ORCID Profile
0000-0002-5045-2051
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In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Publisher: Wiley
Date: 18-03-2010
DOI: 10.1111/J.1558-5646.2010.00991.X
Abstract: Phenotypic plasticity is an important mechanism via which populations can respond to changing environmental conditions, but we know very little about how natural populations vary with respect to plasticity. Here we use random-regression animal models to understand the multivariate phenotypic and genetic patterns of plasticity variation in two key life-history traits, laying date and clutch size, using data from long-term studies of great tits in The Netherlands (Hoge Veluwe [HV]) and UK (Wytham Woods [WW]). We show that, while population-level responses of laying date and clutch size to temperature were similar in the two populations, between-in idual variation in plasticity differed markedly. Both populations showed significant variation in phenotypic plasticity (IxE) for laying date, but IxE was significantly higher in HV than in WW. There were no significant genotype-by-environment interactions (GxE) for laying date, yet differences in GxE were marginally nonsignificant between HV and WW. For clutch size, we only found significant IxE and GxE in WW but no significant difference between populations. From a multivariate perspective, plasticity in laying date was not correlated with plasticity in clutch size in either population. Our results suggest that generalizations about the form and cause of any response to changing environmental conditions across populations may be difficult.
Publisher: Wiley
Date: 27-10-2004
DOI: 10.1111/J.1420-9101.2004.00824.X
Abstract: Heritable maternal effects have important consequences for the evolutionary dynamics of phenotypic traits under selection, but have only rarely been tested for or quantified in evolutionary studies. Here we estimate maternal effects on early-life traits in a feral population of Soay sheep (Ovis aries) from St Kilda, Scotland. We then partition the maternal effects into genetic and environmental components to obtain the first direct estimates of maternal genetic effects in a free-living population, and furthermore test for covariance between direct and maternal genetic effects. Using an animal model approach, direct heritabilities (h2) were low but maternal genetic effects (m2) represented a relatively large proportion of the total phenotypic variance for each trait (birth weight m2=0.119, birth date m2=0.197, natal litter size m2=0.211). A negative correlation between direct and maternal genetic effects was estimated for each trait, but was only statistically significant for natal litter size (ram= -0.714). Total heritabilities (incorporating variance from heritable maternal effects and the direct-maternal genetic covariance) were significant for birth weight and birth date but not for natal litter size. Inadequately specified models greatly overestimated additive genetic variance and hence direct h2 (by a factor of up to 6.45 in the case of birth date). We conclude that failure to model heritable maternal variance can result in over- or under-estimation of the potential for traits to respond to selection, and advocate an increased effort to explicitly measure maternal genetic effects in evolutionary studies.
Publisher: The Royal Society
Date: 07-04-2010
Publisher: University of Chicago Press
Date: 04-2012
DOI: 10.1086/664686
Abstract: Trade-offs among life-history traits are central to evolutionary theory. In quantitative genetic terms, trade-offs may be manifested as negative genetic covariances relative to the direction of selection on phenotypic traits. Although the expression and selection of ecologically important phenotypic variation are fundamentally multivariate phenomena, the in situ quantification of genetic covariances is challenging. Even for life-history traits, where well-developed theory exists with which to relate phenotypic variation to fitness variation, little evidence exists from in situ studies that negative genetic covariances are an important aspect of the genetic architecture of life-history traits. In fact, the majority of reported estimates of genetic covariances among life-history traits are positive. Here we apply theory of the genetics and selection of life histories in organisms with complex life cycles to provide a framework for quantifying the contribution of multivariate genetically based relationships among traits to evolutionary constraint. We use a Bayesian framework to link pedigree-based inference of the genetic basis of variation in life-history traits to evolutionary demography theory regarding how life histories are selected. Our results suggest that genetic covariances may be acting to constrain the evolution of female life-history traits in a wild population of red deer Cervus elaphus: genetic covariances are estimated to reduce the rate of adaptation by about 40%, relative to predicted evolutionary change in the absence of genetic covariances. Furthermore, multivariate phenotypic (rather than genetic) relationships among female life-history traits do not reveal this constraint.
Publisher: Public Library of Science (PLoS)
Date: 13-06-2006
Publisher: Wiley
Date: 03-12-2012
Publisher: Oxford University Press (OUP)
Date: 04-2009
DOI: 10.1534/GENETICS.108.086801
Abstract: This work demonstrates that environmental conditions experienced by in iduals can shape their development and affect the stability of genetic associations. The implication of this observation is that the environmental response may influence the evolution of traits in the wild. Here, we examined how the genetic architecture of a suite of sexually dimorphic traits changed as a function of environmental conditions in an unmanaged population of Soay sheep (Ovis aries) on the island of Hirta, St. Kilda, northwest Scotland. We examined the stability of phenotypic, genetic, and environmental (residual) covariance in males during the first year of life between horn length, body weight, and parasite load in environments of different quality. We then examined the same covariance structures across environments within and between the adult sexes. We found significant genotype-by-environment interactions for lamb male body weight and parasite load, leading to a change in the genetic correlation among environments. Horn length was genetically correlated with body weight in males but not females and the genetic correlation among traits within and between the sexes was dependent upon the environmental conditions experienced during adulthood. Genetic correlations were smaller in more favorable environmental conditions, suggesting that in good environments, loci are expressed that have sex-specific effects. The reduction in genetic correlation between the sexes may allow independent evolutionary trajectories for each sex. This study demonstrates that the genetic architecture of traits is not stable under temporally varying environments and highlights the fact that evolutionary processes may depend largely upon ecological conditions.
Publisher: Elsevier BV
Date: 10-2015
DOI: 10.1016/J.TREE.2015.07.006
Abstract: The recent trend for journals to require open access to primary data included in publications has been embraced by many biologists, but has caused apprehension amongst researchers engaged in long-term ecological and evolutionary studies. A worldwide survey of 73 principal investigators (Pls) with long-term studies revealed positive attitudes towards sharing data with the agreement or involvement of the PI, and 93% of PIs have historically shared data. Only 8% were in favor of uncontrolled, open access to primary data while 63% expressed serious concern. We present here their viewpoint on an issue that can have non-trivial scientific consequences. We discuss potential costs of public data archiving and provide possible solutions to meet the needs of journals and researchers.
Publisher: The Royal Society
Date: 08-07-2009
Abstract: Despite widespread empirical evidence for a general deterioration in the majority of traits with advancing age, it is unclear whether the progress of senescence is chronologically determined, or whether factors such as environmental conditions experienced over the lifespan are more important. We explored the relative importance of ‘chronological’ and ‘environmental’ measures of age to changes in parasite resistance across the lifespan of free-living Soay sheep. Our results show that in iduals experience an increase in parasite burden, as indicated by gastrointestinal helminth faecal egg count (FEC) with chronological age. However, chronological age fails to fully explain changes in FEC because a measure of environmental age, cumulative environmental stress, predicts an additional increase in FEC once chronological age has been accounted for. Additionally, we show that in females age-specific changes are dependent upon the environmental conditions experienced across in iduals' life histories: increases in FEC with age were greatest among in iduals that had experienced the highest degree of stress. Our results illustrate that chronological age alone may not always correspond to biological age, particularly in variable environments. In these circumstances, measures of age that capture the cumulative stresses experienced by an in idual may be useful for understanding the process of senescence.
Publisher: Oxford University Press (OUP)
Date: 08-12-2017
Publisher: Wiley
Date: 31-03-2021
DOI: 10.1111/MEC.15888
Abstract: Many organisms are capable of growing faster than they do. Restrained growth rate has functionally been explained by negative effects on lifespan of accelerated growth. However, the underlying mechanisms remain elusive. Telomere attrition has been proposed as a causal agent and has been mostly studied in endothermic vertebrates. We established that telomeres exist as chromosomal‐ends in a model insect, the field cricket Gryllus c estris , using terminal restriction fragment and Bal 31 methods. Telomeres comprised TTAGGn repeats of 38 kb on average, more than four times longer than the telomeres of human infants. Bal 31 assays confirmed that telomeric repeats were located at the chromosome‐ends. We tested whether rapid growth between day 1, day 65, day 85, and day 125 is achieved at the expense of telomere length by comparing nymphs reared at 23°C with their siblings reared at 28°C, which grew three times faster in the initial 65 days. Surprisingly, neither temperature treatment nor age affected average telomere length. Concomitantly, the broad sense heritability of telomere length was remarkably high at ~100%. Despite high heritability, the evolvability (a mean‐standardized measure of genetic variance) was low relative to that of body mass. We discuss our findings in the context of telomere evolution. Some important features of vertebrate telomere biology are evident in an insect species dating back to the Triassic. The apparent lack of an effect of growth rate on telomere length is puzzling, suggesting strong telomere length maintenance during the growth phase. Whether such maintenance of telomere length is adaptive remains elusive and requires further study investigating the links with fitness in the wild.
Publisher: Wiley
Date: 10-04-2012
DOI: 10.1111/J.1558-5646.2012.01632.X
Abstract: Adaptive evolution occurs when fitness covaries with genetic merit for a trait (or traits). The breeder's equation (BE), in both its univariate and multivariate forms, allows us to predict this process by combining estimates of selection on phenotype with estimates of genetic (co)variation. However, predictions are only valid if all factors causal for trait-fitness covariance are measured. Although this requirement will rarely (if ever) be met in practice, it can be avoided by applying Robertson's secondary theorem of selection (STS). The STS predicts evolution by directly estimating the genetic basis of trait-fitness covariation without any explicit model of selection. Here we apply the BE and STS to four morphological traits measured in Soay sheep (Ovis aries) from St. Kilda. Despite apparently positive selection on heritable size traits, sheep are not getting larger. However, although the BE predicts increasing size, the STS does not, which is a discrepancy that suggests unmeasured factors are upwardly biasing our estimates of selection on phenotype. We suggest this is likely to be a general issue, and that wider application of the STS could offer at least a partial resolution to the common discrepancy between naive expectations and observed trait dynamics in natural populations.
Publisher: Springer Science and Business Media LLC
Date: 21-10-2006
Publisher: Annual Reviews
Date: 12-2008
DOI: 10.1146/ANNUREV.ECOLSYS.39.110707.173542
Abstract: Recent years have seen a rapid expansion in the scope of quantitative genetic analyses undertaken in wild populations. We illustrate here the potential for such studies to address fundamental evolutionary questions about the maintenance of genetic ersity and to reveal hidden genetic conflicts or constraints not apparent at the phenotypic level. Trade-offs between different components of fitness, sexually-antagonistic genetic effects, maternal effects, genotype-by-environment interactions, genotype-by-age interactions, and variation between different regions of the genome in localized genetic correlations may all prevent the erosion of genetic variance. We consider ways in which complex interactions between ecological conditions and the expression of genetic variation can be elucidated, and emphasize the benefits of conducting selection analyses within a quantitative genetic framework. We also review potential developments associated with rapid advances in genomic technology, in particular the increased availability of extensive marker information. Our conclusions highlight the complexity of processes contributing to the maintenance of genetic ersity in wild populations, and underline the value of a quantitative genetic approach in parameterizing models of life-history evolution.
Publisher: Wiley
Date: 12-07-2017
DOI: 10.1111/EVO.13299
Publisher: Springer Science and Business Media LLC
Date: 08-08-2018
Publisher: Wiley
Date: 09-09-2010
DOI: 10.1111/J.1420-9101.2010.02084.X
Abstract: The breeder's equation, which predicts evolutionary change when a phenotypic covariance exists between a heritable trait and fitness, has provided a key conceptual framework for studies of adaptive microevolution in nature. However, its application requires strong assumptions to be made about the causation of fitness variation. In its univariate form, the breeder's equation assumes that the trait of interest is not correlated with other traits having causal effects on fitness. In its multivariate form, the validity of predicted change rests on the assumption that all such correlated traits have been measured and incorporated into the analysis. Here, we (i) highlight why these assumptions are likely to be seriously violated in studies of natural, rather than artificial, selection and (ii) advocate wider use of the Robertson-Price identity as a more robust, and less assumption-laden, alternative to the breeder's equation for applications in evolutionary ecology.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 18-01-2008
Abstract: The evolutionary changes that occur over a small number of generations in natural populations often run counter to what is expected on the basis of the heritability of traits and the selective forces acting upon them. In Soay sheep, dark coat color is associated with large size, which is heritable and positively correlated with fitness, yet the frequency of dark sheep has decreased. This unexpected microevolutionary trend is explained by genetic linkage between the causal mutation underlying the color polymorphism and quantitative trait loci with antagonistic effects on size and fitness. As a consequence, homozygous dark sheep are large, but have reduced fitness relative to phenotypically indistinguishable dark heterozygotes and light sheep. This result demonstrates the importance of understanding the genetic basis of fitness variation when making predictions about the microevolutionary consequences of selection.
Publisher: Oxford University Press (OUP)
Date: 2018
DOI: 10.1534/GENETICS.117.300498
Abstract: To understand how organisms may adapt to environmental changes, it is necessary to determine how environmental conditions influence evolution in wild... How do environmental conditions influence selection and genetic variation in wild populations? There is widespread evidence for selection-by-environment interactions (S*E), but we reviewed studies of natural populations estimating the extent of genotype-by-environment interactions (G*E) in response to natural variation in environmental conditions and found that evidence for G*E appears to be rare within single populations in the wild. Studies estimating the simultaneous impact of environmental variation on both selection and genetic variation are especially scarce. Here, we used 24 years of data collected from a wild Soay sheep population to quantify how an important environmental variable, population density, impacts upon (1) selection through annual contribution to fitness and (2) expression of genetic variation, in six morphological and life history traits: body weight, hind leg length, parasite burden, horn length, horn growth, and testicular circumference. Our results supported the existence of S*E: selection was stronger in years of higher population density for all traits apart from horn growth, with directional selection being stronger under more adverse conditions. Quantitative genetic models revealed significant additive genetic variance for body weight, leg length, parasite burden, horn length, and testes size, but not for horn growth or our measure of annual fitness. However, random regression models found variation between in iduals in their responses to the environment in only three traits, and did not support the presence of G*E for any trait. Our analyses of St Kilda Soay sheep data thus concurs with our cross-study review that, while natural environmental variation within a population can profoundly alter the strength of selection on phenotypic traits, there is less evidence for its effect on the expression of genetic variance in the wild.
Publisher: Elsevier BV
Date: 12-2007
DOI: 10.1016/J.CUB.2007.11.043
Abstract: Aging, or senescence, defined as a decline in physiological function with age, has long been a focus of research interest for evolutionary biologists. How has natural selection failed to remove genetic effects responsible for such reduced fitness among older in iduals? Current evolutionary theory explains this phenomenon by showing that, as a result of the risk of death from environmental causes that in iduals experience, the force of selection inevitably weakens with age. This in turn means that genetic mutations having detrimental effects that are only felt late in life might persist in a population. Although widely accepted, this theory rests on the assumption that there is genetic variation for aging in natural systems, or (equivalently), that genotype-by-age interactions (GxA) occur for fitness. To date, empirical support for this assumption has come almost entirely from laboratory studies on invertebrate systems, most notably Drosophila and C. elegans, whereas tests of genetic variation for aging are largely lacking from natural populations. By using data from two wild mammal populations, we perform quantitative genetic analyses of fitness and provide the first evidence for a genetic basis of senescence to come from a study in the natural environment. We find evidence that genetic differences among in iduals cause variation in their rates of aging and that additive genetic variance for fitness increases with age, as predicted by the evolutionary theory of senescence.
Publisher: Wiley
Date: 03-2009
DOI: 10.1111/J.1365-2656.2008.01489.X
Abstract: 1. Given energetic constraints, female reproductive strategy is expected to be shaped by a trade-off between offspring size and offspring number, the optimal resolution of which may vary with environmental conditions. 2. We tested the hypothesis that selection will favour the production of larger litters, even at some expense to offspring size, under good conditions (and vice versa in harsh environments) using data from a long-term study of an unmanaged population of Soay sheep on the islands of St Kilda, NW Scotland. 3. Both litter size (which is either 1 or 2) and offspring birth weight are under positive selection through female annual fitness, but the strength of selection varies systematically with environmental conditions. Age effects were also detected, with selection weakening as female age increases. 4. Consistent with theoretical predictions, the selective trade-off between litter and offspring size is shifted in favour of the latter under poor environmental conditions. Thus, direct selection on offspring birth weight increases under harsh environmental conditions, particularly for females producing twins. 5. However, singletons are only favoured when environmental conditions are very poor, and offspring weight is constrained to be low. Thus, the current low incidence of twinning (13.5% of litters produced since 1985) appears to be suboptimal with respect to the empirically estimated selection regime. Thus, litter size, a trait known to be heritable, may be expected to evolve upwards in this population. 6. Our study highlights the necessity of incorporating environmental heterogeneity and age structure into analyses of natural selection, and suggests that the common assumption of optimality used in models of life history may sometimes be problematic.
Publisher: University of Chicago Press
Date: 12-2005
DOI: 10.1086/497441
Abstract: Body size is an important determinant of fitness in many organisms. While size will typically change over the lifetime of an in idual, heritable components of phenotypic variance may also show ontogenetic variation. We estimated genetic (additive and maternal) and environmental covariance structures for a size trait (June weight) measured over the first 5 years of life in a natural population of bighorn sheep Ovis canadensis. We also assessed the utility of random regression models for estimating these structures. Additive genetic variance was found for June weight, with heritability increasing over ontogeny because of declining environmental variance. This pattern, mirrored at the phenotypic level, likely reflects viability selection acting on early size traits. Maternal genetic effects were significant at ages 0 and 1, having important evolutionary implications for early weight, but declined with age being negligible by age 2. Strong positive genetic correlations between age-specific traits suggest that selection on June weight at any age will likely induce positively correlated responses across ontogeny. Random regression modeling yielded similar results to traditional methods. However, by facilitating more efficient data use where phenotypic s ling is incomplete, random regression should allow better estimation of genetic (co)variances for size and growth traits in natural populations.
Publisher: Cold Spring Harbor Laboratory
Date: 31-05-2020
DOI: 10.1101/2020.05.29.123216
Abstract: Many organisms are capable of growing faster than they do. Restrained growth rate has functionally been explained by negative effects on lifespan of accelerated growth. However, the underlying mechanisms remain elusive. Telomere attrition has been proposed as a causal agent and has been studied in endothermic vertebrates. We established that telomeres exist as chromosomal-ends in a model insect, the field cricket, using terminal restriction fragment and Bal 31 methods. Telomeres comprised TTAGGn repeats of 38kb on average, more than four times longer than the telomeres of human infants. Bal 31 assays confirmed that telomeric repeats were located at the chromosome-ends. We tested whether rapid growth is achieved at the expense of telomere length by comparing crickets reared at 23°C with their siblings reared at 28°C, which grew three times faster. Surprisingly, neither temperature treatment nor age affected average telomere length. Concomitantly, the broad sense heritability of telomere length was remarkably high at ~100%. Despite high heritability, the evolvability (a mean standardized measure of genetic variance) was low relative to that of body mass. We discuss the different interpretations of these scaling methods in the context of telomere evolution. It is clear that some important features of vertebrate telomere biology are evident in an insect species dating back to the Triassic, but also that there are some striking differences. The apparent lack of an effect of growth rate and the total number of cell isions on telomere length is puzzling, suggesting that telomere length could be actively maintained during the growth phase. Whether such maintenance of telomere length is adaptive remains elusive and requires further study investigating the links with fitness in the wild.
Publisher: The Royal Society
Date: 23-01-2008
Abstract: The antagonistic pleiotropy (AP) theory of ageing predicts genetically based trade-offs between investment in reproduction in early life and survival and performance in later life. Laboratory-based research has shown that such genetic trade-offs exist, but little is currently known about their prevalence in natural populations. We used random regression ‘animal model’ techniques to test the genetic basis of trade-offs between early-life fecundity (ELF) and maternal performance in late life in a wild population of red deer ( Cervus elaphus ) on the Isle of Rum, Scotland. Significant genetic variation for both ageing rates in a key maternal performance measure (offspring birth weight) and ELF was present in this population. We found some evidence for a negative genetic covariance between the rate of ageing in offspring birth weight and ELF, and also for a negative environmental covariance. Our results suggest rare support for the AP theory of ageing from a wild population.
Publisher: University of Chicago Press
Date: 2010
DOI: 10.1086/648604
Abstract: Best linear unbiased prediction (BLUP) is a method for obtaining point estimates of a random effect in a mixed effect model. Over the past decade it has been used extensively in ecology and evolutionary biology to predict in idual breeding values and reaction norms. These predictions have been used to infer natural selection, evolutionary change, spatial-genetic patterns, in idual reaction norms, and frailties. In this article we show analytically and through simulation and ex le why BLUP often gives anticonservative and biased estimates of evolutionary and ecological parameters. Although some concerns with BLUP methodology have been voiced before, the scale and breadth of the problems have probably not been widely appreciated. Bias arises because BLUPs are often used to estimate effects that are not explicitly accounted for in the model used to make the predictions. In these cases, predicted breeding values will often say more about phenotypic patterns than the genetic patterns of interest. An additional problem is that BLUPs are point estimates of quantities that are usually known with little certainty. Failure to account for this uncertainty in subsequent tests can lead to both bias and extreme anticonservatism. We demonstrate that restricted maximum likelihood and Bayesian solutions exist for these problems and show how unbiased and powerful tests can be derived that adequately quantify uncertainty. Of particular utility is a new test for detecting evolutionary change that not only accounts for prediction error in breeding values but also accounts for drift. To illustrate the problem, we apply these tests to long-term data on the Soay sheep (Ovis aries) and the great tit (Parus major) and show that previously reported temporal trends in breeding values are not supported.
Publisher: Oxford University Press (OUP)
Date: 04-2011
DOI: 10.1534/GENETICS.110.124990
Abstract: Cryptic evolution has been defined as adaptive evolutionary change being masked by concurrent environmental change. Empirical studies of cryptic evolution have usually invoked a changing climate and/or increasing population density as the form of detrimental environmental change experienced by a population undergoing cryptic evolution. However, Fisher (1958) emphasized that evolutionary change in itself is likely to be an important component of “environmental deterioration,” a point restated by Cookeet al. (1990) in the context of intraspecific competition. In this form, environmental deterioration arises because a winning lineage has to compete against more winners in successive generations as the population evolves. This “evolutionary environmental deterioration” has different implications for the selection and evolution of traits influenced by resource competition than general environmental change. We reformulate Cooke's model as a quantitative genetic model to show that it is identical in form to more recent developments proposed by quantitative geneticists. This provides a statistical framework for discriminating between the alternative hypotheses of environmental change and environmental deterioration caused by evolutionary change. We also demonstrate that in systems where no phenotypic change has occurred, there are many reasonable biological processes that will generate patterns in predicted breeding values that are consistent with what has been interpreted as cryptic evolution, and care needs to be taken when interpreting these patterns. These processes include mutation, sib competition, and invisible fractions.
Publisher: Wiley
Date: 10-06-2011
DOI: 10.1111/J.1420-9101.2011.02300.X
Abstract: Parasites detrimentally affect host fitness, leading to expectations of positive selection on host parasite resistance. However, as immunity is costly, host fitness may be maximized at low, but nonzero, parasite infection intensities. These hypotheses are rarely tested on natural variation in free-living populations. We investigated selection on a measure of host parasite resistance in a naturally regulated Soay sheep population using a longitudinal data set and found negative correlations between parasite infection intensity and annual fitness in lambs, male yearlings and adult females. However, having accounted for confounding effects of body weight, the effect was only significant in lambs. Associations between fitness and parasite resistance were environment-dependent, being strong during low-mortality winters, but negligible during harsher high-mortality winters. There was no evidence for stabilizing selection. Our findings reveal processes that may shape variation in parasite resistance in natural populations and illustrate the importance of accounting for correlated traits in selection analysis.
Publisher: Wiley
Date: 03-02-2011
DOI: 10.1111/J.1420-9101.2010.02212.X
Abstract: By determining access to limited resources, social dominance is often an important determinant of fitness. Thus, if heritable, standard theory predicts mean dominance should evolve. However, dominance is usually inferred from the tendency to win contests, and given one winner and one loser in any dyadic contest, the mean proportion won will always equal 0.5. Here, we argue that the apparent conflict between quantitative genetic theory and common sense is resolved by recognition of indirect genetic effects (IGEs). We estimate selection on, and genetic (co)variance structures for, social dominance, in a wild population of red deer Cervus elaphus, on the Scottish island of Rum. While dominance is heritable and positively correlated with lifetime fitness, contest outcomes depend as much on the genes carried by an opponent as on the genotype of a focal in idual. We show how this dependency imposes an absolute evolutionary constraint on the phenotypic mean, thus reconciling theoretical predictions with common sense. More generally, we argue that IGEs likely provide a widespread but poorly recognized source of evolutionary constraint for traits influenced by competition.
Publisher: Wiley
Date: 2010
DOI: 10.1111/J.1365-2656.2009.01639.X
Abstract: 1. Efforts to understand the links between evolutionary and ecological dynamics hinge on our ability to measure and understand how genes influence phenotypes, fitness and population dynamics. Quantitative genetics provides a range of theoretical and empirical tools with which to achieve this when the relatedness between in iduals within a population is known. 2. A number of recent studies have used a type of mixed-effects model, known as the animal model, to estimate the genetic component of phenotypic variation using data collected in the field. Here, we provide a practical guide for ecologists interested in exploring the potential to apply this quantitative genetic method in their research. 3. We begin by outlining, in simple terms, key concepts in quantitative genetics and how an animal model estimates relevant quantitative genetic parameters, such as heritabilities or genetic correlations. 4. We then provide three detailed ex le tutorials, for implementation in a variety of software packages, for some basic applications of the animal model. We discuss several important statistical issues relating to best practice when fitting different kinds of mixed models. 5. We conclude by briefly summarizing more complex applications of the animal model, and by highlighting key pitfalls and dangers for the researcher wanting to begin using quantitative genetic tools to address ecological and evolutionary questions.
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Start Date: 02-2021
End Date: 2025
Amount: $451,000.00
Funder: Australian Research Council
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