scholarly journals Environmental variability affects optimal trade‐offs in ecological immunology

Ecosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Devin Kirk ◽  
Megan Greischar ◽  
Nicole Mideo ◽  
Martin Krkošek
Keyword(s):  
Environmental Variability ◽  
Ecological Immunology ◽  
Trade Offs

scholarly journals Breaking through evolutionary constraint by environmental fluctuations

2015 ◽  
Author(s):  
Marjon GJ de Vos ◽  
Alexandre Dawid ◽  
Vanda Sunderlikova ◽  
Sander J Tans
Keyword(s):  
Escherichia Coli ◽  
Environmental Variability ◽  
Model System ◽  
Evolutionary Constraint ◽  
Apparent Paradox ◽  
Epistatic Interactions ◽  
Genetic Constraints ◽  
Trade Offs ◽  
Fluctuating Environments ◽  
Genetic Constraint

Epistatic interactions can frustrate and shape evolutionary change. Indeed, phenotypes may fail to evolve because essential mutations can only be selected positively if fixed simultaneously. How environmental variability affects such constraints is poorly understood. Here we studied genetic constraints in fixed and fluctuating environments, using theEscherichia coli lacoperon as a model system for genotype-environment interactions. The data indicated an apparent paradox: in different fixed environments, mutational trajectories became trapped at sub-optima where no further improvements were possible, while repeated switching between these same environments allowed unconstrained adaptation by continuous improvements. Pervasive cross-environmental trade-offs transformed peaks into valleys upon environmental change, thus enabling escape from entrapment. This study shows that environmental variability can lift genetic constraint, and that trade-offs not only impede but can also facilitate adaptive evolution.

Community Ecology of Stream Fishes: Concepts, Approaches, and Techniques

2010 ◽  
Keyword(s):  
Great Plains ◽  
Life Histories ◽  
Environmental Heterogeneity ◽  
Environmental Variability ◽  
Spatial Scales ◽  
Stream Fish ◽  
Metapopulation Dynamics ◽  
Stream Fishes ◽  
Spatial And Temporal Scales ◽  
Trade Offs

<em>Abstract</em>.—Stream fishes carry out their life histories across broad spatial and temporal scales, leading to spatially structured populations. Therefore, incorporating metapopulation dynamics into models of stream fish populations may improve our ability to understand mechanisms regulating them. First, we reviewed empirical research on metapopulation dynamics in the stream fish ecology literature and found 31 papers that used the metapopulation framework. The majority of papers applied no specific metapopulation model, or included space only implicitly. Although parameterization of spatially realistic models is challenging, we suggest that stream fish ecologists should incorporate space into models and recognize that metapopulation types may change across scales. Second, we considered metacommunity theory, which addresses how trade-offs among dispersal, environmental heterogeneity, and biotic interactions structure communities across spatial scales. There are no explicit tests of metacommunity theory using stream fishes to date, so we used data from our research in a Great Plains stream to test the utility of these paradigms. We found that this plains fish metacommunity was structured mainly by spatial factors related to dispersal opportunity and, to a lesser extent, by environmental heterogeneity. Currently, metacommunity models are more heuristic than predictive. Therefore, we propose that future stream fish metacommunity research should focus on developing testable hypotheses that incorporate stream fish life history attributes, and seasonal environmental variability, across spatial scales. This emerging body of research is likely to be valuable not only for basic stream fish ecological research, but also multispecies conservation and management.

Ecological immunology

2021 ◽  
pp. 109-142
Author(s):  
Paul Schmid-Hempel
Keyword(s):  
Energy Consumption ◽  
Natural Selection ◽  
Ecological Immunology ◽  
Costs And Benefits ◽  
Response Delay ◽  
Genetic Covariance ◽  
Trade Offs ◽  
Immunological Factors ◽  
Immune Defences

Infections and parasite loads vary among hosts. Variation results from ecological, genetic, and immunological factors. Immune defences provide benefits as well as costs and are, therefore, a compromise. Costs result from trade-offs with other needs and can be genetically encoded or plastic (i.e. can change depending on circumstances). Costs are physiological (e.g. energy consumption) or based on evolved genetic covariance. Self-damage (immunopathology) is a further, important cost. Natural selection should optimize the costs and benefits of defences and thus leads to various outcomes in terms of specificity, response delay and strength, or the formation of memory. Moreover, hosts can either resist an infection by eventual clearance, or tolerate the consequences of parasitism.

Current immunity markers in insect ecological immunology: assumed trade-offs and methodological issues

2012 ◽  
Vol 103 (2) ◽  
pp. 127-139 ◽  
Author(s):  
M. Moreno-García ◽  
A. Córdoba-Aguilar ◽  
R. Condé ◽  
H. Lanz-Mendoza
Keyword(s):  
Nitric Oxide ◽  
Evolutionary Ecology ◽  
Nitric Oxide Production ◽  
Ecological Immunology ◽  
Methodological Issues ◽  
Phenoloxidase Activity ◽  
Capsule Formation ◽  
Trade Offs ◽  
Physiologically Based ◽  
Shed Light

AbstractThe field of ecological immunology currently relies on using a number of immune effectors or markers. These markers are usually used to infer ecological trade-offs (via conflicts in resource allocation), though physiological nature of these markers remains elusive. Here, we review markers frequently used in insect evolutionary ecology research: cuticle darkening, haemocyte density, nodule/capsule formation, phagocytosis and encapsulation/melanization via use of nylon filaments and beads, phenoloxidase activity, nitric oxide production, lysozyme and antimicrobial peptide production. We also provide physiologically based information that may shed light on the probable trade-offs inferred when these markers are used. In addition, we provide a number of methodological suggestions to improve immune marker assessment.

scholarly journals Introduction. Ecological immunology

2008 ◽  
Vol 364 (1513) ◽  
pp. 3-14 ◽  
Author(s):  
Hinrich Schulenburg ◽  
Joachim Kurtz ◽  
Yannick Moret ◽  
Michael T Siva-Jothy
Keyword(s):  
Life History ◽  
Ecological Factors ◽  
Future Research ◽  
Ecological Immunology ◽  
Defence Mechanisms ◽  
Theme Issue ◽  
Trade Offs ◽  
Abiotic Interactions ◽  
Evolution Of Immunity

An organism's fitness is critically reliant on its immune system to provide protection against parasites and pathogens. The structure of even simple immune systems is surprisingly complex and clearly will have been moulded by the organism's ecology. The aim of this review and the theme issue is to examine the role of different ecological factors on the evolution of immunity. Here, we will provide a general framework of the field by contextualizing the main ecological factors, including interactions with parasites, other types of biotic as well as abiotic interactions, intraspecific selective constraints (life-history trade-offs, sexual selection) and population genetic processes. We then elaborate the resulting immunological consequences such as the diversity of defence mechanisms (e.g. avoidance behaviour, resistance, tolerance), redundancy and protection against immunopathology, life-history integration of the immune response and shared immunity within a community (e.g. social immunity and microbiota-mediated protection). Our review summarizes the concepts of current importance and directs the reader to promising future research avenues that will deepen our understanding of the defence against parasites and pathogens.

Behavioural plasticity in variable environments

1997 ◽  
Vol 75 (2) ◽  
pp. 161-169 ◽  
Author(s):  
Petr E. Komers
Keyword(s):  
Resource Availability ◽  
Response Curve ◽  
Environmental Variability ◽  
Population Viability ◽  
Behavioural Plasticity ◽  
Behavioural Ecology ◽  
Costs And Benefits ◽  
Behavioural Responses ◽  
Trade Offs ◽  
Variable Environments

The plasticity of behaviour consists of an array of behavioural responses to varying environmental conditions. It is widely predicted that the range of behavioural responses will increase with environmental variability. According to this prediction, the slopes of a response curve representing behavioural plasticity would be identical in environments with different variability. However, the range of behaviours can also increase with the slope of the curve, so that in a given range of environments, the plasticity of behaviour would vary. For example, where two environments are similar in terms of resource availability, the costs of exploiting the resource may differ. An improved ability to assess costs and benefits is predicted to increase behavioural plasticity because it decreases the costs and increases the benefits of alternative behaviours. Moreover, because trade-offs change with age and plasticity is related to trade-offs, plasticity should also change with age. While the ability of animals to adjust to current trade-offs is fundamental for behavioural ecology, demonstration of ranges, slopes, and shapes of plastic behavioural responses is virtually absent from the literature. Knowledge concerning the ability of animals to adjust to environmental fluctuations is important for making predictions about population viability, but empirical evidence is greatly needed to validate current generalizations.

scholarly journals Trade-offs between sight lines and escape habitat determine spatial strategies of risk management by a keystone herbivore

FACETS ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 338-357 ◽  
Author(s):  
Douglas W. Morris ◽  
Sundararaj Vijayan
Keyword(s):  
Time Allocation ◽  
Environmental Variability ◽  
A Priori ◽  
Space Use ◽  
Coarse Grained ◽  
Predator Detection ◽  
Trade Off ◽  
Spatial Strategies ◽  
Trade Offs ◽  
Open Versus

Prey individuals possess four basic strategies to manage predation risk while foraging: time allocation, space use, apprehension, and foraging tenacity. But there are no direct tests of theory detailing how spatial strategies change and covary from fine to coarse scales of environmental variability. We address this shortcoming with experiments that estimated space use and vigilance of snowshoe hares while we measured foraging tenacity in artificial resource patches placed in risky open versus safe alder habitat. Hares employed only two of eight a priori options to manage risk. Hares increased vigilance and reduced foraging in open areas as the distance from cover increased. Hares did not differentiate between open and alder habitats, increase vigilance at the coarse-grained scale, or reduce vigilance and foraging tenacity under supplemental cover. Hares were more vigilant in the putatively safe alder than in the purportedly risky open habitat. These apparently paradoxical results appear to reflect a trade-off between the benefit of alder as escape habitat and the cost of obscured sight lines that reduce predator detection. The trade-off also appears to equalize safety between habitats at small scales and suggests that common-sense predictions detailing how prey reduce risk may make no sense at all.

Sign in / Sign up

Export Citation Format

Share Document