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.

732

datasets available to search

ShareScore release 0.9.0

Dataset results

732 results for “population variation”

Learn how ShareScore rates datasets ↗

dryad36/100

Genetic variation for upper thermal tolerance diminishes within and between populations with increasing acclimation temperature in Atlantic salmon

Populations may counteract lasting temperature changes or recurrent extremes through plasticity or adaptation. However, it remains underexplored how outbreeding, either naturally, unintentionally, or facilitated, may modify a local response potential and whether genotype-by-environment interactions or between-trait correlations can restrict this potential. We quantified population differences and outbreeding effects, within-population genetic variation, and plasticity of these, for thermal performance proxy traits using 32 pedigreed wild, domesticated, and wild-domesticated Atlantic salmon families reared under common-garden conditions. Following exposure to ambient cold (11.6°C) or ~4- and ~8-degree warmer summer temperatures, populations differed notably for body length and critical thermal maximum (CTmax) and for thermal plasticity of length, condition, and CTmax, but not for haematocrit. Line-cross analysis suggested mostly additive and some dominant outbreeding effects on means and solely additive outbreeding effects on plasticity. Heritability was detected for all traits. However, with increasing acclimation temperature, differences in CTmax between populations and CTmax heritability diminished, and CTmax breeding values re-ranked. Furthermore, CTmax and body size were negatively correlated at the genetic and phenotypic levels, and there was indirect evidence for a positive correlation between growth potential and thermal performance breadth for growth. Thus, population differences (including those between wild and domesticated populations) in thermal performance and plasticity may present a genetic resource in addition to the within-population genetic variance to facilitate, or impede, thermal adaptation. However, unfavourable genotype-by-environment interactions and negative between-trait correlations may generally hamper joint evolution in response to increase in average temperature and temporary extremes.

opencc-zeroAug 2021View details →

zenodo36/100

Fig. 2 in Evidence of the color pattern variation in populations of Gymnotus pantanal (Gymnotiformes) from three streams in the upper Paraná River basin, Brazil

Fig. 2. Gymnotus pantanal, holotype, 196.0 mm TL, MZUSP 67874.

opencc-by-4.0May 2011View details →

dryad36/100

Crossing design shapes patterns of genetic variation in synthetic recombinant populations of Saccharomyces cerevisiae

"Synthetic recombinant" populations have emerged as a useful tool for dissecting the genetics of complex traits. They can be used to derive inbred lines for fine QTL mapping, or the populations themselves can be sampled for experimental evolution. In latter application, investigators generally value maximizing genetic variation in constructed populations. This is because in evolution experiments initiated from such populations, adaptation is primarily fueled by standing genetic variation. Despite this reality, little has been done to systematically evaluate how different methods of constructing synthetic populations shape initial patterns of variation. Here we seek to address this issue by comparing outcomes in synthetic recombinant Saccharomyces cerevisiae populations created using one of two strategies: pairwise crossing of isogenic strains or simple mixing of strains in equal proportion. We also explore the impact of the varying the number of parental strains. We find that more genetic variation is initially present and maintained when population construction includes a round of pairwise crossing. As perhaps expected, we also observe that increasing the number of parental strains typically increases genetic diversity. In summary, we suggest that when constructing populations for use in evolution experiments, simply mixing founder strains in equal proportion may limit the adaptive potential.

opencc-zeroOct 2021View details →

dryad36/100

Pleistocene divergence in the absence of gene flow among populations of a viviparous reptile with intraspecific variation in sex determination

Polymorphisms can lead to speciation if there is differential mating success among conspecifics divergent for a trait. Polymorphism for sex determining system might be particularly expected to isolate gene pools, given strong selection for the production of viable males and females and the low success of heterogametic hybrids when sex chromosomes differ (Haldane's rule). We investigated this question using a rare example of a species exhibiting polymorphism for sex determination: the viviparous snow skink Carinascincus ocellatus. While a coparatively high elevation population has entirely genotypic sex determination, in a lower elevation population there is an additional environmental component to sex determination. These systems also exhibit minor differences in sex-linked genotypes. Using 'Isolation with Migration' analysis of neutral loci, we estimated that these populations and their sex determining systems diverged in the absence of gene flow, across multiple periods of geographic proximity during Pleistocene glaciations. Our analysis suggests that populations of C. ocellatus with divergent sex determining systems are likely reproductively isolated, even though they are presently underlined by only subtle DNA differences. Given the influence of temperature on sex in one lineage, we also discuss the implications for the persistence of this polymorphism under climate change.

opencc-zeroOct 2021View details →

dryad36/100

Population-specific responses of an insect herbivore to variation in host-plant quality

Anthropogenic climate change poses a substantial challenge to many organisms, to which they need to respond to avoid fitness reductions. Investigating responses to environmental change is particularly interesting in herbivores, as they are potentially affected by indirect effects mediated via variation in host-plant quality. We here use the herbivorous insect Pieris napi to investigate geographic variation in the response to variation in food quality. We performed a common garden experiment using replicated populations from Germany and Italy, and manipulating host quality by growing host plants at different temperature and water regimes. We found that feeding on plants grown at a higher temperature generally diminished the performance of P. napi, evidenced by a prolonged development time and reduced larval growth rate, body mass, fat content, and phenoloxidase activity. Genotype by environment interactions (G x E) were present in several performance traits, indicating that Italian populations (1) respond more strongly to variation in host-plant quality and (2) are more sensitive to poor food quality than German ones. This may reflect a cost of the rapid lifestyle found in Italian populations. Consequently, German populations may be more resilient against environmental perturbations and may perhaps even benefit from warmer temperatures, while Italian populations will likely suffer from the concomitantly reduced host-plant quality. Our study thus exemplifies how investigating G x E may help to better understand the vulnerability of populations to climate change.

opencc-zeroNov 2022View details →

dryad36/100

Foraging behaviour variations, for gene expression and transcriptomic divergence in parasitic wasp populations of Venturia canescens

Foraging behaviours encompass strategies to locate resources and to exploit them. In many taxa, these behaviours are driven by a major gene called for, but mechanisms vary between species. In the parasitoid wasp Venturia canescens, sexual and asexual populations coexist in sympatry but differ in life-history trait, physiology and behaviours, which could impact their foraging strategies. Here, we explored the molecular bases underpinning divergence in behaviours by testing two mutually nonexclusive hypotheses: first, the divergence in the for gene correlates with difference in foraging strategies, and second, the latter rely on a divergence in whole-genome expression. Using comparative genomics, we showed that the for gene was conserved across insects considering both sequence and gene model complexity. Polymorphism analysis did not support the occurrence of two allelic variants diverging across the two populations, yet the asexual population exhibited less polymorphism than the sexual population. Sexual and asexual transcriptomes sharply split, with 10.9% of differentially expressed genes, but these were not enriched in behavioural-related genes. We showed that the for gene was more highly expressed in asexual female heads than in sexual heads and that those differences correlate with divergence in foraging behaviours in our experiment since asexuals explored the environment more and exploited more host patches. Overall, these results suggested that fine tuning of for gene expression between populations may have led to distinct foraging behaviours. We hypothesized that reproductive polymorphism and coexistence in sympatry of sexual and asexual populations specialized to different ecological niches via divergent optima on phenotypic traits could imply adaptation through different expression patterns of the for gene and at many other loci throughout the genome.

opencc-zeroDec 2022View details →

dryad36/100

Long-term responses to large-scale disturbances: Spatiotemporal variation in gastropod populations and communities

The Anthropocene is characterized by complex, primarily human-generated, disturbance regimes that include combinations of long-term press (e.g. climate change, pollution) and episodic pulse (e.g. cyclonic storms, floods, wildfires, land use change) disturbances. Within any regime, disturbances occur at multiple spatial and temporal scales, creating complex and varied interactions that influence spatiotemporal dynamics in the abundance, distribution, and biodiversity of organisms. Moreover, responses to disturbance are context-dependent, with the legacies of previous disturbances affecting responses to ensuing perturbations. We use three decades of annual data to evaluate the effects of repeated pulse disturbances and global warming on gastropod populations and communities in Puerto Rico at multiple spatial scales. More specifically, we quantify (1) the relative importance of large-scale and small-scale aspects of disturbance on variation in abundance, biodiversity, and species composition; and (2) the spatial scales at which populations and communities integrate information in the spatially heterogenous environments created by disturbances. Gastropods do not exhibit consistent decreases in abundance or biodiversity in association with global warming: abundance for many species has increased over time and species richness does not evince a temporal trend. Nonetheless, gastropods are sensitive to hurricane severity, spatial environmental variation, and successional trajectories of the flora. In addition, they exhibit context-dependent (i.e. legacy effects) responses that are scale-dependent. The Puerto Rican biota has evolved in a disturbance-mediated system. This historical exposure to repeated, severe hurricane-induced disturbances has imbued the biota with high resistance and resilience to the current disturbance regime, resulting in an ability to persist or thrive under current environmental conditions. Nonetheless, these ecosystems may yet be threatened by worsening direct and indirect effects of climate change. In particular, more frequent and severe hurricanes may prevent the establishment of closed-canopy forests, negatively impacting populations and communities that rely on these habitats.

opencc-zeroJan 2023View details →

dryad36/100

Open-population SCR model to estimate spatiotemporal variation in individual birth locations, detection rates, and survival

This is an open population SCR model developed by R. Chandler and K. Engebretsen. The full model incorporates 4 spatial covariates in birth location density submodel, 3 location-specific, temporal covariates in the detection submodel, and 4 spatial covariates in the survival submodel. Formatted data is provided for the 2015 and 2016 fawning season in south Florida and the model can be fit using the script fitFawnModel.R.

opencc-zeroMar 2023View details →

dryad36/100

Raw data for: Sex and population differences underlie variation in reproductive success in a warming environment

Current rising temperatures are threatening biodiversity. It is therefore crucial to understand how climate change impacts male and female fertility and whether evolutionary responses can help in coping with heat stress. We use experimental evolution to study male and female fertility during real-time evolution of two historically differentiated populations of Drosophila subobscura under different thermal selection regimes for 23 generations. We aim to (1) tease apart sex-specific differences in fertility after exposure to warming conditions during development, (2) test whether thermal selection can enhance fertility under thermal stress, and (3) address the role of historically distinct genetic backgrounds. Contrary to expectations, heat stress during development had a higher negative impact on female fertility than on male fertility. We did not find clear evidence for enhanced fertility in males or females evolving under warming conditions. Population history had a clear impact on fertility response under thermal stress, particularly in males with those from lower latitudes presenting better performance than their higher latitude counterparts. We show that the impact of thermal stress on fertility varies between traits, sexes and genetic backgrounds. Incorporating these several levels of variation is crucial for a deeper understanding of how fertility evolves under climate change.

opencc-zeroJun 2023View details →

dryad36/100

Variation among strains of Borrelia burgdorferi in host tissue abundance and lifetime transmission determine the population strain structure in nature

Pathogen life history theory assumes a positive relationship between pathogen load in host tissues and pathogen transmission. Empirical evidence for this relationship is surprisingly rare due to the difficulty of measuring transmission for many pathogens. The comparative method, where a common host is experimentally infected with a set of pathogen strains, is a powerful approach for investigating the relationships between pathogen load and transmission. The validity of such experimental estimates of strain-specific transmission is greatly enhanced if they can predict the pathogen population strain structure in nature. Borrelia burgdorferi is a multi-strain, tick-borne spirochete that causes Lyme disease in North America. This study used 11 field-collected strains of B. burgdorferi, a rodent host (Mus musculus, C3H/HeJ) and its tick vector (Ixodes scapularis) to determine the relationship between pathogen load in host tissues and lifetime host-to-tick transmission (HTT). Mice were experimentally infected via tick bite with 1 of 11 strains. Lifetime HTT was measured by infesting mice with I. scapularis larval ticks on 3 separate occasions. The prevalence and abundance of the strains in the mouse tissues and the ticks were determined by qPCR. We used published databases to obtain estimates of the frequencies of these strains in wild I. scapularis populations. Spirochete loads in ticks and lifetime HTT varied significantly among the 11 strains of B. burgdorferi. Strains with higher spirochete loads in the host tissues were more likely to infect feeding larvae, which molted into nymphs with a higher probability of B. burgdorferi infection (i.e., higher HTT). Our laboratory-based estimates of lifetime HTT were predictive of the frequencies of these strains in wild I. scapularis populations. For B. burgdorferi, the strains that establish high abundance in host tissues and that have high lifetime transmission are the strains that are most common in nature.

opencc-zeroJul 2023View details →

dryad36/100