@article{7205, abstract = {Genetic incompatibilities contribute to reproductive isolation between many diverging populations, but it is still unclear to what extent they play a role if divergence happens with gene flow. In contact zones between the "Crab" and "Wave" ecotypes of the snail Littorina saxatilis, divergent selection forms strong barriers to gene flow, while the role of post‐zygotic barriers due to selection against hybrids remains unclear. High embryo abortion rates in this species could indicate the presence of such barriers. Post‐zygotic barriers might include genetic incompatibilities (e.g. Dobzhansky–Muller incompatibilities) but also maladaptation, both expected to be most pronounced in contact zones. In addition, embryo abortion might reflect physiological stress on females and embryos independent of any genetic stress. We examined all embryos of >500 females sampled outside and inside contact zones of three populations in Sweden. Females' clutch size ranged from 0 to 1,011 embryos (mean 130 ± 123), and abortion rates varied between 0% and 100% (mean 12%). We described female genotypes by using a hybrid index based on hundreds of SNPs differentiated between ecotypes with which we characterized female genotypes. We also calculated female SNP heterozygosity and inversion karyotype. Clutch size did not vary with female hybrid index, and abortion rates were only weakly related to hybrid index in two sites but not at all in a third site. No additional variation in abortion rate was explained by female SNP heterozygosity, but increased female inversion heterozygosity added slightly to increased abortion. Our results show only weak and probably biologically insignificant post‐zygotic barriers contributing to ecotype divergence, and the high and variable abortion rates were marginally, if at all, explained by hybrid index of females.}, author = {Johannesson, Kerstin and Zagrodzka, Zuzanna and Faria, Rui and Westram, Anja M and Butlin, Roger K.}, issn = {14209101}, journal = {Journal of Evolutionary Biology}, number = {3}, pages = {342--351}, publisher = {Wiley}, title = {{Is embryo abortion a post-zygotic barrier to gene flow between Littorina ecotypes?}}, doi = {10.1111/jeb.13570}, volume = {33}, year = {2020}, } @phdthesis{8574, abstract = {This thesis concerns itself with the interactions of evolutionary and ecological forces and the consequences on genetic diversity and the ultimate survival of populations. It is important to understand what signals processes leave on the genome and what we can infer from such data, which is usually abundant but noisy. Furthermore, understanding how and when populations adapt or go extinct is important for practical purposes, such as the genetic management of populations, as well as for theoretical questions, since local adaptation can be the first step toward speciation. In Chapter 2, we introduce the method of maximum entropy to approximate the demographic changes of a population in a simple setting, namely the logistic growth model with immigration. We show that this method is not only a powerful tool in physics but can be gainfully applied in an ecological framework. We investigate how well it approximates the real behavior of the system, and find that is does so, even in unexpected situations. Finally, we illustrate how it can model changing environments. In Chapter 3, we analyze the co-evolution of allele frequencies and population sizes in an infinite island model. We give conditions under which polygenic adaptation to a rare habitat is possible. The model we use is based on the diffusion approximation, considers eco-evolutionary feedback mechanisms (hard selection), and treats both drift and environmental fluctuations explicitly. We also look at limiting scenarios, for which we derive analytical expressions. In Chapter 4, we present a coalescent based simulation tool to obtain patterns of diversity in a spatially explicit subdivided population, in which the demographic history of each subpopulation can be specified. We compare the results to existing predictions, and explore the relative importance of time and space under a variety of spatial arrangements and demographic histories, such as expansion and extinction. In the last chapter, we give a brief outlook to further research. }, author = {Szep, Eniko}, issn = {2663-337X}, pages = {158}, publisher = {Institute of Science and Technology Austria}, title = {{Local adaptation in metapopulations}}, doi = {10.15479/AT:ISTA:8574}, year = {2020}, } @misc{8254, abstract = {Here are the research data underlying the publication "Estimating inbreeding and its effects in a long-term study of snapdragons (Antirrhinum majus)". Further information are summed up in the README document. The files for this record have been updated and are now found in the linked DOI https://doi.org/10.15479/AT:ISTA:9192.}, author = {Arathoon, Louise S}, publisher = {Institute of Science and Technology Austria}, title = {{Estimating inbreeding and its effects in a long-term study of snapdragons (Antirrhinum majus)}}, doi = {10.15479/AT:ISTA:8254}, year = {2020}, } @misc{9839, abstract = {More than 100 years after Grigg’s influential analysis of species’ borders, the causes of limits to species’ ranges still represent a puzzle that has never been understood with clarity. The topic has become especially important recently as many scientists have become interested in the potential for species’ ranges to shift in response to climate change—and yet nearly all of those studies fail to recognise or incorporate evolutionary genetics in a way that relates to theoretical developments. I show that range margins can be understood based on just two measurable parameters: (i) the fitness cost of dispersal—a measure of environmental heterogeneity—and (ii) the strength of genetic drift, which reduces genetic diversity. Together, these two parameters define an ‘expansion threshold’: adaptation fails when genetic drift reduces genetic diversity below that required for adaptation to a heterogeneous environment. When the key parameters drop below this expansion threshold locally, a sharp range margin forms. When they drop below this threshold throughout the species’ range, adaptation collapses everywhere, resulting in either extinction or formation of a fragmented metapopulation. Because the effects of dispersal differ fundamentally with dimension, the second parameter—the strength of genetic drift—is qualitatively different compared to a linear habitat. In two-dimensional habitats, genetic drift becomes effectively independent of selection. It decreases with ‘neighbourhood size’—the number of individuals accessible by dispersal within one generation. Moreover, in contrast to earlier predictions, which neglected evolution of genetic variance and/or stochasticity in two dimensions, dispersal into small marginal populations aids adaptation. This is because the reduction of both genetic and demographic stochasticity has a stronger effect than the cost of dispersal through increased maladaptation. The expansion threshold thus provides a novel, theoretically justified, and testable prediction for formation of the range margin and collapse of the species’ range.}, author = {Polechova, Jitka}, publisher = {Dryad}, title = {{Data from: Is the sky the limit? On the expansion threshold of a species' range}}, doi = {10.5061/dryad.5vv37}, year = {2019}, } @article{5911, abstract = {Empirical data suggest that inversions in many species contain genes important for intraspecific divergence and speciation, yet mechanisms of evolution remain unclear. While genes inside an inversion are tightly linked, inversions are not static but evolve separately from the rest of the genome by new mutations, recombination within arrangements, and gene flux between arrangements. Inversion polymorphisms are maintained by different processes, for example, divergent or balancing selection, or a mix of multiple processes. Moreover, the relative roles of selection, drift, mutation, and recombination will change over the lifetime of an inversion and within its area of distribution. We believe inversions are central to the evolution of many species, but we need many more data and new models to understand the complex mechanisms involved.}, author = {Faria, Rui and Johannesson, Kerstin and Butlin, Roger K. and Westram, Anja M}, issn = {01695347}, journal = {Trends in Ecology and Evolution}, number = {3}, pages = {239--248}, publisher = {Elsevier}, title = {{Evolving inversions}}, doi = {10.1016/j.tree.2018.12.005}, volume = {34}, year = {2019}, } @article{5680, abstract = {Pollinators display a remarkable diversity of foraging strategies with flowering plants, from primarily mutualistic interactions to cheating through nectar robbery. Despite numerous studies on the effect of nectar robbing on components of plant fitness, its contribution to reproductive isolation is unclear. We experimentally tested the impact of different pollinator strategies in a natural hybrid zone between two subspecies of Antirrhinum majus with alternate flower colour guides. On either side of a steep cline in flower colour between Antirrhinum majus pseudomajus (magenta) and A. m. striatum (yellow), we quantified the behaviour of all floral visitors at different time points during the flowering season. Using long-run camera surveys, we quantify the impact of nectar robbing on the number of flowers visited per inflorescence and the flower probing time. We further experimentally tested the effect of nectar robbing on female reproductive success by manipulating the intensity of robbing. While robbing increased over time the number of legitimate visitors tended to decrease concomitantly. We found that the number of flowers pollinated on a focal inflorescence decreased with the number of prior robbing events. However, in the manipulative experiment, fruit set and fruit volume did not vary significantly between low robbing and control treatments. Our findings challenge the idea that robbers have a negative impact on plant fitness through female function. This study also adds to our understanding of the components of pollinator-mediated reproductive isolation and the maintenance of Antirrhinum hybrid zones.}, author = {Andalo, Christophe and Burrus, Monique and Paute, Sandrine and Lauzeral, Christine and Field, David}, issn = {23818115}, journal = {Botany Letters}, number = {1}, pages = {80--92}, publisher = {Taylor and Francis}, title = {{Prevalence of legitimate pollinators and nectar robbers and the consequences for fruit set in an Antirrhinum majus hybrid zone}}, doi = {10.1080/23818107.2018.1545142}, volume = {166}, year = {2019}, } @article{6022, abstract = {The evolution of new species is made easier when traits under divergent ecological selection are also mating cues. Such ecological mating cues are now considered more common than previously thought, but we still know little about the genetic changes underlying their evolution or more generally about the genetic basis for assortative mating behaviors. Both tight physical linkage and the existence of large-effect preference loci will strengthen genetic associations between behavioral and ecological barriers, promoting the evolution of assortative mating. The warning patterns of Heliconius melpomene and H. cydno are under disruptive selection due to increased predation of nonmimetic hybrids and are used during mate recognition. We carried out a genome-wide quantitative trait locus (QTL) analysis of preference behaviors between these species and showed that divergent male preference has a simple genetic basis. We identify three QTLs that together explain a large proportion (approximately 60%) of the difference in preference behavior observed between the parental species. One of these QTLs is just 1.2 (0-4.8) centiMorgans (cM) from the major color pattern gene optix, and, individually, all three have a large effect on the preference phenotype. Genomic divergence between H. cydno and H. melpomene is high but broadly heterogenous, and admixture is reduced at the preference-optix color pattern locus but not the other preference QTLs. The simple genetic architecture we reveal will facilitate the evolution and maintenance of new species despite ongoing gene flow by coupling behavioral and ecological aspects of reproductive isolation.}, author = {Merrill, Richard M. and Rastas, Pasi and Martin, Simon H. and Melo Hurtado, Maria C and Barker, Sarah and Davey, John and Mcmillan, W. Owen and Jiggins, Chris D.}, journal = {PLoS Biology}, number = {2}, publisher = {Public Library of Science}, title = {{Genetic dissection of assortative mating behavior}}, doi = {10.1371/journal.pbio.2005902}, volume = {17}, year = {2019}, } @misc{9801, author = {Merrill, Richard M. and Rastas, Pasi and Martin, Simon H. and Melo Hurtado, Maria C and Barker, Sarah and Davey, John and Mcmillan, W. Owen and Jiggins, Chris D.}, publisher = {Public Library of Science}, title = {{Raw behavioral data}}, doi = {10.1371/journal.pbio.2005902.s006}, year = {2019}, } @article{6095, abstract = {Both classical and recent studies suggest that chromosomal inversion polymorphisms are important in adaptation and speciation. However, biases in discovery and reporting of inversions make it difficult to assess their prevalence and biological importance. Here, we use an approach based on linkage disequilibrium among markers genotyped for samples collected across a transect between contrasting habitats to detect chromosomal rearrangements de novo. We report 17 polymorphic rearrangements in a single locality for the coastal marine snail, Littorina saxatilis. Patterns of diversity in the field and of recombination in controlled crosses provide strong evidence that at least the majority of these rearrangements are inversions. Most show clinal changes in frequency between habitats, suggestive of divergent selection, but only one appears to be fixed for different arrangements in the two habitats. Consistent with widespread evidence for balancing selection on inversion polymorphisms, we argue that a combination of heterosis and divergent selection can explain the observed patterns and should be considered in other systems spanning environmental gradients.}, author = {Faria, Rui and Chaube, Pragya and Morales, Hernán E. and Larsson, Tomas and Lemmon, Alan R. and Lemmon, Emily M. and Rafajlović, Marina and Panova, Marina and Ravinet, Mark and Johannesson, Kerstin and Westram, Anja M and Butlin, Roger K.}, issn = {1365-294X}, journal = {Molecular Ecology}, number = {6}, pages = {1375--1393}, publisher = {Wiley}, title = {{Multiple chromosomal rearrangements in a hybrid zone between Littorina saxatilis ecotypes}}, doi = {10.1111/mec.14972}, volume = {28}, year = {2019}, } @article{6230, abstract = {Great care is needed when interpreting claims about the genetic basis of human variation based on data from genome-wide association studies.}, author = {Barton, Nicholas H and Hermisson, Joachim and Nordborg, Magnus}, issn = {2050084X}, journal = {eLife}, publisher = {eLife Sciences Publications}, title = {{Why structure matters}}, doi = {10.7554/eLife.45380}, volume = {8}, year = {2019}, } @article{6466, abstract = {One of the most striking and consistent results in speciation genomics is the heterogeneous divergence observed across the genomes of closely related species. This pattern was initially attributed to different levels of gene exchange—with divergence preserved at loci generating a barrier to gene flow but homogenized at unlinked neutral loci. Although there is evidence to support this model, it is now recognized that interpreting patterns of divergence across genomes is not so straightforward. One problem is that heterogenous divergence between populations can also be generated by other processes (e.g. recurrent selective sweeps or background selection) without any involvement of differential gene flow. Thus, integrated studies that identify which loci are likely subject to divergent selection are required to shed light on the interplay between selection and gene flow during the early phases of speciation. In this issue of Molecular Ecology, Rifkin et al. (2019) confront this challenge using a pair of sister morning glory species. They wisely design their sampling to take the geographic context of individuals into account, including geographically isolated (allopatric) and co‐occurring (sympatric) populations. This enabled them to show that individuals are phenotypically less differentiated in sympatry. They also found that the loci that resist introgression are enriched for those most differentiated in allopatry and loci that exhibit signals of divergent selection. One great strength of the study is the combination of methods from population genetics and molecular evolution, including the development of a model to simultaneously infer admixture proportions and selfing rates.}, author = {Field, David and Fraisse, Christelle}, issn = {1365294X}, journal = {Molecular ecology}, number = {7}, pages = {1579--1581}, publisher = {Wiley}, title = {{Breaking down barriers in morning glories}}, doi = {10.1111/mec.15048}, volume = {28}, year = {2019}, } @article{6467, abstract = {Fitness interactions between mutations can influence a population’s evolution in many different ways. While epistatic effects are difficult to measure precisely, important information is captured by the mean and variance of log fitnesses for individuals carrying different numbers of mutations. We derive predictions for these quantities from a class of simple fitness landscapes, based on models of optimizing selection on quantitative traits. We also explore extensions to the models, including modular pleiotropy, variable effect sizes, mutational bias and maladaptation of the wild type. We illustrate our approach by reanalysing a large dataset of mutant effects in a yeast snoRNA (small nucleolar RNA). Though characterized by some large epistatic effects, these data give a good overall fit to the non-epistatic null model, suggesting that epistasis might have limited influence on the evolutionary dynamics in this system. We also show how the amount of epistasis depends on both the underlying fitness landscape and the distribution of mutations, and so is expected to vary in consistent ways between new mutations, standing variation and fixed mutations.}, author = {Fraisse, Christelle and Welch, John J.}, issn = {1744957X}, journal = {Biology Letters}, number = {4}, publisher = {Royal Society of London}, title = {{The distribution of epistasis on simple fitness landscapes}}, doi = {10.1098/rsbl.2018.0881}, volume = {15}, year = {2019}, } @article{6637, abstract = {The environment changes constantly at various time scales and, in order to survive, species need to keep adapting. Whether these species succeed in avoiding extinction is a major evolutionary question. Using a multilocus evolutionary model of a mutation‐limited population adapting under strong selection, we investigate the effects of the frequency of environmental fluctuations on adaptation. Our results rely on an “adaptive‐walk” approximation and use mathematical methods from evolutionary computation theory to investigate the interplay between fluctuation frequency, the similarity of environments, and the number of loci contributing to adaptation. First, we assume a linear additive fitness function, but later generalize our results to include several types of epistasis. We show that frequent environmental changes prevent populations from reaching a fitness peak, but they may also prevent the large fitness loss that occurs after a single environmental change. Thus, the population can survive, although not thrive, in a wide range of conditions. Furthermore, we show that in a frequently changing environment, the similarity of threats that a population faces affects the level of adaptation that it is able to achieve. We check and supplement our analytical results with simulations.}, author = {Trubenova, Barbora and Krejca, Martin and Lehre, Per Kristian and Kötzing, Timo}, journal = {Evolution}, number = {7}, pages = {1356--1374}, publisher = {Wiley}, title = {{Surfing on the seascape: Adaptation in a changing environment}}, doi = {10.1111/evo.13784}, volume = {73}, year = {2019}, } @article{6680, abstract = {This paper analyzes how partial selfing in a large source population influences its ability to colonize a new habitat via the introduction of a few founder individuals. Founders experience inbreeding depression due to partially recessive deleterious alleles as well as maladaptation to the new environment due to selection on a large number of additive loci. I first introduce a simplified version of the Inbreeding History Model (Kelly, 2007) in order to characterize mutation‐selection balance in a large, partially selfing source population under selection involving multiple non‐identical loci. I then use individual‐based simulations to study the eco‐evolutionary dynamics of founders establishing in the new habitat under a model of hard selection. The study explores how selfing rate shapes establishment probabilities of founders via effects on both inbreeding depression and adaptability to the new environment, and also distinguishes the effects of selfing on the initial fitness of founders from its effects on the long‐term adaptive response of the populations they found. A high rate of (but not complete) selfing is found to aid establishment over a wide range of parameters, even in the absence of mate limitation. The sensitivity of the results to assumptions about the nature of polygenic selection are discussed.}, author = {Sachdeva, Himani}, issn = {1558-5646}, journal = {Evolution}, number = {9}, pages = {1729--1745}, publisher = {Wiley}, title = {{Effect of partial selfing and polygenic selection on establishment in a new habitat}}, doi = {10.1111/evo.13812}, volume = {73}, year = {2019}, } @misc{9804, abstract = {Evolutionary studies are often limited by missing data that are critical to understanding the history of selection. Selection experiments, which reproduce rapid evolution under controlled conditions, are excellent tools to study how genomes evolve under selection. Here we present a genomic dissection of the Longshanks selection experiment, in which mice were selectively bred over 20 generations for longer tibiae relative to body mass, resulting in 13% longer tibiae in two replicates. We synthesized evolutionary theory, genome sequences and molecular genetics to understand the selection response and found that it involved both polygenic adaptation and discrete loci of major effect, with the strongest loci tending to be selected in parallel between replicates. We show that selection may favor de-repression of bone growth through inactivating two limb enhancers of an inhibitor, Nkx3-2. Our integrative genomic analyses thus show that it is possible to connect individual base-pair changes to the overall selection response.}, author = {Castro, João Pl and Yancoskie, Michelle N. and Marchini, Marta and Belohlavy, Stefanie and Hiramatsu, Layla and Kučka, Marek and Beluch, William H. and Naumann, Ronald and Skuplik, Isabella and Cobb, John and Barton, Nicholas H and Rolian, Campbell and Chan, Yingguang Frank}, publisher = {Dryad}, title = {{Data from: An integrative genomic analysis of the Longshanks selection experiment for longer limbs in mice}}, doi = {10.5061/dryad.0q2h6tk}, year = {2019}, } @misc{9802, abstract = {This paper analyzes how partial selfing in a large source population influences its ability to colonize a new habitat via the introduction of a few founder individuals. Founders experience inbreeding depression due to partially recessive deleterious alleles as well as maladaptation to the new environment due to selection on a large number of additive loci. I first introduce a simplified version of the Inbreeding History Model (Kelly, 2007) in order to characterize mutation-selection balance in a large, partially selfing source population under selection involving multiple non-identical loci. I then use individual-based simulations to study the eco-evolutionary dynamics of founders establishing in the new habitat under a model of hard selection. The study explores how selfing rate shapes establishment probabilities of founders via effects on both inbreeding depression and adaptability to the new environment, and also distinguishes the effects of selfing on the initial fitness of founders from its effects on the long-term adaptive response of the populations they found. A high rate of (but not complete) selfing is found to aid establishment over a wide range of parameters, even in the absence of mate limitation. The sensitivity of the results to assumptions about the nature of polygenic selection are discussed.}, author = {Sachdeva, Himani}, publisher = {Dryad}, title = {{Data from: Effect of partial selfing and polygenic selection on establishment in a new habitat}}, doi = {10.5061/dryad.8tp0900}, year = {2019}, } @article{6795, abstract = {The green‐beard effect is one proposed mechanism predicted to underpin the evolu‐tion of altruistic behavior. It relies on the recognition and the selective help of altruists to each other in order to promote and sustain altruistic behavior. However, this mechanism has often been dismissed as unlikely or uncommon, as it is assumed that both the signaling trait and altruistic trait need to be encoded by the same gene or through tightly linked genes. Here, we use models of indirect genetic effects (IGEs) to find the minimum correlation between the signaling and altruistic trait required for the evolution of the latter. We show that this correlation threshold depends on the strength of the interaction (influence of the green beard on the expression of the altruistic trait), as well as the costs and benefits of the altruistic behavior. We further show that this correlation does not necessarily have to be high and support our analytical results by simulations.}, author = {Trubenova, Barbora and Hager, Reinmar}, issn = {20457758}, journal = {Ecology and Evolution}, number = {17}, pages = {9597--9608}, publisher = {Wiley}, title = {{Green beards in the light of indirect genetic effects}}, doi = {10.1002/ece3.5484}, volume = {9}, year = {2019}, } @article{6831, abstract = {* Understanding the mechanisms causing phenotypic differences between females and males has long fascinated evolutionary biologists. An extensive literature exists on animal sexual dimorphism but less information is known about sex differences in plants, particularly the extent of geographical variation in sexual dimorphism and its life‐cycle dynamics. * Here, we investigated patterns of genetically based sexual dimorphism in vegetative and reproductive traits of a wind‐pollinated dioecious plant, Rumex hastatulus, across three life‐cycle stages using open‐pollinated families from 30 populations spanning the geographic range and chromosomal variation (XY and XY1Y2) of the species. * The direction and degree of sexual dimorphism was highly variable among populations and life‐cycle stages. Sex‐specific differences in reproductive function explained a significant amount of temporal change in sexual dimorphism. For several traits, geographical variation in sexual dimorphism was associated with bioclimatic parameters, likely due to the differential responses of the sexes to climate. We found no systematic differences in sexual dimorphism between chromosome races. * Sex‐specific trait differences in dioecious plants largely result from a balance between sexual and natural selection on resource allocation. Our results indicate that abiotic factors associated with geographical context also play a role in modifying sexual dimorphism during the plant life‐cycle.}, author = {Puixeu Sala, Gemma and Pickup, Melinda and Field, David and Barrett, Spencer C.H.}, issn = {1469-8137}, journal = {New Phytologist}, number = {3}, pages = {1108--1120}, publisher = {Wiley}, title = {{Variation in sexual dimorphism in a wind-pollinated plant: The influence of geographical context and life-cycle dynamics}}, doi = {10.1111/nph.16050}, volume = {224}, year = {2019}, } @misc{9803, abstract = {Understanding the mechanisms causing phenotypic differences between females and males has long fascinated evolutionary biologists. An extensive literature exists on animal sexual dimorphism but less is known about sex differences in plants, particularly the extent of geographical variation in sexual dimorphism and its life-cycle dynamics. Here, we investigate patterns of genetically-based sexual dimorphism in vegetative and reproductive traits of a wind-pollinated dioecious plant, Rumex hastatulus, across three life-cycle stages using open-pollinated families from 30 populations spanning the geographic range and chromosomal variation (XY and XY1Y2) of the species. The direction and degree of sexual dimorphism was highly variable among populations and life-cycle stages. Sex-specific differences in reproductive function explained a significant amount of temporal change in sexual dimorphism. For several traits, geographical variation in sexual dimorphism was associated with bioclimatic parameters, likely due to the differential responses of the sexes to climate. We found no systematic differences in sexual dimorphism between chromosome races. Sex-specific trait differences in dioecious plants largely result from a balance between sexual and natural selection on resource allocation. Our results indicate that abiotic factors associated with geographical context also play a role in modifying sexual dimorphism during the plant life cycle.}, author = {Puixeu Sala, Gemma and Pickup, Melinda and Field, David and Barrett, Spencer C.H.}, publisher = {Dryad}, title = {{Data from: Variation in sexual dimorphism in a wind-pollinated plant: the influence of geographical context and life-cycle dynamics}}, doi = {10.5061/dryad.n1701c9}, year = {2019}, } @article{6855, abstract = {Many traits of interest are highly heritable and genetically complex, meaning that much of the variation they exhibit arises from differences at numerous loci in the genome. Complex traits and their evolution have been studied for more than a century, but only in the last decade have genome-wide association studies (GWASs) in humans begun to reveal their genetic basis. Here, we bring these threads of research together to ask how findings from GWASs can further our understanding of the processes that give rise to heritable variation in complex traits and of the genetic basis of complex trait evolution in response to changing selection pressures (i.e., of polygenic adaptation). Conversely, we ask how evolutionary thinking helps us to interpret findings from GWASs and informs related efforts of practical importance.}, author = {Sella, Guy and Barton, Nicholas H}, issn = {1545-293X}, journal = {Annual Review of Genomics and Human Genetics}, pages = {461--493}, publisher = {Annual Reviews}, title = {{Thinking about the evolution of complex traits in the era of genome-wide association studies}}, doi = {10.1146/annurev-genom-083115-022316}, volume = {20}, year = {2019}, }