Eco-Evolutionary Feedbacks and the Maintenance of Metacommunity Diversity in a Changing Environment.

Aidan P Fielding,Jelena H Pantel

doi:10.3390/genes11121433

Aidan P Fielding, Jelena H Pantel

Open Access

https://doi.org/10.3390/genes11121433

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Abstract

The presence and strength of resource competition can influence how organisms adaptively respond to environmental change. Selection may thus reflect a balance between two forces, adaptation to an environmental optimum and evolution to avoid strong competition. While this phenomenon has previously been explored in the context of single communities, its implications for eco-evolutionary dynamics at the metacommunity scale are largely unknown. We developed a simulation model for the evolution of a quantitative trait that influences both an organism’s carrying capacity and its intra- and interspecific competitive ability. In the model, multiple species inhabit a three-patch landscape, and we investigated the effect of varying the connectivity level among patches, the presence and pace of directional environmental change, and the strength of competition between the species. Our model produced some patterns previously observed in evolving metacommunity models, such as species sorting and community monopolization. However, we found that species sorting was diminished even at low rates of dispersal and was influenced by competition strength, and that monopolization was observed only when environmental change was very rapid. We also detected an eco-evolutionary feedback loop between local phenotypic evolution at one site and competition at another site, which maintains species diversity in some conditions. The existence of a feedback loop maintained by dispersal indicates that eco-evolutionary dynamics in communities operate at a landscape scale.

Highlights

Competition for resources is a critical component structuring biodiversity in nature [1,2].Many ecological theories developed to understand competition, coexistence, and biodiversity treat the traits that influence species interactions as fixed (e.g. [3])
Our model is a stochastic simulation of an adaptive dynamics model [35,36], which has been shown in some conditions to exhibit evolutionary branching
Evolutionary dynamics and consequent species composition in our model are determined by the position of both symmetric functions α(x) and K(x) on the resource optimum xopt, and the shape of the functional form for α(x)

Summary

Introduction

Competition for resources is a critical component structuring biodiversity in nature [1,2].Many ecological theories developed to understand competition, coexistence, and biodiversity treat the traits that influence species interactions as fixed (e.g. [3]). Recent experimental studies have demonstrated, that critical parameters, such as the interaction strength of competitors (α) and the minimum resource level required for positive growth (R*), can evolve on an ecological time scale [4,5]. Studies have demonstrated that ecological competition can either inhibit or enhance evolutionary diversification and speciation, and can play an important role for understanding biodiversity over macroevolutionary time scales [6,7,8]. It is important that theory is developed to predict how coexistence and consequent biodiversity are affected when traits influencing ecological competition can evolve [9,10]. This is especially important as anthropogenic climate change increases existing or introduces novel selection pressures [11]

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