scholarly journals Evolution of diversity in metabolic strategies

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Rodrigo Caetano ◽  
Yaroslav Ispolatov ◽  
Michael Doebeli

Understanding the origin and maintenance of biodiversity is a fundamental problem. Many theoretical approaches have been investigating ecological interactions, such as competition, as potential drivers of diversification. Classical consumer-resource models predict that the number of coexisting species should not exceed the number of distinct resources, a phenomenon known as the competitive exclusion principle. It has recently been argued that including physiological tradeoffs in consumer-resource models can lead to violations of this principle and to ecological coexistence of very high numbers of species. Here we show that these results crucially depend on the functional form of the tradeoff. We investigate the evolutionary dynamics of resource use constrained by tradeoffs and show that if the tradeoffs are non-linear, the system either does not diversify, or diversifies into a number of coexisting species that does not exceed the number of resources. In particular, very high diversity can only be observed for linear tradeoffs.

2020 ◽  
Author(s):  
R. A. Caetano ◽  
Y. Ispolatov ◽  
M. Doebeli

Understanding the origin and maintenance of biodiversity is a fundamental problem. Many theoretical approaches have been investigating ecological interactions, such as competition, as potential drivers of diversification. Classical consumer-resource models predict that the number of coexisting species should not exceed the number of distinct resources, a phenomenon known as the competitive exclusion principle. It has recently been argued that including physiological tradeoffs in consumer-resource models can lead to violations of this principle and to ecological coexistence of very high numbers of species. Here we show that these results crucially depend on the functional form of the tradeoff. We investigate the evolutionary dynamics of resource use constrained by tradeoffs and show that if the tradeoffs are non-linear, the system either does not diversify, or diversifies into a number of coexisting species that does not exceed the number of resources. In particular, very high diversity can only be observed for linear tradeoffs.


2018 ◽  
Author(s):  
Xin Wang ◽  
Yang-Yu Liu

AbstractExplaining biodiversity in nature is a fundamental problem in ecology. One great challenge is embodied in the so-called competitive exclusion principle1-4: the number of species in steady coexistence cannot exceed the number of resources4-7. In the past five decades, various mechanisms have been proposed to overcome the limit on diversity set by the competitive exclusion principle8-25. Yet, none of the existing mechanisms can generically overcome competitive exclusion at steady state4,26. Here we show that by forming chasing triplets in the predation process among the consumers and resources, the number of coexisting species of consumers can exceed that of resources at steady state, naturally breaking the competitive exclusion principle. Our model can be broadly applicable to explain the biodiversity of many consumer-resource ecosystems and deepen our understanding of biodiversity in nature.


2019 ◽  
Author(s):  
Wenping Cui ◽  
Robert Marsland ◽  
Pankaj Mehta

The competitive exclusion principle asserts that coexisting species must occupy distinct ecological niches (i.e. the number of surviving species can not exceed the number of resources). An open question is to understand if and how different resource dynamics affect this bound. Here, we analyze a generalized consumer resource model with externally supplied resources and show that – in contrast to self-renewing resources – species can occupy only half of all available environmental niches. This motivates us to construct a new schema for classifying ecosystems based on species packing properties.


2018 ◽  
Author(s):  
Leonardo Pacciani-Mori ◽  
Andrea Giometto ◽  
Samir Suweis ◽  
Amos Maritan

AbstractBacteria are able to adapt to different environments by changing their “metabolic strategies”, i.e. the ways in which they uptake available resources from the environment. For example, in a celebrated experiment Jacques Monod showed that bacteria cultured in media containing two different sugars consume them sequentially, resulting in bi-phasic growth curves called “diauxic shifts”. From the theoretical point of view, microbial communities are commonly described using MacArthur’s consumer-resource model, which describes the population dynamics of species competing for a given set of resources. In this model, however, metabolic strategies are treated as constant parameters. Here, we introduce adaptive metabolic strategies in the framework of consumer-resource models, allowing the strategies to evolve to maximize each species’ relative fitness. By doing so, we are able to describe quantitatively, and without invoking any specific molecular mechanisms for the metabolism of the microbial species, growth curves of the baker’s yeastSaccharomyces cerevisiaemeasured in a controlled experimental set-up, with galactose as the primary carbon source. We also show that metabolic adaptation enables the community to self-organize, allowing species to coexist even in the presence of few resources, and to respond optimally to a time-dependent environment. A connection between the Competitive Exclusion Principle and the metabolic theory of ecology is also discussed.


2017 ◽  
Vol 89 (10) ◽  
pp. 1429-1448 ◽  
Author(s):  
Mikhail A. Vorotyntsev ◽  
Anatoly E. Antipov ◽  
Dmıtry V. Konev

Abstract Recent theoretical studies of the bromate electroreduction from strongly acidic solution have been overviewed in view of very high redox-charge and energy densities of this process making it attractive for electric energy sources. Keeping in mind non-electroactivity of the bromate ion the possibility to ensure its rapid transformation via a redox-mediator cycle (EC′ mechanism) is analyzed. Alternative route via the bromine/bromide redox couple and the comproportionation reaction inside the solution phase is considered within the framework of several theoretical approaches based on the conventional Nernst layer model, or on its recently proposed advanced version (Generalized Nernst layer model), on the convective diffusion transport equations. This analysis has revealed that this process corresponds to a novel (EC″) electrochemical mechanism since the transformation of the principal oxidant (bromate) is carried out via autocatalytic redox cycle where the bromate consumption leads to progressive accumulation of the bromine/bromide redox couple catalyzing the process. As a result, even a tracer amount of its component, bromine, in the bulk solution leads under certain conditions to extremely high current densities which may even overcome the diffusion-limited one for bromate, i.e. be well over 1 A/cm2 for concentrated bromate solutions. This analysis allows one to expect that the hydrogen–bromate flow battery may generate very high values of both the current density and specific electric power, over 1 A/cm2 and 1 W/cm2.


2019 ◽  
Vol 47 (1) ◽  
pp. 105-123
Author(s):  
James Justus ◽  

Perhaps no concept has been thought more important to ecological theorizing than the niche. Without it, technically sophisticated and well-regarded accounts of character displacement, ecological equivalence, limiting similarity, and others would seemingly never have been developed. The niche is also widely considered the centerpiece of the best candidate for a distinctively ecological law, the competitive exclusion principle. But the incongruous array and imprecise character of proposed definitions of the concept square poorly with its apparent scientific centrality. I argue this definitional diversity and imprecision reflects a problematic conceptual indeterminacy that challenges its putative indispensability in ecology.


Sign in / Sign up

Export Citation Format

Share Document