scholarly journals Pathogen evolution: slow and steady spreads the best

2017 ◽  
Author(s):  
Todd L. Parsons ◽  
Amaury Lambert ◽  
Troy Day ◽  
Sylvain Gandon
Keyword(s):  
Life History ◽  
Population Size ◽  
Evolutionary Dynamics ◽  
Finite Population ◽  
Adaptive Dynamics ◽  
Life History Evolution ◽  
Demographic Stochasticity ◽  
Deterministic Models ◽  
Evolutionary Forces ◽  
History Evolution

AbstractThe theory of life history evolution provides a powerful framework to understand the evolutionary dynamics of pathogens in both epidemic and endemic situations. This framework, however, relies on the assumption that pathogen populations are very large and that one can neglect the effects of demographic stochasticity. Here we expand the theory of life history evolution to account for the effects of finite population size on the evolution of pathogen virulence. We show that demographic stochasticity introduces additional evolutionary forces that can qualitatively affect the dynamics and the evolutionary outcome. We discuss the importance of the shape of pathogen fitness landscape and host heterogeneity on the balance between mutation, selection and genetic drift. In particular, we discuss scenarios where finite population size can dramatically affect classical predictions of deterministic models. This analysis reconciles Adaptive Dynamics with population genetics in finite populations and thus provides a new theoretical toolbox to study life-history evolution in realistic ecological scenarios.

scholarly journals Pathogen evolution in finite populations: slow and steady spreads the best

2018 ◽  
Vol 15 (147) ◽  
pp. 20180135 ◽  
Author(s):  
Todd L. Parsons ◽  
Amaury Lambert ◽  
Troy Day ◽  
Sylvain Gandon
Keyword(s):  
Life History ◽  
Evolutionary Dynamics ◽  
Fitness Landscape ◽  
Adaptive Dynamics ◽  
Life History Evolution ◽  
Demographic Stochasticity ◽  
Finite Populations ◽  
Evolutionary Forces ◽  
Pathogen Fitness ◽  
History Evolution

The theory of life-history evolution provides a powerful framework to understand the evolutionary dynamics of pathogens. It assumes, however, that host populations are large and that one can neglect the effects of demographic stochasticity. Here, we expand the theory to account for the effects of finite population size on the evolution of pathogen virulence. We show that demographic stochasticity introduces additional evolutionary forces that can qualitatively affect the dynamics and the evolutionary outcome. We discuss the importance of the shape of the pathogen fitness landscape on the balance between mutation, selection and genetic drift. This analysis reconciles Adaptive Dynamics with population genetics in finite populations and provides a new theoretical toolbox to study life-history evolution in realistic ecological scenarios.

Daphnia as a Model for Eco-evolutionary Dynamics

2018 ◽  
pp. 403-424
Author(s):  
Matthew R. Walsh ◽  
Michelle Packer ◽  
Shannon Beston ◽  
Collin Funkhouser ◽  
Michael Gillis ◽  
...  
Keyword(s):  
Life History ◽  
Evolutionary Dynamics ◽  
Model Organism ◽  
Life History Evolution ◽  
Ecological Processes ◽  
Evolutionary Forces ◽  
Evolutionary Changes ◽  
History Evolution ◽  
Ecological Importance ◽  
The Many

Much research has shown that variation in ecological processes can drive rapid evolutionary changes over periods of years to decades. Such contemporary adaptation sets the stage for evolution to have reciprocal impacts on the properties of populations, communities, and ecosystems, with ongoing interactions between ecological and evolutionary forces. The importance and generality of these eco-evolutionary dynamics are largely unknown. In this chapter, we promote the use of water fleas (Daphnia sp.) as a model organism in the exploration of eco-evolutionary interactions in nature. The many characteristics of Daphnia that make them suitable for laboratory study in conjunction with their well-known ecological importance in lakes, position Daphnia to contribute new and important insights into eco-evolutionary dynamics. We first review the influence of key environmental stressors in Daphnia evolution. We then highlight recent work documenting the pathway from life history evolution to ecology using Daphnia as a model. This review demonstrates that much is known about the influence of ecology on Daphnia life history evolution, while research exploring the genomic basis of adaptation as well as the influence of Daphnia life history traits on ecological processes is beginning to accumulate.

scholarly journals Spatial selection and local adaptation jointly shape life-history evolution during range expansion

2015 ◽  
Author(s):  
Katrien Van Petegem ◽  
Jeroen Boeye ◽  
Robby Stoks ◽  
Dries Bonte
Keyword(s):  
Life History ◽  
Local Adaptation ◽  
Range Expansion ◽  
Life History Traits ◽  
Evolutionary Dynamics ◽  
Life History Evolution ◽  
Range Shifts ◽  
Evolutionary Processes ◽  
Spatial Selection ◽  
History Evolution

In the context of climate change and species invasions, range shifts increasingly gain attention because the rates at which they occur in the Anthropocene induce fast shifts in biological assemblages. During such range shifts, species experience multiple selection pressures. Especially for poleward expansions, a straightforward interpretation of the observed evolutionary dynamics is hampered because of the joint action of evolutionary processes related to spatial selection and to adaptation towards local climatic conditions. To disentangle the effects of these two processes, we integrated stochastic modeling and empirical approaches, using the spider mite Tetranychus urticae as a model species. We demonstrate considerable latitudinal quantitative genetic divergence in life-history traits in T. urticae, that was shaped by both spatial selection and local adaptation. The former mainly affected dispersal behavior, while development was mainly shaped by adaptation to the local climate. Divergence in life-history traits in species shifting their range poleward can consequently be jointly determined by fast local adaptation to the environmental gradient and contemporary evolutionary dynamics resulting from spatial selection. The integration of modeling with common garden experiments provides a powerful tool to study the contribution of these two evolutionary processes on life-history evolution during range expansion.

scholarly journals Directionality theory: an empirical study of an entropic principle in life‐history evolution

2005 ◽  
Vol 272 (1568) ◽  
pp. 1185-1194 ◽  
Author(s):  
Martin Ziehe ◽  
Lloyd Demetrius
Keyword(s):  
Life History ◽  
Population Size ◽  
Growth Phase ◽  
Evolutionary History ◽  
Evolutionary Process ◽  
Life History Evolution ◽  
Stationary Growth Phase ◽  
Exponential Growth Phase ◽  
Opportunistic Species ◽  
History Evolution

Understanding the relationship between ecological constraints and life-history properties constitutes a central problem in evolutionary ecology. Directionality theory, a model of the evolutionary process based on demographic entropy, a measure of the uncertainty in the age of the mother of a randomly chosen newborn, provides an analytical framework for addressing this problem. The theory predicts that in populations that spend the greater part of their evolutionary history in the stationary growth phase (equilibrium species), entropy will increase. Equilibrium species will be characterized by high iteroparity and strong demographic stability. In populations that spend the greater part of their evolutionary history in the exponential growth phase (opportunistic species), entropy will decrease when population size is large, and will undergo random variation when population size is small. Opportunistic species will be characterized by weak iteroparity and weak demographic stability when population size is large, and random variations in these attributes when population size is small. This paper assesses the validity of these predictions by employing a demographic dataset of 66 species of perennial plants. This empirical analysis is consistent with directionality theory and provides support for its significance as an explanatory and predictive model of life-history evolution.

scholarly journals The importance and adaptive value of life history evolution for metapopulation dynamics

2017 ◽  
Author(s):  
Dries Bonte ◽  
Quinten Bafort
Keyword(s):  
Life History ◽  
Evolutionary Dynamics ◽  
Local Density ◽  
Life History Evolution ◽  
Individual Performance ◽  
Structured Populations ◽  
Metapopulation Dynamics ◽  
Systems Modelling ◽  
Metapopulation Persistence ◽  
History Evolution

1. The spatial configuration and size of patches influence metapopulation dynamics by altering colonisation-extinction dynamics and local density-dependency. This spatial forcing as determined by the metapopulation typology then imposes strong selection pressures on life history traits, which will in turn feedback on the ecological metapopulation dynamics. Given the relevance of metapopulation persistence for biological conservation, and the potential rescuing role of evolution, a firm understanding of the relevance of these eco-evolutionary processes is essential. 2. We here follow a systems modelling approach to quantify the importance of spatial forcing and experimentally observed life history evolution for metapopulation demography as quantified by (meta)population size and variability. We therefore developed an individual based model matching an earlier experimental evolution with spider mites to perform virtual translocation and invasion experiments that would have been otherwise impossible to conduct. 3. We show that (1) metapopulation demography is more affected by spatial forcing than by life history evolution, but that life history evolution contributes substantially to changes in local and especially metapopulation-level population sizes, (2) extinction rates are minimised by evolution in classical metapopulations, and (3) evolution is optimising individual performance in metapopulations when considering the importance of more cryptic stress resistance evolution. 4. Ecological systems modelling opens up a promising avenue to quantify the importance of eco-evolutionary feedbacks for larger-scale population dynamics. Metapopulation sizes are especially impacted by evolution but its variability is mainly determined by the spatial forcing. 5. Eco-evolutionary dynamics can increase the persistence of classical metapopulations. The maintenance of evolutionary dynamics in spatially structured populations is thus not only essential in the face of environmental change; it also generates feedbacks that impact metapopulation persistence.

scholarly journals Gene Trees versus Species Trees: Reassessing Life-History Evolution in a Freshwater Fish Radiation

2010 ◽  
Vol 59 (5) ◽  
pp. 504-517 ◽  
Author(s):  
Jonathan M. Waters ◽  
Diane L. Rowe ◽  
Christopher P. Burridge ◽  
Graham P. Wallis
Keyword(s):  
Life History ◽  
Freshwater Fish ◽  
Life History Evolution ◽  
Gene Trees ◽  
Species Trees ◽  
History Evolution
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