scholarly journals Negative frequency-dependent selection maintains coexisting genotypes during fluctuating selection

2019 ◽  
Author(s):  
Caroline B. Turner ◽  
Sean W. Buskirk ◽  
Katrina B. Harris ◽  
Vaughn S. Cooper
Keyword(s):  
Evolutionary Dynamics ◽  
Burkholderia Cenocepacia ◽  
Natural Environments ◽  
Fluctuating Selection ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Fluctuating Environment ◽  
Fluctuating Environments ◽  
Negative Frequency Dependent Selection ◽  
Selection For

AbstractNatural environments are rarely static; rather selection can fluctuate on time scales ranging from hours to centuries. However, it is unclear how adaptation to fluctuating environments differs from adaptation to constant environments at the genetic level. For bacteria, one key axis of environmental variation is selection for planktonic or biofilm modes of growth. We conducted an evolution experiment with Burkholderia cenocepacia, comparing the evolutionary dynamics of populations evolving under constant selection for either biofilm formation or planktonic growth with populations in which selection fluctuated between the two environments on a weekly basis. Populations evolved in the fluctuating environment shared many of the same genetic targets of selection as those evolved in constant biofilm selection, but were genetically distinct from the constant planktonic populations. In the fluctuating environment, mutations in the biofilm-regulating genes wspA and rpfR rose to high frequency in all replicate populations. A mutation in wspA first rose rapidly and nearly fixed during the initial biofilm phase but was subsequently displaced by a collection of rpfR mutants upon the shift to the planktonic phase. The wspA and rpfR genotypes coexisted via negative frequency-dependent selection around an equilibrium frequency that shifted between the environments. The maintenance of coexisting genotypes in the fluctuating environment was unexpected. Under temporally fluctuating environments coexistence of two genotypes is only predicted under a narrow range of conditions, but the frequency-dependent interactions we observed provide a mechanism that can increase the likelihood of coexistence in fluctuating environments.

scholarly journals Negative frequency‐dependent selection maintains coexisting genotypes during fluctuating selection

2019 ◽  
Vol 29 (1) ◽  
pp. 138-148 ◽  
Author(s):  
Caroline B. Turner ◽  
Sean W. Buskirk ◽  
Katrina B. Harris ◽  
Vaughn S. Cooper
Keyword(s):  
Fluctuating Selection ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Negative Frequency Dependent Selection

scholarly journals A geographic cline induced by negative frequency-dependent selection

2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuma Takahashi ◽  
Satoru Morita ◽  
Jin Yoshimura ◽  
Mamoru Watanabe
Keyword(s):  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Negative Frequency Dependent Selection

scholarly journals Intruder colour and light environment jointly determine how nesting male stickleback respond to simulated territorial intrusions

2016 ◽  
Vol 12 (8) ◽  
pp. 20160467 ◽  
Author(s):  
Daniel I. Bolnick ◽  
Kimberly Hendrix ◽  
Lyndon Alexander Jordan ◽  
Thor Veen ◽  
Chad D. Brock
Keyword(s):  
Frequency Dependence ◽  
Three Dimensional ◽  
Light Environment ◽  
Depth Gradient ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Negative Frequency Dependent Selection ◽  
Colour Signals

Variation in male nuptial colour signals might be maintained by negative frequency-dependent selection. This can occur if males are more aggressive towards rivals with locally common colour phenotypes. To test this hypothesis, we introduced red or melanic three-dimensional printed-model males into the territories of nesting male stickleback from two optically distinct lakes with different coloured residents. Red-throated models were attacked more in the population with red males, while melanic models were attacked more in the melanic male lake. Aggression against red versus melanic models also varied across a depth gradient within each lake, implying that the local light environment also modulated the strength of negative frequency dependence acting on male nuptial colour.

scholarly journals Evolutionary dynamics of phage resistance in bacterial biofilms

2019 ◽  
Author(s):  
Matthew Simmons ◽  
Matthew C. Bond ◽  
Knut Drescher ◽  
Vanni Bucci ◽  
Carey D. Nadell
Keyword(s):  
Evolutionary Dynamics ◽  
Physiological State ◽  
Computational Simulation ◽  
Phage Infection ◽  
Resistant Bacteria ◽  
Phage Resistance ◽  
Natural Environments ◽  
Biofilm Growth ◽  
Single Strain ◽  
Negative Frequency Dependent Selection

AbstractInteractions among bacteria and their viral predators, the bacteriophages, are likely among the most common ecological phenomena on Earth. The constant threat of phage infection to bacterial hosts, and the imperative of achieving infection on the part of phages, drives an evolutionary contest in which phage-resistant bacteria emerge, often followed by phages with new routes of infection. This process has received abundant theoretical and experimental attention for decades and forms an important basis for molecular genetics and theoretical ecology and evolution. However, at present, we know very little about the nature of phage-bacteria interaction – and the evolution of phage resistance – inside the surface-bound communities that microbes usually occupy in natural environments. These communities, termed biofilms, are encased in a matrix of secreted polymers produced by their microbial residents. Biofilms are spatially constrained such that interactions become limited to neighbors or near-neighbors; diffusion of solutes and particulates is reduced; and there is pronounced heterogeneity in nutrient access and therefore physiological state. These factors can dramatically impact the way phage infections proceed even in simple, single-strain biofilms, but we still know little of their effect on phage resistance evolutionary dynamics. Here we explore this problem using a computational simulation framework customized for implementing phage infection inside multi-strain biofilms. Our simulations predict that it is far easier for phage-susceptible and phage-resistant bacteria to coexist inside biofilms relative to planktonic culture, where phages and hosts are well-mixed. We characterize the negative frequency dependent selection that underlies this coexistence, and we then test and confirm this prediction using an experimental model of biofilm growth measured with confocal microscopy at single-cell and single-phage resolution.

scholarly journals Negative frequency dependent selection contributes to the maintenance of a global polymorphism in mitochondrial DNA

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Zorana Kurbalija Novičić ◽  
Ahmed Sayadi ◽  
Mihailo Jelić ◽  
Göran Arnqvist
Keyword(s):  
Mitochondrial Dna ◽  
Genetic Variation ◽  
Life History ◽  
Balancing Selection ◽  
Food Resource ◽  
Ecological Processes ◽  
Central Process ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Negative Frequency Dependent Selection

Abstract Background Understanding the forces that maintain diversity across a range of scales is at the very heart of biology. Frequency-dependent processes are generally recognized as the most central process for the maintenance of ecological diversity. The same is, however, not generally true for genetic diversity. Negative frequency dependent selection, where rare genotypes have an advantage, is often regarded as a relatively weak force in maintaining genetic variation in life history traits because recombination disassociates alleles across many genes. Yet, many regions of the genome show low rates of recombination and genetic variation in such regions (i.e., supergenes) may in theory be upheld by frequency dependent selection. Results We studied what is essentially a ubiquitous life history supergene (i.e., mitochondrial DNA) in the fruit fly Drosophila subobscura, showing sympatric polymorphism with two main mtDNA genotypes co-occurring in populations world-wide. Using an experimental evolution approach involving manipulations of genotype starting frequencies, we show that negative frequency dependent selection indeed acts to maintain genetic variation in this region. Moreover, the strength of selection was affected by food resource conditions. Conclusions Our work provides novel experimental support for the view that balancing selection through negative frequency dependency acts to maintain genetic variation in life history genes. We suggest that the emergence of negative frequency dependent selection on mtDNA is symptomatic of the fundamental link between ecological processes related to resource use and the maintenance of genetic variation.

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