scholarly journals Trade‐offs affect the adaptive value of plasticity: stronger cannibal‐induced defenses incur greater costs in toad larvae

2020 ◽  
Author(s):  
Jayna L. DeVore ◽  
Michael R. Crossland ◽  
Richard Shine
Keyword(s):  
Induced Defenses ◽  
Adaptive Value ◽  
Trade Offs

scholarly journals Animal activity around the clock with no overt circadian rhythms: patterns, mechanisms and adaptive value

2013 ◽  
Vol 280 (1765) ◽  
pp. 20130019 ◽  
Author(s):  
Guy Bloch ◽  
Brian M. Barnes ◽  
Menno P. Gerkema ◽  
Barbara Helm
Keyword(s):  
Circadian Rhythms ◽  
Activity Patterns ◽  
Polar Regions ◽  
Life History Stages ◽  
Adaptive Value ◽  
Physical Environments ◽  
Trade Offs ◽  
Animal Activity ◽  
Underlying Mechanisms ◽  
Organizational Principles

Circadian rhythms are ubiquitous in many organisms. Animals that are forced to be active around the clock typically show reduced performance, health and survival. Nevertheless, we review evidence of animals showing prolonged intervals of activity with attenuated or nil overt circadian rhythms and no apparent ill effects. We show that around-the-clock and ultradian activity patterns are more common than is generally appreciated, particularly in herbivores, in animals inhabiting polar regions and habitats with constant physical environments, in animals during specific life-history stages (such as migration or reproduction), and in highly social animals. The underlying mechanisms are diverse, but studies suggest that some circadian pacemakers continue to measure time in animals active around the clock. The prevalence of around-the-clock activity in diverse animals and habitats, and an apparent diversity of underlying mechanisms, are consistent with convergent evolution. We suggest that the basic organizational principles of the circadian system and its complexity encompass the potential for chronobiological plasticity. There may be trade-offs between benefits of persistent daily rhythms versus plasticity, which for reasons still poorly understood make overt daily arrhythmicity functionally adaptive only in selected habitats and for selected lifestyles.

scholarly journals Costs and trade-offs of grazer-induced defenses in Scenedesmus under deficient resource

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Xuexia Zhu ◽  
Jun Wang ◽  
Qinwen Chen ◽  
Ge Chen ◽  
Yuan Huang ◽  
...  
Keyword(s):  
Induced Defenses ◽  
Trade Offs

scholarly journals Intrinsic adaptive value and early fate of gene duplication revealed by a bottom-up approach

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Guillermo Rodrigo ◽  
Mario A Fares
Keyword(s):  
Gene Duplication ◽  
Genome Rearrangement ◽  
Quantitative Description ◽  
Selective Advantage ◽  
Gene Copy ◽  
Adaptive Value ◽  
Trade Offs ◽  
Molecular Noise ◽  
Genetic Mechanisms ◽  
Selection Of

The population genetic mechanisms governing the preservation of gene duplicates, especially in the critical very initial phase, have remained largely unknown. Here, we demonstrate that gene duplication confers per se a weak selective advantage in scenarios of fitness trade-offs. Through a precise quantitative description of a model system, we show that a second gene copy serves to reduce gene expression inaccuracies derived from pervasive molecular noise and suboptimal gene regulation. We then reveal that such an accuracy in the phenotype yields a selective advantage in the order of 0.1% on average, which would allow the positive selection of gene duplication in populations with moderate/large sizes. This advantage is greater at higher noise levels and intermediate concentrations of the environmental molecule, when fitness trade-offs become more evident. Moreover, we discuss how the genome rearrangement rates greatly condition the eventual fixation of duplicates. Overall, our theoretical results highlight an original adaptive value for cells carrying new-born duplicates, broadly analyze the selective conditions that determine their early fates in different organisms, and reconcile population genetics with evolution by gene duplication.

scholarly journals Intrinsic adaptive value and early fate of gene duplication revealed by a bottom-up approach

2017 ◽  
Author(s):  
Guillermo Rodrigo ◽  
Mario A. Fares
Keyword(s):  
Population Genetics ◽  
Gene Regulation ◽  
Natural Selection ◽  
Gene Duplication ◽  
Genetic Drift ◽  
Evolutionary Process ◽  
Selective Advantage ◽  
Gene Copy ◽  
Adaptive Value ◽  
Trade Offs

ABSTRACTGene duplication is a major source of functional innovations and genome complexity, albeit this evolutionary process requires the preservation of duplicates in the genomes for long time. However, the population genetic mechanisms governing this preservation, especially in the critical very initial phase, have remained largely unknown. Here, we demonstrate that gene duplication confers per se a weak selective advantage in scenarios of fitness trade-offs. Through a precise quantitative description of a model system, we show that a second gene copy enhances the information transfer from the environmental signal to the phenotypic response by reducing gene expression inaccuracies derived from pervasive molecular noise and suboptimal gene regulation. We then reveal that such a phenotypic accuracy yields a selective advantage in the order of 0.1% on average, which would allow the positive selection of gene duplication in populations with moderate or large sizes. This advantage is greater at higher noise levels and intermediate concentrations of the environmental molecule, when fitness trade-offs become more evident. Moreover, we show that the genome rearrangement rates greatly condition the eventual fixation of duplicated genes, either by natural selection or by random genetic drift. Overall, our theoretical results highlight an original adaptive value for cells carrying new-born duplicates, broadly analyze the selective conditions that determine their early fates in different organisms, and reconcile population genetics with evolution by gene duplication.SIGNIFICANCEGene duplication is considered a major driver for the evolution of biological complexity. However, it is still enigmatic to what extent natural selection and genetic drift have governed this evolutionary process. This work uncovers a selective advantage for genotypes carrying duplicates, called phenotypic accuracy, widely characterized thanks to a multi-scale mathematical model coupling gene regulation with population genetics. Importantly, the integrative results presented here provide a detailed mechanistic description for the fixation of duplicates, which allows making predictions about the genome architectures, and which is relevant to understand the origins of complexity.

scholarly journals On Trade-offs and Communal Breeding The Behavioural Ecology of Agta Foragers

2021 ◽  
Author(s):  
Abigail Emma Page
Keyword(s):  
Life History Strategies ◽  
Energy Budgets ◽  
Small Scale ◽  
Network Centrality ◽  
Communal Breeding ◽  
Household Energy ◽  
Trade Off ◽  
Adaptive Value ◽  
Trade Offs ◽  
Fitness Consequences

Time is finite and no organism can avoid the allocation dilemma that this necessarily entails. A quintessential trade-off is that between parental investment and reproduction, otherwise known as the quality-quantity trade-off. However, humans may be exceptional among apes given our high quantity production of high quality offspring. This success has been argued only to be possible by breeding communally. In this thesis I explore questions surrounding trade-offs, communal breeding and their fitness consequences in a small-scale foraging society, the Agta. The first analysis examines the composition of Agta childcare using an innovative form of data collection to maximise sample sizes, previously a major limitation in hunter-gatherer research. The Agta, like many small-scale societies are prolific communal breeders. However, contra previous conclusions, juveniles and non-kin appeared to provide more allocare than grandmothers. Interactions with non-kin were associated with significant decreases in maternal workload, while interactions with siblings and grandmothers were not. The next analysis explores why both kin and non-kin behave cooperatively, finding support for kin selection among close kin and reciprocity for distant kin and non-kin allocare. Communal breeding appears to be an important mechanism to ensure enough childcare was received in the absence of other strategies to counter shortfalls in household energy budgets. The next analysis asks, what are the fitness consequences of maternal social networks and allocare? Mothers’ network centrality positively correlated with non-kin allocare as well as reproductive success, revealing the adaptive value of communal breeding. These results highlight the optimising nature of hunter-gatherer cooperation and life history strategies.

Metabolic power budgeting and adaptive strategies in zoology: examples from scallops and fishThe present review is one of a series of occasional review articles that have been invited by the Editors and will feature the broad range of disciplines and expertise represented in our Editorial Advisory Board.

2010 ◽  
Vol 88 (8) ◽  
pp. 753-763 ◽  
Author(s):  
Helga Guderley ◽  
Hans Otto Pörtner
Keyword(s):  
Energy Use ◽  
Aerobic Power ◽  
Reproductive Investment ◽  
Energy Availability ◽  
Metabolic Power ◽  
Metabolic Capacity ◽  
Fitness Functions ◽  
Adaptive Value ◽  
Trade Offs ◽  
Distribution Limits

Evolutionary explanations of the adaptive value of animal characteristics are often expressed in energetic terms, but unless they are accompanied by demonstrations of limited energy availability, they remain speculative. In this review, we argue that metabolic power budgeting provides easily testable mechanisms through which energetically efficient attributes could become adaptive. Given each organism’s maximal aerobic (and metabolic) capacity, available metabolic power (energy use per unit time) is limited and must be partitioned between different processes. This leads to compromises among the major fitness functions of growth, locomotor activity, and reproductive investment. As examples of such conflicts, we examine the compromise among growth, reproduction, and predator avoidance in scallops, as well as the means whereby thermal limitations on oxygen uptake reflect the geographical distribution limits and associated energetic trade-offs of temperate zone and polar fishes. These examples show several means whereby the budgeting of aerobic power is implicated in the major fitness trade-offs faced by animals.

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