1
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Augustijnen H, Lucek K. Beyond gene flow: (non)-parallelism of secondary contact in a pair of highly differentiated sibling species. Mol Ecol 2024:e17488. [PMID: 39119885 DOI: 10.1111/mec.17488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 07/01/2024] [Accepted: 07/10/2024] [Indexed: 08/10/2024]
Abstract
Replicated secondary contact zones can provide insights into the barriers to gene flow that are important during speciation and can reveal to which degree secondary contact may result in similar evolutionary outcomes. Here, we studied two secondary contact zones between highly differentiated Alpine butterflies of the genus Erebia using whole-genome resequencing data. We assessed the genomic relationships between populations and species and found hybridization to be rare, with no to little current or historical introgression in either contact zone. There are large similarities between contact zones, consistent with an allopatric origin of interspecific differentiation, with no indications for ongoing reinforcing selection. Consistent with expected reduced effective population size, we further find that scaffolds related to the Z-chromosome show increased differentiation compared to the already high levels across the entire genome, which could also hint towards a contribution of the Z chromosome to species divergence in this system. Finally, we detected the presence of the endosymbiont Wolbachia, which can cause reproductive isolation between its hosts, in all E. cassioides, while it appears to be fully or largely absent in contact zone populations of E. tyndarus. We discuss how this rare pattern may have arisen and how it may have affected the dynamics of speciation upon secondary contact.
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Affiliation(s)
- Hannah Augustijnen
- Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Kay Lucek
- Biodiversity Genomics Laboratory, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
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2
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Martins ARP, Warren NB, McMillan WO, Barrett RDH. Spatiotemporal dynamics in butterfly hybrid zones. INSECT SCIENCE 2024; 31:328-353. [PMID: 37596954 DOI: 10.1111/1744-7917.13262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 07/13/2023] [Accepted: 07/21/2023] [Indexed: 08/21/2023]
Abstract
Evaluating whether hybrid zones are stable or mobile can provide novel insights for evolution and conservation biology. Butterflies exhibit high sensitivity to environmental changes and represent an important model system for the study of hybrid zone origins and maintenance. Here, we review the literature exploring butterfly hybrid zones, with a special focus on their spatiotemporal dynamics and the potential mechanisms that could lead to their movement or stability. We then compare different lines of evidence used to investigate hybrid zone dynamics and discuss the strengths and weaknesses of each approach. Our goal with this review is to reveal general conditions associated with the stability or mobility of butterfly hybrid zones by synthesizing evidence obtained using different types of data sampled across multiple regions and spatial scales. Finally, we discuss spatiotemporal dynamics in the context of a speciation/divergence continuum, the relevance of hybrid zones for conservation biology, and recommend key topics for future investigation.
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Affiliation(s)
- Ananda R Pereira Martins
- Redpath Museum, McGill University, 859 Sherbrooke Street West, Montreal, Quebec, Canada
- Smithsonian Tropical Research Institute, Gamboa, Panama City, Panama
| | - Natalie B Warren
- Redpath Museum, McGill University, 859 Sherbrooke Street West, Montreal, Quebec, Canada
| | - W Owen McMillan
- Smithsonian Tropical Research Institute, Gamboa, Panama City, Panama
| | - Rowan D H Barrett
- Redpath Museum, McGill University, 859 Sherbrooke Street West, Montreal, Quebec, Canada
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3
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Page E, Queste LM, Rosser N, Salazar PA, Nadeau NJ, Mallet J, Srygley RB, McMillan WO, Dasmahapatra KK. Pervasive mimicry in flight behavior among aposematic butterflies. Proc Natl Acad Sci U S A 2024; 121:e2300886121. [PMID: 38408213 PMCID: PMC10945825 DOI: 10.1073/pnas.2300886121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 01/10/2024] [Indexed: 02/28/2024] Open
Abstract
Flight was a key innovation in the adaptive radiation of insects. However, it is a complex trait influenced by a large number of interacting biotic and abiotic factors, making it difficult to unravel the evolutionary drivers. We investigate flight patterns in neotropical heliconiine butterflies, well known for mimicry of their aposematic wing color patterns. We quantify the flight patterns (wing beat frequency and wing angles) of 351 individuals representing 29 heliconiine and 9 ithomiine species belonging to ten color pattern mimicry groupings. For wing beat frequency and up wing angles, we show that heliconiine species group by color pattern mimicry affiliation. Convergence of down wing angles to mimicry groupings is less pronounced, indicating that distinct components of flight are under different selection pressures and constraints. The flight characteristics of the Tiger mimicry group are particularly divergent due to convergence with distantly related ithomiine species. Predator-driven selection for mimicry also explained variation in flight among subspecies, indicating that this convergence can occur over relatively short evolutionary timescales. Our results suggest that the flight convergence is driven by aposematic signaling rather than shared habitat between comimics. We demonstrate that behavioral mimicry can occur between lineages that have separated over evolutionary timescales ranging from <0.5 to 70 My.
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Affiliation(s)
- Edward Page
- Department of Biology, University of York, HeslingtonYO10 5DD, United Kingdom
| | - Lucie M. Queste
- Department of Biology, University of York, HeslingtonYO10 5DD, United Kingdom
- Division of Evolutionary Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried82152, Germany
| | - Neil Rosser
- Department of Biology, University of York, HeslingtonYO10 5DD, United Kingdom
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA02138
| | - Patricio A. Salazar
- Ecology and Evolutionary Biology, School of Biosciences, The University of Sheffield, SheffieldS10 2TN, United Kingdom
- Tree of Life Programme, Wellcome Sanger Institute, Hinxton, CambridgeCB10 1SA, United Kingdom
| | - Nicola J. Nadeau
- Ecology and Evolutionary Biology, School of Biosciences, The University of Sheffield, SheffieldS10 2TN, United Kingdom
| | - James Mallet
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA02138
| | - Robert B. Srygley
- Smithsonian Tropical Research Institute, Apartado, Panamá0843-03092, Republic of Panama
- Pest Management Research Unit, Agricultural Research Service, United States Department of Agriculture, Sidney, MT59270
| | - W. Owen McMillan
- Smithsonian Tropical Research Institute, Apartado, Panamá0843-03092, Republic of Panama
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4
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Quigley KM. Breeding and Selecting Corals Resilient to Global Warming. Annu Rev Anim Biosci 2024; 12:209-332. [PMID: 37931139 DOI: 10.1146/annurev-animal-021122-093315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
Selective breeding of resilient organisms is an emerging topic in marine conservation. It can help us predict how species will adapt in the future and how we can help restore struggling populations effectively in the present. Scleractinian corals represent a potential tractable model system given their widescale phenotypic plasticity across fitness-related traits and a reproductive life history based on mass synchronized spawning. Here, I explore the justification for breeding in corals, identify underutilized pathways of acclimation, and highlight avenues for quantitative targeted breeding from the coral host and symbiont perspective. Specifically, the facilitation of enhanced heat tolerance by targeted breeding of plasticity mechanisms is underutilized. Evidence from theoretical genetics identifies potential pitfalls, including inattention to physical and genetic characteristics of the receiving environment. Three criteria for breeding emerge from this synthesis: selection from warm, variable reefs that have survived disturbance. This information will be essential to protect what we have and restore what we can.
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Affiliation(s)
- K M Quigley
- The Minderoo Foundation, Perth, Western Australia, Australia;
- James Cook University, Townsville, Queensland, Australia
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5
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Shang H, Field DL, Paun O, Rendón-Anaya M, Hess J, Vogl C, Liu J, Ingvarsson PK, Lexer C, Leroy T. Drivers of genomic landscapes of differentiation across a Populus divergence gradient. Mol Ecol 2023; 32:4348-4361. [PMID: 37271855 DOI: 10.1111/mec.17034] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 04/20/2023] [Accepted: 05/23/2023] [Indexed: 06/06/2023]
Abstract
Speciation, the continuous process by which new species form, is often investigated by looking at the variation of nucleotide diversity and differentiation across the genome (hereafter genomic landscapes). A key challenge lies in how to determine the main evolutionary forces at play shaping these patterns. One promising strategy, albeit little used to date, is to comparatively investigate these genomic landscapes as progression through time by using a series of species pairs along a divergence gradient. Here, we resequenced 201 whole-genomes from eight closely related Populus species, with pairs of species at different stages along the divergence gradient to learn more about speciation processes. Using population structure and ancestry analyses, we document extensive introgression between some species pairs, especially those with parapatric distributions. We further investigate genomic landscapes, focusing on within-species (i.e. nucleotide diversity and recombination rate) and among-species (i.e. relative and absolute divergence) summary statistics of diversity and divergence. We observe relatively conserved patterns of genomic divergence across species pairs. Independent of the stage across the divergence gradient, we find support for signatures of linked selection (i.e. the interaction between natural selection and genetic linkage) in shaping these genomic landscapes, along with gene flow and standing genetic variation. We highlight the importance of investigating genomic patterns on multiple species across a divergence gradient and discuss prospects to better understand the evolutionary forces shaping the genomic landscapes of diversity and differentiation.
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Affiliation(s)
- Huiying Shang
- Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
- Vienna Graduate School of Population Genetics, Vienna, Austria
- Xi'an Botanical Garden of Shaanxi Province, Institute of Botany of Shaanxi Province, Xi'an, China
| | - David L Field
- School of Science, Edith Cowan University, Joondalup, Western Australia, Australia
| | - Ovidiu Paun
- Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
| | - Martha Rendón-Anaya
- Department of Plant Biology, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
| | - Jaqueline Hess
- Helmholtz Centre for Environmental Research, Halle (Saale), Germany
| | - Claus Vogl
- Department of Biomedical Sciences, Vetmeduni Vienna, Vienna, Austria
| | - Jianquan Liu
- Key Laboratory for Bio-resources and Eco-environment, College of Life Science, Sichuan University, Chengdu, China
| | - Pär K Ingvarsson
- Department of Plant Biology, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
| | - Christian Lexer
- Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
| | - Thibault Leroy
- Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
- GenPhySE, INRAE, INP, ENVT, Université de Toulouse, Castanet-Tolosan, France
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6
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Van Belleghem SM, Ruggieri AA, Concha C, Livraghi L, Hebberecht L, Rivera ES, Ogilvie JG, Hanly JJ, Warren IA, Planas S, Ortiz-Ruiz Y, Reed R, Lewis JJ, Jiggins CD, Counterman BA, McMillan WO, Papa R. High level of novelty under the hood of convergent evolution. Science 2023; 379:1043-1049. [PMID: 36893249 PMCID: PMC11000492 DOI: 10.1126/science.ade0004] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 02/08/2023] [Indexed: 03/11/2023]
Abstract
Little is known about the extent to which species use homologous regulatory architectures to achieve phenotypic convergence. By characterizing chromatin accessibility and gene expression in developing wing tissues, we compared the regulatory architecture of convergence between a pair of mimetic butterfly species. Although a handful of color pattern genes are known to be involved in their convergence, our data suggest that different mutational paths underlie the integration of these genes into wing pattern development. This is supported by a large fraction of accessible chromatin being exclusive to each species, including the de novo lineage-specific evolution of a modular optix enhancer. These findings may be explained by a high level of developmental drift and evolutionary contingency that occurs during the independent evolution of mimicry.
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Affiliation(s)
- Steven M. Van Belleghem
- Department of Biology, University of Puerto Rico, Rio Piedras, Puerto Rico
- Ecology, Evolution and Conservation Biology, Biology Department, KU Leuven, Leuven, Belgium
| | - Angelo A. Ruggieri
- Department of Biology, University of Puerto Rico, Rio Piedras, Puerto Rico
| | - Carolina Concha
- Department of Biology, University of Puerto Rico, Rio Piedras, Puerto Rico
- Smithsonian Tropical Research Institute, Panama City, Republic of Panama
| | - Luca Livraghi
- Smithsonian Tropical Research Institute, Panama City, Republic of Panama
- Department of Biological Sciences, The George Washington University, Washington, DC, USA
| | - Laura Hebberecht
- Smithsonian Tropical Research Institute, Panama City, Republic of Panama
- School of Biological Sciences, Bristol University, Bristol, UK
- Department of Zoology, University of Cambridge, Cambridge, UK
| | - Edgardo Santiago Rivera
- Department of Biology, University of Puerto Rico, Rio Piedras, Puerto Rico
- Smithsonian Tropical Research Institute, Panama City, Republic of Panama
- Department of Biomaterials, Universität Bayreuth, Bayreuth, Germany
| | - James G. Ogilvie
- Smithsonian Tropical Research Institute, Panama City, Republic of Panama
- Department of Biological Sciences, Auburn University, Auburn, Alabama, USA
| | - Joseph J. Hanly
- Smithsonian Tropical Research Institute, Panama City, Republic of Panama
- Department of Biological Sciences, The George Washington University, Washington, DC, USA
| | - Ian A. Warren
- Department of Zoology, University of Cambridge, Cambridge, UK
| | - Silvia Planas
- Molecular Sciences and Research Center, University of Puerto Rico, San Juan, Puerto Rico
| | - Yadira Ortiz-Ruiz
- Department of Biology, University of Puerto Rico, Rio Piedras, Puerto Rico
- Molecular Sciences and Research Center, University of Puerto Rico, San Juan, Puerto Rico
| | - Robert Reed
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
| | - James J. Lewis
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
| | | | | | - W. Owen McMillan
- Smithsonian Tropical Research Institute, Panama City, Republic of Panama
| | - Riccardo Papa
- Department of Biology, University of Puerto Rico, Rio Piedras, Puerto Rico
- Molecular Sciences and Research Center, University of Puerto Rico, San Juan, Puerto Rico
- Comprehensive Cancer Center, University of Puerto Rico, San Juan, Puerto Rico
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7
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Augustijnen H, Patsiou T, Lucek K. Secondary contact rather than coexistence-Erebia butterflies in the Alps. Evolution 2022; 76:2669-2686. [PMID: 36117267 PMCID: PMC9828779 DOI: 10.1111/evo.14615] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 08/05/2022] [Accepted: 08/30/2022] [Indexed: 01/22/2023]
Abstract
Secondary contact zones are ideal systems to study the processes that govern the evolution of reproductive barriers, especially at advanced stages of the speciation process. An increase in reproductive isolation resulting from selection against maladaptive hybrids is thought to contribute to reproductive barrier buildup in secondary contact zones. Although such processes have been invoked for many systems, it remains unclear to which extent they influence contact zone dynamics in nature. Here, we study a very narrow contact zone between the butterfly species Erebia cassioides and Erebia tyndarus in the Swiss Alps. We quantified phenotypic traits related to wing shape and reproduction as well as ecology to compare the degree of intra- and interspecific differentiation. Even though only very few first-generation hybrids occur, we find no strong indications for current reinforcing selection, suggesting that if reinforcement occurred in our system, it likely operated in the past. Additionally, we show that both species differ less in their ecological niche at the contact zone than elsewhere, which could explain why coexistence between these butterflies may currently not be possible.
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Affiliation(s)
- Hannah Augustijnen
- Department of Environmental SciencesUniversity of BaselBaselCH‐4056Switzerland
| | - Theofania Patsiou
- Institute of Plant SciencesUniversity of BernBernCH‐3013Switzerland,Department of BiologyUniversity of FribourgFribourgCH‐1700Switzerland
| | - Kay Lucek
- Department of Environmental SciencesUniversity of BaselBaselCH‐4056Switzerland
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8
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Repeated genetic adaptation to altitude in two tropical butterflies. Nat Commun 2022; 13:4676. [PMID: 35945236 PMCID: PMC9363431 DOI: 10.1038/s41467-022-32316-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 07/26/2022] [Indexed: 01/02/2023] Open
Abstract
Repeated evolution can provide insight into the mechanisms that facilitate adaptation to novel or changing environments. Here we study adaptation to altitude in two tropical butterflies, Heliconius erato and H. melpomene, which have repeatedly and independently adapted to montane habitats on either side of the Andes. We sequenced 518 whole genomes from altitudinal transects and found many regions differentiated between highland (~ 1200 m) and lowland (~ 200 m) populations. We show repeated genetic differentiation across replicate populations within species, including allopatric comparisons. In contrast, there is little molecular parallelism between the two species. By sampling five close relatives, we find that a large proportion of divergent regions identified within species have arisen from standing variation and putative adaptive introgression from high-altitude specialist species. Taken together our study supports a role for both standing genetic variation and gene flow from independently adapted species in promoting parallel local adaptation to the environment. Here, the authors study adaptation to altitude in 518 whole genomes from two species of tropical butterflies. They find repeated genetic differentiation within species, little molecular parallelism between these species, and introgression from closely related species, concluding that standing genetic variation promotes parallel local adaptation.
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9
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Duranton M, Pool JE. Interactions between natural selection and recombination shape the genomic landscape of introgression. Mol Biol Evol 2022; 39:6603329. [PMID: 35666817 PMCID: PMC9317171 DOI: 10.1093/molbev/msac122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Hybridization between lineages that have not reached complete reproductive isolation appears more and more like a common phenomenon. Indeed, speciation genomics studies have now extensively shown that many species' genomes have hybrid ancestry. However, genomic patterns of introgression are often heterogeneous across the genome. In many organisms, a positive correlation between introgression levels and recombination rate has been observed. It is usually explained by the purging of deleterious introgressed material due to incompatibilities. However, the opposite relationship was observed in a North American population of Drosophila melanogaster with admixed European and African ancestry. In order to explore how directional and epistatic selection can impact the relationship between introgression and recombination, we performed forward simulations of whole D. melanogaster genomes reflecting the North American population's history. Our results revealed that the simplest models of positive selection often yield negative correlations between introgression and recombination such as the one observed in D. melanogaster. We also confirmed that incompatibilities tend to produce positive introgression-recombination correlations. And yet, we identify parameter space under each model where the predicted correlation is reversed. These findings deepen our understanding of the evolutionary forces that may shape patterns of ancestry across genomes, and they strengthen the foundation for future studies aimed at estimating genome-wide parameters of selection in admixed populations.
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Affiliation(s)
- Maud Duranton
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, USA
| | - John E Pool
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, USA
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10
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Dalbosco Dell'Aglio D, Mena S, Mauxion R, McMillan WO, Montgomery S. Divergence in Heliconius flight behaviour is associated with local adaptation to different forest structures. J Anim Ecol 2022; 91:727-737. [PMID: 35157315 DOI: 10.1111/1365-2656.13675] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 02/02/2022] [Indexed: 11/29/2022]
Abstract
1. Micro-habitat choice plays a major role in shaping local patterns of biodiversity. In butterflies, stratification in flight height has an important role in maintaining community diversity. Despite its presumed importance, the role of behavioural shifts in early stages of speciation in response to differences in habitat structure is yet to be established. 2. Here, we investigated variation in flight height behaviour in two closely related Heliconius species, H. erato cyrbia and H. himera, which produce viable hybrids but are isolated across an environmental gradient, spanning lowland wet forest to high altitude scrub forest. Speciation in this pair is associated with strong assortative mating, but ecological isolation and local adaptation are also considered essential for complete reproductive isolation. 3. We quantified differences in flight height and forest structure across the environmental gradient and test the importance of resource distribution in explaining flight behaviour. We then use common garden experiments to test whether differences in flight height reflect individual responses to resource distribution or genetically determined shifts in foraging behaviour. 4. We found that the two species fly at different heights in the wild, and demonstrate that this can be explained by differences in the vertical distribution of plant resources. In both the wild and captivity, H. himera choose to fly lower and feed at lower positions, closely mirroring differences in resource availability in the wild. 5. Given expectations that foraging efficiency contributes to survival and reproductive success, we suggest that foraging behaviour may reflect local adaptation to divergent forest structures. Our results highlight the potential role of habitat-dependent divergence in behaviour during the early stages of speciation.
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Affiliation(s)
| | - Sebastián Mena
- Smithsonian Tropical Research Institute, Panama City, Panama
| | - Rémi Mauxion
- Smithsonian Tropical Research Institute, Panama City, Panama
| | - W Owen McMillan
- Smithsonian Tropical Research Institute, Panama City, Panama
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11
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Thawornwattana Y, Seixas FA, Yang Z, Mallet J. OUP accepted manuscript. Syst Biol 2022; 71:1159-1177. [PMID: 35169847 PMCID: PMC9366460 DOI: 10.1093/sysbio/syac009] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 02/01/2022] [Accepted: 02/08/2022] [Indexed: 11/21/2022] Open
Abstract
Introgressive hybridization plays a key role in adaptive evolution and species diversification in many groups of species. However, frequent hybridization and gene flow between species make estimation of the species phylogeny and key population parameters challenging. Here, we show that by accounting for phasing and using full-likelihood methods, introgression histories and population parameters can be estimated reliably from whole-genome sequence data. We employ the multispecies coalescent (MSC) model with and without gene flow to infer the species phylogeny and cross-species introgression events using genomic data from six members of the erato-sara clade of Heliconius butterflies. The methods naturally accommodate random fluctuations in genealogical history across the genome due to deep coalescence. To avoid heterozygote phasing errors in haploid sequences commonly produced by genome assembly methods, we process and compile unphased diploid sequence alignments and use analytical methods to average over uncertainties in heterozygote phase resolution. There is robust evidence for introgression across the genome, both among distantly related species deep in the phylogeny and between sister species in shallow parts of the tree. We obtain chromosome-specific estimates of key population parameters such as introgression directions, times and probabilities, as well as species divergence times and population sizes for modern and ancestral species. We confirm ancestral gene flow between the sara clade and an ancestral population of Heliconius telesiphe, a likely hybrid speciation origin for Heliconius hecalesia, and gene flow between the sister species Heliconius erato and Heliconius himera. Inferred introgression among ancestral species also explains the history of two chromosomal inversions deep in the phylogeny of the group. This study illustrates how a full-likelihood approach based on the MSC makes it possible to extract rich historical information of species divergence and gene flow from genomic data. [3s; bpp; gene flow; Heliconius; hybrid speciation; introgression; inversion; multispecies coalescent]
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Affiliation(s)
- Yuttapong Thawornwattana
- Correspondence to be sent to: Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA; E-mail: ; (Y.T. and J.M.); Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK; E-mail: (Z.Y.)
| | - Fernando A Seixas
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Ziheng Yang
- Correspondence to be sent to: Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA; E-mail: ; (Y.T. and J.M.); Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK; E-mail: (Z.Y.)
| | - James Mallet
- Correspondence to be sent to: Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA; E-mail: ; (Y.T. and J.M.); Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK; E-mail: (Z.Y.)
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