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Wang L, Chen J, Xue X, Qin G, Gao Y, Li K, Zhang Y, Li XJ. Comparative analysis of mitogenomes among three species of grasshoppers (Orthoptera: Acridoidea: Gomphocerinae) and their phylogenetic implications. PeerJ 2023; 11:e16550. [PMID: 38111661 PMCID: PMC10726767 DOI: 10.7717/peerj.16550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 11/09/2023] [Indexed: 12/20/2023] Open
Abstract
Whole mitochondrial genomes have been widely used in phylogenetic analysis, population genetics and biogeography studies. This study sequenced and characterized three complete mitochondrial genomes (Dasyhippus peipingensis, Myrmeleotettix palpalis, Aeropedellus prominemarginis) and determined their phylogenetic position in Acrididae. The length of the mitochondrial genomes ranged from 15,621-15,629 bp and composed of 13 PCGs, 2 rRNA, 22 tRNA genes and an AT control region. The arrangement and structure of the mitochondrial genomes were similar to those of other invertebrates. Comparative genomics revealed that the three mitochondrial genomes were highly conserved in terms of gene size, structure, and codon usage, all PCGs were purified selections with an ATN start codon and a TAN stop codon. All tRNAs could be folded into the typical clover-leaf structure, except tRNA Ser (AGN) that lacked a dihydrouridine (DHU) arm. Phylogenetic analysis based on 13 PCGs of 34 Acrididae species and seven outgroup species revealed that differences in the shape of antennae within the family Acrididae should be given less weight as a taxonomic character for higher-level classification. Moreover, the divergence time estimates indicates that in Gomphocerinae, the species with clubbed antennae were formed within the nearest 18 Mya, and Pacris xizangensis is more ancient.
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Affiliation(s)
- Li Wang
- The Key Laboratory of Zoological Systematics and Application, School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, China
| | - Jianyu Chen
- The Key Laboratory of Zoological Systematics and Application, School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, China
| | - Xiaobao Xue
- The Key Laboratory of Zoological Systematics and Application, School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, China
| | - Guoqing Qin
- The Key Laboratory of Zoological Systematics and Application, School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, China
| | - Yuanyi Gao
- The Key Laboratory of Zoological Systematics and Application, School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, China
| | - Kai Li
- The Key Laboratory of Zoological Systematics and Application, School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, China
| | - Yulong Zhang
- The Key Laboratory of Zoological Systematics and Application, School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, China
| | - Xin-Jiang Li
- The Key Laboratory of Zoological Systematics and Application, School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, China
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2
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Burggren WW, Mendez-Sanchez JF. "Bet hedging" against climate change in developing and adult animals: roles for stochastic gene expression, phenotypic plasticity, epigenetic inheritance and adaptation. Front Physiol 2023; 14:1245875. [PMID: 37869716 PMCID: PMC10588650 DOI: 10.3389/fphys.2023.1245875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/12/2023] [Indexed: 10/24/2023] Open
Abstract
Animals from embryos to adults experiencing stress from climate change have numerous mechanisms available for enhancing their long-term survival. In this review we consider these options, and how viable they are in a world increasingly experiencing extreme weather associated with climate change. A deeply understood mechanism involves natural selection, leading to evolution of new adaptations that help cope with extreme and stochastic weather events associated with climate change. While potentially effective at staving off environmental challenges, such adaptations typically occur very slowly and incrementally over evolutionary time. Consequently, adaptation through natural selection is in most instances regarded as too slow to aid survival in rapidly changing environments, especially when considering the stochastic nature of extreme weather events associated with climate change. Alternative mechanisms operating in a much shorter time frame than adaptation involve the rapid creation of alternate phenotypes within a life cycle or a few generations. Stochastic gene expression creates multiple phenotypes from the same genotype even in the absence of environmental cues. In contrast, other mechanisms for phenotype change that are externally driven by environmental clues include well-understood developmental phenotypic plasticity (variation, flexibility), which can enable rapid, within-generation changes. Increasingly appreciated are epigenetic influences during development leading to rapid phenotypic changes that can also immediately be very widespread throughout a population, rather than confined to a few individuals as in the case of favorable gene mutations. Such epigenetically-induced phenotypic plasticity can arise rapidly in response to stressors within a generation or across a few generations and just as rapidly be "sunsetted" when the stressor dissipates, providing some capability to withstand environmental stressors emerging from climate change. Importantly, survival mechanisms resulting from adaptations and developmental phenotypic plasticity are not necessarily mutually exclusive, allowing for classic "bet hedging". Thus, the appearance of multiple phenotypes within a single population provides for a phenotype potentially optimal for some future environment. This enhances survival during stochastic extreme weather events associated with climate change. Finally, we end with recommendations for future physiological experiments, recommending in particular that experiments investigating phenotypic flexibility adopt more realistic protocols that reflect the stochastic nature of weather.
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Affiliation(s)
- Warren W. Burggren
- Developmental Integrative Biology Group, Department of Biological Sciences, University of North Texas, Denton, TX, United States
| | - Jose Fernando Mendez-Sanchez
- Laboratorio de Ecofisiología Animal, Departamento de Biología, Facultad de Ciencias, Universidad Autónoma del Estado de México, Toluca, Mexico
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3
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Samad‐zada F, Kelemen EP, Rehan SM. The impact of geography and climate on the population structure and local adaptation in a wild bee. Evol Appl 2023; 16:1154-1168. [PMID: 37360027 PMCID: PMC10286232 DOI: 10.1111/eva.13558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 04/25/2023] [Accepted: 04/26/2023] [Indexed: 06/28/2023] Open
Abstract
Deciphering processes that contribute to genetic differentiation and divergent selection of natural populations is useful for evaluating the adaptive potential and resilience of organisms faced with various anthropogenic stressors. Insect pollinator species, including wild bees, provide critical ecosystem services but are highly susceptible to biodiversity declines. Here, we use population genomics to infer the genetic structure and test for evidence of local adaptation in an economically important native pollinator, the small carpenter bee (Ceratina calcarata). Using genome-wide SNP data (n = 8302), collected from specimens across the species' entire distribution, we evaluated population differentiation and genetic diversity and identified putative signatures of selection in the context of geographic and environmental variation. Results of the analyses of principal component and Bayesian clustering were concordant with the presence of two to three genetic clusters, associated with landscape features and inferred phylogeography of the species. All populations examined in our study demonstrated a heterozygote deficit, along with significant levels of inbreeding. We identified 250 robust outlier SNPs, corresponding to 85 annotated genes with known functional relevance to thermoregulation, photoperiod, and responses to various abiotic and biotic stressors. Taken together, these data provide evidence for local adaptation in a wild bee and highlight genetic responses of native pollinators to landscape and climate features.
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4
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Moreira LR, Smith BT. Convergent genomic signatures of local adaptation across a continental-scale environmental gradient. SCIENCE ADVANCES 2023; 9:eadd0560. [PMID: 37205757 PMCID: PMC10198635 DOI: 10.1126/sciadv.add0560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 04/17/2023] [Indexed: 05/21/2023]
Abstract
Convergent local adaptation offers a glimpse into the role of constraint and stochasticity in adaptive evolution, in particular the extent to which similar genetic mechanisms drive adaptation to common selective forces. Here, we investigated the genomics of local adaptation in two nonsister woodpeckers that are codistributed across an entire continent and exhibit remarkably convergent patterns of geographic variation. We sequenced the genomes of 140 individuals of Downy (Dryobates pubescens) and Hairy (Dryobates villosus) woodpeckers and used a suite of genomic approaches to identify loci under selection. We showed evidence that convergent genes have been targeted by selection in response to shared environmental pressures, such as temperature and precipitation. Among candidates, we found multiple genes putatively linked to key phenotypic adaptations to climate, including differences in body size (e.g., IGFPB) and plumage (e.g., MREG). These results are consistent with genetic constraints limiting the pathways of adaptation to broad climatic gradients, even after genetic backgrounds diverge.
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Affiliation(s)
- Lucas R. Moreira
- Department of Ecology, Evolution and Environmental Biology, Columbia University, NY, USA
- Department of Ornithology, American Museum of Natural History, New York City, NY, USA
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Brian Tilston Smith
- Department of Ornithology, American Museum of Natural History, New York City, NY, USA
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5
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Poore HA, Stuart YE, Rennison DJ, Roesti M, Hendry AP, Bolnick DI, Peichel CL. Repeated genetic divergence plays a minor role in repeated phenotypic divergence of lake-stream stickleback. Evolution 2023; 77:110-122. [PMID: 36622692 DOI: 10.1093/evolut/qpac025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 09/22/2022] [Accepted: 11/15/2022] [Indexed: 01/10/2023]
Abstract
Recent studies have shown that the repeated evolution of similar phenotypes in response to similar ecological conditions (here "parallel evolution") often occurs through mutations in the same genes. However, many previous studies have focused on known candidate genes in a limited number of systems. Thus, the question of how often parallel phenotypic evolution is due to parallel genetic changes remains open. Here, we used quantitative trait locus (QTL) mapping in F2 intercrosses between lake and stream threespine stickleback (Gasterosteus aculeatus) from four independent watersheds on Vancouver Island, Canada to determine whether the same QTL underlie divergence in the same phenotypes across, between, and within watersheds. We find few parallel QTL, even in independent crosses from the same watershed or for phenotypes that have diverged in parallel. These findings suggest that different mutations can lead to similar phenotypes. The low genetic repeatability observed in these lake-stream systems contrasts with the higher genetic repeatability observed in other stickleback systems. We speculate that differences in evolutionary history, gene flow, and/or the strength and direction of selection might explain these differences in genetic parallelism and emphasize that more work is needed to move beyond documenting genetic parallelism to identifying the underlying causes.
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Affiliation(s)
- Hilary A Poore
- Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland.,Divisions of Basic Sciences and Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | - Yoel E Stuart
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, United States.,Department of Biology, Loyola University Chicago, Chicago, IL, United States
| | - Diana J Rennison
- Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland.,Division of Biological Sciences, University of California at San Diego, La Jolla, CA, United States
| | - Marius Roesti
- Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Andrew P Hendry
- Redpath Museum and Department of Biology, McGill University, Montreal, Quebec, Canada
| | - Daniel I Bolnick
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, United States.,Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, United States
| | - Catherine L Peichel
- Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland.,Divisions of Basic Sciences and Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
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Whiting JR, Paris JR, van der Zee MJ, Fraser BA. AF‐vapeR
: A multivariate genome scan for detecting parallel evolution using allele frequency change vectors. Methods Ecol Evol 2022. [DOI: 10.1111/2041-210x.13952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- James R. Whiting
- Department of Biosciences University of Exeter Exeter UK
- Department of Biological Sciences University of Calgary Calgary Alberta Canada
| | - Josephine R. Paris
- Department of Biosciences University of Exeter Exeter UK
- Department of Health, Life and Environmental Sciences University of L'Aquila L'Aquila Italy
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7
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Reeve J, Li Q, Lindtke D, Yeaman S. Comparing genome scans among species of the stickleback order reveals three different patterns of genetic diversity. Ecol Evol 2022; 12:e8502. [PMID: 35127027 PMCID: PMC8796908 DOI: 10.1002/ece3.8502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 12/09/2021] [Accepted: 12/14/2021] [Indexed: 12/03/2022] Open
Abstract
Comparing genome scans among species is a powerful approach for investigating the patterns left by evolutionary processes. In particular, this offers a way to detect candidate genes that drive convergent evolution. We compared genome scan results to investigate if patterns of genetic diversity and divergence are shared among divergent species within the stickleback order (Gasterosteiformes): the threespine stickleback (Gasterosteus aculeatus), ninespine stickleback (Pungitius pungitus), and tubesnout (Aulorhynchus flavidus). Populations were sampled from the southern and northern edges of each species' range, to identify patterns associated with latitudinal changes in genetic diversity. Weak correlations in genetic diversity (F ST and expected heterozygosity) and three different patterns in the genomic landscape were found among these species. Additionally, no candidate genes for convergent evolution were detected. This is a counterexample to the growing number of studies that have shown overlapping genetic patterns, demonstrating that genome scan comparisons can be noisy due to the effects of several interacting evolutionary forces.
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Affiliation(s)
- James Reeve
- Department of Biological SciencesUniversity of CalgaryCalgaryAlbertaCanada
- Present address:
Tjärnö Marina LaboratoriumGöteborgs UniversitetStrömstadSweden
| | - Qiushi Li
- Department of Biological SciencesUniversity of CalgaryCalgaryAlbertaCanada
- Present address:
Institute of Chinese Materia MedicaChina Academy of Chinese Medical SciencesBeijingChina
| | - Dorothea Lindtke
- Department of Biological SciencesUniversity of CalgaryCalgaryAlbertaCanada
- Present address:
Institute of Plant SciencesUniversity of BernBernSwitzerland
| | - Samuel Yeaman
- Department of Biological SciencesUniversity of CalgaryCalgaryAlbertaCanada
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Samad-Zada F, Nakayama K, Russello MA. Genome-Wide Investigation of the Multiple Origins Hypothesis for Deep-Spawning Kokanee Salmon (Oncorhynchus nerka) across its Pan-Pacific Distribution. J Hered 2021; 112:602-613. [PMID: 34618898 DOI: 10.1093/jhered/esab060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 10/01/2021] [Indexed: 11/14/2022] Open
Abstract
Salmonids have emerged as important study systems for investigating molecular processes underlying parallel evolution given their tremendous life history variation. Kokanee, the resident form of anadromous sockeye salmon (Oncorhynchus nerka), have evolved multiple times across the species' pan-Pacific distribution, exhibiting multiple reproductive ecotypes including those that spawn in streams, on lake-shores, and at lake depths >50 m. The latter has only been detected in 5 locations in Japan and British Columbia, Canada. Here, we investigated the multiple origins hypothesis for deep-spawning kokanee, using 9721 single nucleotide polymorphisms distributed across the genome analyzed for the vast majority of known populations in Japan (Saiko Lake) and Canada (Anderson, Seton, East Barrière Lakes) relative to stream-spawning populations in both regions. We detected 397 outlier loci, none of which were robustly identified in paired-ecotype comparisons in Japan and Canada independently. Bayesian clustering and principal components analyses based on neutral loci revealed 6 distinct clusters, largely associated with geography or translocation history, rather than ecotype. Moreover, a high level of divergence between Canadian and Japanese populations, and between deep- and stream-spawning populations regionally, suggests the deep-spawning ecotype independently evolved on the 2 continents. On a finer level, Japanese kokanee populations exhibited low estimates of heterozygosity, significant levels of inbreeding, and reduced effective population sizes relative to Canadian populations, likely associated with transplantation history. Along with preliminary evidence for hybridization between deep- and stream-spawning ecotypes in Saiko Lake, these findings should be considered within the context of on-going kokanee fisheries management in Japan.
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Affiliation(s)
- Farida Samad-Zada
- Department of Biology, University of British Columbia, Kelowna, BC, Canada
| | - Kouji Nakayama
- Division of Applied Biosciences, Kyoto University, Kyoto, Japan
| | - Michael A Russello
- Department of Biology, University of British Columbia, Kelowna, BC, Canada
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9
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Whiting JR, Paris JR, van der Zee MJ, Parsons PJ, Weigel D, Fraser BA. Drainage-structuring of ancestral variation and a common functional pathway shape limited genomic convergence in natural high- and low-predation guppies. PLoS Genet 2021; 17:e1009566. [PMID: 34029313 PMCID: PMC8177651 DOI: 10.1371/journal.pgen.1009566] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 06/04/2021] [Accepted: 04/27/2021] [Indexed: 01/21/2023] Open
Abstract
Studies of convergence in wild populations have been instrumental in understanding adaptation by providing strong evidence for natural selection. At the genetic level, we are beginning to appreciate that the re-use of the same genes in adaptation occurs through different mechanisms and can be constrained by underlying trait architectures and demographic characteristics of natural populations. Here, we explore these processes in naturally adapted high- (HP) and low-predation (LP) populations of the Trinidadian guppy, Poecilia reticulata. As a model for phenotypic change this system provided some of the earliest evidence of rapid and repeatable evolution in vertebrates; the genetic basis of which has yet to be studied at the whole-genome level. We collected whole-genome sequencing data from ten populations (176 individuals) representing five independent HP-LP river pairs across the three main drainages in Northern Trinidad. We evaluate population structure, uncovering several LP bottlenecks and variable between-river introgression that can lead to constraints on the sharing of adaptive variation between populations. Consequently, we found limited selection on common genes or loci across all drainages. Using a pathway type analysis, however, we find evidence of repeated selection on different genes involved in cadherin signaling. Finally, we found a large repeatedly selected haplotype on chromosome 20 in three rivers from the same drainage. Taken together, despite limited sharing of adaptive variation among rivers, we found evidence of convergent evolution associated with HP-LP environments in pathways across divergent drainages and at a previously unreported candidate haplotype within a drainage.
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Affiliation(s)
- James R. Whiting
- Department of Biosciences, University of Exeter, Exeter, United Kingdom
| | | | | | - Paul J. Parsons
- Department of Biosciences, University of Exeter, Exeter, United Kingdom
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Detlef Weigel
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Bonnie A. Fraser
- Department of Biosciences, University of Exeter, Exeter, United Kingdom
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10
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Taylor RS, Manseau M, Horn RL, Keobouasone S, Golding GB, Wilson PJ. The role of introgression and ecotypic parallelism in delineating intraspecific conservation units. Mol Ecol 2020; 29:2793-2809. [PMID: 32567754 PMCID: PMC7496186 DOI: 10.1111/mec.15522] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 06/04/2020] [Accepted: 06/15/2020] [Indexed: 01/03/2023]
Abstract
Parallel evolution can occur through selection on novel mutations, standing genetic variation or adaptive introgression. Uncovering parallelism and introgressed populations can complicate management of threatened species as parallelism may have influenced conservation unit designations and admixed populations are not generally considered under legislations. We examined high coverage whole-genome sequences of 30 caribou (Rangifer tarandus) from across North America and Greenland, representing divergent intraspecific lineages, to investigate parallelism and levels of introgression contributing to the formation of ecotypes. Caribou are split into four subspecies and 11 extant conservation units, known as designatable units (DUs), in Canada. Using genomes from all four subspecies and six DUs, we undertake demographic reconstruction and confirm two previously inferred instances of parallel evolution in the woodland subspecies and uncover an additional instance of parallelism of the eastern migratory ecotype. Detailed investigations reveal introgression in the woodland subspecies, with introgressed regions found spread throughout the genomes encompassing both neutral and functional sites. Our investigations using whole genomes highlight the difficulties in unequivocally demonstrating parallelism through adaptive introgression in nonmodel species with complex demographic histories, with standing variation and introgression both potentially involved. Additionally, the impact of parallelism and introgression on conservation policy for management units needs to be considered in general, and the caribou designations will need amending in light of our results. Uncovering and decoupling parallelism and differential patterns of introgression will become prevalent with the availability of comprehensive genomic data from nonmodel species, and we highlight the need to incorporate this into conservation unit designations.
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Affiliation(s)
| | - Micheline Manseau
- Biology DepartmentTrent UniversityPeterboroughONCanada
- Landscape Science and Technology DivisionEnvironment and Climate Change CanadaOttawaONCanada
| | - Rebekah L. Horn
- Biology DepartmentTrent UniversityPeterboroughONCanada
- Columbia River Inter‐Tribal Fish CommissionHagermanIDUSA
| | - Sonesinh Keobouasone
- Landscape Science and Technology DivisionEnvironment and Climate Change CanadaOttawaONCanada
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11
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Whiting JR, Fraser BA. Contingent Convergence: The Ability To Detect Convergent Genomic Evolution Is Dependent on Population Size and Migration. G3 (BETHESDA, MD.) 2020; 10:677-693. [PMID: 31871215 PMCID: PMC7003088 DOI: 10.1534/g3.119.400970] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 12/19/2019] [Indexed: 12/02/2022]
Abstract
Outlier scans, in which the genome is scanned for signatures of selection, have become a prominent tool in studies of local adaptation, and more recently studies of genetic convergence in natural populations. However, such methods have the potential to be confounded by features of demographic history, such as population size and migration, which are considerably varied across natural populations. In this study, we use forward-simulations to investigate and illustrate how several measures of genetic differentiation commonly used in outlier scans (FST, DXY and Δπ) are influenced by demographic variation across multiple sampling generations. In a factorial design with 16 treatments, we manipulate the presence/absence of founding bottlenecks (N of founding individuals), prolonged bottlenecks (proportional size of diverging population) and migration rate between two populations with ancestral and diverged phenotypic optima. Our results illustrate known constraints of individual measures associated with reduced population size and a lack of migration; but notably we demonstrate how relationships between measures are similarly dependent on these features of demography. We find that false-positive signals of convergent evolution (the same simulated outliers detected in independent treatments) are attainable as a product of similar population size and migration treatments (particularly for DXY), and that outliers across different measures (for e.g., FST and DXY) can occur with little influence of selection. Taken together, we show how underappreciated, yet quantifiable measures of demographic history can influence commonly employed methods for detecting selection.
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Affiliation(s)
- James R Whiting
- Department of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, EX4 4QD
| | - Bonnie A Fraser
- Department of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, EX4 4QD
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