a species hypothesis: the asymmetric hybrid origin of Arsapnia arapahoe (Plecoptera, Capniidae)
Molecular tools are commonly directed at refining taxonomies and the species that constitute their fundamental units. This has been especially insightful for groups for which species hypotheses are ambiguous and have largely been based on morphological differences between certain life stages or sexes, and has added importance when taxa are a focus of conservation efforts. Here we examine the taxonomic status of Arsapnia arapahoe, a winter stonefly in the family Capniidae that is a species of conservation concern because of its limited abundance and restricted range in northern Colorado, USA. Phylogenetic analyses of sequences of mitochondrial and nuclear genes of this and other capniid stoneflies from this region and elsewhere in western North America indicated extensive haplotype sharing, limited genetic differences, and a lack of reciprocal monophyly between A. arapahoe and the sympatric A. decepta, despite distinctive and consistent morphological differences in the sexual apparatus of males of both species. Analyses of autosomal and sex-linked single nucleotide polymorphisms detected using genotyping by sequencing, however, indicated that all individuals of A. arapahoe consisted of F1 hybrids between female A. decepta and males of another sympatric stonefly, Capnia gracilaria. Rather than constitute a self-sustaining evolutionary lineage, A. arapahoe appears to represent the product of nonintrogressive hybridization in the limited area of syntopy between two widely distributed taxa. This offers a cautionary tale for taxonomists and conservation biologists working on the less-studied components of the global fauna.
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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.