scholarly journals Jack, Master or Both? The Invasive Ladybird Harmonia Axyridis Outperforms Its Native Counterpart Despite Similar Levels of Plasticity

Author(s):  
Ingrid Ané Minnaar ◽  
Cang Hui ◽  
Susana Clusella-Trullas

Abstract The plasticity of performance traits is expected to promote the successful invasion of species. Therefore, the comparison of reaction norms of invasive species with native competitors should enhance predictions of alien species establishment. Yet, most studies focus on a reduced set of traits, rarely in combination, or do not include trait variability to make predictions of establishment success. Here, we acclimated individuals to a cold, medium or warm temperature regime and measured critical thermal limits, life-history traits, and starvation resistance of the globally invasive Harmonia axyridis and its native counterpart Cheilomenes lunata. The native C. lunata had higher thermal plasticity of starvation resistance and higher upper thermal tolerance than H. axyridis. By contrast, H. axyridis outperformed C. lunata in most life-history traits. We combined trait responses, transport duration and propagule pressure to simulate the final number of beetles established in the introduced site in cold, medium and warm scenarios, where beetles also experienced a heatwave once established. Although C. lunata initially outcompeted the invasive species during transport, more H. axyridis survived in all environments because of higher life-history trait responses, in particular, higher fecundity. Despite increased starvation mortality in the warm scenario, H. axyridis established successfully given sufficient propagule size. By contrast, in the event of a heatwave, H. axyridis numbers plummeted and higher numbers of the native species established in the cold scenario. This study underscores the importance of considering a combination of traits and respective cascading effects when estimating the establishment potential of species and responses to climate warming.

2021 ◽  
Author(s):  
Anik Dutta ◽  
Fanny E. Hartmann ◽  
Carolina Sardinha Francisco ◽  
Bruce A. McDonald ◽  
Daniel Croll

AbstractThe adaptive potential of pathogens in novel or heterogeneous environments underpins the risk of disease epidemics. Antagonistic pleiotropy or differential resource allocation among life-history traits can constrain pathogen adaptation. However, we lack understanding of how the genetic architecture of individual traits can generate trade-offs. Here, we report a large-scale study based on 145 global strains of the fungal wheat pathogen Zymoseptoria tritici from four continents. We measured 50 life-history traits, including virulence and reproduction on 12 different wheat hosts and growth responses to several abiotic stressors. To elucidate the genetic basis of adaptation, we used genome-wide association mapping coupled with genetic correlation analyses. We show that most traits are governed by polygenic architectures and are highly heritable suggesting that adaptation proceeds mainly through allele frequency shifts at many loci. We identified negative genetic correlations among traits related to host colonization and survival in stressful environments. Such genetic constraints indicate that pleiotropic effects could limit the pathogen’s ability to cause host damage. In contrast, adaptation to abiotic stress factors was likely facilitated by synergistic pleiotropy. Our study illustrates how comprehensive mapping of life-history trait architectures across diverse environments allows to predict evolutionary trajectories of pathogens confronted with environmental perturbations.


Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 71
Author(s):  
Charalampos Dimitriadis ◽  
Ivoni Fournari-Konstantinidou ◽  
Laurent Sourbès ◽  
Drosos Koutsoubas ◽  
Stelios Katsanevakis

Understanding the interactions among invasive species, native species and marine protected areas (MPAs), and the long-term regime shifts in MPAs is receiving increased attention, since biological invasions can alter the structure and functioning of the protected ecosystems and challenge conservation efforts. Here we found evidence of marked modifications in the rocky reef associated biota in a Mediterranean MPA from 2009 to 2019 through visual census surveys, due to the presence of invasive species altering the structure of the ecosystem and triggering complex cascading effects on the long term. Low levels of the populations of native high-level predators were accompanied by the population increase and high performance of both native and invasive fish herbivores. Subsequently the overgrazing and habitat degradation resulted in cascading effects towards the diminishing of the native and invasive invertebrate grazers and omnivorous benthic species. Our study represents a good showcase of how invasive species can coexist or exclude native biota and at the same time regulate or out-compete other established invaders and native species.


Author(s):  
Gaotian Zhang ◽  
Jake D Mostad ◽  
Erik C Andersen

Abstract Life history traits underlie the fitness of organisms and are under strong natural selection. A new mutation that positively impacts a life history trait will likely increase in frequency and become fixed in a population (e.g. a selective sweep). The identification of the beneficial alleles that underlie selective sweeps provides insights into the mechanisms that occurred during the evolution of a species. In the global population of Caenorhabditis elegans, we previously identified selective sweeps that have drastically reduced chromosomal-scale genetic diversity in the species. Here, we measured the fecundity of 121 wild C. elegans strains, including many recently isolated divergent strains from the Hawaiian islands and found that strains with larger swept genomic regions have significantly higher fecundity than strains without evidence of the recent selective sweeps. We used genome-wide association (GWA) mapping to identify three quantitative trait loci (QTL) underlying the fecundity variation. Additionally, we mapped previous fecundity data from wild C. elegans strains and C. elegans recombinant inbred advanced intercross lines that were grown in various conditions and detected eight QTL using GWA and linkage mappings. These QTL show the genetic complexity of fecundity across this species. Moreover, the haplotype structure in each GWA QTL region revealed correlations with recent selective sweeps in the C. elegans population. North American and European strains had significantly higher fecundity than most strains from Hawaii, a hypothesized origin of the C. elegans species, suggesting that beneficial alleles that caused increased fecundity could underlie the selective sweeps during the worldwide expansion of C. elegans.


2018 ◽  
Author(s):  
Jacob W. Malcom ◽  
Thomas E. Juenger ◽  
Mathew A. Leibold

ABSTRACTBackgroundIdentifying the molecular basis of heritable variation provides insight into the underlying mechanisms generating phenotypic variation and the evolutionary history of organismal traits. Life history trait variation is of central importance to ecological and evolutionary dynamics, and contemporary genomic tools permit studies of the basis of this variation in non-genetic model organisms. We used high density genotyping, RNA-Seq gene expression assays, and detailed phenotyping of fourteen ecologically important life history traits in a wild-caught panel of 32Daphnia pulexclones to explore the molecular basis of trait variation in a model ecological species.ResultsWe found extensive phenotypic and a range of heritable genetic variation (~0 < H2< 0.44) in the panel, and accordingly identify 75-261 genes—organized in 3-6 coexpression modules—associated with genetic variation in each trait. The trait-related coexpression modules possess well-supported promoter motifs, and in conjunction with marker variation at trans- loci, suggest a relatively small number of important expression regulators. We further identify a candidate genetic network with SNPs in eight known transcriptional regulators, and dozens of differentially expressed genes, associated with life history variation. The gene-trait associations include numerous un-annotated genes, but also support several a priori hypotheses, including an ecdysone-induced protein and several Gene Ontology pathways.ConclusionThe genetic and gene expression architecture ofDaphnialife history traits is complex, and our results provide numerous candidate loci, genes, and coexpression modules to be tested as the molecular mechanisms that underlieDaphniaeco-evolutionary dynamics.


2014 ◽  
Vol 60 (3) ◽  
pp. 417-427 ◽  
Author(s):  
Tristan Juette ◽  
Julien Cucherousset ◽  
Julien Cote

Abstract While the ecological impacts of invasive species have been demonstrated for many taxonomic groups, the potential effects of behavioural variation among non-native individuals (i.e. personality) on these impacts have been largely overlooked. This is despite the fact that recent studies have demonstrated that, by nature, the three first stages of biological invasions (i.e. transport, establishment and spread) can lead to personality-biased populations. Freshwater ecosystems provide a unique opportunity to investigate this issue, notably because the ecological impacts of non-native species have been extensively documented and because animal personality has been widely studied using freshwater model species. Here, we aim at developing some perspectives on the potential effects of animal personality on the ecological impacts of freshwater non-native species across levels of biological organizations. At the individual level, personality types have been demonstrated to affect the physiolo- gy, metabolism, life history traits and fitness of individuals. We used these effects to discuss how they could subsequently impact invaded populations and, in turn, recipient communities. We also discussed how these might translate into changes in the structure of food webs and the functioning of invaded ecosystems. Finally we discussed how these perspectives could interact with the management of invasive species.


2010 ◽  
Vol 100 (2) ◽  
pp. 329-336 ◽  
Author(s):  
MATTHEW J. GREENLEES ◽  
BENJAMIN L. PHILLIPS ◽  
RICHARD SHINE

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