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Data from: Disentangling elevational richness: a multi-scale hierarchical Bayesian occupancy model of Colorado ant communities
- 负责人：
- DOI：
- doi:10.5061/dryad.rt679ng
- 摘要：
- Understanding the forces that shape the distribution of biodiversity across spatial scales is central in ecology and critical to effective conservation. To assess effects of possible richness drivers, we sampled ant communities on four elevational transects across two mountain ranges in Colorado, USA, with seven or eight sites on each transect and twenty repeatedly sampled pitfall trap pairs at each site each for a total of 90 days. With a multi-scale hierarchical Bayesian community occupancy model, we simultaneously evaluated the effects of temperature, productivity, area, habitat diversity, vegetation structure, and temperature variability on ant richness at two spatial scales, quantifying detection error and genus-level phylogenetic effects. We fit the model with data from one mountain range and tested predictive ability with data from the other mountain range. In total, we detected 105 ant species, and richness peaked at intermediate elevations on each transect. Species-specific thermal preferences drove richness at each elevation with marginal effects of site-scale productivity. Trap-scale richness was primarily influenced by elevation-scale variables along with a negative impact of canopy cover. Soil diversity had a marginal negative effect while daily temperature variation had a marginal positive effect. We detected no impact of area, land cover diversity, trap-scale productivity, or tree density. While phylogenetic relationships among genera had little influence, congeners tended to respond similarly. The hierarchical model, trained on data from the first mountain range, predicted the trends on the second mountain range better than multiple regression, reducing root mean squared error up to 65%. Compared to a more standard approach, this modeling framework better predicts patterns on a novel mountain range and provides a nuanced, detailed evaluation of ant communities at two spatial scales.
Data from: Genomic changes following the reversal of a Y chromosome to an autosome in Drosophila pseudoobscura
- 负责人：
- 关键词：
- SMRT sequencing;Robertsonian translocation;Y chromosome;dot chromosome;Drosophila pseudoobsucra
- DOI：
- doi:10.5061/dryad.rp949
- 摘要：
- Robertsonian translocations resulting in fusions between sex chromosomes and autosomes shape karyotype evolution by creating new sex chromosomes from autosomes. These translocations can also reverse sex chromosomes back into autosomes, which is especially intriguing given the dramatic differences between autosomes and sex chromosomes. To study the genomic events following a Y chromosome reversal, we investigated an autosome-Y translocation in Drosophila pseudoobscura. The ancestral Y chromosome fused to a small autosome (the dot chromosome) approximately 10–15 Mya. We used single molecule real-time sequencing reads to assemble the D. pseudoobscura dot chromosome, including this Y-to-dot translocation. We find that the intervening sequence between the ancestral Y and the rest of the dot chromosome is only ?78 Kb and is not repeat-dense, suggesting that the centromere now falls outside, rather than between, the fused chromosomes. The Y-to-dot region is 100 times smaller than the D. melanogaster Y chromosome, owing to changes in repeat landscape. However, we do not find a consistent reduction in intron sizes across the Y-to-dot region. Instead, deletions in intergenic regions and possibly a small ancestral Y chromosome size may explain the compact size of the Y-to-dot translocation.
Data from: A comparison of regression methods for model selection in individual-based landscape genetic analysis
- 负责人：
- DOI：
- doi:10.5061/dryad.p7m1v
- 摘要：
- Anthropogenic migration barriers fragment many populations and limit the ability of species to respond to climate-induced biome shifts. Conservation actions designed to conserve habitat connectivity and mitigate barriers are needed to unite fragmented populations into larger, more viable metapopulations, and to allow species to track their climate envelope over time. Landscape genetic analysis provides an empirical means to infer landscape factors influencing gene flow, and thereby inform such conservation actions. However, there are currently many methods available for model selection in landscape genetics, and considerable uncertainty as to which provide the greatest accuracy in identifying the true landscape model influencing gene flow among competing alternative hypotheses. In this study, we used population genetic simulations to evaluate the performance of seven regression-based model selection methods on a broad array of landscapes that varied by the number and type of variables contributing to resistance, the magnitude and cohesion of resistance, as well as the functional relationship between variables and resistance. We also assessed the effect of transformations designed to linearize the relationship between genetic and landscape distances. We found that linear mixed effects models had the highest accuracy in every way we evaluated model performance, however, other methods also performed well in many circumstances, particularly when landscape resistance was high and the correlation among competing hypotheses was limited. Our results provide guidance for which regression-based model selection methods provide the most accurate inferences in landscape genetic analysis and thereby best inform connectivity conservation actions.
Data from: How stabilizing selection and nongenetic inheritance combine to shape the evolution of phenotypic plasticity
- 负责人：
- DOI：
- doi:10.5061/dryad.rm041kb
- 摘要：
- Relatively little is known about whether and how nongenetic inheritance interacts with selection to impact the evolution of phenotypic plasticity. Here, we empirically evaluated how stabilizing selection and a common form of nongenetic inheritance––maternal environmental effects––jointly influence the evolution of phenotypic plasticity in natural populations of spadefoot toads. We compared populations that previous field work has shown to have evolved conspicuous plasticity in resource-use phenotypes (‘resource polyphenism’) with those that, owing to stabilizing selection favouring a narrower range of such phenotypes, appear to have lost this plasticity. We show that: 1) this apparent loss of plasticity in nature reflects a condition-dependent maternal effect and not a genetic loss of plasticity; i.e., ‘genetic assimilation’, and 2) this plasticity is not costly. By shielding non-costly plasticity from selection, nongenetic inheritance generally, and maternal effects specifically, can preclude genetic assimilation from occurring and consequently impede adaptive (genetic) evolution.
Data from: Sexual selection in a hermaphroditic plant through female reproductive success
- 负责人：
- 关键词：
- Bateman gradient Natural selection path analysis phenotypic selection pollinator-mediated selection structural equation model experimental manipulation
- DOI：
- doi:10.5061/dryad.s1q0h
- 摘要：
- Sexual selection is well accepted as a mechanism of shaping traits in animals. However, whether and how floral traits are sexually selected in hermaphroditic plants remains less clear. Here, we use Passiflora incarnata to address how floral traits that affect pollination success are selected via female function. We manipulated the ecological context by limiting pollination and adding resources to expand the phenotypic distribution and alter the intensity of sexual selection. Total sexual selection favoured lower style deflexion because of its impact on pollen receipt and subsequent seed number. However, total selection on style deflexion was not significant, indicating additional selection on style deflexion through routes other than mating. Limited pollination and enhanced resources were expected to alter the distribution of pollen deposition and seed production and therefore intensify the Bateman gradient – the relationship between pollen receipt and seed production. Indeed, the Bateman gradient was strongest when pollination was limited, suggesting potential for sexual selection to influence floral trait evolution under these conditions. Overall, we found floral traits may be shaped by sexual selection through female reproductive success in this hermaphroditic plant. These results support manipulations to enhance the variance in mating as a mechanism to understand patterns of sexual selection.
Data from: Being a bright snake: testing aposematism and mimicry in a Neotropical forest
- 负责人：
- DOI：
- doi:10.5061/dryad.s1rn8pk4z
- 摘要：
- Based on color patterns and behavioral similarities, venomous coral snake Micrurus corallinus (Elapidae) may act as a model for two polymorphic species, Erythrolamprus aesculapii (Dipsadidae) and Micrurus decoratus (Elapidae). Plasticine replicas were used to investigate the aposematism of these coloration patterns and whether these species may be part of mimetic complexes in two Atlantic Forest localities in South-east Brazil. Coral replicas were more avoided when set upon a white background, evincing that the pattern may act aposematically in contrast with light substrates. Birds attacked all four patterns equally during the mimicry experiments. Birds of prey, known to be effective in predating snakes, are quite abundant in the study areas, which may have led to this lack of avoidance. Accordingly, they predated more adult-sized replicas, which could be more dangerous. Interestingly, opossum avoided the Micrurus corallinus and Erythrolamprus aesculapii replicas that resembled the model. This suggests that opportunistic predators, as the opossum may be important selective agents in mimicry complexes.
Data from: Kin discrimination increases with odor distance in the German cockroach
- 负责人：
- van Zweden, Jelle S.
- 关键词：
- kin recognition aggregation cuticular hydrocarbons animal model odor–gene covariance quantitative genetics
- DOI：
- doi:10.5061/dryad.s20g8
- 摘要：
- Kin recognition mediates altruistic behavior and inbreeding avoidance in many animal societies. So far, evidence for accurate kin recognition, when individuals distinguish fine scale differences in genetic relatedness, in social insects is mixed. Although this ability should be counter selected to reduce risks of nepotism in eusocial colonies, accurate kin recognition may be beneficial in less integrated societies where genetic conflicts are reduced. Here we show that gregarious cockroaches Blattella germanica discriminate multiple levels of relatedness and identify inherited cuticular odors as potential kin recognition cues. When given a choice between aggregation sites containing either full siblings or less related conspecifics, cockroaches showed an increasing preference for resting with full siblings with increasing genetic distance between stimuli groups, from 50% of choices in the presence of half siblings or cousins, to 60.7% with less related cockroaches from the same strain, and 72.9% with cockroaches from a different strain. Examination of the cuticular hydrocarbon profiles of 288 nymphs and their 54 parents revealed that the chemical distance between cockroaches was negatively correlated to their relatedness. Using a Bayesian animal model approach for quantitative genetic analyses, we identified several highly heritable methyl-branched alkanes as good candidates for kin recognition cues. Our results suggest that kin recognition is based on genetically inherited odors in this gregarious insect and highlight mechanistic similarities with nestmate recognition in eusocial species.
Data from: Carbon resource richness shapes bacterial competitive interactions by alleviating growth-antibiosis trade-off
- 负责人：
- DOI：
- doi:10.5061/dryad.s24mq59
- 摘要：
- Antibiosis and resource competition are major drivers shaping the assembly, diversity and functioning of microbial communities. While it is recognised that competition is sensitive to environmental conditions, it is unclear to what extent this mediated by the availability of different carbon resources. Here we used a model laboratory system to directly test this by exploring how carbon resource richness and identity shape resource competition and antibiosis between plant probiotic Bacillus amyloliquefaciens and phytopathogenic Ralstonia solanacearum bacteria. We found that while sugars typically promoted B. amyloliquefaciens growth, organic and amino acids increased the production of both bacillaene and macrolactin antibiotics and the direct inhibition of R. solanacearum. In contrast, when multiple different carbon resources were available, B. amyloliquefaciens could efficiently grow and produce antibiotics at the same time. Together, these results suggest that high carbon resource richness allows concurrent expression of growth- and antibiosis-related traits, potentially altering bacterial competitive dynamics and plant growth promotion in microbial communities.
Data from: Desynchronizations in bee-plant interactions cause severe fitness losses in solitary bees
- 负责人：
- Schenk, Mariela
- 关键词：
- conditional sex allocation emergence mitigation strategies mutualism phenological shift pollination species interactions
- DOI：
- doi:10.5061/dryad.rm317
- 摘要：
- 1. Global warming can disrupt mutualistic interactions between solitary bees and plants when increasing temperature differentially changes the timing of interacting partners. One possible scenario is for insect phenology to advance more rapidly than plant phenology. 2. However, empirical evidence for fitness consequences due to temporal mismatches is lacking for pollinators and it remains unknown if bees have developed strategies to mitigate fitness losses following temporal mismatches. 3. We tested the effect of temporal mismatches on the fitness of three spring-emerging solitary bee species, including one pollen specialist. Using flight cages, we simulated (i) a perfect synchronization (from a bee perspective): bees and flowers occur simultaneously, (ii) a mismatch of three days and (iii) a mismatch of six days, with bees occurring earlier than flowers in the latter two cases. 4. A mismatch of six days caused severe fitness losses in all three bee species, as few bees survived without flowers. Females showed strongly reduced activity and reproductive output compared to synchronized bees. Fitness consequences of a three day mismatch were species-specific. Both the early-spring species Osmia cornuta and the mid-spring species Osmia bicornis produced the same number of brood cells after a mismatch of three days as under perfect synchronization. However, O. cornuta decreased the number of female offspring, whereas O. bicornis spread the brood cells over fewer nests, which may increase offspring mortality e.g. due to parasitoids. The late-spring specialist Osmia brevicornis produced fewer brood cells even after a mismatch of three days. Additionally, our results suggest that fitness losses after temporal mismatches are higher during warm than cold springs, as the naturally occurring temperature variability revealed that warm temperatures during starvation decreased the survival rate of O. bicornis. 5. We conclude that short temporal mismatches can cause clear fitness losses in solitary bees. Although our results suggest that bees have evolved species-specific strategies to mitigate fitness losses after temporal mismatches, the bees were not able to completely compensate for impacts on their fitness after temporal mismatches with their food resources.
Data from: Identification of the notothenioid sister lineage illuminates the biogeographic history of an Antarctic adaptive radiation
- 负责人：
- DOI：
- doi:10.5061/dryad.s355k
- 摘要：
- Background: Antarctic notothenioids are an impressive adaptive radiation. While they share recent common ancestry with several species-depauperate lineages that exhibit a relictual distribution in areas peripheral to the Southern Ocean, an understanding of their evolutionary origins and biogeographic history is limited as the sister lineage of notothenioids remains unidentified. The phylogenetic placement of notothenioids among major lineages of perciform fishes, which include sculpins, rockfishes, sticklebacks, eelpouts, scorpionfishes, perches, groupers and soapfishes, remains unresolved. We investigate the phylogenetic position of notothenioids using DNA sequences of 10 protein coding nuclear genes sampled from more than 650 percomorph species. The biogeographic history of notothenioids is reconstructed using a maximum likelihood method that integrates phylogenetic relationships, estimated divergence times, geographic distributions and paleogeographic history. Results: Percophis brasiliensis is resolved, with strong node support, as the notothenioid sister lineage. The species is endemic to the subtropical and temperate Atlantic coast of southern South America. Biogeographic reconstructions imply the initial diversification of notothenioids involved the western portion of the East Gondwanan Weddellian Province. The geographic disjunctions among the major lineages of notothenioids show biogeographic and temporal correspondence with the fragmentation of East Gondwana. Conclusions: The phylogenetic resolution of Percophis requires a change in the classification of percomorph fishes and provides evidence for a western Weddellian origin of notothenioids. The biogeographic reconstruction highlights the importance of the geographic and climatic isolation of Antarctica in driving the radiation of cold-adapted notothenioids.
