scholarly journals Decomposing phenotypic skew and its effects on the predicted response to strong selection

2021 ◽  
Author(s):  
Joel L Pick ◽  
Hannah Lemon ◽  
Caroline Elizabeth Thomson ◽  
Jarrod Hadfield

The major frameworks for predicting evolutionary change assume that a phenotype's underlying genetic and environmental components are normally distributed. However, the predictions of these frameworks may no longer hold if distributions are skewed. Despite this, phenotypic skew has never been decomposed, meaning the fundamental assumptions of quantitative genetics remain untested. Here, we demonstrate that the substantial phenotypic skew in the body size of juvenile blue tits (Cyanistes caeruleus) is driven by environmental factors. Although skew had little impact on our predictions of selection response in this case, our results highlight the impact of skew on the estimation of inheritance and selection. Specifically, the non-linear parent-offspring regressions induced by skew, alongside selective disappearance, can strongly bias estimates of heritability. The ubiquity of skew and strong directional selection on juvenile body size implies that heritability is commonly overestimated, which may in part explain the discrepancy between predicted and observed trait evolution.

2020 ◽  
Author(s):  
Melanie Tietje ◽  
William J. Foster ◽  
Jana Gliwa ◽  
Clara Lembke ◽  
Autumn Pugh ◽  
...  

<p> The impact of mass extinctions on the body sizes of animals has received considerable attention and debate, as to whether the reduced size of post-extinction organisms is due to the selective extinction of large species, absence of large species as a stochastic effect of low-diversity faunas, or a size decrease within surviving genera and species. Here, we investigated the body sizes of bivalves following the end-Permian mass extinction event and show that the shell size increase of bivalve genera was driven by both evolutionary and ecophenotypic responses. First, some genera show significant increases in body size with the evolution of new species. Further, the same genera record significant within-species increases in average and maximum body size into the late Induan, indicating that ecophenotypic changes were also involved on long-term body size trends. These increases are associated with invigorated ocean circulation, improved oxygenation of the seafloor, and probably increased food supply.</p>


2021 ◽  
Author(s):  
David N Fisher ◽  
Rebecca J LeGrice ◽  
Christina J Painting

AbstractSocial selection occurs when traits of interaction partners influence an individual’s fitness and can fundamentally alter total selection strength. Unlike for direct selection, however, we have little idea of what factors influence the strength of social selection. Further, social selection only contributes to overall selection when there is phenotypic assortment, but simultaneous estimates of social selection and phenotypic assortment are rare. Here we estimated social selection on body size in a wild population of New Zealand giraffe weevils (Lasiorhynchus barbicornis). We did this in a range of contexts and measured phenotypic assortment for both sexes. Social selection was mostly absent and not affected by sex ratio or the body size of the focal individual. However, at high densities selection was negative for both sexes, consistent with competitive interactions based on size for access to mates. Phenotypic assortment was also density dependent, flipping from positive at low densities to negative at high densities. However, it was always close to zero, indicating negative social selection at high densities will not greatly impede the evolution of larger body sizes. Despite its predicted importance, social selection may only influence evolutionary change in specific contexts, leaving direct selection as the dominant driver of evolutionary change.


2018 ◽  
Vol 97 (2) ◽  
pp. 124-131 ◽  
Author(s):  
V. M. Prusakov ◽  
Aleksandra V. Prusakova

There were studied: The role of the disease dynamics at the background area in the formation of the risk for childhood morbidity in the study area; the value of indices of the long-term wavelike risk dynamics and the corresponding adaptation process for the identification and classification of mass non-infectious diseases. The waviness dynamics of the children morbidity risk is caused by the wave-like nature of the disease dynamics in the study and background areas. The disease risk level is formed not only by differences in the incidence rates of the background and study areas but also from differences in phases of high and low non-specific resistance of children contingent in these territories. The different character of the dynamics of the risk for the disease and related waviness of the adaptation process among children reflects the existence of differences in exposure to characteristics of local environmental factors in each territory. The average risk of disease, around which there are carried out annual fluctuations risks and phase states of the adaptation process, and the corresponding levels of reactivity and resistance of the body are the result of the absolute magnitude of the impact of local factors on the study area. The average relative risk of the morbidity, around which there are carried out annual fluctuations risks and phase states of the adaptation process is an integral index of the level of mass non-infectious diseases and the degree of severity of the medical and environmental situation, the level of reactivity and work mismatch of the body subsystems of children and the degree of their intensity. This is the measure of the absolute magnitude of the impact of local factors. The waviness to the development of states of high and low resistance is both always an index of antistress activation responses (or non-specifically high resistance state) and relative to the average force of impact factors (for the observed reactivity level). On the basis of the accounting for the level of the risk, there is suggested the classification of infectious diseases, including 1) the background or relatively satisfactory morbidity, 2) mass morbidity with the increased risk, 3) mass incidence of the high-risk, and 4) a mass incidence of the very high risk.


Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 981
Author(s):  
Slobodan Milanović ◽  
Katarina Mladenović ◽  
Bojan Stojnić ◽  
Alejandro Solla ◽  
Ivan Milenković ◽  
...  

Food webs on forest trees include plant pathogens, arthropods, and their natural enemies. To increase the understanding of the impact of a plant pathogen on herbivore-natural enemy interactions, we studied the powdery mildew fungus Erysiphe alphitoides, the phytophagous mite Schizotetranychus garmani, and the predatory and mycophagous mite Euseius finlandicus in pedunculate oak (Quercus robur) leaves. In June, July and August of 2016, we assessed the severity of powdery mildew, mite population density and adult female mite size in 30 trees in three forests near Belgrade, Serbia. In August, the infection severity of E. alphitoides related positively to the population density of S. garmani and negatively to the body size of S. garmani females. Throughout the vegetative season, the infection severity of E. alphitoides related positively to the population density of E. finlandicus but not to its body size. The effect of E. alphitoides on the population density and adult size of S. garmani was not mediated by the population density of E. finlandicus, and vice versa. Interactions were consistent in all forests and varied with the summer month. Our findings indicate that E. alphitoides can influence the average body size and population densities of prey and predatory mites studied, irrespective of predator-prey relationships.


2019 ◽  
Vol 21 (2) ◽  
pp. 148-166 ◽  
Author(s):  
Kemal Yıldırım ◽  
Elif Güneş ◽  
Gülcan Pervan Yilmaz

Purpose The purpose of this paper is to determine the effects of environmental factors in open-plan offices with the same characteristics but with different workstation partition heights (1.10, 1.40 and 1.65 m) on perceptual evaluations of office employees. Design/methodology/approach In this research, the effects of environmental factors on employees’ perceptual evaluations in open-plan offices at the Gölbaşı Region of Ankara were measured with a detailed questionnaire. The research data were obtained from 81 employees who agreed to fill out the questionnaire and who use open-plan offices. Findings It was found that the office environments with 1.65 m workstation partition heights were more favorably assessed for each of the items of planning and of privacy that form the dependent variables compared to the office environments with 1.10  and 1.40 m partition heights. On the other hand, the office environments with the 1.10 and 1.40 m partition heights were more favorable for lighting items than the 1.65 m partition height office environments. In addition, young employees had a more positive tendency toward the perceptions of environmental factors, including different workstation partition heights in open-plan offices, compared to older employees. Research limitations/implications Results of this research provide a fundamental contribution for the impact of various partition heights that have substantial implications on the perceptions of open-plan office environments. At this point, as open-plan offices have important effects on the quality of employees’ work experiences, the influence of various partition heights on the performance of employees should be emphasized in future studies. The diversity of performance (reading comprehension, calculation, design, drawing, etc.) will be an important decision. Originality/value The significant contribution of this research is that it provides valid data and makes a valuable contribution to the body of knowledge in open-plan office design.


2016 ◽  
Vol 1 (62) ◽  
pp. 8-15 ◽  
Author(s):  
Татьяна Виткина ◽  
Tatyana Vitkina ◽  
Людмила Веремчук ◽  
Lyudmila Veremchuk ◽  
Ирина Симонова ◽  
...  

The aim of the research is to examine the relationship between the integral parameters of respiratory function, the values of LPO-AOD system and NO level at bronchopulmonary pathology in individuals living in different ecological areas of the city of Vladivostok. 206 patients living in different ecological conditions (healthy individuals, patients with respiratory disorders) were examined. Lung function and the state of LPO-AOD system were studied; the concentration of NO metabolites was assessed in blood serum. The nature and strength of the impact of environmental factors on respiratory function, the state of LPO-AOD, NO level were studied by the method based on correlation analysis. There was calculated power index (D) which was differentiated into power within the system (Ds) which in its turn reflects the in-system interrelationship tension (LPO-AOD, respiratory) and power between systems (Dm) characterizing the activity of interconnections and response to an external stimulus. Intra-system dependences typical for the unfavorable zone were viewed in relation to the favorable zone. It was found out that in ecologically unfavorable regions in individuals with different bronchopulmonary pathologies the value of Ds increases. This indicates that the pathogenic influence of environmental factors increases. In healthy people living in ecologically unfavourable area physiological adaptive-compensatory reaction of the body was revealed, which was proved by high power interconnections (Dm). In the patients with chronic bronchitis there was maintained an adequate level of functioning of the body systems studied. In patients with COPD living in an unfavourable zone there were found strong links between the indicators of the system of LPO-AOD and of NO, and in patients with bronchial asthma - supplementary relationship between lung function and NO. At the same time pathologic changes in the system of LPO-AOD and NO depend on the general pollution, metal and gas components contained in the air. Thus, the people with respiratory diseases being in environmentally unfavorable conditions have the most negative influence. The analysis of the activity of relationships proved that violations of interaction of LPO-AOD systems and NO in ecologically unfavorable regions may contribute to the occurrence and progression of bronchopulmonary diseases.


1990 ◽  
Vol 70 (2) ◽  
pp. 389-400
Author(s):  
R. M. McKAY ◽  
G. W. RAHNEFELD ◽  
G. M. WEISS ◽  
H. T. FREDEEN ◽  
J. A. NEWMAN ◽  
...  

Live body measurements were evaluated in F1 and backcross females ranging in age from 1 to 5 yr, inclusive, maintained at Manyberries, Alberta (extensive range management) and Brandon, Manitoba (semi-intensive management). The objectives of this study were to examine measures of size, weight, and subcutaneous fat cover to determine: (1) their relationship with age of cow; (2) the impact of varying proportions of Simmental and Charolais breeding; (3) the similarity between generalized and specific contrasts involving 1/4 and 3/4 European continental and British breeding; and (4) differences between four consecutive lactations and three out of four possible lactations. Body length, height at the hips and withers, and cow weight at weaning reached or approached their mature levels by 5 yr of age and subcutaneous fat cover was more dependent upon environmental factors than age. Incremental increases in Simmental and Charolais breeding in the cow crosses resulted in corresponding increases in body size and weight. The generalized comparisons between 1/4 and 3/4 Simmental, Charolais, Angus, Hereford, and Shorthorn breeding provided useful information regarding generic comparisons but there was a need for evaluating specific backcross comparisons. Cows experiencing four consecutive lactations, compared to those that had three lactations out of a possible four, had decreased physical dimensions in addition to weight and subcutaneous fat cover. Key words: Beef cattle, body measurements, backcrosses, heifers, cows


2021 ◽  
Vol 17 (2) ◽  
pp. 131-138
Author(s):  
Adeeb Fae ◽  
Bandar E Almansouri ◽  
Diane E Heck ◽  
Hong Duck Kim

Chronic obstructive pulmonary disease (COPD) represented as inflammatory complication of chronic bronchitis which is characterized by oxidative stress driven phenotypic changes likely enlarged alveoli and increased mucus along with tightened smooth muscle which exaggerate pathological consequences such as breathing problems. The association between COPD and obesity as a metabolic disorder following a variety of environmental stressors include lifestyle change (e.g., diet and e-smoking or marijuana) and air pollution are less likely to be evaluated. People who are suffering with COPD developed extensive suffocation and difficulty breathing, which ultimately leads to fatal conditions in severe cases, for example lung cancer, heart attack, and stroke. Previous studies showed metabolic disorder like obesity appeared as a risk determinant to COPD like breathing problem or deep vein thrombosis and its genetic modification resulted from abnormality of molecular dynamics turned out key trigger in case of immune alteration and inflammation following exposure of several environmental factors which could be linked with comorbidity in secondary chronic diseases pairing with other metabolic disorders (e.g., diabetes, heart disease, cancer or fatty liver disease). Lifestyle changes along with physical activities and management of the diet is worth to reduce COPD symptomatic firing. However, environmental factors like air pollution or particle matter owing to industrialization and urbanization include a variety of dust within indoor life, certain type of e-smoke also triggers the establishment of emphysema and enhances the progression of COPD aligned with molecular alteration in the lung tissue or interaction between different organs. Prediction and prevention skills as key tools of health management and evaluation in case of COPD remains unclear. Integrative care includes clinic assessment (e.g., the body mass index, diets, and metabolic profile using survey following physician guidance) could be coupled cellular and topological interaction between obesity and COPD supplemented with advanced functional and genetic variation utilize human genomics study like single nucleotide polymorphism (SNP). To understand the impact of environmental risk better (e.g., air pollution or particle matter) on pathogenesis of disease or onset of the disease underlying the pulmonary system stratified lifestyle, age, metabolic disorders, diets, and medications, we envision exploring risks such as disease barrier and social determinants along with detection tools which may assess molecular dynamics and their alteration following stress might be associated with COPD in the pathogenesis. Environmental stressors (e.g., air pollution, particle matter, food addictive chemicals, and stress) as epigenetic modifiers could attribute to early phase of COPD onset and pathogenesis which reflect the molecular dynamics and redirection of networking pathways depending on gut immunity. Profiling of secondary metabolites is worth to explicate intervention of metabolism cascade owing to alter molecular sensitivity and connectivity. Utilized multi-dimensional omics such as metabolomics, genomics with exome sequencing, and epigenomics, prevention and prediction skills could visualize a new angle of disease diagnostic under the platform of integrative health care and surveillance supporting to patient’s quality of life.


2020 ◽  
Vol 10 (5) ◽  
pp. 316-324
Author(s):  
Purnima Tripathi ◽  
Peeyush Bhardwaj

Psoriasis is an auto-immune disorder of the skin. It is characterized by the hyperproliferation of keratinocytes.  Severity of the disease depends on the body area affected. Both genetic as well as environmental factors are responsible for it. It affects around 2-3% of world’s population. Psoriasis not only causes physical problems, it also affects mental and social well being of the patient. It may also lead to some Comorbidities like heart problems, diabetes, psychological problems, Crohn’s disease , etc.  Keeping in view the impact it creats in the patient’s life, steps should be taken to create awareness of psoriasis. This article attempts to provide a comprehensive view on the psoriasis. It includes the various forms of psoriasis with their specific features, causes of psoriasis, diagnosis and assessment tools used, treatments available for its management including topical as well as systemic therapy and associated problems. Keywords: Plaque, Psoriasis, Pustules


2018 ◽  
Vol 25 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Hayat Didaoui ◽  
Méghit Boumediene Khaled

Abstract Background and aims: The aim of the current study was to assess the impact of environmental factors; food, socio-economic, and physical activity, on a group of obese children living in Ain-Defla (Center Algeria) and Sidi-Bel-Abbes (West Algeria). Material and methods: The protocol was carried out on a cohort of 125 school children aged of 5 to 11 years, including 64 boys and 61 girls, and 139 school children, including 93 boys and 46 girls in Ain Defla and Sidi-Bel-Abbes respectively. Concerning the classification of obesity and overweight, we referred to the International Obesity Task Force and the French References' curves. Results: Regarding dietary intake our results showed that 34% of students from both regions took their breakfast, compared to 66% who did not take. Furthermore, 73% of students skipped at least one meal, however 23% respected meals frequency i.e. 4 meals a day. Regarding socio-economic factors and physical activity, our findings showed that obesity rates were high (36%) among children whose fathers are workers. However, for mothers who are housewives, obesity increases among their children (88%). The relationship was reversed between the parents' education level and the Body Mass Index. We found an opposite relationship between Body Mass Index and physical activity, and investigated children use screen devices for long time periods. Conclusions: Our study showed a positive relationship between obesity and overweight and environmental factors.


Sign in / Sign up

Export Citation Format

Share Document