scholarly journals Relaxation of herbivore-mediated selection drives the evolution of genetic covariances between plant competitive and defense traits

Evolution ◽  
2017 ◽  
Vol 71 (6) ◽  
pp. 1700-1709 ◽  
Author(s):  
Akane Uesugi ◽  
Tim Connallon ◽  
André Kessler ◽  
Keyne Monro
Keyword(s):  
Genetic Covariances

scholarly journals Evolution and evolvability: celebrating Darwin 200

2008 ◽  
Vol 5 (1) ◽  
pp. 44-46 ◽  
Author(s):  
John F.Y Brookfield
Keyword(s):  
Genetic Variation ◽  
Natural Selection ◽  
Time Scales ◽  
Evolutionary Change ◽  
Adaptive Mutation ◽  
Genetic Covariances ◽  
The Relationship ◽  
The Way

The concept of ‘evolvability’ is increasingly coming to dominate considerations of evolutionary change. There are, however, a number of different interpretations that have been put on the idea of evolvability, differing in the time scales over which the concept is applied. For some, evolvability characterizes the potential for future adaptive mutation and evolution. Others use evolvability to capture the nature of genetic variation as it exists in populations, particularly in terms of the genetic covariances between traits. In the latter use of the term, the applicability of the idea of evolvability as a measure of population's capacity to respond to natural selection rests on one, but not the only, view of the way in which we should envisage the process of natural selection. Perhaps the most potentially confusing aspects of the concept of evolvability are seen in the relationship between evolvability and robustness.

scholarly journals Predicting evolutionary responses to selection on polyandry in the wild: additive genetic covariances with female extra-pair reproduction

2012 ◽  
Vol 279 (1747) ◽  
pp. 4652-4660 ◽  
Author(s):  
Jane M. Reid
Keyword(s):  
Additive Genetic Variance ◽  
Phenotypic Selection ◽  
Relative Fitness ◽  
Pedigree Data ◽  
Evolutionary Forces ◽  
Socially Monogamous ◽  
Credible Intervals ◽  
In The Wild ◽  
Variance Estimates ◽  
Genetic Covariances

The evolutionary forces that underlie polyandry, including extra-pair reproduction (EPR) by socially monogamous females, remain unclear. Selection on EPR and resulting evolution have rarely been explicitly estimated or predicted in wild populations, and evolutionary predictions are vulnerable to bias due to environmental covariances and correlated selection through unmeasured traits. However, evolutionary responses to (correlated) selection on any trait can be directly predicted as additive genetic covariances (cov A ) with appropriate components of relative fitness. I used comprehensive life-history, paternity and pedigree data from song sparrows ( Melospiza melodia ) to estimate cov A between a female's liability to produce extra-pair offspring and two specific fitness components: relative annual reproductive success (ARS) and survival to recruitment. All three traits showed non-zero additive genetic variance. Estimates of cov A were positive, predicting evolution towards increased EPR, but 95% credible intervals overlapped zero. There was therefore no conclusive prediction of evolutionary change in EPR due to (correlated) selection through female ARS or recruitment. Negative environmental covariance between EPR and ARS would have impeded evolutionary prediction from phenotypic selection differentials. These analyses demonstrate an explicit quantitative genetic approach to predicting evolutionary responses to components of (correlated) selection on EPR that should be unbiased by environmental covariances and unmeasured traits.

scholarly journals THE EVOLUTIONARY STABILITY OF CROSS-SEX, CROSS-TRAIT GENETIC COVARIANCES

Evolution ◽  
2014 ◽  
Vol 68 (6) ◽  
pp. 1687-1697 ◽  
Author(s):  
Thomas P. Gosden ◽  
Stephen F. Chenoweth
Keyword(s):  
Evolutionary Stability ◽  
Genetic Covariances

scholarly journals Directional selection rather than functional constraints can shape the G matrix in rapidly adapting asexuals

2018 ◽  
Author(s):  
Kevin Gomez ◽  
Jason Bertram ◽  
Joanna Masel
Keyword(s):  
Linkage Disequilibrium ◽  
Population Genetic ◽  
Genetic Variance ◽  
Genetic Models ◽  
Relative Fitness ◽  
Functional Constraints ◽  
Selective Sweeps ◽  
Genetic Covariance ◽  
Wave Models ◽  
Genetic Covariances

ABSTRACTGenetic covariances represent a combination of pleiotropy and linkage disequilibrium, shaped by the population’s history. Observed genetic covariance is most often interpreted in pleiotropic terms. In particular, functional constraints restricting which phenotypes are physically possible can lead to a stable G matrix with high genetic variance in fitness-associated traits and high pleiotropic negative covariance along the phenotypic curve of constraint. In contrast, population genetic models of relative fitness assume endless adaptation without constraint, through a series of selective sweeps that are well described by recent traveling wave models. We describe the implications of such population genetic models for the G matrix when pleiotropy is excluded by design, such that all covariance comes from linkage disequilibrium. The G matrix is far less stable than has previously been found, fluctuating over the timescale of selective sweeps. However, its orientation is relatively stable, corresponding to high genetic variance in fitness-associated traits and strong negative covariance - the same pattern often interpreted in terms of pleiotropic constraints but caused instead by linkage disequilibrium. We find that different mechanisms drive the instabilities along versus perpendicular to the fitness gradient. The origin of linkage disequilibrium is not drift, but small amounts of linkage disequilibrium are instead introduced by mutation and then amplified during competing selective sweeps. This illustrates the need to integrate a broader range of population genetic phenomena into quantitative genetics.

scholarly journals Analysis of genotype by environment interactions in a maize mapping population

2021 ◽  
Author(s):  
Asher I Hudson ◽  
Sarah G Odell ◽  
Pierre Dubreuil ◽  
Marie-Helene Tixier ◽  
Sebastien Praud ◽  
...  
Keyword(s):  
Genome Wide Association Study ◽  
Genetic Correlations ◽  
Genotype By Environment Interaction ◽  
Environment Interaction ◽  
Crop Breeding ◽  
Genotype By Environment Interactions ◽  
Genotype By Environment ◽  
Genome Wide ◽  
A Genome ◽  
Genetic Covariances

Genotype by environment interactions are a significant challenge for crop breeding as well as being important for understanding the genetic basis of environmental adaptation. In this study, we analyzed genotype by environment interaction in a maize multi-parent advanced generation intercross population grown across five environments. We found that genotype by environment interactions contributed as much as genotypic effects to the variation in some agronomically important traits. In order to understand how genetic correlations between traits change across environments, we estimated the genetic variance-covariance matrix in each environment. Changes in genetic covariances between traits across environments were common, even among traits that show low genotype by environment variance. We also performed a genome-wide association study to identify markers associated with genotype by environment interactions but found only a small number of significantly associated markers, possibly due to the highly polygenic nature of genotype by environment interactions in this population.

scholarly journals Evolvability and constraint in the primate basicranium, shoulder, and hip and the importance of multi-trait evolution

2021 ◽  
Author(s):  
Elizabeth R Agosto ◽  
Benjamin M Auerbach
Keyword(s):  
Vertebral Column ◽  
Quantitative Methods ◽  
Morphological Evolution ◽  
Evolutionary Relationship ◽  
Shoulder Girdle ◽  
Evolutionary Relationships ◽  
Trait Evolution ◽  
Functional Relationships ◽  
Genetic Covariances

The scapula shares developmental and functional relationships with traits of the basicranium, vertebral column, humerus, and clavicle. As a limb girdle, it also shares analogous characteristics with the pelvis. Despite these relationships, studies of primate shoulder evolution often focus on traits of the scapula in isolation. Such analyses may lead to spurious conclusions, as they implicitly model the scapula as evolving independent of other anatomical regions. Traits of the shoulder girdle share genetic covariances with each other, as well as potential covariances with dimensions of other skeletal elements. To create accurate models of shoulder evolution, it is imperative to account for the constraints imposed by these sources of covariance. Here, we use evolutionary quantitative methods to test a model in which shoulder morphological evolution is influenced by its developmental and functional covariances with the basicranium in the Colobus genus. This evolutionary relationship is also assessed with morphology of the pelvis to provide context to the evolutionary covariance among traits of the basicranium and shoulder girdle. Our results indicate potential evolutionary implications arising from covariances among the basicranium, shoulder, and pelvis. We further propose that the shoulder and basicranium may be examples of developmental, functional, and genetic covariances among traits that manifest an evolutionary suite of mutually constrained morphologies. We demonstrate novel evolutionary relationships among the shoulder girdle and basicranium that affect not only models of primate shoulder evolution but have broader implications for modeling trait evolution across the skeleton.

scholarly journals Genetic covariances promote climatic adaptation in Australian Drosophila *

Evolution ◽  
2019 ◽  
Vol 74 (2) ◽  
pp. 326-337 ◽  
Author(s):  
Sandra Hangartner ◽  
Clementine Lasne ◽  
Carla M. Sgrò ◽  
Tim Connallon ◽  
Keyne Monro
Keyword(s):  
Climatic Adaptation ◽  
Genetic Covariances

scholarly journals Cross‐sex genetic covariances limit the evolvability of wing‐shape within and among species of Drosophila

Evolution ◽  
2019 ◽  
Vol 73 (8) ◽  
pp. 1617-1633 ◽  
Author(s):  
Jacqueline L. Sztepanacz ◽  
David Houle
Keyword(s):  
Wing Shape ◽  
Genetic Covariances

scholarly journals Direct and maternal genetic covariances by age of dam for weaning weight.

1996 ◽  
Vol 74 (8) ◽  
pp. 1801 ◽  
Author(s):  
L D Van Vleck ◽  
K E Gregory ◽  
G L Bennett
Keyword(s):  
Weaning Weight ◽  
Genetic Covariances
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