1
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Yukilevich R, Aoki F, Egan S, Zhang L. Coevolutionary Interactions between Sexual and Habitat Isolation during Reinforcement. Cold Spring Harb Perspect Biol 2024; 16:a041431. [PMID: 38316551 PMCID: PMC11065176 DOI: 10.1101/cshperspect.a041431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Speciation often involves the evolution of multiple genetic-based barriers to gene flow (i.e., "coupling"). However, barriers may exhibit a diversity of evolutionary interactions during speciation. These dynamics are important in reinforcement, where selection may favor different prezygotic isolating barriers to avoid maladaptive hybridization. Here we study the interaction between evolution of sexual and habitat isolation. We first review the empirical literature where both barriers were explicitly considered, and then develop a population genetic model of reinforcement. Most studies of both sexual and habitat isolation were found in phytophagous insect systems. In 76% of these studies, both barriers coevolved; the remaining cases either showed only habitat isolation (21%) or only sexual isolation (3%). Our two-allele genetic mechanism model of each barrier also found that these often coevolved, but habitat isolation was generally more effective during reinforcement. Depending on the fitness of hybrids (e.g., Dobzhansky-Muller incompatibilities) and initial migration rate, these barriers could either facilitate, curtail, or have no effect on each other. This indicates that basic parameters will alter the underlying evolutionary dynamics, and thus the nature of "speciation coupling" will be highly variable in natural systems. Finally, we studied initially asymmetrical migration rates and found that populations with higher initial emigration evolved stronger habitat isolation, while populations that initially received more immigrants exhibited stronger sexual isolation. These results are in line with observations in some empirical studies, but more data is needed to test their generality.
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Affiliation(s)
- Roman Yukilevich
- Department of Biology, Union College, Integrated Science and Engineering Complex, Schenectady, New York 12308, USA
| | - Fumio Aoki
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York 11794, USA
| | - Scott Egan
- Department of Biosciences, Rice University, Houston, Texas 77005, USA
| | - Linyi Zhang
- Department of Biological Sciences, George Washington University, Washington, D.C. 20052, USA
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2
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Castilho LB. Divergent preference functions generate directional selection in a jumping spider. Sci Rep 2023; 13:22794. [PMID: 38129564 PMCID: PMC10739821 DOI: 10.1038/s41598-023-50241-x] [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] [Received: 03/01/2023] [Accepted: 12/17/2023] [Indexed: 12/23/2023] Open
Abstract
Sexual selection has long been thought to promote speciation, but this possibility still remains a topic of controversy. Many theoretical models have been developed to understand the relationship between sexual selection and speciation, but such relationship seems complex and sexual selection has also been argued to prevent speciation in many scenarios. Here, I model for the first time the tendency of speciation due to sexual selection using realistic model parameters input collected from an existing species, the jumping spider Hasarius adansoni. I show that, even though the species has substantial female variance in preference (the model typically thought to link sexual selection to speciation), when realistic parameters are input in the model, it predicts directional selection, rather than disruptive selection. I propose that including realistic parameters in speciation models is a new tool that will help us understand how common sexual selection helps or hinders speciation in the real world.
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3
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Haghighatnia M, Machac A, Schmickl R, Lafon Placette C. Darwin's 'mystery of mysteries': the role of sexual selection in plant speciation. Biol Rev Camb Philos Soc 2023; 98:1928-1944. [PMID: 37337476 DOI: 10.1111/brv.12991] [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] [Received: 12/14/2022] [Revised: 06/02/2023] [Accepted: 06/07/2023] [Indexed: 06/21/2023]
Abstract
Sexual selection is considered one of the key processes that contribute to the emergence of new species. While the connection between sexual selection and speciation has been supported by comparative studies, the mechanisms that mediate this connection remain unresolved, especially in plants. Similarly, it is not clear how speciation processes within plant populations translate into large-scale speciation dynamics. Here, we review the mechanisms through which sexual selection, pollination, and mate choice unfold and interact, and how they may ultimately produce reproductive isolation in plants. We also overview reproductive strategies that might influence sexual selection in plants and illustrate how functional traits might connect speciation at the population level (population differentiation, evolution of reproductive barriers; i.e. microevolution) with evolution above the species level (macroevolution). We also identify outstanding questions in the field, and suitable data and tools for their resolution. Altogether, this effort motivates further research focused on plants, which might potentially broaden our general understanding of speciation by sexual selection, a major concept in evolutionary biology.
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Affiliation(s)
- Mohammadjavad Haghighatnia
- Department of Botany, Faculty of Science, Charles University, Benatska 2, Prague, CZ-128 01, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, Průhonice, 252 43, Czech Republic
| | - Antonin Machac
- Laboratory of Environmental Microbiology, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, Prague, 14220, Czech Republic
| | - Roswitha Schmickl
- Department of Botany, Faculty of Science, Charles University, Benatska 2, Prague, CZ-128 01, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Zámek 1, Průhonice, 252 43, Czech Republic
| | - Clément Lafon Placette
- Department of Botany, Faculty of Science, Charles University, Benatska 2, Prague, CZ-128 01, Czech Republic
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4
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Kustra MC, Alonzo SH. The coevolutionary dynamics of cryptic female choice. Evol Lett 2023; 7:191-202. [PMID: 37475752 PMCID: PMC10355280 DOI: 10.1093/evlett/qrad025] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 05/04/2023] [Accepted: 05/11/2023] [Indexed: 07/22/2023] Open
Abstract
In contrast to sexual selection on traits that affect interactions between the sexes before mating, little theoretical research has focused on the coevolution of postmating traits via cryptic female choice (when females bias fertilization toward specific males). We used simulation models to ask (a) whether and, if so, how nondirectional cryptic female choice (female-by-male interactions in fertilization success) causes deviations from models that focus exclusively on male-mediated postmating processes, and (b) how the risk of sperm competition, the strength of cryptic female choice, and tradeoffs between sperm number and sperm traits interact to influence the coevolutionary dynamics between cryptic female choice and sperm traits. We found that incorporating cryptic female choice can result in males investing much less in their ejaculates than predicted by models with sperm competition only. We also found that cryptic female choice resulted in the evolution of genetic correlations between cryptic female choice and sperm traits, even when the strength of cryptic female choice was weak, and the risk of sperm competition was low. This suggests that cryptic female choice may be important even in systems with low multiple mating. These genetic correlations increased with the risk of sperm competition and as the strength of cryptic female choice increased. When the strength of cryptic female choice and risk of sperm competition was high, extreme codivergence of sperm traits and cryptic female choice preference occurred even when the sperm trait traded off with sperm number. We also found that male traits lagged behind the evolution of female traits; this lag decreased with increasing strength of cryptic female choice and risk of sperm competition. Overall, our results suggest that cryptic female choice deserves more attention theoretically and may be driving trait evolution in ways just beginning to be explored.
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Affiliation(s)
- Matthew C Kustra
- Corresponding author: Department of Ecology and Evolutionary Biology Coastal Biology Building, 130 McAllister Way, University of California, Santa Cruz, CA 95060, United States.
| | - Suzanne H Alonzo
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95060, United States
- Institute of Marine Sciences, University of California, Santa Cruz, California 95060, USA
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5
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Murali G, Meiri S, Roll U. Chemical signaling glands are unlinked to species diversification in lizards. Evolution 2023; 77:1829-1841. [PMID: 37279331 DOI: 10.1093/evolut/qpad101] [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] [Received: 09/04/2022] [Revised: 05/17/2023] [Accepted: 05/31/2023] [Indexed: 06/08/2023]
Abstract
Sexual selection has long been thought to increase species diversification. Sexually selected traits, such as sexual signals that contribute to reproductive isolation, were thought to promote diversification. However, studies exploring links between sexually selected traits and species diversification have thus far primarily focused on visual or acoustic signals. Many animals often employ chemical signals (i.e., pheromones) for sexual communications, but large-scale analyses on the role of chemical communications in driving species diversification have been missing. Here, for the first time, we investigate whether traits associated with chemical communications-the presence of follicular epidermal glands-promote diversification across 6,672 lizard species. In most analyses, we found no strong association between the presence of follicular epidermal glands and species diversification rates, either across all lizard species or at lower phylogenetic scales. Previous studies suggest that follicular gland secretions act as species recognition signals that prevent hybridization during speciation in lizards. However, we show that geographic range overlap was no different in sibling species pairs with and without follicular epidermal glands. Together, these results imply that either follicular epidermal glands do not primarily function in sexual communications or sexually selected traits in general (here chemical communication) have a limited effect on species diversification. In our additional analysis accounting for sex-specific differences in glands, we again found no detectable effect of follicular epidermal glands on species diversification rates. Thus, our study challenges the general role of sexually selected traits in broad-scale species diversification patterns.
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Affiliation(s)
- Gopal Murali
- Jacob Blaustein Center for Scientific Cooperation, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
- Mitrani Department of Desert Ecology, The Swiss Institute for Dryland Environments and Energy Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, United States
| | - Shai Meiri
- School of Zoology and The Steinhardt Museum of Natural History, Tel Aviv University, Tel Aviv, Beersheva, Sede-Boqer Campus, 8499000, Israel
| | - Uri Roll
- Mitrani Department of Desert Ecology, The Swiss Institute for Dryland Environments and Energy Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
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6
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Cutter AD. Speciation and development. Evol Dev 2023; 25:289-327. [PMID: 37545126 DOI: 10.1111/ede.12454] [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] [Received: 03/07/2023] [Revised: 06/13/2023] [Accepted: 07/20/2023] [Indexed: 08/08/2023]
Abstract
Understanding general principles about the origin of species remains one of the foundational challenges in evolutionary biology. The genomic divergence between groups of individuals can spawn hybrid inviability and hybrid sterility, which presents a tantalizing developmental problem. Divergent developmental programs may yield either conserved or divergent phenotypes relative to ancestral traits, both of which can be responsible for reproductive isolation during the speciation process. The genetic mechanisms of developmental evolution involve cis- and trans-acting gene regulatory change, protein-protein interactions, genetic network structures, dosage, and epigenetic regulation, all of which also have roots in population genetic and molecular evolutionary processes. Toward the goal of demystifying Darwin's "mystery of mysteries," this review integrates microevolutionary concepts of genetic change with principles of organismal development, establishing explicit links between population genetic process and developmental mechanisms in the production of macroevolutionary pattern. This integration aims to establish a more unified view of speciation that binds process and mechanism.
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Affiliation(s)
- Asher D Cutter
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
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7
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Tosto NM, Beasley ER, Wong BBM, Mank JE, Flanagan SP. The roles of sexual selection and sexual conflict in shaping patterns of genome and transcriptome variation. Nat Ecol Evol 2023; 7:981-993. [PMID: 36959239 DOI: 10.1038/s41559-023-02019-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 02/21/2023] [Indexed: 03/25/2023]
Abstract
Sexual dimorphism is one of the most prevalent, and often the most extreme, examples of phenotypic variation within species, and arises primarily from genomic variation that is shared between females and males. Many sexual dimorphisms arise through sex differences in gene expression, and sex-biased expression is one way that a single, shared genome can generate multiple, distinct phenotypes. Although many sexual dimorphisms are expected to result from sexual selection, and many studies have invoked the possible role of sexual selection to explain sex-specific traits, the role of sexual selection in the evolution of sexually dimorphic gene expression remains difficult to differentiate from other forms of sex-specific selection. In this Review, we propose a holistic framework for the study of sex-specific selection and transcriptome evolution. We advocate for a comparative approach, across tissues, developmental stages and species, which incorporates an understanding of the molecular mechanisms, including genomic variation and structure, governing gene expression. Such an approach is expected to yield substantial insights into the evolution of genetic variation and have important applications in a variety of fields, including ecology, evolution and behaviour.
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Affiliation(s)
- Nicole M Tosto
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Emily R Beasley
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Bob B M Wong
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Judith E Mank
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sarah P Flanagan
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.
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8
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Rushworth CA, Wardlaw AM, Ross-Ibarra J, Brandvain Y. Conflict over fertilization underlies the transient evolution of reinforcement. PLoS Biol 2022; 20:e3001814. [PMID: 36228022 PMCID: PMC9560609 DOI: 10.1371/journal.pbio.3001814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 09/02/2022] [Indexed: 11/16/2022] Open
Abstract
When two species meet in secondary contact, the production of low fitness hybrids may be prevented by the adaptive evolution of increased prezygotic isolation, a process known as reinforcement. Theoretical challenges to the evolution of reinforcement are generally cast as a coordination problem, i.e., "how can statistical associations between traits and preferences be maintained in the face of recombination?" However, the evolution of reinforcement also poses a potential conflict between mates. For example, the opportunity costs to hybridization may differ between the sexes or species. This is particularly likely for reinforcement based on postmating prezygotic (PMPZ) incompatibilities, as the ability to fertilize both conspecific and heterospecific eggs is beneficial to male gametes, but heterospecific mating may incur a cost for female gametes. We develop a population genetic model of interspecific conflict over reinforcement inspired by "gametophytic factors", which act as PMPZ barriers among Zea mays subspecies. We demonstrate that this conflict results in the transient evolution of reinforcement-after females adaptively evolve to reject gametes lacking a signal common in conspecific gametes, this gamete signal adaptively introgresses into the other population. Ultimately, the male gamete signal fixes in both species, and isolation returns to pre-reinforcement levels. We interpret geographic patterns of isolation among Z. mays subspecies considering these findings and suggest when and how this conflict can be resolved. Our results suggest that sexual conflict over fertilization may pose an understudied obstacle to the evolution of reinforcement.
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Affiliation(s)
- Catherine A. Rushworth
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, Minnesota, United States of America
- Department of Evolution and Ecology and Center for Population Biology, University of California, Davis, California, United States of America
- Department of Biology, Utah State University, Logan, Utah, United States of America
| | - Alison M. Wardlaw
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, Minnesota, United States of America
- Canada Revenue Agency—Agence du revenu du Canada, Ottawa, Ontario, Canada
| | - Jeffrey Ross-Ibarra
- Department of Evolution and Ecology and Center for Population Biology, University of California, Davis, California, United States of America
- Genome Center, University of California, Davis, California, United States of America
| | - Yaniv Brandvain
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, Minnesota, United States of America
- * E-mail:
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9
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Ponkshe A, Endler JA. Joint effects of female preference intensity and frequency-dependent predation on the polymorphism maintenance in aposematic sexual traits. Ecol Evol 2022; 12:e9356. [PMID: 36248673 PMCID: PMC9551523 DOI: 10.1002/ece3.9356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 11/19/2022] Open
Abstract
Maintenance of variation in aposematic traits within and among populations is paradoxical because aposematic species are normally under positive frequency‐dependent predation (PFD), which is expected to erode variation. Aposematic traits can evolve in an ecological context where aposematic traits are simultaneously under mate choice. Here, we examine how the mate preference intensity affects the permissiveness of polymorphism in sexually selected aposematic traits under different PFD regimes. We use the haploid version of the classical sexual selection model and show that strong mate preferences can substantially increase the permissiveness of polymorphism in aposematic traits under different PFD regimes. The Fisher process can interact with PFD, and their interaction can promote the maintenance of polymorphism within populations when mate preferences are strong. We show that the same selective conditions that promote the maintenance of polymorphism within populations reduce the likelihood of divergence in aposematic traits among populations.
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Affiliation(s)
- Aditya Ponkshe
- Centre for Integrative Ecology, School of Life & Environmental SciencesDeakin UniversityWaurn PondsVictoriaAustralia,MINT Lab, Edificio Luis Vives, Campus EspinardoUniversity of MurciaMurciaSpain
| | - John A. Endler
- Centre for Integrative Ecology, School of Life & Environmental SciencesDeakin UniversityWaurn PondsVictoriaAustralia
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10
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Hare RM, Kennington WJ, Simmons LW. Evolutionary divergence via sexual selection acting on females in a species with sex role reversal. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Robin M. Hare
- Centre for Evolutionary Biology, School of Biological Sciences University of Western Australia Perth Australia
| | - W. Jason Kennington
- Centre for Evolutionary Biology, School of Biological Sciences University of Western Australia Perth Australia
| | - Leigh W. Simmons
- Centre for Evolutionary Biology, School of Biological Sciences University of Western Australia Perth Australia
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11
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Muralidhar P, Coop G, Veller C. Assortative mating enhances postzygotic barriers to gene flow via ancestry bundling. Proc Natl Acad Sci U S A 2022; 119:e2122179119. [PMID: 35858444 PMCID: PMC9335313 DOI: 10.1073/pnas.2122179119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 06/06/2022] [Indexed: 01/21/2023] Open
Abstract
Hybridization and subsequent genetic introgression are now known to be common features of the histories of many species, including our own. Following hybridization, selection often purges introgressed DNA genome-wide. While assortative mating can limit hybridization in the first place, it is also known to play an important role in postzygotic selection against hybrids and, thus, the purging of introgressed DNA. However, this role is usually thought of as a direct one: a tendency for mates to be conspecific reduces the sexual fitness of hybrids, reducing the transmission of introgressed ancestry. Here, we explore a second, indirect role of assortative mating as a postzygotic barrier to gene flow. Under assortative mating, parents covary in their ancestry, causing ancestry to be "bundled" in their offspring and later generations. This bundling effect increases ancestry variance in the population, enhancing the efficiency with which postzygotic selection purges introgressed DNA. Using whole-genome simulations, we show that the bundling effect can comprise a substantial portion of mate choice's overall effect as a postzygotic barrier to gene flow. We then derive a simple method for estimating the impact of the bundling effect from standard metrics of assortative mating. Applying this method to data from a diverse set of hybrid zones, we find that the bundling effect increases the purging of introgressed DNA by between 1.2-fold (in a baboon system with weak assortative mating) and 14-fold (in a swordtail system with strong assortative mating). Thus, assortative mating's bundling effect contributes substantially to the genetic isolation of species.
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Affiliation(s)
- Pavitra Muralidhar
- Department of Evolution and Ecology, University of California, 95616 Davis, CA
- Center for Population Biology, University of California, 95616 Davis, CA
| | - Graham Coop
- Department of Evolution and Ecology, University of California, 95616 Davis, CA
- Center for Population Biology, University of California, 95616 Davis, CA
| | - Carl Veller
- Department of Evolution and Ecology, University of California, 95616 Davis, CA
- Center for Population Biology, University of California, 95616 Davis, CA
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12
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Yukilevich R, Aoki F. Evolution of choosiness dictates whether search costs of mate choice enhance speciation by sexual selection. J Evol Biol 2022; 35:1045-1059. [PMID: 35830473 DOI: 10.1111/jeb.14036] [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: 11/02/2021] [Accepted: 05/25/2022] [Indexed: 11/29/2022]
Abstract
The role of sexual selection in speciation is implicated in both empirical case studies and larger comparative works. However, sexual selection faces two major problems in driving speciation. First, because females with novel preferences search for their initially rare males, search costs are expected to curtail initial sexual divergence. Second, if these populations come back into sympatry, sexual divergence may be erased due to hybridization. A major goal is to understand which conditions increase the likelihood of overcoming these problems. Here we generated a diploid population genetic model of how female search costs and evolution of female 'choosiness' (i.e. preference strength) interact to drive speciation in allopatry and secondary contact. We studied the model using numerical simulations in the context of two different male traits, ecologically 'arbitrary' versus 'magic' traits. First, in allopatry, without female search costs only minor and fluctuating sexual isolation evolved. In contrast, with female search costs, sexual isolation was highly curtailed with arbitrary male traits but was greatly facilitated with magic traits. However, because search costs selected for reduced choosiness, sexual isolation with magic traits was eventually eroded, the rate determined by the genetic architecture of choosiness. These factors also played a key role in secondary contact; with evolvable choosiness and female search costs, pure sexual selection models collapsed upon secondary contact. However, when we added selection against hybrids (i.e. reinforcement) to this model, we found that speciation could be maintained under a wide range of conditions with arbitrary male traits, but not with magic male traits. This surprisingly suggests that arbitrary male traits are in some cases more likely to aid speciation than magic male traits. We discuss these findings and relate them to empirical literature on female choosiness within species and in hybrids.
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Affiliation(s)
- Roman Yukilevich
- Department of Biology, Union College, Schenectady, New York, USA
| | - Fumio Aoki
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, USA
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13
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Barrera-Guzmán AO, Aleixo A, Faccio M, de Melo Dantas S, Weir JT. Gene flow, genomic homogenization and the timeline to speciation in Amazonian manakins. Mol Ecol 2022; 31:4050-4066. [PMID: 35665558 DOI: 10.1111/mec.16562] [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: 10/29/2021] [Revised: 02/28/2022] [Accepted: 05/12/2022] [Indexed: 11/26/2022]
Abstract
Phylogeographic studies of the most species rich region of the planet - the Amazon basin - repeatedly uncover genetically distinctive, allopatric lineages within currently named species, but understanding whether such lineages are reproductively isolated species is challenging. Here we harness the power of genome-wide datasets together with detailed phylogeographic sampling to both characterize the number of unique lineages and infer levels of reproductive isolation for three parapatric manakin species that make up the genus Pipra. The mitochondrial and nuclear genomes both support six distinctive lineages. The youngest lineages are now highly admixed with each other across major portions of their geographic ranges with one lineage now extinct in a genomically unadmixed state. In contrast, the oldest sets of lineages - dated to 1.4 million years - exhibit narrow hybrid zones. By fitting demographic models to parapatric lineage pairs we found that levels of gene flow and genomic homogenization decline with increasing evolutionary age. Only lineages descending from the 1.4 Ma basal node in the genus experience negligible gene flow, possess genomes resistant to homogenization and are separated by narrow hybrid zones. We conclude that a million years or more were required for Pipra manakins to become reproductively isolated. We suggest the six lineages be reclassified as two or three reproductively isolated species. Our unique approach to quantifying reproductive isolation in parapatric lineages could be applied broadly to other phylogeographic studies and would help determine species classification of the plethora of newly identified lineages in the Amazon basin and other regions.
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Affiliation(s)
- Alfredo O Barrera-Guzmán
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.,Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada.,Departamento de Biología Marina, Campus de Ciencias biológicas y Agropecuarias, Universidad Autónoma de Yucatán
| | - Alexandre Aleixo
- Pós-graduação em Biodiversidade e Evolução, Museu Paraense Emílio Goeldi, Belém, Brazil.,Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| | - Maya Faccio
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.,Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Sidnei de Melo Dantas
- Pós-graduação em Biodiversidade e Evolução, Museu Paraense Emílio Goeldi, Belém, Brazil
| | - Jason T Weir
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.,Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada.,Department of ornithology, Royal Ontario Museum, Toronto, Ontario, Canada
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14
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Jin B, Barbash DA, Castillo DM. Divergent selection on behavioural and chemical traits between reproductively isolated populations of Drosophila melanogaster. J Evol Biol 2022; 35:693-707. [PMID: 35411988 PMCID: PMC9320809 DOI: 10.1111/jeb.14007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 03/17/2022] [Accepted: 03/21/2022] [Indexed: 11/29/2022]
Abstract
Speciation is driven by traits that can act to prevent mating between nascent lineages, including male courtship and female preference for male traits. Mating barriers involving these traits evolve quickly because there is strong selection on males and females to maximize reproductive success, and the tight co-evolution of mating interactions can lead to rapid diversification of sexual behaviour. Populations of Drosophila melanogaster show strong asymmetrical reproductive isolation that is correlated with geographic origin. Using strains that capture natural variation in mating traits, we ask two key questions: which specific male traits are females selecting, and are these traits under divergent sexual selection? These questions have proven extremely challenging to answer, because even in closely related lineages males often differ in multiple traits related to mating behaviour. We address these questions by estimating selection gradients for male courtship and cuticular hydrocarbons for two different female genotypes. We identify specific behaviours and particular cuticular hydrocarbons that are under divergent sexual selection and could potentially contribute to premating reproductive isolation. Additionally, we report that a subset of these traits are plastic; males adjust these traits based on the identity of the female genotype they interact with. These results suggest that even when male courtship is not fixed between lineages, ongoing selection can act on traits that are important for reproductive isolation.
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Affiliation(s)
- Bozhou Jin
- Department of Molecular Biology and GeneticsCornell UniversityIthacaNew YorkUSA
| | - Daniel A. Barbash
- Department of Molecular Biology and GeneticsCornell UniversityIthacaNew YorkUSA
| | - Dean M. Castillo
- Department of BiologyUniversity of Nebraska at OmahaOmahaNebraskaUSA
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15
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Boughman JW, Servedio MR. The ecological stage maintains preference differentiation and promotes speciation. Ecol Lett 2022; 25:926-938. [DOI: 10.1111/ele.13970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 10/12/2021] [Accepted: 12/31/2021] [Indexed: 12/19/2022]
Affiliation(s)
- Janette W. Boughman
- Department of Integrative Biology; Ecology, Evolution & Behavior Program Michigan State University East Lansing Michigan USA
| | - Maria R. Servedio
- Department of Biology University of North Carolina Chapel Hill North Carolina USA
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16
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Rosenthal GG, Ryan MJ. Sexual selection and the ascent of women: Mate choice research since Darwin. Science 2022; 375:eabi6308. [PMID: 35050648 DOI: 10.1126/science.abi6308] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Darwin's theory of sexual selection fundamentally changed how we think about sex and evolution. The struggle over mating and fertilization is a powerful driver of diversification within and among species. Contemporaries dismissed Darwin's conjecture of a "taste for the beautiful" as favoring particular mates over others, but there is now overwhelming evidence for a primary role of both male and female mate choice in sexual selection. Darwin's misogyny precluded much analysis of the "taste"; an increasing focus on mate choice mechanisms before, during, and after mating reveals that these often evolve in response to selection pressures that have little to do with sexual selection on chosen traits. Where traits and preferences do coevolve, they can do so whether fitness effects on choosers are positive, neutral, or negative. The spectrum of selection on traits and preferences, and how traits and preferences respond to social effects, determine how sexual selection and mate choice influence broader-scale processes like reproductive isolation and population responses to environmental change.
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Affiliation(s)
- Gil G Rosenthal
- Department of Biology, University of Padova, Padova, Italy.,Centro de Investigaciones Científicas de las Huastecas "Aguazarca," Calnali, Hidalgo, Mexico
| | - Michael J Ryan
- Department of Integrative Biology, University of Texas, Austin, TX, USA.,Smithsonian Tropical Research Institute, Balboa, Republic of Panama
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17
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Tschol M, Reid JM, Bocedi G. Strong spatial population structure shapes the temporal coevolutionary dynamics of costly female preference and male display. Evolution 2021; 76:636-648. [PMID: 34964487 PMCID: PMC9302702 DOI: 10.1111/evo.14426] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/17/2021] [Accepted: 11/26/2021] [Indexed: 12/01/2022]
Abstract
Female mating preferences for exaggerated male display traits are commonplace. Yet, comprehensive understanding of the evolution and persistence of costly female preference through indirect (Fisherian) selection in finite populations requires some explanation for the persistence of additive genetic variance (Va) underlying sexual traits, given that directional preference is expected to deplete Va in display and hence halt preference evolution. However, the degree to which Va, and hence preference‐display coevolution, may be prolonged by spatially variable sexual selection arising solely from limited gene flow and genetic drift within spatially structured populations has not been examined. Our genetically and spatially explicit model shows that spatial population structure arising in an ecologically homogeneous environment can facilitate evolution and long‐term persistence of costly preference given small subpopulations and low dispersal probabilities. Here, genetic drift initially creates spatial variation in female preference, leading to persistence of Va in display through “migration‐bias” of genotypes maladapted to emerging local sexual selection, thus fueling coevolution of costly preference and display. However, costs of sexual selection increased the probability of subpopulation extinction, limiting persistence of high preference‐display genotypes. Understanding long‐term dynamics of sexual selection systems therefore requires joint consideration of coevolution of sexual traits and metapopulation dynamics.
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Affiliation(s)
- Maximilian Tschol
- School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK
| | - Jane M Reid
- School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK.,Centre for Biodiversity Dynamics, Institutt for Biologi, NTNU, Realfagbygget, Gløshaugen, Høgskoleringen 5, Trondheim, N-7491, Norway
| | - Greta Bocedi
- School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK
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18
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Peters L, Huisman J, Kruuk LEB, Pemberton JM, Johnston SE. Genomic analysis reveals a polygenic architecture of antler morphology in wild red deer (Cervus elaphus). Mol Ecol 2021; 31:1281-1298. [PMID: 34878674 DOI: 10.1111/mec.16314] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 11/26/2021] [Accepted: 12/01/2021] [Indexed: 11/28/2022]
Abstract
Sexually selected traits show large variation and rapid evolution across the animal kingdom, yet genetic variation often persists within populations despite apparent directional selection. A key step in solving this long-standing paradox is to determine the genetic architecture of sexually selected traits to understand evolutionary drivers and constraints at the genomic level. Antlers are a form of sexual weaponry in male red deer (Cervus elaphus). On the island of Rum, Scotland, males with larger antlers have increased breeding success, yet there has been no evidence of any response to selection at the genetic level. To try and understand the mechanisms underlying this observation, we investigate the genetic architecture of ten antler traits and their principal components using genomic data from >38,000 SNPs. We estimate the heritabilities and genetic correlations of the antler traits using a genomic relatedness approach. We then use genome-wide association and haplotype-based regional heritability to identify regions of the genome underlying antler morphology, and an empirical Bayes approach to estimate the underlying distributions of allele effect sizes. We show that antler morphology is highly repeatable over an individual's lifetime, heritable and has a polygenic architecture and that almost all antler traits are positively genetically correlated with some loci identified as having pleiotropic effects. Our findings suggest that a large mutational target and genetic covariances among antler traits, in part maintained by pleiotropy, are likely to contribute to the maintenance of genetic variation in antler morphology in this population.
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Affiliation(s)
- Lucy Peters
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Jisca Huisman
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Loeske E B Kruuk
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.,Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Josephine M Pemberton
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Susan E Johnston
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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19
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Clancey E, Johnson TR, Harmon LJ, Hohenlohe PA. Estimation of the strength of mate preference from mated pairs observed in the wild. Evolution 2021; 76:29-41. [PMID: 34792183 PMCID: PMC9300214 DOI: 10.1111/evo.14397] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 10/18/2021] [Indexed: 11/27/2022]
Abstract
A number of key processes in evolution are driven by individuals preferring mates with particular phenotypes. However, despite long‐standing interest, it is difficult to quantify the strength of mate preference from phenotypic observations in nature in a way that connects directly to key parameters in theoretical models. To bridge the gap between mathematical models and empirical data, we develop a novel maximum likelihood‐based method to estimate the strength and form of mate preference, where preference depends on traits expressed in both males and females. Using simulated data, we demonstrate that our method accurately infers model parameters, including the strength of mate preference and the optimal offset match between trait values in mated pairs when model assumptions are satisfied. Applying our method to two previous studies of assortative mating in marine gastropods and the European common frog, we support previous findings, but also give additional insight into the role of mate preference in each system. Our method can be generalized to a variety of plant and animal taxa that exhibit mating preferences to facilitate the testing of evolutionary hypotheses and link empirical data to theoretical models of assortative mating, sexual selection, and speciation.
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Affiliation(s)
- Erin Clancey
- Department of Mathematics and Statistical Science, University of Idaho, Moscow, Idaho, 83844, USA
| | - Timothy R Johnson
- Department of Mathematics and Statistical Science, University of Idaho, Moscow, Idaho, 83844, USA
| | - Luke J Harmon
- Department of Biological Sciences, Institute for Bioinformatics and Evolutionary Studies, University of Idaho, Moscow, Idaho, 83844, USA
| | - Paul A Hohenlohe
- Department of Mathematics and Statistical Science, University of Idaho, Moscow, Idaho, 83844, USA.,Department of Biological Sciences, Institute for Bioinformatics and Evolutionary Studies, University of Idaho, Moscow, Idaho, 83844, USA
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20
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Speciation by sexual selection: 20 years of progress. Trends Ecol Evol 2021; 36:1153-1163. [PMID: 34607719 DOI: 10.1016/j.tree.2021.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 08/26/2021] [Accepted: 09/01/2021] [Indexed: 11/21/2022]
Abstract
Twenty years ago, a seminal paper summarized the role of sexual selection in speciation as the coordinated evolution of (male) courtship signals and (female) preferences leading to prezygotic (behavioral) isolation between divergent lineages. Here, we discuss areas of progress that inspire an updated perspective. First, research has identified multiple mechanisms of sexual selection, in addition to female mate choice, that drive the origin and maintenance of species. Second, reviews and empirical data now conclude that sexual selection alone will rarely lead to reproductive isolation without ecological divergence, and we discuss the assumptions and possible exceptions underlying that conclusion. Finally, we consider the variable ways in which sexual selection contributes to divergence according to the spatial, temporal, social, ecological, and genomic context of speciation.
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21
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Lin SW, Lopardo L, Uhl G. Diversification through gustatory courtship: an X-ray micro-computed tomography study on dwarf spiders. Front Zool 2021; 18:51. [PMID: 34583721 PMCID: PMC8480068 DOI: 10.1186/s12983-021-00435-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 09/13/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sexual selection has been considered to promote diversification and speciation. Sexually dimorphic species have been used to explore the supposed effect, however, with mixed results. In dwarf spiders (Erigoninae), many species are sexually dimorphic-males possess marked prosomal modifications. These male traits vary from moderate elevations to bizarre shapes in various prosomal regions. Previous studies established that male dwarf spiders produce substances in these prosomal modifications that are taken up by the females. These substances can act as nuptial gifts, which increase the mating probability of males and the oviposition rate in females. Therefore, these dimorphic traits have evolved in the context of sexual selection. Here, we explore the evolutionary lability of this gustatory trait complex with the aim of assessing the role of this trait complex in species divergence by investigating (1) if erigonine modified prosomata are inherently linked to nuptial-gift-producing glands, (2) if the evolution of the glands evolution preceded that of the modified prosomal shapes, and by assessing (3) the occurrence of convergent/divergent evolution and cryptic differentiation. RESULTS We reconstructed the position and extent of the glandular tissue along with the muscular anatomy in the anterior part of the prosoma of 76 erigonine spiders and three outgroup species using X-ray micro-computed tomography. In all but one case, modified prosomata are associated with gustatory glands. We incorporated the location of glands and muscles into an existing matrix of somatic and genitalic morphological traits of these taxa and reanalyzed their phylogenetic relationship. Our analysis supports that the possession of glandular equipment is the ancestral state and that the manifold modifications of the prosomal shape have evolved convergently multiple times. We found differences in gland position between species with both modified and unmodified prosomata, and reported on seven cases of gland loss. CONCLUSIONS Our findings suggest that the occurrence of gustatory glands in sexually monomorphic ancestors has set the stage for the evolution of diverse dimorphic external modifications in dwarf spiders. Differences among congeners suggest that the gland position is highly susceptible to evolutionary changes. The multiple incidences might reflect costs of glandular tissue maintenance and nuptial feeding. Our results indicate divergent evolutionary patterns of gustatory-courtship-related traits, and thus a likely facilitating effect of sexual selection on speciation.
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Affiliation(s)
- Shou-Wang Lin
- Zoological Institute and Museum, General and Systematic Zoology, University of Greifswald, Greifswald, Germany.
| | - Lara Lopardo
- Zoological Institute and Museum, General and Systematic Zoology, University of Greifswald, Greifswald, Germany
| | - Gabriele Uhl
- Zoological Institute and Museum, General and Systematic Zoology, University of Greifswald, Greifswald, Germany
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22
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Harkness A, Brandvain Y. Non-self recognition-based self-incompatibility can alternatively promote or prevent introgression. THE NEW PHYTOLOGIST 2021; 231:1630-1643. [PMID: 33533069 DOI: 10.1111/nph.17249] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 01/19/2021] [Indexed: 06/12/2023]
Abstract
Self-incompatibility alleles (S-alleles), which prevent self-fertilisation in plants, have historically been expected to benefit from negative frequency-dependent selection and invade when introduced to a new population through gene flow. However, the most taxonomically widespread form of self-incompatibility, the ribonuclease-based system ancestral to the core eudicots, functions through collaborative non-self recognition, which can affect both short-term patterns of gene flow and the long-term process of S-allele diversification. We analysed a model of S-allele evolution in two populations connected by migration, focussing on comparisons among the fates of S-alleles initially unique to each population and those shared among populations. We found that both shared and unique S-alleles from the population with more unique S-alleles were usually fitter compared with S-alleles from the population with fewer S-alleles. Resident S-alleles often became extinct and were replaced by migrant S-alleles, although this outcome could be averted by pollen limitation or biased migration. Collaborative non-self recognition will usually either result in the whole-sale replacement of S-alleles from one population with those from another or else disfavour introgression of S-alleles altogether.
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Affiliation(s)
- Alexander Harkness
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St Paul, MN, 55108, USA
| | - Yaniv Brandvain
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, 55108, USA
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23
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Miller EC, Mesnick SL, Wiens JJ. Sexual Dichromatism Is Decoupled from Diversification over Deep Time in Fishes. Am Nat 2021; 198:232-252. [PMID: 34260865 DOI: 10.1086/715114] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractSexually selected traits have long been thought to drive diversification, but support for this hypothesis has been persistently controversial. In fishes, sexually dimorphic coloration is associated with assortative mating and speciation among closely related species, as shown in classic studies. However, it is unclear whether these results can generalize to explain diversity patterns across ray-finned fishes, which contain the majority of vertebrate species and 96% of fishes. Here, we use phylogenetic approaches to test for an association between sexual dichromatism and diversification rates (speciation minus extinction) in ray-finned fishes. We assembled dichromatism data for 10,898 species, a data set of unprecedented size. We found no difference in diversification rates between monochromatic and dichromatic species when including all ray-finned fishes. However, at lower phylogenetic scales (within orders and families), some intermediate-sized clades did show an effect of dichromatism on diversification. Surprisingly, dichromatism could significantly increase or decrease diversification rates. Moreover, we found no effect in many of the clades initially used to link dichromatism to speciation in fishes (e.g., cichlids) or an effect only at shallow scales (within subclades). Overall, we show how the effects of dichromatism on diversification are highly variable in direction and restricted to certain clades and phylogenetic scales.
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24
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Yukilevich R. Reproductive Character Displacement Drives Diversification of Male Courtship Songs in Drosophila. Am Nat 2021; 197:690-707. [PMID: 33989143 DOI: 10.1086/714046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractMale secondary sexual traits are one of the most striking and diverse features of the animal kingdom. While these traits are often thought to evolve via sexual selection, many questions remain about their patterns of diversification and their role in speciation. To address these questions, I performed a comparative study of precopulatory male courtship songs of 119 Drosophila species across 10 distinct species groups. I related song divergence to genetic distances, geographic relationships, and sexual isolation between species. On the basis of pairwise Euclidean song distances, species groups typically retained their phylogenetic signal while species within groups diverged five times more in sympatry relative to allopatry, producing a pattern of reproductive character displacement. This occurred despite similar genetic distances in allopatry and sympatry, was exaggerated among younger species pairs, and was driven primarily by the parameter interpulse interval. While sexual isolation in sympatry was high even with low song divergence, these variables were correlated with each other and with increased divergence of female mating preferences in sympatry. The widespread pattern of character displacement implies that allopatric divergence due to processes like sexual selection are very slow relative to sympatric processes such as reinforcement and reproductive interference in driving song diversification across Drosophila.
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25
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Martin CH, Gould KJ. Surprising spatiotemporal stability of a multi-peak fitness landscape revealed by independent field experiments measuring hybrid fitness. Evol Lett 2020; 4:530-544. [PMID: 33312688 PMCID: PMC7719547 DOI: 10.1002/evl3.195] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 07/23/2020] [Accepted: 09/14/2020] [Indexed: 12/14/2022] Open
Abstract
The effect of the environment on fitness in natural populations is a fundamental question in evolutionary biology. However, experimental manipulations of both environment and phenotype at the same time are rare. Thus, the relative importance of the competitive environment versus intrinsic organismal performance in shaping the location, height, and fluidity of fitness peaks and valleys remains largely unknown. Here, we experimentally tested the effect of competitor frequency on the complex fitness landscape driving adaptive radiation of a generalist and two trophic specialist pupfishes, a scale-eater and molluscivore, endemic to hypersaline lakes on San Salvador Island (SSI), Bahamas. We manipulated phenotypes, by generating 3407 F4/F5 lab-reared hybrids, and competitive environment, by altering the frequency of rare transgressive hybrids between field enclosures in two independent lake populations. We then tracked hybrid survival and growth rates across these four field enclosures for 3-11 months. In contrast to competitive speciation theory, we found no evidence that the frequency of hybrid phenotypes affected their survival. Instead, we observed a strikingly similar fitness landscape to a previous independent field experiment, each supporting multiple fitness peaks for generalist and molluscivore phenotypes and a large fitness valley isolating the divergent scale-eater phenotype. These features of the fitness landscape were stable across manipulated competitive environments, multivariate trait axes, and spatiotemporal heterogeneity. We suggest that absolute performance constraints and divergent gene regulatory networks shape macroevolutionary (interspecific) fitness landscapes in addition to microevolutionary (intraspecific) competitive dynamics. This interplay between organism and environment underlies static and dynamic features of the adaptive landscape.
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Affiliation(s)
- Christopher H. Martin
- Department of Integrative BiologyUniversity of California, BerkeleyBerkeleyCalifornia94720
- Museum of Vertebrate ZoologyUniversity of California, BerkeleyBerkeleyCalifornia94720
| | - Katelyn J. Gould
- Department of BiologyUniversity of North Carolina at Chapel HillChapel HillNorth Carolina27515
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26
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Tobias JA, Ottenburghs J, Pigot AL. Avian Diversity: Speciation, Macroevolution, and Ecological Function. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2020. [DOI: 10.1146/annurev-ecolsys-110218-025023] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The origin, distribution, and function of biological diversity are fundamental themes of ecology and evolutionary biology. Research on birds has played a major role in the history and development of these ideas, yet progress was for many decades limited by a focus on patterns of current diversity, often restricted to particular clades or regions. Deeper insight is now emerging from a recent wave of integrative studies combining comprehensive phylogenetic, environmental, and functional trait data at unprecedented scales. We review these empirical advances and describe how they are reshaping our understanding of global patterns of bird diversity and the processes by which it arises, with implications for avian biogeography and functional ecology. Further expansion and integration of data sets may help to resolve longstanding debates about the evolutionary origins of biodiversity and offer a framework for understanding and predicting the response of ecosystems to environmental change.
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Affiliation(s)
- Joseph A. Tobias
- Department of Life Sciences, Imperial College London, Silwood Park, Ascot SL5 7PY, United Kingdom
| | - Jente Ottenburghs
- Department of Evolutionary Biology, Uppsala University, 752 36 Uppsala, Sweden
| | - Alex L. Pigot
- Centre for Biodiversity and Environment Research, Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom
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27
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Hosner PA, Owens HL, Braun EL, Kimball RT. Phylogeny and diversification of the gallopheasants (Aves: Galliformes): Testing roles of sexual selection and environmental niche divergence. ZOOL SCR 2020. [DOI: 10.1111/zsc.12441] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peter A. Hosner
- Natural History Museum of Denmark University of Copenhagen Copenhagen Denmark
- Center for Macroecology, Evolution, and Climate Globe Institute University of Copenhagen Copenhagen Denmark
| | - Hannah L. Owens
- Center for Macroecology, Evolution, and Climate Globe Institute University of Copenhagen Copenhagen Denmark
| | - Edward L. Braun
- Department of Biology University of Florida Gainesville FL USA
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28
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Abstract
It has long been acknowledged that changes in the regulation of gene expression may account for major organismal differences. However, we still do not fully understand how changes in gene expression evolve and how do such changes influence organisms' differences. We are even less aware of the impact such changes might have in restricting gene flow between species. Here, we focus on studies of gene expression and speciation in the Drosophila model. We review studies that have identified gene interactions in post-mating reproductive isolation and speciation, particularly those that modulate male gene expression. We also address studies that have experimentally manipulated changes in gene expression to test their effect in post-mating reproductive isolation. We highlight the need for a more in-depth analysis of the role of selection causing disrupted gene expression of such candidate genes in sterile/inviable hybrids. Moreover, we discuss the relevance to incorporate more routinely assays that simultaneously evaluate the potential effects of environmental factors and genetic background in modulating plastic responses in male genes and their potential role in speciation.
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Affiliation(s)
- Bahar Patlar
- Department of Biology, University of Winnipeg, Winnipeg, MB R3B 2E9, Canada.,Department of Biology, University of Winnipeg, Winnipeg, MB R3B 2E9, Canada
| | - Alberto Civetta
- Department of Biology, University of Winnipeg, Winnipeg, MB R3B 2E9, Canada
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29
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Irwin DE. Assortative Mating in Hybrid Zones Is Remarkably Ineffective in Promoting Speciation. Am Nat 2020; 195:E150-E167. [DOI: 10.1086/708529] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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30
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Bürger R. Multilocus population-genetic theory. Theor Popul Biol 2020; 133:40-48. [DOI: 10.1016/j.tpb.2019.09.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 09/01/2019] [Accepted: 09/09/2019] [Indexed: 01/03/2023]
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31
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Eliason CM, Maia R, Parra JL, Shawkey MD. Signal evolution and morphological complexity in hummingbirds (Aves:
Trochilidae
). Evolution 2020; 74:447-458. [DOI: 10.1111/evo.13893] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 11/11/2019] [Accepted: 11/12/2019] [Indexed: 02/04/2023]
Affiliation(s)
- Chad M. Eliason
- Grainger Bioinformatics Center Field Museum of Natural History Chicago
| | - Rafael Maia
- Grainger Bioinformatics Center Field Museum of Natural History Chicago
| | - Juan L. Parra
- Grupo de Ecología y Evolución de Vertebrados, Instituto de Biología Universidad de Antioquia Medellín Colombia
| | - Matthew D. Shawkey
- Evolution and Optics of Nanostructures Group, Department of Biology University of Ghent 9000 Ghent Belgium
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32
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Marie-Orleach L, Sanz AM, Bailey NW, Ritchie MG. Does the response of D. melanogaster males to intrasexual competitors influence sexual isolation? Behav Ecol 2020. [DOI: 10.1093/beheco/arz209] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AbstractThe evolutionary consequences of phenotypic plasticity are debated. For example, reproductive barriers between incipient species can depend on the social environment, but most evidence for this comes from studies focusing on the effects of experiencing heterospecific individuals of the opposite sex. In Drosophila melanogaster, males are well known to invest strategically in ejaculate components and show different courtship behavior when reared in the presence of male competitors. It is unknown whether such plasticity in response to same-sex social experience influences sexual isolation, so we tested this using African and cosmopolitan lines, which show partial sexual isolation. Males were housed in social isolation, with homopopulation, or with heteropopulation male partners. We then measured their mating success, latency, and duration, their paternity share, and female remating success. Isolated males copulated for a shorter duration than males housed with any male partners. However, we found no difference in any measure between homopopulation or heteropopulation treatments. Our findings suggest that the male intrasexual competitive social environment does not strongly influence sexual isolation in D. melanogaster, and that plastic effects on reproductive isolation may be influenced more strongly by the experience of social isolation than by the composition of individuals within different social environments.
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Affiliation(s)
- Lucas Marie-Orleach
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews, United Kingdom
- Natural History Museum, University of Oslo, Oslo, Norway
- CNRS, Université de Rennes 1, ECOBIO (Écosystèmes, Biodiversité, Évolution)—UMR 6553, Rennes, France
| | - Annui M Sanz
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews, United Kingdom
| | - Nathan W Bailey
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews, United Kingdom
| | - Michael G Ritchie
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews, United Kingdom
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33
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Aubier TG, Kokko H, Joron M. Coevolution of male and female mate choice can destabilize reproductive isolation. Nat Commun 2019; 10:5122. [PMID: 31719522 PMCID: PMC6851176 DOI: 10.1038/s41467-019-12860-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 09/17/2019] [Indexed: 11/09/2022] Open
Abstract
Sexual interactions play an important role in the evolution of reproductive isolation, with important consequences for speciation. Theoretical studies have focused on the evolution of mate preferences in each sex separately. However, mounting empirical evidence suggests that premating isolation often involves mutual mate choice. Here, using a population genetic model, we investigate how female and male mate choice coevolve under a phenotype matching rule and how this affects reproductive isolation. We show that the evolution of female preferences increases the mating success of males with reciprocal preferences, favouring mutual mate choice. However, the evolution of male preferences weakens indirect selection on female preferences and, with weak genetic drift, the coevolution of female and male mate choice leads to periodic episodes of random mating with increased hybridization (deterministic 'preference cycling' triggered by stochasticity). Thus, counterintuitively, the process of establishing premating isolation proves rather fragile if both male and female mate choice contribute to assortative mating.
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Affiliation(s)
- Thomas G Aubier
- Centre d'Ecologie Fonctionnelle et Evolutive, CEFE - UMR 5175 - CNRS, Université de Montpellier, EPHE, Université Paul Valéry, 1919 route de Mende, F-34293, Montpellier 5, France.
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.
| | - Hanna Kokko
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Mathieu Joron
- Centre d'Ecologie Fonctionnelle et Evolutive, CEFE - UMR 5175 - CNRS, Université de Montpellier, EPHE, Université Paul Valéry, 1919 route de Mende, F-34293, Montpellier 5, France.
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34
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Lindsay WR, Andersson S, Bererhi B, Höglund J, Johnsen A, Kvarnemo C, Leder EH, Lifjeld JT, Ninnes CE, Olsson M, Parker GA, Pizzari T, Qvarnström A, Safran RJ, Svensson O, Edwards SV. Endless forms of sexual selection. PeerJ 2019; 7:e7988. [PMID: 31720113 PMCID: PMC6839514 DOI: 10.7717/peerj.7988] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 10/04/2019] [Indexed: 12/11/2022] Open
Abstract
In recent years, the field of sexual selection has exploded, with advances in theoretical and empirical research complementing each other in exciting ways. This perspective piece is the product of a “stock-taking” workshop on sexual selection and sexual conflict. Our aim is to identify and deliberate on outstanding questions and to stimulate discussion rather than provide a comprehensive overview of the entire field. These questions are organized into four thematic sections we deem essential to the field. First we focus on the evolution of mate choice and mating systems. Variation in mate quality can generate both competition and choice in the opposite sex, with implications for the evolution of mating systems. Limitations on mate choice may dictate the importance of direct vs. indirect benefits in mating decisions and consequently, mating systems, especially with regard to polyandry. Second, we focus on how sender and receiver mechanisms shape signal design. Mediation of honest signal content likely depends on integration of temporally variable social and physiological costs that are challenging to measure. We view the neuroethology of sensory and cognitive receiver biases as the main key to signal form and the ‘aesthetic sense’ proposed by Darwin. Since a receiver bias is sufficient to both initiate and drive ornament or armament exaggeration, without a genetically correlated or even coevolving receiver, this may be the appropriate ‘null model’ of sexual selection. Thirdly, we focus on the genetic architecture of sexually selected traits. Despite advances in modern molecular techniques, the number and identity of genes underlying performance, display and secondary sexual traits remains largely unknown. In-depth investigations into the genetic basis of sexual dimorphism in the context of long-term field studies will reveal constraints and trajectories of sexually selected trait evolution. Finally, we focus on sexual selection and conflict as drivers of speciation. Population divergence and speciation are often influenced by an interplay between sexual and natural selection. The extent to which sexual selection promotes or counteracts population divergence may vary depending on the genetic architecture of traits as well as the covariance between mating competition and local adaptation. Additionally, post-copulatory processes, such as selection against heterospecific sperm, may influence the importance of sexual selection in speciation. We propose that efforts to resolve these four themes can catalyze conceptual progress in the field of sexual selection, and we offer potential avenues of research to advance this progress.
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Affiliation(s)
- Willow R Lindsay
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - Staffan Andersson
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - Badreddine Bererhi
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - Jacob Höglund
- Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Arild Johnsen
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Charlotta Kvarnemo
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - Erica H Leder
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Jan T Lifjeld
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Calum E Ninnes
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden.,Department of Entomology and Nematology, University of Florida, Gainesville, FL, United States of America
| | - Mats Olsson
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - Geoff A Parker
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Tommaso Pizzari
- Department of Zoology, Edward Grey Institute, University of Oxford, Oxford, United Kingdom
| | - Anna Qvarnström
- Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Rebecca J Safran
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, United States of America
| | - Ola Svensson
- School of Natural Sciences, Technology and Environmental Studies, Södertörn University, Huddinge, Sweden
| | - Scott V Edwards
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, MA, United States of America.,Gothenburg Centre for Advanced Studies in Science and Technology, Chalmers University of Technology, Göteborg, Sweden
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35
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MARTIN CHRISTOPHERH, RICHARDS EMILIEJ. The paradox behind the pattern of rapid adaptive radiation: how can the speciation process sustain itself through an early burst? ANNUAL REVIEW OF ECOLOGY, EVOLUTION, AND SYSTEMATICS 2019; 50:569-593. [PMID: 36237480 PMCID: PMC9555815 DOI: 10.1146/annurev-ecolsys-110617-062443] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2023]
Abstract
Rapid adaptive radiation poses a distinct question apart from speciation and adaptation: what happens after one speciation event? That is, how are some lineages able to continue speciating through a rapid burst? This question connects global macroevolutionary patterns to microevolutionary processes. Here we review major features of rapid radiations in nature and their mismatch with theoretical models and what is currently known about speciation mechanisms. Rapid radiations occur on three major diversification axes - species richness, phenotypic disparity, and ecological diversity - with exceptional outliers on each axis. The paradox is that the hallmark early stage of adaptive radiation, a rapid burst of speciation and niche diversification, is contradicted by most existing speciation models which instead predict continuously decelerating speciation rates and niche subdivision through time. Furthermore, while speciation mechanisms such as magic traits, phenotype matching, and physical linkage of co-adapted alleles promote speciation, it is often not discussed how these mechanisms could promote multiple speciation events in rapid succession. Additional mechanisms beyond ecological opportunity are needed to understand how rapid radiations occur. We review the evidence for five emerging theories: 1) the 'transporter' hypothesis: introgression and the ancient origins of adaptive alleles, 2) the 'signal complexity' hypothesis: the dimensionality of sexual traits, 3) the connectivity of fitness landscapes, 4) 'diversity begets diversity', and 5) flexible stem/'plasticity first'. We propose new questions and predictions to guide future work on the mechanisms underlying the rare origins of rapid radiation.
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Affiliation(s)
- CHRISTOPHER H. MARTIN
- Department of Biology, University of North Carolina at Chapel Hill, NC, USA
- Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA
| | - EMILIE J. RICHARDS
- Department of Biology, University of North Carolina at Chapel Hill, NC, USA
- Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA
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36
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Janicke T, Marie-Orleach L, Aubier TG, Perrier C, Morrow EH. Assortative Mating in Animals and Its Role for Speciation. Am Nat 2019; 194:865-875. [PMID: 31738105 DOI: 10.1086/705825] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Evolutionary theory predicts that positive assortative mating-the tendency of similar individuals to mate with each other-plays a key role for speciation by generating reproductive isolation between diverging populations. However, comprehensive tests for an effect of assortative mating on species richness at the macroevolutionary scale are lacking. We used a meta-analytic approach to test the hypothesis that the strength of assortative mating within populations is positively related to species richness across a broad range of animal taxa. Specifically, we ran a phylogenetically independent meta-analysis using an extensive database of 1,447 effect sizes for the strength of assortative mating, encompassing 307 species from 130 families and 14 classes. Our results suggest that there is no relationship between the strength of assortative mating and species richness across and within major taxonomic groups and trait categories. Moreover, our analysis confirms an earlier finding that animals typically mate assortatively (global Pearson correlation coefficient: r=0.36; 95% confidence interval: 0.19-0.52) when accounting for phylogenetic nonindependence. We argue that future advances will rely on a better understanding of the evolutionary causes and consequences of the observed intra- and interspecific variation in the strength of assortative mating.
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37
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Civetta A, Ranz JM. Genetic Factors Influencing Sperm Competition. Front Genet 2019; 10:820. [PMID: 31572439 PMCID: PMC6753916 DOI: 10.3389/fgene.2019.00820] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 08/08/2019] [Indexed: 12/26/2022] Open
Abstract
Females of many different species often mate with multiple males, creating opportunities for competition among their sperm. Although originally unappreciated, sperm competition is now considered a central form of post-copulatory male–male competition that biases fertilization. Assays of differences in sperm competitive ability between males, and interactions between females and males, have made it possible to infer some of the main mechanisms of sperm competition. Nevertheless, classical genetic approaches have encountered difficulties in identifying loci influencing sperm competitiveness while functional and comparative genomic methodologies, as well as genetic variant association studies, have uncovered some interesting candidate genes. We highlight how the systematic implementation of approaches that incorporate gene perturbation assays in experimental competitive settings, together with the monitoring of progeny output or sperm features and behavior, has allowed the identification of genes unambiguously linked to sperm competitiveness. The emerging portrait from 45 genes (33 from fruit flies, 8 from rodents, 2 from nematodes, and 2 from ants) is their remarkable breadth of biological roles exerted through males and females, the non-preponderance of sperm genes, and their overall pleiotropic nature.
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Affiliation(s)
- Alberto Civetta
- Department of Biology, University of Winnipeg, Winnipeg, MB, Canada
| | - José M Ranz
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, United States
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38
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Abstract
The morphology of male genitalia evolves rapidly, probably driven by sexual selection. However, little is known about the genes underlying genitalia differences between species. Identifying these genes is key to understanding how sexual selection acts to produce rapid phenotypic change. We have found that the gene tartan underlies differences between male Drosophila mauritiana and Drosophila simulans in the size and bristle number of the claspers—genital projections that grasp the female during copulation. Moreover, since tartan encodes a protein that is involved in cell interactions, this may represent an alternative developmental mechanism for morphological change. Therefore, our study provides insights into the genetic and developmental bases for the rapid evolution of male genitalia and organ size more generally. Male genital structures are among the most rapidly evolving morphological traits and are often the only features that can distinguish closely related species. This process is thought to be driven by sexual selection and may reinforce species separation. However, while the genetic bases of many phenotypic differences have been identified, we still lack knowledge about the genes underlying evolutionary differences in male genital organs and organ size more generally. The claspers (surstyli) are periphallic structures that play an important role in copulation in insects. Here, we show that divergence in clasper size and bristle number between Drosophila mauritiana and Drosophila simulans is caused by evolutionary changes in tartan (trn), which encodes a transmembrane leucine-rich repeat domain protein that mediates cell–cell interactions and affinity. There are no fixed amino acid differences in trn between D. mauritiana and D. simulans, but differences in the expression of this gene in developing genitalia suggest that cis-regulatory changes in trn underlie the evolution of clasper morphology in these species. Finally, analyses of reciprocal hemizygotes that are genetically identical, except for the species from which the functional allele of trn originates, determined that the trn allele of D. mauritiana specifies larger claspers with more bristles than the allele of D. simulans. Therefore, we have identified a gene underlying evolutionary change in the size of a male genital organ, which will help to better understand not only the rapid diversification of these structures, but also the regulation and evolution of organ size more broadly.
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39
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Chen AL, Chen CC, Katoh T, Katoh TK, Watada M, Toda MJ, Ritchie MG, Wen SY. Evolution and diversity of the courtship repertoire in the Drosophila montium species group (Diptera: Drosophilidae). J Evol Biol 2019; 32:1124-1140. [PMID: 31386239 DOI: 10.1111/jeb.13515] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 07/31/2019] [Indexed: 02/04/2023]
Abstract
Changes in elements of courtship behaviour can influence sexual isolation between species. Large-scale analyses of changes, including loss and gain of courtship elements, across a relatively complete phylogenetic group are rare but needed to understand the significance of such changes, for example whether the gain and loss of courtship elements are essentially arbitrary or equally reversible. In most species of Drosophila, courtship, including singing, mainly occurs before mounting as premounting courtship. The Drosophila montium species group is unusual because loss of premounting courtship and gain of post-mounting one has been detected in this group. Here, we provide an extensive analysis on the courtship repertoire and songs of 42 species in this group. Synchronously captured video and audio recordings were analysed to describe courtship patterns and male courtship songs, and changes were analysed in a phylogenetic context. Ancestral state reconstruction suggests that a gain of post-mounting courtship singing at the ancestor of this species group has been accompanied by a concurrent decrease in the incidence of premounting courtship singing and has led to subsequent further decrease and eventually complete loss of premounting courtship song in several lineages. Alongside this evolutionary trend towards post-mounting courtship, sine song and a special type of "high pulse repetition song" have become more widely used for courtship during species diversification in the montium group. It is likely that the elaboration of post-mounting courtship behaviours is associated with changes in the relative importance of pre- and post-mounting components of mating systems, such as sperm competition or cryptic female choice.
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Affiliation(s)
- Ai-Li Chen
- Department of Entomology, College of Agriculture, South China Agricultural University, Guangzhou, China
| | - Chuan-Cheng Chen
- Department of Entomology, College of Agriculture, South China Agricultural University, Guangzhou, China
| | - Toru Katoh
- Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo, Japan
| | - Takehiro K Katoh
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime, Japan
| | - Masayoshi Watada
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime, Japan
| | - Masanori J Toda
- The Hokkaido University Museum, Hokkaido University, Sapporo, Japan
| | | | - Shuo-Yang Wen
- Department of Entomology, College of Agriculture, South China Agricultural University, Guangzhou, China
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40
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Alonzo SH, Servedio MR. Grey zones of sexual selection: why is finding a modern definition so hard? Proc Biol Sci 2019; 286:20191325. [PMID: 31431160 DOI: 10.1098/rspb.2019.1325] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Sexual selection has long been acknowledged as an important evolutionary force, capable of shaping phenotypes ranging from fascinating and unusual displays to cryptic traits whose function is only uncovered by careful study. Yet, despite decades of research, reaching a consensus definition of the term 'sexual selection' has proved difficult. Here we explore why arriving at a unifying definition of sexual selection is so hard. While some researchers have argued about whether sexual selection should be considered a form of natural selection, we concentrate on where the line between sexual selection and other forms of selection falls. We focus on identifying the 'grey zones' of sexual selection by illustrating cases in which application of the term 'sexual selection' would be considered controversial or ambiguous. We believe that clarifying why sexual selection is so difficult to define is an essential first step forward towards greater clarity, and if possible towards reaching a consensus definition. We suggest that a more nuanced perspective may be necessary, particularly one that specifies for cases of 'sexual selection' why the term is used or whether they fall into a grey zone.
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Affiliation(s)
- Suzanne H Alonzo
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Maria R Servedio
- Department of Biology, University of North Carolina, Chapel Hill, NC 27516, USA
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41
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Miles MC, Fuxjager MJ. Phenotypic Diversity Arises from Secondary Signal Loss in the Elaborate Visual Displays of Toucans and Barbets. Am Nat 2019; 194:152-167. [PMID: 31318292 DOI: 10.1086/704088] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Complexity and diversity are fundamental characteristics of life, but the relationship between the two remains murky. For example, both gaining and losing complexity can support diversity-so how exactly does complexity influence the emergence of unique phenotypes? Here we address this question by examining how complexity underlies the diversity of elaborate visual displays in the avian clade Ramphastides (toucans and barbets). These species communicate in part by using body movement and colorful ornaments on the tail. We find that sexual size dimorphism predicts the evolution of one specific signal, the tail-cock gesture, implying that tail cocking is more likely to evolve under stronger sexual selection. We also discover process-level constraints on the evolution of complexity: signals are gained along a strict order of operations, where the tail-cock gesture arises before other colors and gestures. Yet virtually any signal can be lost at any time. As a result, many extant phenotypes were more likely to arise through loss of complexity, highlighting the importance of secondary signal loss to phenotypic diversity. Collectively, our results demonstrate how sexual selection catalyzes the evolution of complex phenotypes, which indirectly support diversity by allowing different traits to be modified or lost in the future.
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42
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Janicke T, Ritchie MG, Morrow EH, Marie-Orleach L. Sexual selection predicts species richness across the animal kingdom. Proc Biol Sci 2019; 285:rspb.2018.0173. [PMID: 29720412 DOI: 10.1098/rspb.2018.0173] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 04/10/2018] [Indexed: 12/13/2022] Open
Abstract
Our improving knowledge of the animal tree of life consistently demonstrates that some taxa diversify more rapidly than others, but what contributes to this variation remains poorly understood. An influential hypothesis proposes that selection arising from competition for mating partners plays a key role in promoting speciation. However, empirical evidence showing a link between proxies of this sexual selection and species richness is equivocal. Here, we collected standardized metrics of sexual selection for a broad range of animal taxa, and found that taxonomic families characterized by stronger sexual selection on males show relatively higher species richness. Thus, our data support the hypothesis that sexual selection elevates species richness. This could occur either by promoting speciation and/or by protecting species against extinction.
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Affiliation(s)
- Tim Janicke
- Evolution, Behaviour and Environment Group, School of Life Sciences, University of Sussex, Brighton, UK.,Centre d'Écologie Fonctionnelle et Évolutive, UMR 5175, CNRS, Université de Montpellier, Université Paul-Valéry Montpellier, École Pratique des Hautes Études, 34090 Montpellier, France
| | - Michael G Ritchie
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews, UK
| | - Edward H Morrow
- Evolution, Behaviour and Environment Group, School of Life Sciences, University of Sussex, Brighton, UK
| | - Lucas Marie-Orleach
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews, UK
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43
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Castillo DM, Moyle LC. Conspecific sperm precedence is reinforced, but postcopulatory sexual selection weakened, in sympatric populations of Drosophila. Proc Biol Sci 2019; 286:20182535. [PMID: 30900533 PMCID: PMC6452082 DOI: 10.1098/rspb.2018.2535] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 03/06/2019] [Indexed: 12/21/2022] Open
Abstract
Sexual selection can accelerate speciation by driving the evolution of reproductive isolation, but forces driving speciation could also reciprocally feedback on sexual selection. This might be particularly important in the context of 'reinforcement', where selection acts directly to increase prezygotic barriers to reduce the cost of heterospecific matings. Using assays of sperm competition within and between two sister species, we show a signature of reinforcement where these species interact: populations of Drosophila pseudoobscura that co-occur with sister species D. persimilis have an elevated ability to outcompete heterospecific sperm, consistent with selection for increased postcopulatory isolation. We also find these D. pseudoobscura populations have decreased sperm competitive ability against conspecifics, reducing the opportunity for sexual selection within these populations. Our findings demonstrate that direct selection to increase reproductive isolation against other species can compromise the efficacy of sexual selection within species, a collateral effect of reproductive traits responding to heterospecific interactions.
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Affiliation(s)
- Dean M. Castillo
- Department of Biology, Indiana University, 1001 East Third Street, Bloomington, IN 47405, USA
- Department of Molecular Biology and Genetics, Cornell University, 526 Campus Road, Ithaca, NY 14853, USA
| | - Leonie C. Moyle
- Department of Biology, Indiana University, 1001 East Third Street, Bloomington, IN 47405, USA
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44
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Fox RJ, Fromhage L, Jennions MD. Sexual selection, phenotypic plasticity and female reproductive output. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180184. [PMID: 30966965 PMCID: PMC6365872 DOI: 10.1098/rstb.2018.0184] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2018] [Indexed: 01/17/2023] Open
Abstract
In a rapidly changing environment, does sexual selection on males elevate a population's reproductive output? If so, does phenotypic plasticity enhance or diminish any such effect? We outline two routes by which sexual selection can influence the reproductive output of a population: a genetic correlation between male sexual competitiveness and female lifetime reproductive success; and direct effects of males on females' breeding success. We then discuss how phenotypic plasticity of sexually selected male traits and/or female responses (e.g. plasticity in mate choice), as the environment changes, might influence how sexual selection affects a population's reproductive output. Two key points emerge. First, condition-dependent expression of male sexual traits makes it likely that sexual selection increases female fitness if reproductively successful males disproportionately transfer genes that are under natural selection in both sexes, such as genes for foraging efficiency. Condition-dependence is a form of phenotypic plasticity if some of the variation in net resource acquisition and assimilation is attributable to the environment rather than solely genetic in origin. Second, the optimal allocation of resources into different condition-dependent traits depends on their marginal fitness gains. As male condition improves, this can therefore increase or, though rarely highlighted, actually decrease the expression of sexually selected traits. It is therefore crucial to understand how condition determines male allocation of resources to different sexually selected traits that vary in their immediate effects on female reproductive output (e.g. ornaments versus coercive behaviour). In addition, changes in the distribution of condition among males as the environment shifts could reduce phenotypic variance in certain male traits, thereby reducing the strength of sexual selection imposed by females. Studies of adaptive evolution under rapid environmental change should consider the possibility that phenotypic plasticity of sexually selected male traits, even if it elevates male fitness, could have a negative effect on female reproductive output, thereby increasing the risk of population extinction. This article is part of the theme issue 'The role of plasticity in phenotypic adaptation to rapid environmental change'.
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Affiliation(s)
- Rebecca J. Fox
- Division of Ecology and Evolution, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Lutz Fromhage
- Department of Biological and Environmental Science, University of Jyvaskyla, PO Box 35, Jyvaskyla 40014, Finland
| | - Michael D. Jennions
- Division of Ecology and Evolution, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
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45
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Blankers T, Berdan EL, Hennig RM, Mayer F. Physical linkage and mate preference generate linkage disequilibrium for behavioral isolation in two parapatric crickets. Evolution 2019; 73:777-791. [PMID: 30820950 PMCID: PMC6593781 DOI: 10.1111/evo.13706] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/04/2019] [Indexed: 12/23/2022]
Abstract
Behavioral isolation is a potent barrier to gene flow and a source of striking diversity in the animal kingdom. However, it remains unclear if the linkage disequilibrium (LD) between sex‐specific traits required for behavioral isolation results mostly from physical linkage between signal and preference loci or from directional mate preferences. Here, we test this in the field crickets Gryllus rubens and G. texensis. These closely related species diverged with gene flow and have strongly differentiated songs and preference functions for the mate calling song rhythm. We map quantitative trait loci for signal and preference traits (pQTL) as well as for gene expression associated with these traits (eQTL). We find strong, positive genetic covariance between song traits and between song and preference. Our results show that this is in part explained by incomplete physical linkage: although both linked pQTL and eQTL couple male and female traits, major effect loci for different traits were never on the same chromosome. We suggest that the finely tuned, highly divergent preference functions are likely an additional source of LD between male and female traits in this system. Furthermore, pleiotropy of gene expression presents an underappreciated mechanism to link sexually dimorphic phenotypes.
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Affiliation(s)
- Thomas Blankers
- Department of Behavioral Physiology, Humboldt-Universität zu Berlin, Berlin, Germany.,Leibniz Institute for Evolution and Biodiversity Science, Museum für Naturkunde Berlin, Berlin, Germany.,Current address: Department of Evolutionary and Population Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Emma L Berdan
- Leibniz Institute for Evolution and Biodiversity Science, Museum für Naturkunde Berlin, Berlin, Germany.,Current address: Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
| | - R Matthias Hennig
- Department of Behavioral Physiology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Frieder Mayer
- Leibniz Institute for Evolution and Biodiversity Science, Museum für Naturkunde Berlin, Berlin, Germany.,Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany
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46
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Abstract
Animal signals-involving combinations of acoustic, chemical, visual, and behavioral cues-are among the most diverse traits in nature. Testing hypotheses about signal evolution has been hampered by difficulties with comparing highly divergent signals among species. In this Primer, I describe recent advances in capturing signals and studying their evolution. I highlight new findings using an information theory-based approach to quantifying signal variation in the diverse birds-of-paradise. Growing access to signal databases in tandem with development of new analytical tools will open up new avenues for studying the proximate mechanisms and ultimate evolutionary causes of signal variation, both within and among species.
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Affiliation(s)
- Chad M. Eliason
- Integrative Research Center, Field Museum of Natural History, Chicago, Illinois, United States of America
- * E-mail:
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47
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Miles MC, Goller F, Fuxjager MJ. Physiological constraint on acrobatic courtship behavior underlies rapid sympatric speciation in bearded manakins. eLife 2018; 7:e40630. [PMID: 30375331 PMCID: PMC6207423 DOI: 10.7554/elife.40630] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 10/11/2018] [Indexed: 12/28/2022] Open
Abstract
Physiology's role in speciation is poorly understood. Motor systems, for example, are widely thought to shape this process because they can potentiate or constrain the evolution of key traits that help mediate speciation. Previously, we found that Neotropical manakin birds have evolved one of the fastest limb muscles on record to support innovations in acrobatic courtship display (Fuxjager et al., 2016a). Here, we show how this modification played an instrumental role in the sympatric speciation of a manakin genus, illustrating that muscle specializations fostered divergence in courtship display speed, which may generate assortative mating. However, innovations in contraction-relaxation cycling kinetics that underlie rapid muscle performance are also punctuated by a severe speed-endurance trade-off, blocking further exaggeration of display speed. Sexual selection therefore potentiated phenotypic displacement in a trait critical to mate choice, all during an extraordinarily fast species radiation-and in doing so, pushed muscle performance to a new boundary altogether.
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Affiliation(s)
| | - Franz Goller
- University of UtahSalt Lake CityUnited States
- Institute for ZoophysiologyUniversity of MünsterGermany
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A Stochastic Model for Reproductive Isolation Under Asymmetrical Mating Preferences. Bull Math Biol 2018; 80:2502-2525. [PMID: 30094770 DOI: 10.1007/s11538-018-0479-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 07/23/2018] [Indexed: 10/28/2022]
Abstract
More and more evidence shows that mating preference is a mechanism that may lead to a reproductive isolation event. In this paper, a haploid population living on two patches linked by migration is considered. Individuals are ecologically and demographically neutral on the space and differ only on a trait, a or A, affecting both mating success and migration rate. The special feature of this paper is to assume that the strengths of the mating preference and the migration depend on the trait carried. Indeed, patterns of mating preferences are generally asymmetrical between the subspecies of a population. I prove that mating preference interacting with frequency-dependent migration behavior can lead to a reproductive isolation. Then, I describe the time before reproductive isolation occurs. To reach this result, I use an original method to study the limiting dynamical system, analyzing first the system without migration and adding migration with a perturbation method. Finally, I study how the time before reproductive isolation is influenced by the parameters of migration and of mating preferences, highlighting that large migration rates tend to favor types with weak mating preferences.
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Blankers T, Oh KP, Bombarely A, Shaw KL. The Genomic Architecture of a Rapid Island Radiation: Recombination Rate Variation, Chromosome Structure, and Genome Assembly of the Hawaiian Cricket Laupala. Genetics 2018; 209:1329-1344. [PMID: 29875253 PMCID: PMC6063224 DOI: 10.1534/genetics.118.300894] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 06/03/2018] [Indexed: 12/30/2022] Open
Abstract
Phenotypic evolution and speciation depend on recombination in many ways. Within populations, recombination can promote adaptation by bringing together favorable mutations and decoupling beneficial and deleterious alleles. As populations diverge, crossing over can give rise to maladapted recombinants and impede or reverse diversification. Suppressed recombination due to genomic rearrangements, modifier alleles, and intrinsic chromosomal properties may offer a shield against maladaptive gene flow eroding coadapted gene complexes. Both theoretical and empirical results support this relationship. However, little is known about this relationship in the context of behavioral isolation, where coevolving signals and preferences are the major hybridization barrier. Here we examine the genomic architecture of recently diverged, sexually isolated Hawaiian swordtail crickets (Laupala). We assemble a de novo genome and generate three dense linkage maps from interspecies crosses. In line with expectations based on the species' recent divergence and successful interbreeding in the laboratory, the linkage maps are highly collinear and show no evidence for large-scale chromosomal rearrangements. Next, the maps were used to anchor the assembly to pseudomolecules and estimate recombination rates across the genome to test the hypothesis that loci involved in behavioral isolation (song and preference divergence) are in regions of low interspecific recombination. Contrary to our expectations, the genomic region where a male song and female preference QTL colocalize is not associated with particularly low recombination rates. This study provides important novel genomic resources for an emerging evolutionary genetics model system and suggests that trait-preference coevolution is not necessarily facilitated by locally suppressed recombination.
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Affiliation(s)
- Thomas Blankers
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York 14853
| | - Kevin P Oh
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York 14853
| | - Aureliano Bombarely
- Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Kerry L Shaw
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York 14853
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50
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The Genetics of a Behavioral Speciation Phenotype in an Island System. Genes (Basel) 2018; 9:genes9070346. [PMID: 29996514 PMCID: PMC6070818 DOI: 10.3390/genes9070346] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/03/2018] [Accepted: 07/03/2018] [Indexed: 12/30/2022] Open
Abstract
Mating behavior divergence can make significant contributions to reproductive isolation and speciation in various biogeographic contexts. However, whether the genetic architecture underlying mating behavior divergence is related to the biogeographic history and the tempo and mode of speciation remains poorly understood. Here, we use quantitative trait locus (QTL) mapping to infer the number, distribution, and effect size of mating song rhythm variations in the crickets Laupala eukolea and Laupala cerasina, which occur on different islands (Maui and Hawaii). We then compare these results with a similar study of an independently evolving species pair that diverged within the same island. Finally, we annotate the L. cerasina transcriptome and test whether the QTL fall in functionally enriched genomic regions. We document a polygenic architecture behind the song rhythm divergence in the inter-island species pair that is remarkably similar to that previously found for an intra-island species pair in the same genus. Importantly, the QTL regions were significantly enriched for potential homologs of the genes involved in pathways that may be modulating the cricket song rhythm. These clusters of loci could constrain the spatial genomic distribution of the genetic variation underlying the cricket song variation and harbor several candidate genes that merit further study.
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