Phenotypic Plasticity

12 Key excerpts on "Phenotypic Plasticity"

• 

  eBook - PDF

  Insect Phenotypic Plasticity

  Diversity of Responses

  • T N Ananthakrishnan, Douglas Whitman, T N Ananthakrishnan, Douglas Whitman, T N Ananthakrishnan(Authors)
  • 2005(Publication Date)
  • CRC Press

    (Publisher)

  While literature abounds in theoretical discussion on Phenotypic Plasticity, some especially in relation to plant biology, an understanding of the distinctive ways in which new phenotypes are formed in insects, in relation to environment cues as altitudes, temperature and humidity, crowding and the like cannot be ignored. The capacity to exhibit phenotypic variation may be an inescapable consequence of a complex genome and complex physiological pathways, and environment experienced by a population, which determine the phenotypes and establish their fitness for a particular trait (Nanjundiah, 2003). Maintaining the sensory and regulatory mechanisms needed for plasticity is an important aspect calling for more inputs in relation to the costs and limits of Phenotypic Plasticity (Dewitt, Sih and Wilson, 1998). Aspects related to the diversity of approaches to Phenotypic Plasticity have been briefly indicated, keeping in mind the fact that adaptive plasticity evolved upon the interaction of populations to varied environments. Fluctuations are confronted by populations through phenotypic variations affecting single individuals, within population or in future generations so as to result in different levels of adaptive variation (Meyers and Bull, 2002). The genetic basis of plasticity is an equally important aspect in that some genes may be turned on and of in particular environments and some alleles may be expressed in several different environments. Developmental switches and reaction norms play an important role in Phenotypic Plasticity. Sometimes an organism produces a phenotype that varies as a continuous function of the environmental signal, so that within each phenotype, the morphology, life history and physiology are integrated to function in a specific ecological role (Stearns, 1989).

  Sign up to read

  Learn more about book
• 

  eBook - ePub

  Annual Plant Reviews, The Evolution of Plant Form

  • Barbara A. Ambrose, Michael D. Purugganan, Barbara A. Ambrose, Michael D. Purugganan(Authors)
  • 2012(Publication Date)
  • Wiley-Blackwell

    (Publisher)

  Chapter 10 DEVELOPMENT IN THE WILD: Phenotypic Plasticity Kathleen Donohue Biology Department, Duke University, Durham, NC, USA

  Abstract: Development of organisms in the wild occurs in ecologically variable environments. Phenotypic Plasticity occurs when a single genotype alters its phenotype in response to its environment. Some traits are more plastic than others, and whether a particular trait evolves plasticity depends on the degree of environmental variation experienced by that trait, the quality of environment-dependent natural selection on that trait, and the strength of genetic correlations between the trait expressed in different environments. Thus, identifying the molecular basis of pleiotropy of traits expressed in different environments should be an important agenda in studies of development and plasticity. The strength of pleiotropy across environments can be influenced by environment-dependent gene expression and signal transduction and by the structure of genetic pathways. The degree of environmental dependence of many of these molecular processes, however, is only beginning to be elucidated. Phenotypic Plasticity influences adaptation, niche breadth, and ecological ranges and has the potential to influence the evolution of reproductive isolation. Understanding the genetic and ecological mechanisms of plasticity, therefore, will enhance our knowledge of the genetic basis of adaptation and the evolution of diversity.

  Keywords: adaptation; epigenetics; gene expression; parental effects; phenology; phytochrome; plasticity.

  10.1 Development in the wild is Phenotypic Plasticity

  Plant form is the product of a developmental sequence in which events that occur at early life stages shape events at later life stages. In the wild, this temporal sequence of development occurs within a temporal sequence of seasons and changing ecological conditions. The moist and sunny conditions that a new germinant experiences in early spring do not persist: the canopy closes, the days grow longer, rain showers stop, insects hatch out, fungal spores mobilize, and soil microbes grow, die, replace each other, and alter the soil. Development in the wild is not merely the unfolding of a programmed protocol encoded by DNA sequences. It is a constant dialog between the ecological environment and the developmental processes that determine morphology, physiology, and behavior. It comes down to the interaction between the environment and genes.

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Exploitation of Environmental Heterogeneity by Plants

  Ecophysiological Processes Above- and Belowground

  • Jacques Roy(Author)
  • 2012(Publication Date)
  • Academic Press

    (Publisher)

  III. Evolutionary Ecology of Plasticity Natural populations may comprise not many highly specialized geno-types, but one or a few generalists able to cope with the modest amounts of environmental variance found at small spatial scales. Both extreme points of view, narrow genetic specialization and virtually unlimited phe-notypic plasticity, are contradicted by the most m u n d a n e observations. A more reasonable approach is to recognize both genetic variation in performance and the environmental constraints within which this varia-tion is expressed. We can then recognize that Phenotypic Plasticity is not merely an arbitrary attribute of plants, but instead a property that evolves through the natural selection of genotypes that determine a more or less plastic response to environments that vary in space and in time. T h e crucial concept that we wish to advance here is that the amount of environmental variance expressed by plants grown under different con-ditions is itself a character u n d e r genetic control, that is, plasticity is heritable. This fact has been recognized for a long time (Bradshaw, 1965; Schlichting, 1986), but without receiving the attention it deserves (Stearns, 1989; Thompson, 1991). T h e concepts of plasticity and its heritability can be given precise statistical meaning in experiments where several genotypes or families are each grown and scored in several environments (Lawrence, 1982; Falconer, 1986). T h e variance of average scores among the genotypes is a genetic variance (SQ); T h e variance of average scores among the environments is an environmental variance ( 5 | ) . These two components sum to the total variance, provided that each genotype responds in the same way to differences among environments.

  Sign up to read

  Learn more about book
• 

  eBook - ePub

  Phenotypic Plasticity & Evolution

  Causes, Consequences, Controversies

  • David W. Pfennig(Author)
  • 2021(Publication Date)
  • CRC Press

    (Publisher)

  Section II Causes of Plasticity From Genes to Ecology Passage contains an image

  4 Genetic Variation in Phenotypic Plasticity

  Ilan Goldstein and Ian M. Ehrenreich University of Southern California

  CONTENTS

  4.1   Introduction 4.2   The Geneticist’s View of Phenotypic Plasticity 4.3   Modification of Heritable Phenotypic Variation by the Environment 4.4   Methods for Genetically Dissecting Phenotypic Plasticity 4.5   Empirical Insights into the Genetics of Phenotypic Plasticity 4.6   The Future of the Genetics of Phenotypic Plasticity 4.7   Conclusions Acknowledgments References

  4.1 Introduction

  Most traits of human interest vary among individuals within a population due to a combination of genetic and environmental factors, meaning individuals’ phenotypes will depend on both their genotypes and environments. This relationship between genotype, environment, and phenotype is a major area of research that is central to our understanding of genetics in the real world (Falconer and Mackay 1996; Lynch and Walsh 1998). Indeed, whether the goal be to breed crops that maximize yield in particular climates (Kang 1997; Gage et al. 2017; Lowry et al. 2019), to predict, prevent, and treat hereditary disorders (Hunter 2005; Baye et al. 2011; Manuck and McCaffery 2014), or to understand the mechanisms underlying adaptation to changing environmental conditions (Bradshaw 1965; Via and Lande 1985; Scheiner 1993), all of these topics require knowledge of how genotype and environment jointly produce phenotype.

  Scientists can learn about the relationship between genotype, environment, and phenotype by studying Phenotypic Plasticity, the ability of a genotype to produce different phenotypes in response to different environments (Bradshaw 1965; Scheiner 1993; Pigliucci 2001; West-Eberhard 2003). Within genetically diverse populations, distinct genotypes will commonly show differences in plasticity (Ehrenreich and Pfennig 2016). Geneticists dissect this heritable variation in plasticity in order to better determine the impact of environment on the relationship between individuals’ genotypes and phenotypes (Debat and David 2001; Rockman 2008; Mackay et al. 2009). Here, we review genetic research on variation in plasticity. In addition to summarizing key concepts and methods, we also attempt to synthesize current, empirical work in this area and point to key future directions.

  Sign up to read

  Learn more about book
• 

  eBook - ePub

  Eco-evolutionary Dynamics

  • Andrew P. Hendry(Author)
  • 2016(Publication Date)
  • Princeton University Press

    (Publisher)

  Chapter 11 Plasticity

  Eco-evolutionary dynamics are driven by interactions between environmental features and organismal phenotypes. Although it can be tempting, or at least convenient, to assume that phenotypic change is the result of genetic evolution, a likely alternative is that environmental conditions influence the expression of phenotypic traits for a given genotype. In its various guises, this phenomenon is discussed as Phenotypic Plasticity, developmental plasticity, environmental induction, acclimation, epigenetics, induced defenses, maternal effects, genotype-by-environment interaction (GxE), and indirect genetic effects (West-Eberhard 2003, Wolf and Wade 2009). Plasticity in these various manifestations can influence ecological dynamics through several effects (Miner et al. 2005, Yamamichi et al. 2011, Kovach-Orr and Fussmann 2013, Fischer et al. 2014), which I here briefly list and later discuss in more detail. First, current levels of plasticity are expected to have evolved as a result of past selection, and so plastic changes expressed by individuals in the present can be adaptive and have a genetic basis. In such cases, plasticity can be viewed as a contemporary expression of past evolution. Second, plasticity can evolve on contemporary time scales, and so phenotypic changes in a population can reflect the ongoing evolution of plasticity. Third, plasticity modifies selection on genotypes, and thereby influences evolutionary responses to ecological change and ecological responses to evolutionary change. In short, plasticity must be an integral part of any general framework for eco-evolutionary dynamics.

  Plasticity has been the focus of considerable interest, with summaries of its theoretical and empirical development appearing in several books (Schlichting and Pigliucci 1998, West-Eberhard 2003). Of particularly recent popularity has been the concept of epigenetics, whereby genetic changes (e.g., DNA methylation or stable chromatin modifications) that do not alter the DNA sequence have phenotypic effects that can be heritable (Feil and Fraga 2012, Duncan et al. 2014, Schlicting and Wund 2014). Stated another way, epigenetics provides a genetic mechanism for plasticity and its propagation across generations. My focus in the present chapter will be on interactions between environment and phenotype, and so I will not be concerned with the precise genetic mechanisms. In addition, my specific focus will be on key features of plasticity that are especially relevant for eco-evolutionary dynamics. Another version of this chapter was published as Hendry (2016).

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  A Companion to the Philosophy of Biology

  • Sahotra Sarkar, Anya Plutynski, Sahotra Sarkar, Anya Plutynski(Authors)
  • 2008(Publication Date)
  • Wiley-Blackwell

    (Publisher)

  Recently, Pigliucci (forthcoming) has suggested that even the best candidates for plasticity genes – those genetic resources (genes and suites of genes) involved in Continued jonathan m. kaplan 212 there will of course be genes involved in every kind of Phenotypic Plasticity, in the case of developmental sensitivity these genes will be the same (kinds of) genes that are involved in the development of the phenotypes themselves – not genes whose function is to actively control the phenotypic response. Phenotypic Plasticity is adaptive whenever the fitnesses of the different phenotypes generated in the different environments regularly encountered by organisms of that type are higher in the environments in which they appear than they would be in the other environments, and where no “intermediate” phenotype would do as well in all the environments regularly encountered. In some cases, of course, phenotypes that develop in one kind of environment simply could not develop in other kinds; the case discussed above, of annual plants that are larger and have higher fruit output in high-quality environments (nutrient rich, proper water, high sunlight, etc.) than in low-quality environments is a case in point – the “large plant” phenotype may simply be unobtainable in low-quality environments due to a lack of environmental resources. However, the “large plant” phenotype cannot be fitter than the “small plant” pheno-type in low-quality environments, because the resources to produce the “large plant” phenotype are simply unavailable in that environment; the “small plant” phenotype, then, has, by default, the highest fitness in that low-quality environment. Phenotypic Plasticity is not always adaptive. For example, tragically, various aspects of the human phenotype are sensitive to the presence of thalidomide during early development – limb structure, for example, is plastic with respect to the presence of thalidomide.

  Sign up to read

  Learn more about book
• 

  eBook - ePub

  The Ecology and Evolution of Inducible Defenses

  • Ralph Tollrian, C. Drew Harvell, Ralph Tollrian, C. Drew Harvell(Authors)
  • 2021(Publication Date)
  • Princeton University Press

    (Publisher)

  increasing the breadth of adaptation decreases the fitness at the mode. The fitness integrated over the whole range of environmental states, however, remains constant if the breadth of adaptation changes.

  The genotypic values g 1 and g 2 underlying the phenotypic characters z 1 and z 2 are assumed to be shaped by long-term evolutionary forces and to be genetically correlated with other traits. Phenotypic Plasticity, however, might allow modifications of the phenotype in response to environmental cues.

  Figure 16.1a illustrates the effect of plastic responses in the mode z 1 of the tolerance curve. The breadth of adaptation remains unchanged but the tolerance curve undertakes a shift of the mode from z 1 = 0 to z 1 = 2. If this shift is the optimal response to a change of the environmental state φ from 0 to 2, then the length of the arrow indicates the gain in fitness compared to a non-plastic genotype. For the same change of the environment, figure 16.1b demonstrates how plasticity in breadth of adaptation enhances fitness while the mode is kept constant.

  In reality, such plastic responses might be energetically costly, time consuming, and performed in a suboptimal manner. Whether the plastic modifications are reversible or irreversible might depend on trait, genotype, species, environment, and cue. Important is how well the cue can be perceived, how reliable it is, and what its frequency and probability are.

  The case of irreversible plastic modifications during development is analyzed in detail by Gabriel and Lynch (1992). In the following discussion, this model is expanded to cope with the evolution of reversible plastic responses that are performed by an external trigger like chemical cues and are rebuilt if the trigger is no longer present. One favored application is the evolution of inducible defenses including changes in behavioral traits related to colony forming and swarming. The problem is reduced to a very simple case that is, however, sufficient to gain insight into the minimal conditions for the evolution of such plasticity.

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Insect Molecular Biology and Ecology

  • Klaus H. Hoffmann(Author)
  • 2014(Publication Date)
  • CRC Press

    (Publisher)

  1 Mechanisms of Polyphenism in Insects Stephen M. Rogers Introduction: What is Polyphenism? Polyphenism, broadly defined, is where two or more distinct phenotypes can be produced by the same genotype. Woltereck (1909) coined the term ‘reaction norm’ (Reaktionsnorm) to describe how the phenotype of an individual depends on the interaction between its particular genotype and environmental cues. In practice many or most genes with pleiotropic effects have context-dependent expression or action during development, i.e., the internal environment in which they are expressed. Phenotypic Plasticity is therefore usually defined as a change in phenotype driven by cues in the external environment, which may be abiotic, such as temperature or photoperiod, or biological in origin, deriving from other species or even members of the same species. Phenotypic Plasticity can result from variation in developmental, physiological, biochemical and behavioral processes that are sensitive to these environmental variables (Nijhout and Davidowitz 2009). Polyphenism, in one sense, occurs very widely in insects. In holometabolous insects, larvae and pupal stages often differ radically in appearance and function from the adults; this is a clear example of very different phenotypes being generated from the same genotype during the normal course of post-embryonic development. Even in the School of Biological Sciences, The University of Sydney, Sydney, NSW 2006, Australia. Email: [email protected] 2 Insect Molecular Biology and Ecology hemimetabolous insects where the distinction between larval and adult forms is usually less dramatic, there is typically a clear distinction between specializations for feeding in larvae/nymphs and for dispersal and reproduction in the winged adults, with clear differences in phenotype to accomplish these tasks.

  Sign up to read

  Learn more about book
• 

  eBook - ePub

  Integrative Organismal Biology

  • Lynn B. Martin, Cameron K. Ghalambor, H. Arthur Woods(Authors)
  • 2014(Publication Date)
  • Wiley-Blackwell

    (Publisher)

  2007). Thus, the mix of individuals expressing different degrees and directions of behavioral plasticity will have critical implications for how populations cope with rapid environmental change. Generally, the greater the diversity of behavioral plasticity within a population, the greater the likelihood that the population includes some individuals that exhibit adaptive plasticity in the novel conditions (Dingemanse & Wolf 2013). Consequently, individual differences in behavioral plasticity can lead to greater population stability and persistence. Individual differences in behavioral plasticity also implies that the repeatability (the proportion of phenotypic variation due to differences between-individuals) and possibly also the heritability (the proportion of phenotypic variance caused by additive genetic effects) are environment specific (e.g., Dingemanse et al. 2009; Dingemanse et al. 2012a). This implies that the rate of evolutionary change in response to selection will depend on the environment (Dingemanse & Wolf 2013). Novel ecological and evolutionary consequences emerge when personality and plasticity are correlated (Dingemanse & Wolf 2013). For example, conflicting selection pressures acting on personality and plasticity can have important consequences for species interactions. In Iberian wall lizard, faster explorers show greater plasticity in flight initiation distance (FID) from predators (Rodriguez-Prieto et al. 2011), but fast exploration may also be associated with greater exposure to parasites and pathogens (Barber & Dingemanse 2010; Kortet et al. 2010). Thus on an ecological timescale, the strength of past selection on anti-predator responsiveness will have important consequences for parasite transmission, and the strength of past selection on anti-predator responsiveness will have important consequences for predator–prey dynamics

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Perspectives in Animal Ecology and Reproduction Vol. 07

  • Gupta, V K(Authors)
  • 2021(Publication Date)
  • Daya Publishing House

    (Publisher)

  Chapter 7 Phenotypic Plasticity of Drosophila melanogaster at Different Temperature B.R. Guru Prasad and S.N. Hegde * Department of Studies in Zoology, Manasagangotri, University of Mysore, Mysore – 570 006, India ABSTRACT Influence of temperature on sexual behavior of both male and female of D. melanogaster collected at top of Chamundi hill, Mysore and maintained at 12ºC, 17ºC, 22ºC, 27ºC, and 32ºC was studied. The general sexual behavioral acts such as courtship latency, mating latency, copulation duration and the quantitative behavioral acts of males such as tapping, circling, scissoring, vibration and licking and female quantitative sexual behaviors such as extruding, decamping and ignoring were recorded. The results showed that 22ºC is the optimum temperature for mating in D. melanogaster . The males showed higher vigor and females showed higher receptivity at this temperature. Although mating was fast at 22ºC, it did occur at other temperatures with higher courtship activities. The fast mating observed in the present studies at 22ºC with optimum performance of courtship activities in comparison to mating in other temperatures suggests the sexual behavioral plasticity of D. melanogaster at different temperature. Keywords :Courtship, Drosophila, Mating, Temperature, Plasticity. Introduction Phenotypic Plasticity is the ability of organisms to alter its physiology, This ebook is exclusively for this university only. Cannot be resold/distributed. morphology, behavior in response to changes in its environment. The capacity of a given genotype to produce different phenotypes in different environments is of growing interest among evolutionary biologists (David et al., 2006; Gibert et al., 2004; Moreteau et al., 2003; Karan et al., 1999; Scheiner, 1993; Scheiner and Lyman, 1989; Schlicting and Pigliucci, 1998; Steigenga et al., 2005; West and Packer, 2002; Via, 1993).

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Plastic Materialities

  Politics, Legality, and Metamorphosis in the Work of Catherine Malabou

  • Brenna Bhandar, Jonathan Goldberg-Hiller, Brenna Bhandar, Jonathan Goldberg-Hiller(Authors)
  • 2015(Publication Date)
  • Duke University Press Books

    (Publisher)

  Autoplasticity 77 extent these mutations are transmissible through transgenerational in-heritance rather than cellular division. Some time before it was heralded as the cause of a revolution in mo-lecular biology and as an exemplification of “plasticity” in Malabou’s sense, epigenetics had already given rise to a biological-epistemological theory of plasticity in the shape of Maturana and Varela’s theory of au-topoiesis: “Living beings are autopoietic systems [in that] their being implies the ongoing participation of all their constitutive elements, such that no single one can be said to be solely responsible for its character-istics as such. That is why, stricto sensu, one cannot speak of genetic determinism or [say] that certain traits are genetically determined nor that a specific trait in an organism is determined by the dna of its cells. More properly, every trait or character of the organism emerges from an epigenetic process that consists in an ontogenetic structural drift.” 23 Here, “epigenetics” is given a particular meaning; the “genetic cause” of the organism is not its dna but an ongoing process of self-production: “That living beings have an organisation, of course, is proper not only to them but also to everything we can analyse as a system. What is distinc-tive about them, however, is that their organisation is such that their only product is themselves, with no separation between producer and product. The being and doing of an autopoietic unity are inseparable, and this is their specific mode of organisation.” 24 Maturana and Varela’s theory of autopoiesis is vital to any biologi-cally informed reflection on plasticity because it makes an “autoch-thonous” linkage between plasticity and epigenetics within biological epistemology and because it gives us the essential sense of plasticity as a poietic rather than an ontic process.

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  The Brain's Body

  Neuroscience and Corporeal Politics

  • Victoria Pitts-Taylor(Author)
  • 2016(Publication Date)
  • Duke University Press Books

    (Publisher)

  Woollett and Maguire (2011) speculate that the deciding factor could be genetic dispar-ities between individuals. Those who were successful, they suggest, could “have had a genetic predisposition toward plasticity that the nonqualified individuals lacked” (2113). While the developmental research cited earlier suggests that plasticity is not equally distributed among areas within a sin-gle brain, here plasticity is proposed to be a biological advantage afforded unequally to persons. There are many aspects of plasticity research I have not addressed. But even in this very brief description, it should be clear that plasticity is con-ceptualized, measured, and enacted in multiple ways. While functional or synaptic plasticity as tied to learning and cognition is easily described in global and unlimited terms, the morphological or structural plasticity of the brain can seem to have a stratified economy, being unevenly distributed across various stages, regions, and even groups of persons. The proposed temporal, spatial, and genetic variability of plasticity, along with the brain’s proposed selective vulnerability to various social influences, suggest that its implications for human agency are far from straightforward. A brain that expresses a universal configuration of developmental plasticity at adoles- THE PHENOMENON OF BRAIN PLASTICITY 31 cence, or one that is imprinted by poverty into a recognizable phenotype, is quite different from one that can be modified by the demands of its owner. Social constructionists might believe this diversity delegitimizes any efforts to theorize plasticity as a material reality, but as I explain further, I see this variability instead as evidence of the entanglement of matter, measure, and meaning. Plasticity and Socialization Any discussion of brain plasticity should recognize not only its partial and stratified character but also its absence in some research programs.

  Sign up to read

  Learn more about book