scholarly journals Phenotypic Plasticity and Selection: Nonexclusive Mechanisms of Adaptation

Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
S. Grenier ◽  
P. Barre ◽  
I. Litrico
Keyword(s):  
Genetic Diversity ◽  
Phenotypic Plasticity ◽  
Population Level ◽  
Adaptive Plasticity ◽  
Environment Interaction ◽  
Review Of The Literature ◽  
Individual Fitness ◽  
Population Survival ◽  
Mechanisms Of Adaptation ◽  
The Individual

Selection and plasticity are two mechanisms that allow the adaptation of a population to a changing environment. Interaction between these nonexclusive mechanisms must be considered if we are to understand population survival. This review discusses the ways in which plasticity and selection can interact, based on a review of the literature on selection and phenotypic plasticity in the evolution of populations. The link between selection and phenotypic plasticity is analysed at the level of the individual. Plasticity can affect an individual’s response to selection and so may modify the end result of genetic diversity evolution at population level. Genetic diversity increases the ability of populations or communities to adapt to new environmental conditions. Adaptive plasticity increases individual fitness. However this effect must be viewed from the perspective of the costs of plasticity, although these are not easy to estimate. It is becoming necessary to engage in new experimental research to demonstrate the combined effects of selection and plasticity for adaptation and their consequences on the evolution of genetic diversity.

scholarly journals Phenotypic plasticity of labile traits in the wild

2013 ◽  
Vol 59 (4) ◽  
pp. 485-505 ◽  
Author(s):  
Jon E. Brommer
Keyword(s):  
Life History ◽  
Phenotypic Plasticity ◽  
Statistical Approach ◽  
Scale Up ◽  
Population Level ◽  
Wild Populations ◽  
Quantitative Genetic ◽  
In The Wild ◽  
The Individual ◽  
Quantitative Genetic Parameters

Abstract Individual-based studies allow quantification of phenotypic plasticity in behavioural, life-history and other labile traits. The study of phenotypic plasticity in the wild can shed new light on the ultimate objectives (1) whether plasticity itself can evolve or is constrained by its genetic architecture, and (2) whether plasticity is associated to other traits, including fitness (selection). I describe the main statistical approach for how repeated records of individuals and a description of the environment (E) allow quantification of variation in plasticity across individuals (IxE) and genotypes (GxE) in wild populations. Based on a literature review of life-history and behavioural studies on plasticity in the wild, I discuss the present state of the two objectives listed above. Few studies have quantified GxE of labile traits in wild populations, and it is likely that power to detect statistically significant GxE is lacking. Apart from the issue of whether it is heritable, plasticity tends to correlate with average trait expression (not fully supported by the few genetic estimates available) and may thus be evolutionary constrained in this way. Individual-specific estimates of plasticity tend to be related to other traits of the individual (including fitness), but these analyses may be anti-conservative because they predominantly concern stats-on-stats. Despite the increased interest in plasticity in wild populations, the putative lack of power to detect GxE in such populations hinders achieving general insights. I discuss possible steps to invigorate the field by moving away from simply testing for presence of GxE to analyses that ‘scale up’ to population level processes and by the development of new behavioural theory to identify quantitative genetic parameters which can be estimated.

Environment

2013 ◽  
pp. 290-295
Author(s):  
Christopher R. Holroyd ◽  
Nicholas C. Harvey ◽  
Mark H. Edwards ◽  
Cyrus Cooper
Keyword(s):  
Rheumatoid Arthritis ◽  
Life Course ◽  
Disease Risk ◽  
Association Studies ◽  
Population Level ◽  
Environment Interaction ◽  
Disease Pattern ◽  
The Individual ◽  
The Life Course

Musculoskeletal disease covers a broad spectrum of conditions whose aetiology comprises variable genetic and environmental contributions. More recently it has become clear that, particularly early in life, the interaction of gene and environment is critical to the development of later disease. Additionally, only a small proportion of the variation in adult traits such as bone mineral density has been explained by specific genes in genome-wide association studies, suggesting that gene-environment interaction may explain a much larger part of the inheritance of disease risk than previously thought. It is therefore critically important to evaluate the environmental factors which may predispose to diseases such as osteorthritis, osteoporosis, and rheumatoid arthritis both at the individual and at the population level. In this chapter we describe the environmental contributors, across the whole life course, to osteoarthritis, osteoporosis and rheumatoid arthritis, as exemplar conditions. We consider factors such as age, gender, nutrition (including the role of vitamin D), geography, occupation, and the clues that secular changes of disease pattern may yield. We describe the accumulating evidence that conditions such as osteoporosis may be partly determined by the early interplay of environment and genotype, through aetiological mechanisms such as DNA methylation and other epigenetic phenomena. Such studies, and those examining the role of environmental influences across other stages of the life course, suggest that these issues should be addressed at all ages, starting from before conception, in order to optimally reduce the burden of musculoskeletal disorders in future generations.

scholarly journals Epigenetic Potential in Native and Introduced Populations of House Sparrows (Passer domesticus)

2020 ◽  
Vol 60 (6) ◽  
pp. 1458-1468 ◽  
Author(s):  
Haley E Hanson ◽  
Bilal Koussayer ◽  
Holly J Kilvitis ◽  
Aaron W Schrey ◽  
J Dylan Maddox ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Phenotypic Plasticity ◽  
Statistical Power ◽  
Passer Domesticus ◽  
House Sparrows ◽  
Cpg Sites ◽  
Introduced Populations ◽  
Introduced Birds ◽  
The Individual ◽  
Native Birds

Synopsis Epigenetic potential, defined as the capacity for epigenetically-mediated phenotypic plasticity, may play an important role during range expansions. During range expansions, populations may encounter relatively novel challenges while experiencing lower genetic diversity. Phenotypic plasticity via epigenetic potential might be selectively advantageous at the time of initial introduction or during spread into new areas, enabling introduced organisms to cope rapidly with novel challenges. Here, we asked whether one form of epigenetic potential (i.e., the abundance of CpG sites) in three microbial surveillance genes: Toll-like receptors (TLRs) 1B (TLR1B), 2A (TLR2A), and 4 (TLR4) varied between native and introduced house sparrows (Passer domesticus). Using an opportunistic approach based on samples collected from sparrow populations around the world, we found that introduced birds had more CpG sites in TLR2A and TLR4, but not TLR1B, than native ones. Introduced birds also lost more CpG sites in TLR1B, gained more CpG sites in TLR2A, and lost fewer CpG sites in TLR4 compared to native birds. These results were not driven by differences in genetic diversity or population genetic structure, and many CpG sites fell within predicted transcription factor binding sites (TFBS), with losses and gains of CpG sites altering predicted TFBS. Although we lacked statistical power to conduct the most rigorous possible analyses, these results suggest that epigenetic potential may play a role in house sparrow range expansions, but additional work will be critical to elucidating how epigenetic potential affects gene expression and hence phenotypic plasticity at the individual, population, and species levels.

scholarly journals High differentiation in functional traits but similar phenotypic plasticity in populations of a soil specialist along a climatic gradient

2020 ◽  
Vol 125 (6) ◽  
pp. 969-980 ◽  
Author(s):  
Silvia Matesanz ◽  
Marina Ramos-Muñoz ◽  
Mario Blanco-Sánchez ◽  
Adrián Escudero
Keyword(s):  
Genetic Variation ◽  
Phenotypic Plasticity ◽  
Functional Traits ◽  
Common Garden ◽  
Population Level ◽  
General Purpose ◽  
Climatic Conditions ◽  
Environment Interaction ◽  
Moisture Variation ◽  
Neutral Genetic Variation

Abstract Background and Aims Plants experiencing contrasting environmental conditions may accommodate such heterogeneity by expressing phenotypic plasticity, evolving local adaptation or a combination of both. We investigated patterns of genetic differentiation and plasticity in response to drought in populations of the gypsum specialist Lepidium subulatum. Methods We created an outdoor common garden with rain exclusion structures using 60 maternal progenies from four distinct populations that substantially differ in climatic conditions. We characterized fitness, life history and functional plasticity in response to two contrasting treatments that realistically reflect soil moisture variation in gypsum habitats. We also assessed neutral genetic variation and population structure using microsatellite markers. Key Results In response to water stress, plants from all populations flowered earlier, increased allocation to root tissues and advanced leaf senescence, consistent with a drought escape strategy. Remarkably, these probably adaptive responses were common to all populations, as shown by the lack of population × environment interaction for almost all functional traits. This generally common pattern of response was consistent with substantial neutral genetic variation and large differences in population trait means. However, such population-level trait variation was not related to climatic conditions at the sites of origin. Conclusions Our results show that, rather than ecotypes specialized to local climatic conditions, these populations are composed of highly plastic, general-purpose genotypes in relation to climatic heterogeneity. The strikingly similar patterns of plasticity among populations, despite substantial site of origin differences in climate, suggest past selection on a common norm of reaction due to similarly high levels of variation within sites. It is thus likely that plasticity will have a prevalent role in the response of this soil specialist to further environmental change.

Syndemics: A Cross-Disciplinary Approach to Complex Epidemic Events Like COVID-19

2021 ◽  
Vol 50 (1) ◽  
pp. 41-58
Author(s):  
Merrill Singer ◽  
Nicola Bulled ◽  
Bayla Ostrach ◽  
Shir Lerman Ginzburg
Keyword(s):  
Public Health ◽  
Medical Anthropology ◽  
Population Level ◽  
Review Of The Literature ◽  
Individual Level ◽  
Synergistic Interactions ◽  
Health Related ◽  
The Individual ◽  
Syndemic Theory ◽  
Critical Medical Anthropology

In this review, we trace the origins and dissemination of syndemics, a concept developed within critical medical anthropology that rapidly diffused to other fields. The goal is to provide a review of the literature, with a focus on key debates. After a brief discussion of the nature and significance of syndemic theory and its applications, we trace the history and development of the syndemic framework within anthropology and the contributions of anthropologists who use it. We also look beyond anthropology to the adoption and use of syndemics in other health-related disciplines, including biomedicine, nursing, public health, and psychology, and discuss controversies in syndemics, particularly the perception that existing syndemics research focuses on methodologies at the individual level rather than at the population level and fails to provide evidence of synergistic interactions. Finally, we discuss emerging syndemics research on COVID-19 and provide an overview of the application of syndemics research.

scholarly journals The anatomy of a phenological mismatch: interacting consumer demand and resource characteristics determine the consequences of mismatching

2020 ◽  
Author(s):  
Luke R. Wilde ◽  
Josiah E. Simmons ◽  
Rose J. Swift ◽  
Nathan R. Senner
Keyword(s):  
Consumer Demand ◽  
Population Level ◽  
Climatic Conditions ◽  
Growth And Survival ◽  
Individual Level ◽  
Individual Fitness ◽  
Phenological Mismatch ◽  
Age Structured ◽  
Resource Characteristics ◽  
The Individual

AbstractClimate change has caused shifts in seasonally recurring biological events and the temporal decoupling of consumer-resource pairs – i.e., phenological mismatching. Despite the hypothetical risk mismatching poses to consumers, they do not invariably lead to individual- or population-level effects. This may stem from how mismatches are typically defined, e.g., an individual or population is ‘matched’ or ‘mismatched’ based on the degree of asynchrony with a resource pulse. However, because both resource availability and consumer demands change over time, this categorical definition can obscure within- or among-individual fitness effects. We therefore developed models to identify the effects of resource characteristics on individual- and population-level processes and determine how the strength of these effects change throughout a consumer’s life. We then measured the effects of resource characteristics on the growth, daily survival, and fledging rates of Hudsonian godwit (Limosa haemastica) chicks hatched near Beluga River, Alaska. At the individual-level, chick growth and survival improved following periods of higher invertebrate abundance but were increasingly dependent on the availability of larger prey as chicks aged. At the population level, seasonal fledging rates were best explained by a model including age-structured consumer demand. Our study suggests that modelling the effects of mismatching as a disrupted interaction between consumers and their resources provides a biological mechanism for how mismatching occurs and clarifies when it matters to individuals and populations. Given the variable responses to mismatching across consumer populations, such tools for predicting how populations may respond under future climatic conditions will be invaluable.

Environment

2016 ◽  
Author(s):  
Christopher R. Holroyd ◽  
Nicholas C. Harvey ◽  
Mark H. Edwards ◽  
Cyrus Cooper
Keyword(s):  
Rheumatoid Arthritis ◽  
Life Course ◽  
Disease Risk ◽  
Association Studies ◽  
Population Level ◽  
Environment Interaction ◽  
Genome Wide Association Studies ◽  
Mineral Density ◽  
The Individual

Musculoskeletal disease covers a broad spectrum of conditions whose aetiology comprises variable genetic and environmental contributions. More recently it has become clear that, particularly early in life, the interaction of gene and environment is critical to the development of later disease. Additionally, only a small proportion of the variation in adult traits such as bone mineral density has been explained by specific genes in genome-wide association studies, suggesting that gene-environment interaction may explain a much larger part of the inheritance of disease risk than previously thought. It is therefore critically important to evaluate the environmental factors which may predispose to diseases such as osteorthritis, osteoporosis, and rheumatoid arthritis both at the individual and at the population level. In this chapter we describe the environmental contributors, across the whole life course, to osteoarthritis, osteoporosis and rheumatoid arthritis, as exemplar conditions. We consider factors such as age, gender, nutrition (including the role of vitamin D), geography, occupation, and the clues that secular changes of disease pattern may yield. We describe the accumulating evidence that conditions such as osteoporosis may be partly determined by the early interplay of environment and genotype, through aetiological mechanisms such as DNA methylation and other epigenetic phenomena. Such studies, and those examining the role of environmental influences across other stages of the life course, suggest that these issues should be addressed at all ages, starting from before conception, in order to optimally reduce the burden of musculoskeletal disorders in future generations.

Environment

2013 ◽  
Author(s):  
Christopher R. Holroyd ◽  
Nicholas C. Harvey ◽  
Mark H. Edwards ◽  
Cyrus Cooper
Keyword(s):  
Rheumatoid Arthritis ◽  
Life Course ◽  
Disease Risk ◽  
Association Studies ◽  
Population Level ◽  
Environment Interaction ◽  
Genome Wide Association Studies ◽  
Mineral Density ◽  
The Individual

Musculoskeletal disease covers a broad spectrum of conditions whose aetiology comprises variable genetic and environmental contributions. More recently it has become clear that, particularly early in life, the interaction of gene and environment is critical to the development of later disease. Additionally, only a small proportion of the variation in adult traits such as bone mineral density has been explained by specific genes in genome-wide association studies, suggesting that gene-environment interaction may explain a much larger part of the inheritance of disease risk than previously thought. It is therefore critically important to evaluate the environmental factors which may predispose to diseases such as osteorthritis, osteoporosis, and rheumatoid arthritis both at the individual and at the population level. In this chapter we describe the environmental contributors, across the whole life course, to osteoarthritis, osteoporosis and rheumatoid arthritis, as exemplar conditions. We consider factors such as age, gender, nutrition (including the role of vitamin D), geography, occupation, and the clues that secular changes of disease pattern may yield. We describe the accumulating evidence that conditions such as osteoporosis may be partly determined by the early interplay of environment and genotype, through aetiological mechanisms such as DNA methylation and other epigenetic phenomena. Such studies, and those examining the role of environmental influences across other stages of the life course, suggest that these issues should be addressed at all ages, starting from before conception, in order to optimally reduce the burden of musculoskeletal disorders in future generations.

scholarly journals Genetic diversity at neutral and adaptive loci determines individual fitness in a long-lived territorial bird

2012 ◽  
Vol 279 (1741) ◽  
pp. 3241-3249 ◽  
Author(s):  
Rosa Agudo ◽  
Martina Carrete ◽  
Miguel Alcaide ◽  
Ciro Rico ◽  
Fernando Hiraldo ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mhc Class Ii ◽  
Inbreeding Depression ◽  
Breeding Success ◽  
Negative Impact ◽  
Extinction Risk ◽  
Adaptive Genetic Variation ◽  
Individual Fitness ◽  
Indirect Measures ◽  
The Individual

There is compelling evidence about the manifest effects of inbreeding depression on individual fitness and populations' risk of extinction. The majority of studies addressing inbreeding depression on wild populations are generally based on indirect measures of inbreeding using neutral markers. However, the study of functional loci, such as genes of the major histocompatibility complex (MHC), is highly recommended. MHC genes constitute an essential component of the immune system of individuals, which is directly related to individual fitness and survival. In this study, we analyse heterozygosity fitness correlations of neutral and adaptive genetic variation (22 microsatellite loci and two loci of the MHC class II, respectively) with the age of recruitment and breeding success of a decimated and geographically isolated population of a long-lived territorial vulture. Our results indicate a negative correlation between neutral genetic diversity and age of recruitment, suggesting that inbreeding may be delaying reproduction. We also found a positive correlation between functional (MHC) genetic diversity and breeding success, together with a specific positive effect of the most frequent pair of cosegregating MHC alleles in the population. Globally, our findings demonstrate that genetic depauperation in small populations has a negative impact on the individual fitness, thus increasing the populations' extinction risk.

On Measuring the Social Opportunity Cost of Labour in the Presence of Tariffs and an Informal Sector (The Distinguishedl Lecture)

1992 ◽  
Vol 31 (4I) ◽  
pp. 535-564 ◽  
Author(s):  
M. Ali Khan
Keyword(s):  
Informal Sector ◽  
Opportunity Cost ◽  
Costs And Benefits ◽  
Open Letter ◽  
Review Of The Literature ◽  
The Social ◽  
Action Project ◽  
Relevant Group ◽  
Net Benefits ◽  
The Individual

Harberger introduced his influential 1971 essay with the following words. This paper is intended not as a scientific study, nor as a review of the literature, but rather as a tract - an open letter to the profession, as it were - pleading that three basic postulates be accepted as providing a conventional framework for applied welfare economics. The postulates are: (a) The competitive demand price for a given unit measures the value of that unit to the demander; (b) The competitive supply price for a given unit measures the value of that unit to the supplier; and (c) When evaluating the net benefits or costs of a given action (project, programme, or policy), the costs and benefits accruing to each member of the relevant group (e.g., a nation) should normally be added without regard to the individual(s) to whom they accrue.

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