Phenotypic variability can promote the evolution of adaptive plasticity by reducing the stringency of natural selection

2019 ◽  
Vol 32 (11) ◽  
pp. 1274-1289 ◽  
Author(s):  
Jeremy Draghi
Keyword(s):  
Natural Selection ◽  
Phenotypic Variability ◽  
Adaptive Plasticity

scholarly journals Biased movement drives local cryptic coloration on distinct urban pavements

2019 ◽  
Vol 286 (1912) ◽  
pp. 20191343 ◽  
Author(s):  
Pim Edelaar ◽  
Adrian Baños-Villalba ◽  
David P. Quevedo ◽  
Graciela Escudero ◽  
Daniel I. Bolnick ◽  
...  
Keyword(s):  
Natural Selection ◽  
Habitat Choice ◽  
Mortality Rates ◽  
Urban Environments ◽  
Adaptive Plasticity ◽  
Relative Importance ◽  
Divergent Natural Selection ◽  
Cryptic Coloration ◽  
Selective Agents ◽  
General Studies

Explanations of how organisms might adapt to urban environments have mostly focused on divergent natural selection and adaptive plasticity. However, differential habitat choice has been suggested as an alternative. Here, we test for habitat choice in enhancing crypsis in ground-perching grasshoppers colonizing an urbanized environment, composed of a mosaic of four distinctly coloured substrates (asphalt roads and adjacent pavements). Additionally, we determine its relative importance compared to present-day natural selection and phenotypic plasticity. We found that grasshoppers are very mobile, but nevertheless approximately match the colour of their local substrate. By manipulating grasshopper colour, we confirm that grasshoppers increase the usage of those urban substrates that resemble their own colours. This selective movement actively improves crypsis. Colour divergence between grasshoppers on different substrates is not or hardly owing to present-day natural selection, because observed mortality rates are too low to counteract random substrate use. Additional experiments also show negligible contributions from plasticity in colour. Our results confirm that matching habitat choice can be an important driver of adaptation to urban environments. In general, studies should more fully incorporate that individuals are not only selective targets (i.e. selected on by the environment), but also selective agents (i.e. selecting their own environments).

scholarly journals Plasticity of plant defense and its evolutionary implications in wild populations of Boechera stricta

2017 ◽  
Author(s):  
Maggie R. Wagner ◽  
Thomas Mitchell-Olds
Keyword(s):  
Natural Selection ◽  
Environmental Gradient ◽  
Natural Populations ◽  
Reaction Norm ◽  
Relative Fitness ◽  
Adaptive Plasticity ◽  
Common Gardens ◽  
Evolutionary Trajectories ◽  
Boechera Stricta ◽  
New Habitats

AbstractPhenotypic plasticity is thought to impact evolutionary trajectories by shifting trait values in a direction that is either favored by natural selection (“adaptive plasticity”) or disfavored (“nonadaptive” plasticity). However, it is unclear how commonly each of these types of plasticity occurs in natural populations. To answer this question, we measured glucosinolate defensive chemistry and reproductive fitness in over 1,500 individuals of the wild perennial mustard Boechera stricta, planted in four common gardens across central Idaho, USA. Glucosinolate profiles—including total glucosinolate quantity as well as the relative abundances and overall diversity of different compounds—were strongly plastic both among habitats and within habitats. Patterns of glucosinolate plasticity varied greatly among genotypes. More often than expected by chance, glucosinolate profiles shifted in a direction that matched the direction of natural selection, indicating that plasticity among habitats tended to increase relative fitness. In contrast, we found no evidence for within-habitat selection on glucosinolate reaction norm slopes (i.e., plasticity along a continuous environmental gradient). Together, our results indicate that glucosinolate plasticity may improve the ability of B. stricta populations to persist after migration to new habitats.

scholarly journals How adaptive plasticity evolves when selected against

2018 ◽  
Author(s):  
Alfredo Rago ◽  
Kostas Kouvaris ◽  
Tobias Uller ◽  
Richard Watson
Keyword(s):  
Natural Selection ◽  
Environmental Change ◽  
Coarse Grained ◽  
Adaptive Plasticity ◽  
Short Term ◽  
Local Optima ◽  
Term Selection ◽  
Selection For ◽  
The Individual

AbstractAdaptive plasticity allows organisms to cope with environmental change, thereby increasing the population’s long-term fitness. However, individual selection can only compare the fitness of individuals within each generation: if the environment changes more slowly than the generation time (i.e., a coarse-grained environment) a population will not experience selection for plasticity even if it is adaptive in the long-term. How does adaptive plasticity then evolve? One explanation is that, if competing alleles conferring different degrees of plasticity persist across multiple environments, natural selection between lineages carrying those alleles could select for adaptive plasticity (lineage selection).We show that adaptive plasticity can evolve even in the absence of such lineage selection. Instead, we propose that adaptive plasticity in coarse-grained environments evolves as a by-product of inefficient short-term natural selection. In our simulations, populations that can efficiently respond to selective pressures follow short-term, local, optima and have lower long-term fitness. Conversely, populations that accumulate limited genetic change within each environment evolve long-term adaptive plasticity even when plasticity incurs short-term costs. These results remain qualitatively similar regardless of whether we decrease the efficiency of natural selection by increasing the rate of environmental change or decreasing mutation rate, demonstrating that both factors act via the same mechanism. We demonstrate how this mechanism can be understood through the concept of learning rate.Our work shows how plastic responses that are costly in the short term, yet adaptive in the long term, can evolve as a by-product of inefficient short-term selection, without selection for plasticity at either the individual or lineage level.

The effect of the environment on phenotypic variability

1958 ◽  
Vol 149 (935) ◽  
pp. 192-203 ◽  
Keyword(s):  
Body Weight ◽  
Natural Selection ◽  
Phenotypic Variation ◽  
Selective Breeding ◽  
Environmental Influence ◽  
Phenotypic Variability ◽  
Biometrical Genetics ◽  
Hot Environment

Mice were raised from birth to 4 weeks of age in three climatic chambers maintained at temperatures of 28 °C (‘hot’), 21 °C (‘temperate’) and 5 °C (‘cold’). Their individual weights were recorded at weeks 1, 2, 3 and 4, and analyzed for the sexes separately. Our object was to test the hypothesis of ‘environmental destabilization’, according to which the mice raised in the extreme climates would be expected to be more variable than those raised in the temperate conditions to which the species has been adapted by natural selection. In overall variability the mice raised in the extreme climates greatly exceeded the temperate level. This was partly due to an exacerbation, particularly in the cold, of the normal tendency for body weight to vary inversely with the number of mice in the litter. But it was in part due to an increase of variability among litter-mates: this effect, which we take to be a genuine example of ‘destabilization’, was more pronounced in the hot environment than in the cold. Members of large litters varied more among themselves than members of small litters. All the effects described above were, in general, more pronounced in the female than in the male The possibility, suggested by this work, that phenotypic variation may be affected by the level of a uniformly acting environmental influence during development has implications for biometrical genetics, selective breeding and evolution.

scholarly journals Hypothesis of the conjunct expression gene: can random mutation explain the phenotypic variability?

2018 ◽  
Author(s):  
Víctor A Zapata Trejo
Keyword(s):  
Gene Expression ◽  
Natural Selection ◽  
Functional Role ◽  
Germ Line ◽  
Phenotypic Variability ◽  
Point Of View ◽  
Random Mutation ◽  
Undifferentiated Cells ◽  
Gene Expression Levels

If the environmental conditions can or not influence in the phenotype evolution, is a topic that has been discussed during the last ten years. The epigenome regulates the gene expression of all cells and indicates which specific genes must be transcribed. It is argued that the expression factors that act in specific genes of the somatic cells involved in a behavior also act in the partial transcription of the same genes in the most undifferentiated cells of the germ line. The functional role of the isochores as an epigenetic determinant regulator of the transcription and therefore of gene expression levels is discussed. It is proposed how a probabilistic view of the random mutation can integrate all the evidence pointing to a conjunct phenotype evolution with the environment. This work provides a new point of view on how the environment can influence in adaptation through natural selection considering the theory currently accepted.

scholarly journals How can we estimate natural selection on endocrine traits? Lessons from evolutionary biology

2016 ◽  
Vol 283 (1843) ◽  
pp. 20161887 ◽  
Author(s):  
Frances Bonier ◽  
Paul R. Martin
Keyword(s):  
Life History ◽  
Natural Selection ◽  
Recent Work ◽  
Environmental Conditions ◽  
Evolutionary Biology ◽  
Endocrine System ◽  
Adaptive Plasticity ◽  
Evolutionary Perspective ◽  
System Evolution ◽  
Fitness Consequences

An evolutionary perspective can enrich almost any endeavour in biology, providing a deeper understanding of the variation we see in nature. To this end, evolutionary endocrinologists seek to describe the fitness consequences of variation in endocrine traits. Much of the recent work in our field, however, follows a flawed approach to the study of how selection shapes endocrine traits. Briefly, this approach relies on among-individual correlations between endocrine phenotypes (often circulating hormone levels) and fitness metrics to estimate selection on those endocrine traits. Adaptive plasticity in both endocrine and fitness-related traits can drive these correlations, generating patterns that do not accurately reflect natural selection. We illustrate why this approach to studying selection on endocrine traits is problematic, referring to work from evolutionary biologists who, decades ago, described this problem as it relates to a variety of other plastic traits. We extend these arguments to evolutionary endocrinology, where the likelihood that this flaw generates bias in estimates of selection is unusually high due to the exceptional responsiveness of hormones to environmental conditions, and their function to induce adaptive life-history responses to environmental variation. We end with a review of productive approaches for investigating the fitness consequences of variation in endocrine traits that we expect will generate exciting advances in our understanding of endocrine system evolution.

scholarly journals Evidence for variations in the morphometric traits between two sibling species of Drosophila: D. ananassae and D. pallidosa

Genetika ◽  
2017 ◽  
Vol 49 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Roshni Singh ◽  
Bashisth Singh
Keyword(s):  
Natural Selection ◽  
Sibling Species ◽  
Wing Length ◽  
Phenotypic Variability ◽  
Strain Differences ◽  
Phenotypic Traits ◽  
Morphometric Traits ◽  
Thorax Length ◽  
Interspecific Variations ◽  
Ovariole Number

Darwinian theory of evolution states that, evolution occurs through the natural selection. Therefore, demonstration of natural selection in nature is the central aim of many evolutionary studies and selection acts primarily at the phenotypic level because it is well known that phenotypic traits are the primary target of natural selection. While keeping this in view, we have studied certain morphometric traits in the sibling species pair, D. ananassae and D. pallidosa to test intra- and interspecific variations. The traits studied are wing length, thorax length, ratio of wing length and thorax length, sternopleural bristle number, ovariole number and sex-comb tooth number. In females of D. ananassae, significant strain differences were found for all the traits except ovariole number. In males, significant strain differences were found for all the traits. On the other hand, in D. pallidosa, significant strain differences were found for all the traits in both, males and females. The values of all the morphometric traits were significantly higher in females of both the species in comparison to males. The values of all the morphometric traits were higher in D. ananassae. However, the phenotypic variability, expressed in terms of coefficient of variation, was higher in D. pallidosa. Except for ratio of wing length and thorax length, CV was higher in the case of females in comparison to males. Size related traits are least variable while bristle numbers and reproductive traits are most variable. Except few, most of the traits are positively correlated with each other in both the species. Intra- and interspecific variations were found with respect to different morphometric traits. Although sibling species have been defined as morphologically identical, our results show that sibling species may show variations in certain morphometric traits and these quantitative differences in the morphometric traits act as discriminant marker between these sibling species in the lack of any qualitative differences.

scholarly journals Hypothesis of the conjunct expression gene: can random mutation explain the phenotypic variability?

2018 ◽  
Author(s):  
Víctor A Zapata Trejo
Keyword(s):  
Gene Expression ◽  
Natural Selection ◽  
Functional Role ◽  
Germ Line ◽  
Phenotypic Variability ◽  
Point Of View ◽  
Random Mutation ◽  
Undifferentiated Cells ◽  
Gene Expression Levels

If the environmental conditions can or not influence in the phenotype evolution, is a topic that has been discussed during the last ten years. The epigenome regulates the gene expression of all cells and indicates which specific genes must be transcribed. It is argued that the expression factors that act in specific genes of the somatic cells involved in a behavior also act in the partial transcription of the same genes in the most undifferentiated cells of the germ line. The functional role of the isochores as an epigenetic determinant regulator of the transcription and therefore of gene expression levels is discussed. It is proposed how a probabilistic view of the random mutation can integrate all the evidence pointing to a conjunct phenotype evolution with the environment. This work provides a new point of view on how the environment can influence in adaptation through natural selection considering the theory currently accepted.

scholarly journals Hypothesis of the conjunct expression gene: can random mutation explain the phenotypic variability?

2018 ◽  
Author(s):  
Víctor A Zapata Trejo
Keyword(s):  
Gene Expression ◽  
Natural Selection ◽  
Functional Role ◽  
Germ Line ◽  
Phenotypic Variability ◽  
Point Of View ◽  
Random Mutation ◽  
Undifferentiated Cells ◽  
Gene Expression Levels

If the environmental conditions can or not influence in the phenotype evolution, is a topic that has been discussed during the last ten years. The epigenome regulates the gene expression of all cells and indicates which specific genes must be transcribed. It is argued that the expression factors that act in specific genes of the somatic cells involved in a behavior also act in the partial transcription of the same genes in the most undifferentiated cells of the germ line. The functional role of the isochores as an epigenetic determinant regulator of the transcription and therefore of gene expression levels is discussed. It is proposed how a probabilistic view of the random mutation can integrate all the evidence pointing to a conjunct phenotype evolution with the environment. This work provides a new point of view on how the environment can influence in adaptation through natural selection considering the theory currently accepted.

Temporary deleterious mass mutations relate to originations of cockroach families

Biologia ◽  
2017 ◽  
Vol 72 (8) ◽  
Author(s):  
Peter Vršanský ◽  
Róbert Oružinský ◽  
Danil Aristov ◽  
Dan-Dan Wei ◽  
Ľubomír Vidlička ◽  
...  
Keyword(s):  
Natural Selection ◽  
Genetic Drift ◽  
Fossil Record ◽  
Phenotypic Variability ◽  
Yixian Formation ◽  
Evidence Based ◽  
Insect Wing ◽  
Species Evolution

AbstractHeritably transferred genome mutations extending phenotypic variability together with natural selection (alternatively with genetic drift, draft, stability, and passive selections) are the main conditions of species evolution. Intervals with high rates of detrimental mutations are virtually absent from the fossil record due to the difficulty of identifying them. Our evidence, based on living populations indicate that insect wing deformities represent heritable hypomorphic mutations that are similar to those observed in Chernobyl and Fukushima. Newly collected assemblages from two of the major diversification intervals, the Cretaceous (J/K or K1) Yixian Formation in China and Permian/Triassic (P/T) Poldars Formation in Russia, exhibit cockroach wing deformity rates of 27% and 42.5% (

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