scholarly journals Host–parasitoid evolution in a metacommunity

2016 ◽  
Vol 283 (1831) ◽  
pp. 20160477 ◽  
Author(s):  
Denon Start ◽  
Benjamin Gilbert
Keyword(s):  
Natural Enemies ◽  
Patch Size ◽  
Common Garden ◽  
Species Traits ◽  
Dispersal Ability ◽  
Isolated Populations ◽  
Selection Gradient ◽  
Phenotypic Differences ◽  
Dispersal Abilities ◽  
Phenotypic Shift

Patch size and isolation are predicted to alter both species diversity and evolution; yet, there are few empirical examples of eco-evolutionary feedback in metacommunities. We tested three hypotheses about eco-evolutionary feedback in a gall-forming fly, Eurosta solidaginis and two of its natural enemies that select for opposite traits: (i) specialization and poor dispersal ability constrain a subset of natural enemies from occupying small and isolated patches, (ii) this constraint alters selection on the gall fly, causing phenotypic shifts towards traits resistant to generalist and dispersive enemies in small and isolated patches, and (iii) reduced dispersal evolves in small, isolated populations. We sampled patches in a natural metacommunity and found support for all hypotheses; Eurosta 's specialist wasp parasitoid attacked fewer galls in small and isolated patches, generating a selection gradient that favoured small galls resistant to predation by a dispersive and generalist bird predator. Phenotype distributions matched this selection gradient, and these phenotypic differences were maintained in a common garden experiment. Finally, we found lower dispersal abilities in small and isolated patches, a phenotypic shift that aids in the maintenance of local adaptation. We suggest that the trophic rank and the species traits of consumers are central to evolution in metacommunities.

scholarly journals Phenotypes in phylogeography: Species’ traits, environmental variation, and vertebrate diversification

2016 ◽  
Vol 113 (29) ◽  
pp. 8041-8048 ◽  
Author(s):  
Kelly R. Zamudio ◽  
Rayna C. Bell ◽  
Nicholas A. Mason
Keyword(s):  
Species Traits ◽  
Population Divergence ◽  
Spatially Explicit ◽  
Phenotypic Data ◽  
Phenotypic Differentiation ◽  
Phenotypic Differences ◽  
New Methods ◽  
Temporal And Spatial ◽  
Species Performance ◽  
Intraspecific Phylogeography

Almost 30 y ago, the field of intraspecific phylogeography laid the foundation for spatially explicit and genealogically informed studies of population divergence. With new methods and markers, the focus in phylogeography shifted to previously unrecognized geographic genetic variation, thus reducing the attention paid to phenotypic variation in those same diverging lineages. Although phenotypic differences among lineages once provided the main data for studies of evolutionary change, the mechanisms shaping phenotypic differentiation and their integration with intraspecific genetic structure have been underexplored in phylogeographic studies. However, phenotypes are targets of selection and play important roles in species performance, recognition, and diversification. Here, we focus on three questions. First, how can phenotypes elucidate mechanisms underlying concordant or idiosyncratic responses of vertebrate species evolving in shared landscapes? Second, what mechanisms underlie the concordance or discordance of phenotypic and phylogeographic differentiation? Third, how can phylogeography contribute to our understanding of functional phenotypic evolution? We demonstrate that the integration of phenotypic data extends the reach of phylogeography to explain the origin and maintenance of biodiversity. Finally, we stress the importance of natural history collections as sources of high-quality phenotypic data that span temporal and spatial axes.

scholarly journals Scale-dependent environmental filtering of ground-dwelling predators in winter wheat and adjacent set-aside areas in Hungary

2020 ◽  
Vol 24 (5) ◽  
pp. 751-763
Author(s):  
Jana Růžičková ◽  
Ferenc Kádár ◽  
Ottó Szalkovszki ◽  
Anikó Kovács-Hostyánszki ◽  
András Báldi ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Natural Enemies ◽  
Spatial Scales ◽  
Habitat Type ◽  
Environmental Filtering ◽  
Landscape Scale ◽  
Dispersal Ability ◽  
Field Scale ◽  
Wheat Field ◽  
Activity Density

Abstract Agricultural intensification may act as an environmental filter shaping invertebrate assemblages at multiple spatial scales. However, it is not fully understood which scale is the most influential. Therefore, we utilized a hierarchical approach to examine the effect of local management (inorganic fertilization and soil properties; within-field scale), habitat type (winter wheat field and set-aside field; between-field scale) and landscape complexity (landscape scale) on assemblage structure and functional diversity of two important groups of natural enemies, carabids and spiders, in a cultivated lowland landscape in Hungary. Environmental filtering affected natural enemies at different spatial scales; likely as a result of enemies’ different dispersal ability and sensitivity to fertilizer use. Carabids were strongly affected at the within-field scale: positively by soil pH, negatively by soil organic matter and fertilization. At the between-field scale, carabids had higher activity density in the set-aside fields than in the winter wheat fields and simple landscapes enhanced carabids diversity, species richness and activity density at the landscape scale. Spiders were more abundant and species-rich in the set-aside fields than in the winter wheat fields. Although highly mobile (macropterous) carabids might disperse to arable crops from greater distances, while spiders possibly depended more on the proximity of set-aside fields, the winter wheat fields (where pest control should be delivered) were utilized mostly by common agrobiont species. Increasing crop heterogeneity within arable fields could be a potential option to increase the diversity of carabids and spiders in the studied region.

scholarly journals A populational survey of 45S rDNA polymorphism in the Jefferson salamander Ambystoma jeffersonianum revealed by fluorescence in situ hybridization (FISH)

2009 ◽  
Vol 55 (2) ◽  
pp. 145-149 ◽  
Author(s):  
Ke Bi ◽  
James P. Bogart ◽  
Jinzhong Fu
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Dispersal Ability ◽  
Habitat Isolation ◽  
45S Rdna ◽  
Isolated Populations ◽  
Ambystoma Jeffersonianum ◽  
Rdna Sites ◽  
Rdna Polymorphism

Abstract The chromosomal localization of 45S ribosomal RNA genes in Ambystoma jeffersonianum was determined by fluorescence in situ hybridization with 18S rDNA fragment as a probe (FISH-rDNA). Our results revealed the presence of rDNA polymorphism among A. jeffersonianum populations in terms of number, location and FISH signal intensity on the chromosomes. Nine rDNA cytotypes were found in ten geographically isolated populations and most of them contained derivative rDNA sites. Our preliminary study provides strong indication of karyotypic diversification of A. Jeffersonianum that is demonstrated by intraspecific variation of 45S rDNA cytotypes. rDNA cytotype polymorphism has been described in many other caudate amphibians. We predict that habitat isolation, low dispersal ability and decline of effective population size could facilitate the fixation and accumulation of variable rDNA cytotypes during their chromosome evolution.

scholarly journals Quantitative-genetic variation in morphological and physiological traits within a quaking aspen (Populus tremuloides) population

2008 ◽  
Vol 38 (6) ◽  
pp. 1690-1694 ◽  
Author(s):  
Megan K. Kanaga ◽  
Ronald J. Ryel ◽  
Karen E. Mock ◽  
Michael E. Pfrender
Keyword(s):  
Genetic Variation ◽  
Populus Tremuloides ◽  
Common Garden ◽  
Quaking Aspen ◽  
Common Garden Experiment ◽  
Plant Populations ◽  
Phenotypic Differences ◽  
Quantitative Genetic ◽  
Morphological And Physiological Traits ◽  
Populus Species

Genetic diversity within populations is an important component of adaptive evolution, and recent research has demonstrated that genetic variation within plant populations can have important ecological effects. In this study, we investigate quantitative-genetic variation in several traits within a quaking aspen ( Populus tremuloides Michx.) population. A common garden experiment was planted with replicates of 13 aspen genotypes collected from wet and dry sites within a population in southern Utah, USA. Ten growth, leaf, physiological, and structural traits were measured. There were significant, heritable phenotypic differences among genotypes in every measured trait and differences in 4 of the 10 traits among genotypes originating from wet and dry collection sites. The data were compared with other published studies, showing that aspen heritability (H2) estimates and coefficients of genetic variation (CVG) were comparable or higher than other Populus species and hybrid F1 Populus genotypes, indicating a large amount of quantitative-genetic variation in aspen.

scholarly journals Landscape composition mediates suppression of major pests by natural enemies in conventional cruciferous vegetables

2021 ◽  
Author(s):  
Jie Zhang ◽  
Shijun You ◽  
Dongsheng Niu ◽  
Karla Giovana Gavilanez Guaman ◽  
Ao Wang ◽  
...  
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Natural Enemy ◽  
Positive Impact ◽  
Spatial Scales ◽  
Habitat Diversity ◽  
Landscape Composition ◽  
Dispersal Ability ◽  
Cruciferous Vegetables ◽  
Natural Habitats

ABSTRACTBackgroundConservation biological control provides an environment-friendly approach to improve the efficacy of natural enemies. Although numerous studies have demonstrated the potential of semi-natural habitats in promoting biological control in organic or unsprayed agroecosystems, few studies were conducted in conventional agricultural fields. In this study, we investigated the effects of landscape composition on the major pests of cruciferous vegetables and on the assemblages of their natural enemies in southeastern China.ResultsHabitat diversity, particularly increasing grassland proportion in the landscape, had a positive impact in controlling both small-sized pests (aphids, leaf miners, thrips and flea beetles) and Plutella xylostella. This increasing proportion also promoted greater abundance and diversity of canopy-dwelling predators, more forests supported a higher diversity of airborne enemies (parasitoids and canopy-dwelling predators) as well as a higher abundance of ground-dwelling predators. A general increase in habitat diversity was beneficial to parasitoids and ground-dwelling predators. Additionally, the proportion of forest, grassland, and non-cruciferous vegetable area, as well as habitat diversity, affected the compositions of natural enemy communities. Moreover, inconsistent effects of non-cruciferous and grassland habitats were found between sampling regions for small-sized pests and canopy-dwelling predators. Moreover, the scale at which pests and natural enemies’ abundance and richness responded most to landscape composition varied with their feeding range and dispersal ability.ConclusionOur study provides evidence that increasing the amount of semi-natural habitats and habitat diversity can result in lower pest and higher natural enemy abundance in conventional cruciferous agroecosystems. Regional conditions and spatial scales also should be considered in designing the agricultural landscape mosaic.

scholarly journals Transcriptome analyses of Anguillicola crassus from native and novel hosts

2014 ◽  
Author(s):  
Emanuel Heitlinger ◽  
Horst H. Taraschewski ◽  
Urszula Weclawski ◽  
Karim Gharbi ◽  
Mark Blaxter
Keyword(s):  
Population Differentiation ◽  
Anguilla Anguilla ◽  
Common Garden ◽  
European Eel ◽  
New Host ◽  
Phenotypic Differences ◽  
Secretion Signal ◽  
Anguillicola Crassus ◽  
The Face ◽  
Parasite Populations

Anguillicola crassus is a swim bladder nematode of eels. The parasite is native to the Asian eel Anguilla japonica, but was introduced to Europe and the European eel Anguilla anguilla in the early 1980s. A Taiwanese source has been proposed for this introduction. In the new host in the recipient area, the parasite appears to be more pathogenic. As a reason for these differences, genetically fixed differences in infectivity and development between Taiwanese and European A.crassus have been described and disentangled from plasticity induced by different host environments.To explore whether transcriptional regulation is involved in these lifecycle differences, we have analysed a “common garden”, cross infection experiment, using deep-sequencing transcriptomics. Surprisingly, in the face of clear phenotypic differences in life history traits, we identified no significant differences in gene expression between parasite populations or between experimental host species. From 120,000 SNPs identified in the transcriptome data we found that European A. crassus were not a genetic subset of the Taiwanese nematodes sampled. The loci that have the major contribution to the European-Taiwanese population differentiation show an enrichment of synonymous and non-coding polymorphism. This argues against positive selection in population differentiation. However, genes involved in protein processing in the endoplasmatic reticulum membrane and genes bearing secretion signal sequences were enriched in the set of genes most differentiated between European and Taiwanese A. crassus. These genes could be a source for the phenotypically visible genetically fixed differences between European and Taiwanese A. crassus.

scholarly journals Transcriptome analyses of Anguillicola crassus from native and novel hosts

2014 ◽  
Author(s):  
Emanuel Heitlinger ◽  
Horst H. Taraschewski ◽  
Urszula Weclawski ◽  
Karim Gharbi ◽  
Mark Blaxter
Keyword(s):  
Population Differentiation ◽  
Anguilla Anguilla ◽  
Common Garden ◽  
European Eel ◽  
New Host ◽  
Phenotypic Differences ◽  
Secretion Signal ◽  
Anguillicola Crassus ◽  
The Face ◽  
Parasite Populations

Anguillicola crassus is a swim bladder nematode of eels. The parasite is native to the Asian eel Anguilla japonica, but was introduced to Europe and the European eel Anguilla anguilla in the early 1980s. A Taiwanese source has been proposed for this introduction. In the new host in the recipient area, the parasite appears to be more pathogenic. As a reason for these differences, genetically fixed differences in infectivity and development between Taiwanese and European A.crassus have been described and disentangled from plasticity induced by different host environments.To explore whether transcriptional regulation is involved in these lifecycle differences, we have analysed a “common garden”, cross infection experiment, using deep-sequencing transcriptomics. Surprisingly, in the face of clear phenotypic differences in life history traits, we identified no significant differences in gene expression between parasite populations or between experimental host species. From 120,000 SNPs identified in the transcriptome data we found that European A. crassus were not a genetic subset of the Taiwanese nematodes sampled. The loci that have the major contribution to the European-Taiwanese population differentiation show an enrichment of synonymous and non-coding polymorphism. This argues against positive selection in population differentiation. However, genes involved in protein processing in the endoplasmatic reticulum membrane and genes bearing secretion signal sequences were enriched in the set of genes most differentiated between European and Taiwanese A. crassus. These genes could be a source for the phenotypically visible genetically fixed differences between European and Taiwanese A. crassus.

EICA 2.0: a general model of enemy release and defence in plant and animal invasions.

2020 ◽  
pp. 192-207
Author(s):  
Richard Honor ◽  
Robert I. Colautti
Keyword(s):  
Invasive Species ◽  
Natural Enemies ◽  
General Model ◽  
Rapid Evolution ◽  
Common Garden ◽  
Enemy Release ◽  
Introduced Populations ◽  
Introduced Range ◽  
Common Garden Experiments

Abstract Plants and animals have evolved a variety of strategies to limit the negative fitness consequences of natural enemies (i.e. herbivores, predators, parasites and pathogens). Demographic bottlenecks occurring during the invasion process reduce the number of co-introduced natural enemies, providing opportunities to study rapid evolution in environments with different or reduced enemy loads. Enemy release theory provides a set of hypotheses and predictions about the role of natural enemies in the proliferation of invasive species. This body of theory includes the Enemy Release Hypothesis (ERH) and the related Evolution of Increased Competitive Ability Hypothesis (EICA), but there is often confusion about these hypotheses and the data needed to test them. We introduce a simple, general model of enemy release to identify and clarify some of the key assumptions and predictions implicit in enemy release theory and its impacts on invasion. Although introduced populations likely benefit from a reduction in the direct fitness impacts of natural enemies in the early stages of invasion, an evolutionary shift in resource allocation from defence to growth and reproduction is much less likely and depends on a delicate balance between the fitness costs and benefits of defence and the fitness impacts of natural enemies in both the native and introduced ranges. Even when the abundance of natural enemies is lower in the introduced range, the majority of scenarios do not favour evolution of less defended genotypes that are more competitive or more fecund, contrary to predictions of EICA. Perhaps surprisingly, we find that the level of damage by natural enemies in field surveys is not generally a good parameter for testing enemy release theory. Instead, common garden experiments characterizing fitness reaction norms of multiple genotypes from the native and introduced range are crucial to estimate the historic rate of adaptive evolution or predict it into the future. Incorporating spatial autocorrelation and methods from population genetics can further improve our understanding of the role of enemy release and evolution in the proliferation of invasive species.

scholarly journals Flight capacity increases then declines from the core to the margins of an invasive species' range

2019 ◽  
Vol 15 (11) ◽  
pp. 20190496 ◽  
Author(s):  
Andrew C. Merwin
Keyword(s):  
Invasive Species ◽  
Maternal Effects ◽  
Common Garden ◽  
Spatial Proximity ◽  
Dispersal Ability ◽  
Suitable Habitat ◽  
Dispersal Capacity ◽  
The Core ◽  
Spatial Sorting ◽  
Flight Capacity

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 ( Megacopta cribraria )—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.

scholarly journals Species traits, patch turnover and successional dynamics: when does intermediate disturbance favour metapopulation occupancy?

BMC Ecology ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Frederico Mestre ◽  
Ricardo Pita ◽  
António Mira ◽  
Pedro Beja
Keyword(s):  
Land Use Changes ◽  
Habitat Preferences ◽  
Species Traits ◽  
Intermediate Disturbance Hypothesis ◽  
Dispersal Ability ◽  
Turnover Rates ◽  
Patch Occupancy ◽  
Intermediate Disturbance ◽  
Disturbance Frequency ◽  
Successional Species

Abstract Background In fragmented landscapes, natural and anthropogenic disturbances coupled with successional processes result in the destruction and creation of habitat patches. Disturbances are expected to reduce metapopulation occupancy for species associated with stable habitats, but they may benefit species adapted to transitory habitats by maintaining a dynamic mosaic of successional stages. However, while early-successional species may be favoured by very frequent disturbances resetting successional dynamics, metapopulation occupancy may be highest at intermediate disturbance levels for species with mid-successional habitat preferences, though this may be conditional on species traits and patch network characteristics. Here we test this ‘intermediate disturbance hypothesis’ applied to metapopulations (MIDH), using stochastic patch occupancy simulation modelling to assess when does intermediate disturbance favour metapopulation occupancy. We focused on 54 virtual species varying in their habitat preferences, dispersal abilities and local extinction and colonization rates. Long-term metapopulation dynamics was estimated in landscapes with different habitat amounts and patch turnover rates (i.e. disturbance frequency). Results Equilibrium metapopulation occupancy by late-successional species strongly declined with increasing disturbance frequency, while occupancy by early-successional species increased with disturbance frequency at low disturbance levels and tended to level-off thereafter. Occupancy by mid-successional species tended to increase along with disturbance frequency at low disturbance levels and declining thereafter. Irrespective of habitat preferences, occupancy increased with the amount of habitat, and with species dispersal ability and colonisation efficiency. Conclusions Our study suggests that MIDH is verified only for species associated with mid-successional habitats. These species may be particularly sensitive to land use changes causing either increases or decreases in disturbance frequency. This may be the case, for instance, of species associated with traditional agricultural and pastoral mosaic landscapes, where many species disappear either through intensification or abandonment processes that change disturbance frequency.

Sign in / Sign up

Export Citation Format

Share Document