Human influences on the strength of phenotypic selection

Human activities are driving rapid phenotypic change in many species, with harvesting considered to be a particularly potent evolutionary force. We hypothesized that faster evolutionary change in human-disturbed populations could be caused by a strengthening of phenotypic selection, for example, if human disturbances trigger maladaptation and/or increase the opportunity for selection. We tested this hypothesis by synthesizing 1,366 phenotypic selection coefficients from 37 species exposed to various anthropogenic disturbances, including harvest. We used a paired design that only included studies measuring selection on the same traits in both human-disturbed and control (not obviously human-disturbed “natural”) populations. Surprisingly, this meta-analysis did not reveal stronger selection in human-disturbed environments; in fact, we even found some evidence that human disturbances might slightly reduce selection strength. The only clear exceptions were two fisheries showing very strong harvest selection. On closer inspection, we discovered that many disturbances weakened selection by increasing absolute fitness and by decreasing the opportunity for selection—thus explaining what initially seemed a counterintuitive result. We discuss how human disturbances can sometimes weaken rather than strengthen selection, and why measuring the total effect of disturbances on selection is exceedingly difficult. Despite these challenges, documenting human influences on selection can reveal disturbances with particularly strong effects (e.g., fishing), and thus better inform the management of populations exposed to these disturbances.

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Phenotypic selection in common toad (Bufo bufo)

Archives of Biological Sciences ◽

10.2298/abs0704327c ◽

2007 ◽

Vol 59 (4) ◽

pp. 327-333 ◽

Cited By ~ 1

Author(s):

Dragana Cvetkovic ◽

Natasa Tomasevic ◽

I. Aleksic ◽

Andjelka Crnobrnja-Isailovic

Keyword(s):

Natural Populations ◽

Phenotypic Selection ◽

Bufo Bufo ◽

Leg Length ◽

Regression Approach ◽

Selection For ◽

Correlated Characters ◽

Toad Bufo ◽

Toad Bufo Bufo ◽

Selection Differentials

One of the most important problems for evolutionary biologists is to investigate the patterns and strength of phenotypic selection acting on quantitative traits in natural populations. Measurement of selection is complicated by the presence of correlations between characters; selection on a particular trait produces not only a direct effect, but indirect effects as well. Despite the growing body of phenotypic selection studies in a variety of taxa, studies on amphibians are still sparse. The aim of this study was to estimate patterns and strength of selection acting on a set of correlated characters in a natural population of Bufo bufo from the vicinity of Belgrade, Serbia. Morphological traits (body length, fore- and hind leg length) were measured, while fitness was assayed as fecundity and gonad weight for females and males, respec?tively. The regression approach was used to estimate selection differentials and gradients. Selection patterns differed between the sexes - linear selection differentials showed significant total directional selection for body size in females, but not in males. In males, differentials were significant for both fore- and hind leg lengths. Sample size did not permit identification of significant nonlinear (quadratic) selection.

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Living with relatives offsets the harm caused by pathogens in natural populations

10.1101/2021.02.02.429439 ◽

2021 ◽

Author(s):

Hanna M. Bensch ◽

Emily O’Connor ◽

Charlie K. Cornwallis

Keyword(s):

Kin Selection ◽

Meta Analysis ◽

Natural Populations ◽

Disease Spread ◽

Selection For

AbstractLiving with relatives can be highly beneficial, enhancing reproduction and survival. However, high relatedness can increase susceptibility to pathogens, a phenomenon known as the ‘monoculture effect’. Here we examine if the benefits of living with relatives offsets the harm caused by pathogens, and if this depends if species typically live with kin. Using comparative meta-analysis across plants, animals and bacteria (nspecies= 56), we show that high within-group relatedness increases mortality when pathogens are present. Contrastingly, mortality decreased with relatedness when pathogens were rare, particularly in species that live with kin. Variation in pathogen abundances was lower across groups of relatives, but rates of mortality were more unpredictable. The effects of within-group relatedness were only evident when pathogens were manipulated, suggesting that the harm caused by pathogens is masked by the benefits of living with relatives. These results highlight the importance of kin selection for understanding disease spread in natural populations.

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The pace of modern life, revisited

10.1101/2021.07.30.454364 ◽

2021 ◽

Author(s):

Sarah Sanderson ◽

Marc-Olivier Beausoleil ◽

Rose E. O'dea ◽

Zachary T. Wood ◽

Cristian Correa ◽

...

Keyword(s):

Environmental Changes ◽

Natural Populations ◽

Species Traits ◽

Evolutionary Change ◽

Absolute Difference ◽

Phenotypic Change ◽

Wild Populations ◽

Human Disturbances ◽

Phenotypic Changes ◽

Rates Of Change

Wild populations must continuously adapt to environmental changes or they risk extinction. Such adaptations can be measured as phenotypic rates of change and can allow us to predict patterns of contemporary evolutionary change. About two decades ago, a dataset of phenotypic rates of change in wild populations was compiled. Since then, researchers have used (and expanded) this dataset to look at microevolutionary processes in relation to specific types of human disturbances. Here, we have updated the dataset adding 5257 estimates of phenotypic changes and used it to revisit established patterns of contemporary evolutionary change. Using this newer version, containing 6920 estimates of phenotypic changes, we revisit the conclusions of four published articles. We then synthesize the expanded dataset to compare rates of change across different types of human disturbance. Analyses of this expanded dataset suggests that: 1) a small absolute difference in rates of change exists between human disturbed and natural populations, 2) harvesting by humans results in larger rates of change than other types of disturbances, 3) introduced populations have increased rates of change, and 4) body size does not increase through time. Overall, findings from earlier analyses have largely held-up in analyses of our new dataset that encompass a much larger breadth of species, traits, and human disturbances. Lastly, we found that types of human disturbances affect rates of phenotypic change and we call for this database to serve as a stepping stone for further analyses to understand patterns of contemporary evolution.

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Living with relatives offsets the harm caused by pathogens in natural populations

eLife ◽

10.7554/elife.66649 ◽

2021 ◽

Vol 10 ◽

Author(s):

Hanna M Bensch ◽

Emily A O'Connor ◽

Charlie Kinahan Cornwallis

Keyword(s):

Kin Selection ◽

Meta Analysis ◽

Natural Populations ◽

Disease Spread ◽

Selection For

Living with relatives can be highly beneficial, enhancing reproduction and survival. High relatedness can, however, increase susceptibility to pathogens. Here, we examine whether the benefits of living with relatives offset the harm caused by pathogens, and if this depends on whether species typically live with kin. Using comparative meta-analysis of plants, animals, and a bacterium (nspecies = 56), we show that high within-group relatedness increases mortality when pathogens are present. In contrast, mortality decreased with relatedness when pathogens were rare, particularly in species that live with kin. Furthermore, across groups variation in mortality was lower when relatedness was high, but abundances of pathogens were more variable. The effects of within-group relatedness were only evident when pathogens were experimentally manipulated, suggesting that the harm caused by pathogens is masked by the benefits of living with relatives in nature. These results highlight the importance of kin selection for understanding disease spread in natural populations.

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Indicated preventive interventions for anxiety in children and adolescents: a review and meta-analysis of school based programs

10.31234/osf.io/jadxq ◽

2019 ◽

Author(s):

Siobhan Hugh-Jones ◽

Sophie Beckett ◽

Pavan Mallikarjun

Keyword(s):

Meta Analysis ◽

Child And Adolescent ◽

Sensitivity Analyses ◽

Cochrane Library ◽

Control Groups ◽

Adolescent Anxiety ◽

School Based ◽

Intervention Intensity ◽

Randomised Controlled ◽

And Control

Schools are promising sites for the delivery of prevention and early intervention programs to reduce child and adolescent anxiety. It is unclear whether universal or targeted approaches are most effective. This review and meta-analysis examines the effectiveness of school-based indicated interventions and was registered with PROSPERO [CRD42018087628].MEDLINE, EMBASE, PsycINFO and the Cochrane Library were searched for randomised controlled trials comparing indicated school programs for child and adolescent anxiety to active or inactive control groups. Twenty original studies, with 2076 participants, met the inclusion criteria and 18 were suitable for meta-analysis. Sub-group and sensitivity analyses explored intervention intensity, delivery agent and control type. A small beneficial effect was found for indicated programs compared to controls on self-reported anxiety symptoms at post-test (g = -0.28, CI = -0.50, -0.05, k= 18). The small effect was maintained at 6 (g = -0.35, CI= -0.58, -0.13, k = 9) and 12 months (g = -0.24, CI = -0.48, 0.00, k = 4). Based on two studies, >12 month effects were very small (g = -0.01, CI= -0.38, 0.36). No differences were found based on intervention intensity, delivery agent and control type. There was evidence of publication bias and a relatively high risk of contamination in studies. Findings support the value of school based indicated programs for child and adolescent anxiety. Effects at 12 months outperform many universal programs. High quality, randomised controlled and pragmatic trials are needed, with attention control groups and beyond 12 month diagnostic assessments are needed.

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Recurrent Phenotypic Selection for Resistance to Brown Leaf Spot in Smooth Bromegrass 1

Crop Science ◽

10.2135/cropsci1986.0011183x002600030021x ◽

1986 ◽

Vol 26 (3) ◽

pp. 533-536 ◽

Cited By ~ 7

Author(s):

Clyde C. Berg ◽

Robert T. Sherwood ◽

Kenneth E. Zeiders

Keyword(s):

Leaf Spot ◽

Phenotypic Selection ◽

Smooth Bromegrass ◽

Brown Leaf Spot ◽

Brown Leaf ◽

Selection For

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Independent evolution towards larger body size in the distinctive Faroe Island mice

G3 Genes|Genome|Genetics ◽

10.1093/g3journal/jkaa051 ◽

2021 ◽

Author(s):

Ricardo Wilches ◽

William H Beluch ◽

Ellen McConnell ◽

Diethard Tautz ◽

Yingguang Frank Chan

Keyword(s):

Body Size ◽

Meta Analysis ◽

Small Body ◽

Laboratory Mouse ◽

Large Body ◽

Natural Populations ◽

Size Variation ◽

Phenotypic Traits ◽

Island Population ◽

Multiple Loci

Abstract Most phenotypic traits in nature involve the collective action of many genes. Traits that evolve repeatedly are particularly useful for understanding how selection may act on changing trait values. In mice, large body size has evolved repeatedly on islands and under artificial selection in the laboratory. Identifying the loci and genes involved in this process may shed light on the evolution of complex, polygenic traits. Here, we have mapped the genetic basis of body size variation by making a genetic cross between mice from the Faroe Islands, which are among the largest and most distinctive natural populations of mice in the world, and a laboratory mouse strain selected for small body size, SM/J. Using this F2 intercross of 841 animals, we have identified 111 loci controlling various aspects of body size, weight and growth hormone levels. By comparing against other studies, including the use of a joint meta-analysis, we found that the loci involved in the evolution of large size in the Faroese mice were largely independent from those of a different island population or other laboratory strains. We hypothesize that colonization bottleneck, historical hybridization, or the redundancy between multiple loci have resulted in the Faroese mice achieving an outwardly similar phenotype through a distinct evolutionary path.

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The Anti-PD-1/PD-L1 Immunotherapy for Gastric Esophageal Cancer: A Systematic Review and Meta-Analysis and Literature Review

Cancer Control ◽

10.1177/1073274821997430 ◽

2021 ◽

Vol 28 ◽

pp. 107327482199743

Author(s):

Ke Chen ◽

Xiao Wang ◽

Liu Yang ◽

Zheling Chen

Keyword(s):

Overall Survival ◽

Esophageal Cancer ◽

Survival Rate ◽

Meta Analysis ◽

Response Rates ◽

Control Group ◽

Term Survival ◽

Long Term Survival ◽

And Control

Background: Treatment options for advanced gastric esophageal cancer are quite limited. Chemotherapy is unavoidable at certain stages, and research on targeted therapies has mostly failed. The advent of immunotherapy has brought hope for the treatment of advanced gastric esophageal cancer. The aim of the study was to analyze the safety of anti-PD-1/PD-L1 immunotherapy and the long-term survival of patients who were diagnosed as gastric esophageal cancer and received anti-PD-1/PD-L1 immunotherapy. Method: Studies on anti-PD-1/PD-L1 immunotherapy of advanced gastric esophageal cancer published before February 1, 2020 were searched online. The survival (e.g. 6-month overall survival, 12-month overall survival (OS), progression-free survival (PFS), objective response rates (ORR)) and adverse effects of immunotherapy were compared to that of control therapy (physician’s choice of therapy). Results: After screening 185 studies, 4 comparative cohort studies which reported the long-term survival of patients receiving immunotherapy were included. Compared to control group, the 12-month survival (OR = 1.67, 95% CI: 1.31 to 2.12, P < 0.0001) and 18-month survival (OR = 1.98, 95% CI: 1.39 to 2.81, P = 0.0001) were significantly longer in immunotherapy group. The 3-month survival rate (OR = 1.05, 95% CI: 0.36 to 3.06, P = 0.92) and 18-month survival rate (OR = 1.44, 95% CI: 0.98 to 2.12, P = 0.07) were not significantly different between immunotherapy group and control group. The ORR were not significantly different between immunotherapy group and control group (OR = 1.54, 95% CI: 0.65 to 3.66, P = 0.01). Meta-analysis pointed out that in the PD-L1 CPS ≥10 sub group population, the immunotherapy could obviously benefit the patients in tumor response rates (OR = 3.80, 95% CI: 1.89 to 7.61, P = 0.0002). Conclusion: For the treatment of advanced gastric esophageal cancer, the therapeutic efficacy of anti-PD-1/PD-L1 immunotherapy was superior to that of chemotherapy or palliative care.

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10 Years of Pulsed-Xenon Ultraviolet Disinfection

Infection Control and Hospital Epidemiology ◽

10.1017/ice.2020.1104 ◽

2020 ◽

Vol 41 (S1) ◽

pp. s438-s438

Author(s):

Mark Stibich ◽

Sarah Simmons ◽

Deborah Passey

Keyword(s):

Relative Risk ◽

Meta Analysis ◽

Outcome Studies ◽

Uv Disinfection ◽

Clostridioides Difficile ◽

Environmental Effectiveness ◽

Meta Analyses ◽

Hospital Acquired ◽

And Control ◽

Effectiveness Studies

Background: Ultraviolet light (UV) disinfection using low-pressure mercury lamps has been around since the 1940s. The advent of pulsed-xenon UV for hospital use in 2010 has provided a nontoxic and novel technology for hospital disinfection with the first data presented at the 2010 SHEA Decennial. The purpose of this systematic review and meta-analysis is to examine the current body of evidence for pulsed xenon UV disinfection. Methods: The literature search criteria included the following: research conducted in domestic and international settings using pulsed-xenon for surface disinfection, published between 2000 and 2019, and reporting on environmental effectiveness or hospital-acquired reductions (HAIs). We searched PubMed, Google Scholar, and Web of Science. The meta-analysis included 24 studies: 12 HAI outcome studies and 12 environmental effectiveness studies. Meta-analyses were conducted by calculating the percentage reductions for environmental effectiveness, and for the HAI outcome studies, we used a random-effects model to pool the relative risk of HAI. The outcome studies used 272 and 299 months of data for the experimental and control groups, respectively. Results: There was an overall benefit of using pulsed-xenon UV. The overall relative risk of infection decreased compared to the control arm (RR, 0.64; 95% CI, 0.54–0.76). The percentage reductions in environmental studies were as follows: Clostridioides difficile (94.8%), methicillin-resistant Staphylococcus aureus (91.5%), vancomycin-resistant Enterococcus (99.2%), and aerobic bacteria (94.2%). Conclusions: Overall, pulsed-xenon UV was effective for reducing environmental contamination and had the ability to significantly reduce HAIs.Funding: Xenex, Inc., funded this study.Disclosures: Mark Stibich receives a salary from Xenex and is a shareholder of Xenex. Deborah Passey receives a salary from Xenex Disinfection Services.

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Polygenic and single gene responses to selection for resistance to diazinon in Lucilia cuprina.

Genetics ◽

10.1093/genetics/130.3.613 ◽

1992 ◽

Vol 130 (3) ◽

pp. 613-620 ◽

Cited By ~ 6

Author(s):

J A McKenzie ◽

A G Parker ◽

J L Yen

Keyword(s):

Resistant Strain ◽

Single Gene ◽

Natural Populations ◽

Susceptible Strain ◽

Selection Line ◽

Base Population ◽

Gene Response ◽

Biochemical Profiles ◽

Resistant Strains ◽

Selection For

Abstract Following mutagenesis with ethyl methanesulfonate, selection in a susceptible strain with a concentration of the insecticide diazinon (0.0004%, w/v) above that required to kill 100% of the susceptible strain, the LC100 of that strain, resulted in a single gene response. The resultant four mutant resistant strains have equivalent physiological, genetical and biochemical profiles to a diazinon-resistant strain derived from a natural population and homozygous for the Rop-1 allele. Modification of the microsomal esterase E3 is responsible for resistance in each case. The Rop-1 locus maps approximately 4.4 map units proximal to bu on chromosome IV. Selection within the susceptible distribution, at a concentration of diazinon [0.0001% (w/v)] less than the LC100, resulted in a similar phenotypic response irrespective of whether the base population had been mutagenized. The responses were polygenically based, unique to each selection line and independent of Rop-1. The relevance of the results to selection for insecticide resistance in laboratory and natural populations is discussed.

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