scholarly journals Natural selection and maladaptive plasticity in the red-shouldered soapberry bug

2016 ◽  
Author(s):  
M L Cenzer
Keyword(s):  
Gene Flow ◽  
Natural Selection ◽  
Phenotypic Plasticity ◽  
Host Plant ◽  
Individual Performance ◽  
Negative Effects ◽  
Soapberry Bug ◽  
Maladaptive Plasticity ◽  
Beak Length ◽  
Native Host

AbstractNatural selection and phenotypic plasticity can both produce locally differentiated phenotypes, but novel environments or gene combinations can produce plasticity that works in opposition to adaptive change. The red-shouldered soapberry bug (Jadera haematoloma) was locally adapted to feed on the seeds of an introduced and a native host plant in Florida in the 1980s. By 2014, local differentiation was lost and replaced by phenotypically similar populations all adapted to the introduced host, likely as a result of gene flow. Here, I quantify the effects of these two host plants on individual performance, natural selection, and phenotypic plasticity. I find that the seed coat and seedpod of the native host have strong negative effects on juvenile survival and adult reproduction compared to the introduced host. I find support for the hypothesis that the seedpod is driving diversifying natural selection on beak length, which was previously locally adapted between hosts. I also find maladaptive plasticity induced by host plant: bugs develop beak lengths that are mismatched with the seedpod size of the host they are reared on. This plasticity may be the result of gene flow; hybrids in the 1990s showed the same pattern of maladaptive plasticity, and plasticity is stronger in the present in areas with high gene flow. Although ongoing natural selection has produced locally adapted genotypes in soapberry bugs, maladaptive plasticity has masked the phenotypic difference between populations in the field.

scholarly journals Adult facilitation becomes competition as juvenile soapberry bugs age

2017 ◽  
Author(s):  
Meredith L Cenzer
Keyword(s):  
Host Plant ◽  
Intraspecific Interactions ◽  
Plant Feeding ◽  
Soapberry Bug ◽  
Adult Feeding ◽  
Negative Effect ◽  
Jadera Haematoloma ◽  
Native Host ◽  
Experienced Adult

ABSTRACTWhether intraspecific interactions are facilitative or competitive may change across individual ontogeny. In plant-feeding insects, the direction of this interaction is likely to be mediated by host plant defenses. Here I conducted two experiments looking at the direct effect of a physical seed defense and the role of intraspecific facilitation in reducing the effects of that defense for juveniles. I first demonstrate that juveniles of the red-shouldered soapberry bug (Jadera haematoloma) are severely inhibited by the tough seed coat of their host plant, leading to high mortality early in development. Adults, in contrast, can create holes through which other individuals could potentially feed. I then manipulated whether or not seeds experienced adult feeding on two host plant species: a well-defended native host, balloon vine (Cardiospermum corindum) and a poorly defended introduced golden rain tree species (Koelreuteria elegans). I measured the effect of prior adult feeding on survival, development time, and final body size of soapberry bug juveniles. Survival in the first week of development was dramatically improved by prior adult feeding on both hosts. However, the benefits of prior adult feeding ceased after the first week of development and shifted to having a negative effect on performance. These results indicate that adults breaking through the seedcoat initially facilitate juveniles, but that this facilitation becomes competition as juveniles age.

Adaptation to an invasive host is collapsing a native ecotype

2015 ◽  
Author(s):  
Meredith L Cenzer
Keyword(s):  
Invasive Species ◽  
Gene Flow ◽  
Host Plant ◽  
Local Adaptation ◽  
Ecological Speciation ◽  
Model Systems ◽  
Native Communities ◽  
Multiple Phenotypes ◽  
Jadera Haematoloma ◽  
Native Host

Locally adapted populations are often used as model systems for the early stages of ecological speciation, but most of these young divergent lineages will never become complete species. While the collapse of incipient species is theoretically common, very few examples have been documented in nature. Here I show that soapberry bugs (Jadera haematoloma) have lost adaptations to their native host plant (Cardiospermum corindum) and are regionally specializing on an invasive host plant (Koelreuteria elegans), collapsing a classic and well-documented example of local adaptation. All populations that were adapted to the native host - including those still found on that host today - are now better adapted to the invasive in multiple phenotypes. Weak differentiation remains in two traits, suggesting that homogenization across the region is incomplete. This study highlights the potential for adaptation to invasive species to disrupt native communities by swamping adaptation to native conditions through maladaptive gene flow.

Different Spatial Scales of Natural Selection and Gene Flow: The Evolution of Behavioral Geographic Variation and Phenotypic Plasticity

1999 ◽  
Author(s):  
Daniel B. Thompson
Keyword(s):  
Gene Flow ◽  
Natural Selection ◽  
Phenotypic Plasticity ◽  
Spatial Scale ◽  
Geographic Variation ◽  
Genetic Drift ◽  
Spatial Scales ◽  
Environmental Variation ◽  
Behavioral Adaptation ◽  
Evolutionary Processes

The environmental variables hypothesized to cause behavioral adaptation are distributed across a wide array of spatial scales, from local variation in factors such as food sources and territorial encounters to regional or continental variation in factors such as seasonality and the presence of predators. Geographic variation in behavior, the topic of this book, is just one of the potential evolutionary responses to environmental variation. Because behavioral divergence among populations generated by disparate natural selection can be counterbalanced by the homogenizing influence of gene flow, adaptive geographic variation can evolve only if the spatial scale of variation in natural selection is greater than the scale of gene flow (Endler 1977, Slatkin 1978). If geographic variation does not evolve because the spatial scale of selection is smaller than the scale of gene flow, populations may instead evolve adaptive phenotypic plasticity (Bradshaw 1965); the expression, by a single genotype, of different fitness-enhancing phenotypes in different environments. Because the same evolutionary processes operating on different spatial scales can generate behavioral geographic variation, behavioral phenotypic plasticity, or geographic variation in phenotypic plasticity, I devote this chapter to development of a hierarchical perspective tor studying environmental variation and behavioral evolution. This perspective emphasizes the shared evolutionary processes and research methodologies common to different levels of spatial variation, such as the balance of gene flow, natural selection, and genetic drift, the relationship between environmental patch size and local adaptation, and the effects of historical contingencies and genetic constraints on behavioral adaptation and phenotypic plasticity. In what follows, I review behavioral research in two unrelated taxa to illustrate the range of possible evolutionary responses to different patterns of environmental variation. First, I discuss different spatial scales of adaptation in the climbing behavior of deer mice (Peromyscus maniculatus) and provide a hierarchical analysis of the effects of natural selection, genetic drift, and gene flow. Second, I discuss diet-induced phenotypic plasticity in the feeding behavior of acridid grasshoppers (Melanoplus femurrubrum and M. sanguinipes) and the evolution of behavioral norms of reaction in response to local spatial and temporal variation in plant environments.

Are operating room distractions, interruptions, and disruptions associated with performance and patient safety? A systematic review and meta-analysis

2021 ◽  
Author(s):  
Ryan D McMullan ◽  
Rachel Urwin ◽  
Peter Gates ◽  
Neroli Sunderland ◽  
Johanna I Westbrook
Keyword(s):  
Patient Safety ◽  
Operating Room ◽  
Random Effects ◽  
Team Performance ◽  
Operative Time ◽  
Meta Analysis ◽  
Individual Performance ◽  
Negative Effects ◽  
Total Operative Time ◽  
Operative Duration

Abstract Background The operating room (OR) is a complex environment in which distractions, interruptions, and disruptions (DIDs) are frequent. Our aim was to synthesise research on the relationships between DIDs and (a) operative duration, (b) team performance, (c) individual performance, and (d) patient safety outcomes; in order to better understand how interventions can be designed to mitigate the negative effects of DIDs. Methods Electronic databases (MEDLINE, Embase, CINAHL, PsycINFO) and reference lists were systematically searched. Included studies were required to report quantitative outcomes of the association between DIDs and team performance, individual performance, and patient safety. Two reviewers independently screened articles for inclusion, assessed study quality, and extracted data. A random effects meta-analysis was performed on a subset of studies reporting total operative time and DIDs. Results Twenty-seven studies were identified. The majority were prospective observational studies (n=15), of moderate quality (n=15). DIDs were often defined, measured, and interpreted differently in studies. DIDs were significantly associated with: extended operative duration (n=8), impaired team performance (n=6), self-reported errors by colleagues (n=1), surgical errors (n=1), increased risk and incidence of surgical site infection (n=4), and fewer patient safety checks (n=1). A random effects meta-analysis showed that the proportion of total operative time due to DIDs was 22.0% (95% CI 15.7-29.9). Conclusion DIDs in surgery are associated with a range of negative outcomes. However, significant knowledge gaps exist about the mechanisms that underlie these relationships, as well as the potential clinical and non-clinical benefits that DIDs may deliver. Available evidence indicates that interventions to reduce the negative effects of DIDs are warranted, but current evidence is not sufficient to make recommendations about potentially useful interventions.

scholarly journals Population structure, gene flow and natural selection in populations of Euphydryas phaeton

Heredity ◽  
1975 ◽  
Vol 34 (3) ◽  
pp. 407-415 ◽  
Author(s):  
Peter F Brussard ◽  
A Thomas Vawter
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Natural Selection

scholarly journals Ecological Divergence and the Origins of Intrinsic Postmating Isolation with Gene Flow

2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
Aneil F. Agrawal ◽  
Jeffrey L. Feder ◽  
Patrik Nosil
Keyword(s):  
Linkage Disequilibrium ◽  
Gene Flow ◽  
Natural Selection ◽  
Theoretical Models ◽  
Ecological Speciation ◽  
Divergent Selection ◽  
Postmating Isolation ◽  
Divergent Natural Selection ◽  
Mathematical Exploration ◽  
Neutral Gene

The evolution of intrinsic postmating isolation has received much attention, both historically and in recent studies of speciation genes. Intrinsic isolation often stems from between-locus genetic incompatibilities, where alleles that function well within species are incompatible with one another when brought together in the genome of a hybrid. It can be difficult for such incompatibilities to originate when populations diverge with gene flow, because deleterious genotypic combinations will be created and then purged by selection. However, it has been argued that if genes underlying incompatibilities are themselves subject to divergent selection, then they might overcome gene flow to diverge between populations, resulting in the origin of incompatibilities. Nonetheless, there has been little explicit mathematical exploration of such scenarios for the origin of intrinsic incompatibilities during ecological speciation with gene flow. Here we explore theoretical models for the origin of intrinsic isolation where genes subject to divergent natural selection also affect intrinsic isolation, either directly or via linkage disequilibrium with other loci. Such genes indeed overcome gene flow, diverge between populations, and thus result in the evolution of intrinsic isolation. We also examine barriers to neutral gene flow. Surprisingly, we find that intrinsic isolation sometimes weakens this barrier, by impeding differentiation via ecologically based divergent selection.

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