scholarly journals A general theoretical framework for trait-based eco-evolutionary dynamics: population structure, intraspecific variation, and community assembly

2021 ◽  
Author(s):  
Jonas Wickman ◽  
Thomas Koffel ◽  
Christopher A Klausmeier
Keyword(s):  
Population Structure ◽  
Intraspecific Variation ◽  
Functional Traits ◽  
Community Assembly ◽  
Evolutionary Dynamics ◽  
Resource Competition ◽  
Adaptive Dynamics ◽  
Theoretical Framework ◽  
Community Change ◽  
Structured Populations

To understand how functional traits shape ecological communities it is necessary to understand both how traits across the community affect its functioning and how eco-evolutionary dynamics within the community change the traits over time. Of particular interest are so-called evolutionarily stable communities (ESCs), since these are the end points of eco-evolutionary dynamics and can persist over long time scales. One theoretical framework that has successfully been used for assembling ESCs is adaptive dynamics. However, this framework cannot account for intraspecific variation---neither locally nor across structured populations. On the other hand, in moment-based approaches, intraspecific variation is accommodated, but community assembly has been neglected. This is unfortunate as some questions regarding for example local adaptation vis-a-vis diversification into multiple species requires both facets. In this paper we develop a general theoretical framework that bridges the gap between these two approaches. We showcase how ESCs can be assembled using the framework, and illustrate various aspects of the framework using two simple models of resource competition. We believe this unifying framework could be of great use to address questions regarding the role of functional traits in communities where population structure, intraspecific variation, and eco-evolutionary dynamics are all important.

scholarly journals Bifurcation theory, adaptive dynamics and dynamic energy budget-structured populations of iteroparous species

2010 ◽  
Vol 365 (1557) ◽  
pp. 3579-3590 ◽  
Author(s):  
B. W. Kooi ◽  
J. van der Meer
Keyword(s):  
Energy Budget ◽  
Evolutionary Dynamics ◽  
Adaptive Dynamics ◽  
Structured Populations ◽  
Food Storage ◽  
Evolutionary Development ◽  
Life Stages ◽  
Dynamic Energy Budget ◽  
Iteroparous Species ◽  
Timing Of Spawning

In this paper, we describe a technique to evaluate the evolutionary dynamics of the timing of spawning for iteroparous species. The life cycle of the species consists of three life stages, embryonic, juvenile and adult whereby the transitions of life stages (gametogenesis, birth and maturation) occur at species-specific sizes. The dynamics of the population is studied in a semi-chemostat environment where the inflowing food concentration is periodic (annual). A dynamic energy budget-based continuous-time model is used to describe the uptake of the food, storage in reserves and allocation of the energy to growth, maintenance, development (embryos, juveniles) and reproduction (adults). A discrete-event process is used for modelling reproduction. At a fixed spawning date of the year, the reproduction buffer is emptied and a new cohort is formed by eggs with a fixed size and energy content. The population consists of cohorts: for each year one consisting of individuals with the same age which die after their last reproduction event. The resulting mathematical model is a finite-dimensional set of ordinary differential equations with fixed 1-year periodic boundary conditions yielding a stroboscopic map. We will study the evolutionary development of the population using the adaptive dynamics approach. The trait is the timing of spawning. Pairwise and mutual invasibility plots are calculated using bifurcation analysis of the stroboscopic map. The evolutionary singular strategy value belonging to the evolutionary endpoint for the trait allows for an interpretation of the reproduction strategy of the population. In a case study, parameter values from the literature for the bivalve Macoma balthica are used.

scholarly journals Understanding the evolution of multiple drug resistance in structured populations

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
David V McLeod ◽  
Sylvain Gandon
Keyword(s):  
Population Structure ◽  
Evolutionary Dynamics ◽  
Multiple Drug Resistance ◽  
Drug Prescription ◽  
Structured Populations ◽  
Health Concern ◽  
Multiple Drug ◽  
Unified Framework ◽  
Dynamical Equations

The evolution of multidrug resistance (MDR) is a pressing public health concern. Yet many aspects, such as the role played by population structure, remain poorly understood. Here we argue that studying MDR evolution by focusing upon the dynamical equations for linkage disequilibrium (LD) can greatly simplify the calculations, generate more insight, and provide a unified framework for understanding the role of population structure. We demonstrate how a general epidemiological model of MDR evolution can be recast in terms of the LD equations. These equations reveal how the different forces generating and propagating LD operate in a dynamical setting at both the population and metapopulation levels. We then apply these insights to show how the LD perspective: (i) explains equilibrium patterns of MDR, (ii) provides a simple interpretative framework for transient evolutionary dynamics, and (iii) can be used to assess the consequences of different drug prescription strategies for MDR evolution.

scholarly journals Understanding the evolution of multiple drug resistance in structured populations

2020 ◽  
Author(s):  
David V. McLeod ◽  
Sylvain Gandon
Keyword(s):  
Population Structure ◽  
Evolutionary Dynamics ◽  
Multiple Drug Resistance ◽  
Drug Prescription ◽  
Structured Populations ◽  
Health Concern ◽  
Multiple Drug ◽  
Unified Framework ◽  
Dynamical Equations

AbstractThe evolution of multidrug resistance (MDR) is a pressing public health concern. Yet many aspects, such as the role played by population structure, remain poorly understood. Here we argue that studying MDR evolution by focusing upon the dynamical equations for linkage disequilibrium (LD) can greatly simplify the calculations, generate more insight, and provide a unified framework for understanding the role of population structure. We demonstrate how a general epidemiological model of MDR evolution can be recast in terms of the LD equations. These equations reveal how the different forces generating and propagating LD operate in a dynamical setting at both the population and metapopulation levels. We then apply these insights to show how the LD perspective: (i) explains equilibrium patterns of MDR, (ii) provides a simple interpretative framework for transient evolutionary dynamics, and (iii) can be used to assess the consequences of different drug prescription strategies for MDR evolution.

Environmental factors driving plant trait distributions in coastal zones of Atlantic Forest

Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
Lays Lins ◽  
Juliana Da Silva-Pinheiro ◽  
Ricardo Correia ◽  
Laurício Endres ◽  
Ana Cláudia Mendes Malhado ◽  
...  
Keyword(s):  
Intraspecific Variation ◽  
Functional Traits ◽  
Community Assembly ◽  
Environmental Gradients ◽  
Species Turnover ◽  
Principal Component ◽  
Matter Content ◽  
Dry Matter Content ◽  
Coastal Zones ◽  
Environmental Filters

Abstract Environmental filtering has been defined as the effect of environmental gradients on species in a plant community and can be the dominant driver of community assembly. Here, we evaluate the relationship between plant communities and the environment in the Restinga vegetation. For this, we measured 11 functional traits of plant species present along transects covering a marked edaphic environmental gradient. This gradient was characterized through Principal Component Analysis of soil characteristics. The relationships between the edaphic gradient and functional traits were evaluated using linear models. Finally, we compared the contributions of species turnover and intraspecific variation to among-site variation in functional traits. The gradients associated with soil nutrients (PCA axis 1) and soil acidity and organic matter (PCA axis 2) were then used to test the observed changes in community composition and were significant predictors of the distribution of water potential, leaf dry matter content and K content, height and chlorophyll index. Decomposing the total variation in the distribution of functional traits between species turnover and intraspecific variation revealed that species turnover explains a greater proportion of the observed variation. We conclude that community assembly is strongly limited by environmental filters and mediated by functional traits at the species level.

scholarly journals Multi-morph eco-evolutionary dynamics in structured populations

2021 ◽  
Author(s):  
Sébastien Lion ◽  
Mike Boots ◽  
Akira Sasaki
Keyword(s):  
Evolutionary Dynamics ◽  
Adaptive Dynamics ◽  
Structured Populations ◽  
Ecological Feedbacks ◽  
Future Work ◽  
Practical Implications ◽  
Density Dependent Selection ◽  
Mutational Variance ◽  
Dynamics Of Populations ◽  
Adaptation Model

Our understanding of the evolution of quantitative traits in nature is still limited by the challenge of including realistic trait distributions in the context of frequency-dependent selection and ecological feedbacks. We develop a theoretical framework to analyse the dynamics of populations composed of several morphs and structured into distinct classes (e.g. age, size, habitats, infection status, species...). Our approach extends to class-structured populations a recently introduced "oligomorphic approximation" which bridges the gap between adaptive dynamics and quantitative genetics approaches and allows for the joint description of the dynamics of ecological variables and of the moments of multimodal trait distributions. We also introduce a new approximation to simplify the eco-evolutionary dynamics using reproductive values. This effectively extends Lande's univariate theorem not only to frequency- and density-dependent selection but also to multimodal trait distributions. We illustrate the effectiveness of this approach by applying it to the important conceptual case of two-habitat migration-selection models. In particular, we use our approach to predict the equilibrium trait distributions in a local adaptation model with asymmetric migration and habitat-specific mutational variance. We discuss the theoretical and practical implications of our results and sketch perspectives for future work.

scholarly journals Asymmetric competition causes multimodal size distributions in spatially structured populations

2016 ◽  
Vol 283 (1823) ◽  
pp. 20152404 ◽  
Author(s):  
Jorge Velázquez ◽  
Robert B. Allen ◽  
David A. Coomes ◽  
Markus P. Eichhorn
Keyword(s):  
Resource Competition ◽  
Structured Populations ◽  
Necessary Condition ◽  
Small Scale ◽  
Asymmetric Competition ◽  
Size Distributions ◽  
Long Term Study ◽  
Multimodal Distributions ◽  
Using Data

Plant sizes within populations often exhibit multimodal distributions, even when all individuals are the same age and have experienced identical conditions. To establish the causes of this, we created an individual-based model simulating the growth of trees in a spatially explicit framework, which was parametrized using data from a long-term study of forest stands in New Zealand. First, we demonstrate that asymmetric resource competition is a necessary condition for the formation of multimodal size distributions within cohorts. By contrast, the legacy of small-scale clustering during recruitment is transient and quickly overwhelmed by density-dependent mortality. Complex multi-layered size distributions are generated when established individuals are restricted in the spatial domain within which they can capture resources. The number of modes reveals the effective number of direct competitors, while the separation and spread of modes are influenced by distances among established individuals. Asymmetric competition within local neighbourhoods can therefore generate a range of complex size distributions within even-aged cohorts.

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