scholarly journals Phenotypic Plasticity Promotes Balanced Polymorphism in Periodic Environments by a Genomic Storage Effect

Genetics ◽  
2016 ◽  
Vol 202 (4) ◽  
pp. 1437-1448 ◽  
Author(s):  
Davorka Gulisija ◽  
Yuseob Kim ◽  
Joshua B. Plotkin
Keyword(s):  
Phenotypic Plasticity ◽  
Storage Effect ◽  
Balanced Polymorphism ◽  
Periodic Environments

scholarly journals Phenotypic plasticity promotes balanced polymorphism in periodic environments by a genomic storage effect

2016 ◽  
Author(s):  
Davorka Gulisija ◽  
Yuseob Kim ◽  
Joshua B. Plotkin
Keyword(s):  
Phenotypic Plasticity ◽  
Large Range ◽  
Genetic Model ◽  
Effect Sizes ◽  
Storage Effect ◽  
Recombination Rates ◽  
Modifier Locus ◽  
Balanced Polymorphism ◽  
Analytical Approximations ◽  
Varying Environments

Phenotypic plasticity is known to evolve in perturbed habitats, where it alleviates the deleterious effects of selection. But the effects of plasticity on levels of genetic polymorphism, an important precursor to adaptation in temporally varying environments, are unclear. Here we develop a haploid, two-locus population-genetic model to describe the interplay between a plasticity modifier locus and a target locus subject to periodically varying selection. We find that the interplay between these two loci can produce a 'genomic storage effect' that promotes balanced polymorphism over a large range of parameters, in the absence of all other conditions known to maintain genetic variation. The genomic storage effect arises as recombination allows alleles at the two loci to escape more harmful genetic backgrounds and associate in haplotypes that persist until environmental conditions change. Using both Monte Carlo simulations and analytical approximations we quantify the strength of the genomic storage effect across a range of selection pressures, recombination rates, plasticity modifier effect sizes, and environmental periods.

scholarly journals Phenotypic plasticity promotes recombination and gene clustering in periodic environments

2017 ◽  
Author(s):  
Davorka Gulisija ◽  
Joshua B. Plotkin
Keyword(s):  
Phenotypic Plasticity ◽  
Natural Populations ◽  
Gene Clustering ◽  
Analytic Approximation ◽  
Red Queen Hypothesis ◽  
Modifier Locus ◽  
Balanced Polymorphism ◽  
Target Locus ◽  
Single Target ◽  
Host Parasite

While theory offers clear predictions for when recombination will evolve in changing environments, it is unclear what natural scenarios can generate the necessary conditions. The Red Queen hypothesis provides one such scenario in natural populations, but it requires interaction with antagonistic species such as host-parasite systems. We present a novel scenario for the evolution of recombination in finite populations: the genomic storage effect due to phenotypic plasticity. Using an analytic approximation and Monte Carlo simulations we demonstrate that balanced polymorphism and recombination evolve between a target locus that codes for a seasonally selected trait and a plasticity modifier locus that modulates the effects of target-locus alleles. Unlike in prior models, evolution of recombination by this plasticity effect does not require antagonistic inter-specific interactions or a steady influx of mutation, and it occurs even when a single target locus expresses a trait under selection. Furthermore, we show that selection will suppress the recombination rate among multiple polymorphic target loci, even in the absence of epistasis among them, which produces a cluster of linked loci under selection. These results provide a novel biological scenario for the evolution of recombination and supergenes.

The aquatic and littoral forms of the Patagonian frog Atelognathus patagonicus (Batrachylinae): new molecular evidence

Zootaxa ◽  
2011 ◽  
Vol 3129 (1) ◽  
pp. 62 ◽  
Author(s):  
LIZA B. MARTINAZZO ◽  
NÉSTOR G. BASSO ◽  
CARMEN A. ÚBEDA
Keyword(s):  
Phenotypic Plasticity ◽  
Genetic Variability ◽  
Genetic Differentiation ◽  
Control Region ◽  
National Park ◽  
Diversity Index ◽  
Morphological Data ◽  
Molecular Evidence ◽  
Balanced Polymorphism ◽  
And Control

Atelognathus patagonicus is one of the eight species included in the Patagonian genus Atelognathus, an endemic frog occurring in the system of endorheic basaltic lagoons of the Laguna Blanca National Park (PNLB), Neuquén, Argentina. Based on morphological data, Cei & Roig (1968) described two forms of A. patagonicus, which they called “aquatic” and “littoral”. These morphotypes were first suggested to belong to different species, but later, Cei (1972) proposed that both forms represent a balanced polymorphism within A. patagonicus. More recently, an ecomorphological study showed that aquatic and littoral are reversible forms of the same individual (phenotypic plasticity). In this paper we compare the morphotypes of A. patagonicus using nucleotide sequences of the mtDNA (cytochrome b and control region) in order to test the existence of genetic differentiation between the aquatic and littoral forms. In addition, we present data of genetic variability of A. patagonicus from the Laguna Blanca system. We did not detect genetic differentiation between littoral and aquatic morphotypes for both genes studied. This observation is consistent with the hypothesis of phenotypic plasticity. In contrast with the expected results for low vagility organisms, the diversity index observed in A. patagonicus revealed a low genetic variability.

scholarly journals Phenotypic plasticity promotes recombination and gene clustering in periodic environments

2017 ◽  
Author(s):  
Davorka Gulisija ◽  
Joshua B. Plotkin
Keyword(s):  
Phenotypic Plasticity ◽  
Natural Populations ◽  
Gene Clustering ◽  
Analytic Approximation ◽  
Red Queen Hypothesis ◽  
Modifier Locus ◽  
Balanced Polymorphism ◽  
Target Locus ◽  
Single Target ◽  
Host Parasite

While theory offers clear predictions for when recombination will evolve in changing environments, it is unclear what natural scenarios can generate the necessary conditions. The Red Queen hypothesis provides one such scenario in natural populations, but it requires interaction with antagonistic species such as host-parasite systems. We present a novel scenario for the evolution of recombination in finite populations: the genomic storage effect due to phenotypic plasticity. Using an analytic approximation and Monte Carlo simulations we demonstrate that balanced polymorphism and recombination evolve between a target locus that codes for a seasonally selected trait and a plasticity modifier locus that modulates the effects of target-locus alleles. Unlike in prior models, evolution of recombination by this plasticity effect does not require antagonistic inter-specific interactions or a steady influx of mutation, and it occurs even when a single target locus expresses a trait under selection. Furthermore, we show that selection will suppress the recombination rate among multiple polymorphic target loci, even in the absence of epistasis among them, which produces a cluster of linked loci under selection. These results provide a novel biological scenario for the evolution of recombination and supergenes.

Ecology and biogeography in the introduction to “De bestiis marinis” by Georg Wilhelm Steller

2019 ◽  
Vol 46 (1) ◽  
pp. 63-74
Author(s):  
Stefano Mattioli
Keyword(s):  
Body Size ◽  
Phenotypic Plasticity ◽  
Geographical Distribution ◽  
Functional Traits ◽  
Marine Mammals ◽  
Main Part ◽  
Wide Distribution ◽  
Restricted Range ◽  
Direct Influence ◽  
Modern Biology

The rediscovery of the original, unedited Latin manuscript of Georg Wilhelm Steller's “De bestiis marinis” (“On marine mammals”), first published in 1751, calls for a new translation into English. The main part of the treatise contains detailed descriptions of four marine mammals, but the introduction is devoted to more general issues, including innovative speculation on morphology, ecology and biogeography, anticipating arguments and concepts of modern biology. Steller noted early that climate and food have a direct influence on body size, pelage and functional traits of mammals, potentially affecting reversible changes (phenotypic plasticity). Feeding and other behavioural habits have an impact on the geographical distribution of mammals. Species with a broad diet tend to have a wide distribution, whereas animals with a narrow diet more likely have only a restricted range. According to Steller, both sea and land then still concealed countless animals unknown to science.

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