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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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Mate Choice in Molluscs of the Genus Littorina (Gastropoda: Littorinidae) from White Sea. DIVERSITY 2023. [DOI: 10.3390/d15020297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
We studied the reproductive behaviour associated with mate choice by size in three species of White Sea molluscs of the genus Littorina—L. saxatilis, L. obtusata and L. fabalis. Three behavioural patterns were revealed after a comparative analysis of the behaviour of the male snails. The males of L. obtusata, regardless of their size, could mate with all females but preferred to mate with larger ones. The males of L. fabalis chose females of their own size or larger. The males of L. saxatilis mated with females of approximately their own size. In the first case (L. obtusata), there is a free exchange of genes between all the size groups in the population. In the second case (L. fabalis), the gene transfer from small males to females of any size is free but the gene transfer from large males to small females is limited. In the third case (L. saxatilis), the gene flow is limited between groups of individuals of dramatically different size. Thus, in the case of L. saxatilis and L. fabalis, to varying degrees restriction of random mating associated with size assortativity in choosing a mating partner was expressed, which under certain circumstances (divergence of individuals in different econiches, the presence of ecotypes differing in size, lack of stronger natural selection in the other direction) can favour sympatric speciation. The males of all the three periwinkles’ species preferred larger females but sexual selection in favour of larger females was found only in L. obtusata. In the other two species, there were no statistically significant size differences between copulating and non-copulating females. This appears to be due to the occurrence of size-assortative mating in these species, which limits the ability of males to choose larger female partners.
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3
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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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4
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Home range use in the West Australian seahorse Hippocampus subelongatus is influenced by sex and partner’s home range but not by body size or paired status. J ETHOL 2021. [DOI: 10.1007/s10164-021-00698-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractGenetic monogamy is the rule for many species of seahorse, including the West Australian seahorse Hippocampus subelongatus. In this paper, we revisit mark-recapture and genetic data of H. subelongatus, allowing a detailed characterization of movement distances, home range sizes and home range overlaps for each individual of known sex, paired status (paired or unpaired) and body size. As predicted, we find that females have larger home ranges and move greater distances compared to males. We also confirm our prediction that the home ranges of pair-bonded individuals (members of a pair known to reproduce together) overlap more on average than home ranges of randomly chosen individuals of the opposite or same sex. Both sexes, regardless of paired status, had home ranges that overlapped with, on average, 6–10 opposite-sex individuals. The average overlap area among female home ranges was significantly larger than the overlap among male home ranges, probably reflecting females having larger home ranges combined with a female biased adult sex ratio. Despite a prediction that unpaired individuals would need to move around to find a mate, we find no evidence that unpaired members of either sex moved more than paired individuals of the same sex. We also find no effect of body size on home range size, distance moved or number of other individuals with which a home range overlapped. These patterns of movement and overlap in home ranges among individuals of both sexes suggest that low mate availability is not a likely explanation for the maintenance of monogamy in the West Australian seahorse.
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Masonjones H, Rose E, Elson J, Roberts B, Curtis-Quick J. High density, early maturing, and morphometrically unique Hippocampus erectus population makes a Bahamian pond a priority site for conservation. ENDANGER SPECIES RES 2019. [DOI: 10.3354/esr00949] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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6
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Kvarnemo C. Why do some animals mate with one partner rather than many? A review of causes and consequences of monogamy. Biol Rev Camb Philos Soc 2018; 93:1795-1812. [PMID: 29687607 DOI: 10.1111/brv.12421] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Revised: 03/27/2018] [Accepted: 04/03/2018] [Indexed: 10/17/2022]
Abstract
Why do some animals mate with one partner rather than many? Here, I investigate factors related to (i) spatial constraints (habitat limitation, mate availability), (ii) time constraints (breeding synchrony, length of breeding season), (iii) need for parental care, and (iv) genetic compatibility, to see what support can be found in different taxa regarding the importance of these factors in explaining the occurrence of monogamy, whether shown by one sex (monogyny or monandry) or by both sexes (mutual monogamy). Focusing on reproductive rather than social monogamy whenever possible, I review the empirical literature for birds, mammals and fishes, with occasional examples from other taxa. Each of these factors can explain mating patterns in some taxa, but not in all. In general, there is mixed support for how well the factors listed above predict monogamy. The factor that shows greatest support across taxa is habitat limitation. By contrast, while a need for parental care might explain monogamy in freshwater fishes and birds, there is clear evidence that this is not the case in marine fishes and mammals. Hence, reproductive monogamy does not appear to have a single overriding explanation, but is more taxon specific. Genetic compatibility is a promising avenue for future work likely to improve our understanding of monogamy and other mating patterns. I also discuss eight important consequences of reproductive monogamy: (i) parentage, (ii) parental care, (iii) eusociality and altruism, (iv) infanticide, (v) effective population size, (vi) mate choice before mating, (vii) sexual selection, and (viii) sexual conflict. Of these, eusociality and infanticide have been subject to debate, briefly summarised herein. A common expectation is that monogamy leads to little sexual conflict and no or little sexual selection. However, as reviewed here, sexual selection can be substantial under mutual monogamy, and both sexes can be subject to such selection. Under long-term mutual monogamy, mate quality is obviously more important than mate numbers, which in turn affects the need for pre-mating mate choice. Overall, I conclude that, despite much research on genetic mating patterns, reproductive monogamy is still surprisingly poorly understood and further experimental and comparative work is needed. This review identifies several areas in need of more data and also proposes new hypotheses to test.
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Affiliation(s)
- Charlotta Kvarnemo
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, SE-405 30 Gothenburg, Sweden
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7
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Harrison HB, Berumen ML, Saenz-Agudelo P, Salas E, Williamson DH, Jones GP. Widespread hybridization and bidirectional introgression in sympatric species of coral reef fish. Mol Ecol 2018; 26:5692-5704. [PMID: 29080371 DOI: 10.1111/mec.14279] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 07/07/2017] [Accepted: 07/17/2017] [Indexed: 12/13/2022]
Abstract
Coral reefs are highly diverse ecosystems, where numerous closely related species often coexist. How new species arise and are maintained in these high geneflow environments have been long-standing conundrums. Hybridization and patterns of introgression between sympatric species provide a unique insight into the mechanisms of speciation and the maintenance of species boundaries. In this study, we investigate the extent of hybridization between two closely related species of coral reef fish: the common coral trout (Plectropomus leopardus) and the bar-cheek coral trout (Plectropomus maculatus). Using a complementary set of 25 microsatellite loci, we distinguish pure genotype classes from first- and later-generation hybrids, identifying 124 interspecific hybrids from a collection of 2,991 coral trout sampled in inshore and mid-shelf reefs of the southern Great Barrier Reef. Hybrids were ubiquitous among reefs, fertile and spanned multiple generations suggesting both ecological and evolutionary processes are acting to maintain species barriers. We elaborate on these finding to investigate the extent of genomic introgression and admixture from 2,271 SNP loci recovered from a ddRAD library of pure and hybrid individuals. An analysis of genomic clines on recovered loci indicates that 261 SNP loci deviate from a model of neutral introgression, of which 132 indicate a pattern of introgression consistent with selection favouring both hybrid and parental genotypes. Our findings indicate genome-wide, bidirectional introgression between two sympatric species of coral reef fishes and provide further support to a growing body of evidence for the role of hybridization in the evolution of coral reef fishes.
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Affiliation(s)
- Hugo B Harrison
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia
| | - Michael L Berumen
- Division of Biological and Environmental Science and Engineering, Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Pablo Saenz-Agudelo
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
| | - Eva Salas
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA.,California Academy of Sciences, San Francisco, CA, USA
| | - David H Williamson
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia
| | - Geoffrey P Jones
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia.,College of Marine and Environmental Sciences, James Cook University, Townsville, QLD, Australia
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8
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Baruch O, Mendel Z, Scharf I, Harari AR. Mating system, mate choice and parental care in a bark beetle. BULLETIN OF ENTOMOLOGICAL RESEARCH 2017; 107:611-619. [PMID: 28382882 DOI: 10.1017/s0007485317000311] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The cypress bark beetle, Phloeosinus armatus, is a common element of the dying cypress tree system in East-Mediterranean countries. Adult beetles congregate for breeding on this ephemeral resource. We studied three traits that characterize this beetle's sexual behavior and linked them to its reproductive success: mating system, mate choice, and parental care. We found that the females are the 'pioneering sex', excavating the mating chamber. The average female is slightly larger than the male, and female and male body size is correlated, demonstrating size-assortative mating. The time it takes for a male to enter the mating chamber is positively correlated with female size and negatively correlated with its own size, which is perhaps responsible for this assortative mating. Males remain in the gallery during the period of oviposition, gradually leaving soon after the eggs hatch. The number of eggs laid and tunnel length are positively correlated with male body size. Finally, in the presence of both parents, more eggs are laid than when the female alone is present, demonstrating the important contribution of biparental care for reproductive success. We suggest that the interaction between a monogamous mating system, assortative mating, and biparental care contributes to reproductive success.
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Affiliation(s)
- O Baruch
- Department of Entomology,The Volcani Center,Bet Dagan,Israel
| | - Z Mendel
- Department of Entomology,The Volcani Center,Bet Dagan,Israel
| | - I Scharf
- Department of Zoology,Faculty of Life Sciences,Tel Aviv University,Tel Aviv,Israel
| | - A R Harari
- Department of Entomology,The Volcani Center,Bet Dagan,Israel
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9
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Moura RR, Gonzaga MO. Temporal variation in size-assortative mating and male mate choice in a spider with amphisexual care. Naturwissenschaften 2017; 104:28. [DOI: 10.1007/s00114-017-1448-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 02/15/2017] [Accepted: 02/18/2017] [Indexed: 11/30/2022]
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10
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Faleiro F, Almeida AJ, Ré P, Narciso L. Size does matter: An assessment of reproductive potential in seahorses. Anim Reprod Sci 2016; 170:61-7. [DOI: 10.1016/j.anireprosci.2016.04.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 03/23/2016] [Accepted: 04/03/2016] [Indexed: 10/22/2022]
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11
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Otero-Ferrer F, Herrera R, López A, Socorro J, Molina L, Bouza C. First records of Hippocampus algiricus in the Canary Islands (north-east Atlantic Ocean) with an observation of hybridization with Hippocampus hippocampus. JOURNAL OF FISH BIOLOGY 2015; 87:1080-1089. [PMID: 26365616 DOI: 10.1111/jfb.12760] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Accepted: 06/26/2015] [Indexed: 06/05/2023]
Abstract
Morphometric and genetic analyses confirmed the first records of the West African seahorse Hippocampus algiricus at Gran Canaria Island (north-east Atlantic Ocean), and also the first evidence of interspecific hybridization in seahorses. These results provide additional data on the distribution of H. algiricus that may help to establish future conservation strategies, and uncover a new potential sympatric scenario between H. algiricus and Hippocampus hippocampus.
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Affiliation(s)
- F Otero-Ferrer
- Grupo de Investigación en Acuicultura (GIA) and Universidad de Las Palmas de Gran Canaria (ULPGC), Taliarte, 35200 Telde, Las Palmas, Canary Islands, Spain
| | - R Herrera
- Servicio de Biodiversidad, Viceconsejería de Medio Ambiente, Consejería de Agricultura, Ganadería, Pesca y Medio Ambiente, C/Agustín Millares Carlo, 18, 35003, Las Palmas, Canary Islands, Spain
| | - A López
- Departamento de Xenética, Facultade de Veterinaria, Campus de Lugo, Universidade de Santiago de Compostela, Av. Carballo Calero s/n. 27002, Lugo, Spain
| | - J Socorro
- Grupo de Investigación en Acuicultura (GIA) and Universidad de Las Palmas de Gran Canaria (ULPGC), Taliarte, 35200 Telde, Las Palmas, Canary Islands, Spain
| | - L Molina
- Grupo de Investigación en Acuicultura (GIA) and Universidad de Las Palmas de Gran Canaria (ULPGC), Taliarte, 35200 Telde, Las Palmas, Canary Islands, Spain
| | - C Bouza
- Departamento de Xenética, Facultade de Veterinaria, Campus de Lugo, Universidade de Santiago de Compostela, Av. Carballo Calero s/n. 27002, Lugo, Spain
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12
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Rougemont Q, Gaigher A, Lasne E, Côte J, Coke M, Besnard AL, Launey S, Evanno G. Low reproductive isolation and highly variable levels of gene flow reveal limited progress towards speciation between European river and brook lampreys. J Evol Biol 2015; 28:2248-63. [PMID: 26348652 DOI: 10.1111/jeb.12750] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 09/02/2015] [Accepted: 09/02/2015] [Indexed: 01/10/2023]
Abstract
Ecologically based divergent selection is a factor that could drive reproductive isolation even in the presence of gene flow. Population pairs arrayed along a continuum of divergence provide a good opportunity to address this issue. Here, we used a combination of mating trials, experimental crosses and population genetic analyses to investigate the evolution of reproductive isolation between two closely related species of lampreys with distinct life histories. We used microsatellite markers to genotype over 1000 individuals of the migratory parasitic river lamprey (Lampetra fluviatilis) and freshwater-resident nonparasitic brook lamprey (Lampetra planeri) distributed in 10 sympatric and parapatric population pairs in France. Mating trials, parentage analyses and artificial fertilizations demonstrated a low level of reproductive isolation between species even though size-assortative mating may contribute to isolation. Most parapatric population pairs were strongly differentiated due to the joint effects of geographic distance and barriers to migration. In contrast, we found variable levels of gene flow between sympatric populations ranging from panmixia to moderate differentiation, which indicates a gradient of divergence with some population pairs that may correspond to alternative morphs or ecotypes of a single species and others that remain partially isolated. Ecologically based divergent selection may explain these variable levels of divergence among sympatric population pairs, but incomplete genome swamping following secondary contact could have also played a role. Overall, this study illustrates how highly differentiated phenotypes can be maintained despite high levels of gene flow that limit the progress towards speciation.
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Affiliation(s)
- Q Rougemont
- UMR 985 Ecologie et Santé des Ecosystèmes, INRA, Rennes, France.,UMR ESE, Agrocampus Ouest, Rennes, France
| | - A Gaigher
- UMR 985 Ecologie et Santé des Ecosystèmes, INRA, Rennes, France.,UMR ESE, Agrocampus Ouest, Rennes, France.,Laboratory for Conservation Biology, Department of Ecology and Evolution, University of Lausanne, Biophore, Switzerland
| | - E Lasne
- Muséum National d'Histoire Naturelle, CRESCO, Dinard, France.,UMR CARRTEL, INRA, Thonon-les-Bains, France
| | - J Côte
- UMR 985 Ecologie et Santé des Ecosystèmes, INRA, Rennes, France.,UMR ESE, Agrocampus Ouest, Rennes, France
| | - M Coke
- Unité Expérimentale d'Ecologie et d'Ecotoxicologie Aquatique, INRA, Rennes, France
| | - A-L Besnard
- UMR 985 Ecologie et Santé des Ecosystèmes, INRA, Rennes, France.,UMR ESE, Agrocampus Ouest, Rennes, France
| | - S Launey
- UMR 985 Ecologie et Santé des Ecosystèmes, INRA, Rennes, France.,UMR ESE, Agrocampus Ouest, Rennes, France
| | - G Evanno
- UMR 985 Ecologie et Santé des Ecosystèmes, INRA, Rennes, France.,UMR ESE, Agrocampus Ouest, Rennes, France
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13
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Tibblin P, Forsman A, Koch-Schmidt P, Nordahl O, Johannessen P, Nilsson J, Larsson P. Evolutionary divergence of adult body size and juvenile growth in sympatric subpopulations of a top predator in aquatic ecosystems. Am Nat 2015; 186:98-110. [PMID: 26098342 DOI: 10.1086/681597] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Evolutionary theory predicts that different selective regimes may contribute to divergent evolution of body size and growth rate among populations, but most studies have focused on allopatric populations. Here, we studied five sympatric subpopulations of anadromous northern pike (Esox lucius) in the Baltic Sea subjected to allopatric habitats for a short period of their life cycle due to homing behavior. We report differences in adult body size among subpopulations that were in part due to variation in growth rate. Body size of emigrating juveniles also differed among subpopulations, and differences remained when individuals were reared in a common environment, thus indicating evolutionary divergence among subpopulations. Furthermore, a QST-FST comparison indicated that differences had evolved due to divergent selection rather than genetic drift, possibly in response to differences in selective mortality among spawning habitats during the allopatric life stage. Adult and juvenile size were negatively correlated across subpopulations, and reconstruction of growth trajectories of adult fishes suggested that body size differences developed gradually and became accentuated throughout the first years of life. These results represent rare evidence that sympatric subpopulations can evolve differences in key life-history traits despite being subjected to allopatric habitats during only a very short fraction of their life.
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Affiliation(s)
- Petter Tibblin
- Ecology and Evolution in Microbial Model Systems (EEMiS), Department of Biology and Environmental Science, Linnaeus University, SE-391 82 Kalmar, Sweden
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14
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Galipaud M, Bollache L, Wattier R, Dubreuil C, Dechaume-Moncharmont FX, Lagrue C. Overestimation of the strength of size-assortative pairing in taxa with cryptic diversity: a case of Simpson's paradox. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2015.01.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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15
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López A, Vera M, Planas M, Bouza C. Conservation genetics of threatened Hippocampus guttulatus in vulnerable habitats in NW Spain: temporal and spatial stability of wild populations with flexible polygamous mating system in captivity. PLoS One 2015; 10:e0117538. [PMID: 25646777 PMCID: PMC4315495 DOI: 10.1371/journal.pone.0117538] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 12/26/2014] [Indexed: 11/19/2022] Open
Abstract
This study was focused on conservation genetics of threatened Hippocampus guttulatus on the Atlantic coast of NW Iberian Peninsula. Information about spatial structure and temporal stability of wild populations was obtained based on microsatellite markers, and used for monitoring a captive breeding program firstly initiated in this zone at the facilities of the Institute of Marine Research (Vigo, Spain). No significant major genetic structure was observed regarding the biogeographical barrier of Cape Finisterre. However, two management units under continuous gene flow are proposed based on the allelic differentiation between South-Atlantic and Cantabrian subpopulations, with small to moderate contemporary effective size based on single-sample methods. Temporal stability was observed in South-Atlantic population samples of H. guttulatus for the six-year period studied, suggesting large enough effective population size to buffer the effects of genetic drift within the time frame of three generations. Genetic analysis of wild breeders and offspring in captivity since 2009 allowed us to monitor the breeding program founded in 2006 in NW Spain for this species. Similar genetic diversity in the renewed and founder broodstock, regarding the wild population of origin, supports suitable renewal and rearing processes to maintain genetic variation in captivity. Genetic parentage proved single-brood monogamy in the wild and in captivity, but flexible short- and long-term mating system under captive conditions, from strict monogamy to polygamy within and/or among breeding seasons. Family analysis showed high reproductive success in captivity under genetic management assisted by molecular relatedness estimates to avoid inbreeding. This study provides genetic information about H. guttulatus in the wild and captivity within an uncovered geographical range for this data deficient species, to be taken into account for management and conservation purposes.
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Affiliation(s)
- Almudena López
- Department of Genetics, Faculty of Veterinary Science, Universidade de Santiago de Compostela, Campus de Lugo, Lugo, Spain
| | - Manuel Vera
- Laboratori d’Ictiologia Genètica, Departament of Biology, Faculty of Sciences, Universidad de Girona, Campus de Montilivi, Girona, Spain
| | - Miquel Planas
- Department of Ecology and Marine Resources, Instituto de Investigaciones Marinas (CSIC), Vigo, Spain
| | - Carmen Bouza
- Department of Genetics, Faculty of Veterinary Science, Universidade de Santiago de Compostela, Campus de Lugo, Lugo, Spain
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González R, Dinghi P, Corio C, Medina A, Maggioni M, Storero L, Gosztonyi A. Genetic evidence and new morphometric data as essential tools to identify the Patagonian seahorse Hippocampus patagonicus (Pisces, Syngnathidae). JOURNAL OF FISH BIOLOGY 2014; 84:459-474. [PMID: 24446770 DOI: 10.1111/jfb.12299] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 11/13/2013] [Indexed: 06/03/2023]
Abstract
A genetic study to support morphometric analyses was used to improve the description and validate the Patagonian seahorse Hippocampus patagonicus (Syngnathidae) on the basis of a large number of specimens collected in the type locality (San Antonio Bay, Patagonia, Argentina). DNA sequence data (from the cytochrome b region of the mitochondrial genome) were used to differentiate this species from its relatives cited for the west Atlantic Ocean. Both phylogenetic and genetic distance analyses supported the hypothesis that H. patagonicus is a species clearly differentiated from others, in agreement with morphometric studies. Hippocampus patagonicus can be distinguished from Hippocampus erectus by the combination of the following morphometric characteristics: (1) in both sexes and all sizes of H. patagonicus, the snout length is always less than the postorbital length, whereas the snout length of H. erectus is not shorter than the postorbital length in the largest specimens; (2) in both sexes of H. patagonicus, the trunk length:total length (LTr :LT ) is lower than in H. erectus (in female H. patagonicus: 0·27-0·39, H. erectus: 0·36-0·40 and in male H. patagonicus: 0·24-0·34, H. erectus: 0·33-0·43) and (3) in both sexes, tail length:total length (LTa :LT ) in H. patagonicus is larger than in H. erectus (0·61-0·78 v. 0·54-0·64).
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Affiliation(s)
- R González
- Instituto de Biología Marina y Pesquera Almirante Storni, Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, Güemes 1030, (8520) San Antonio Oeste, Río Negro, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Rivadavia 1917, 5° piso, Ciudad Autónoma de Buenos Aires, Argentina
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Franz-Odendaal TA, Adriaens D. Comparative developmental osteology of the seahorse skeleton reveals heterochrony amongst Hippocampus sp. and progressive caudal fin loss. EvoDevo 2014; 5:45. [PMID: 25908960 PMCID: PMC4407769 DOI: 10.1186/2041-9139-5-45] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 12/12/2014] [Indexed: 12/30/2022] Open
Abstract
Background Seahorses are well known for their highly derived head shape, prehensile tail and armoured body. They belong to the family of teleosts known as Syngnathidae, which also includes the pipefishes, pipehorses and seadragons. Very few studies have investigated the development of the skeleton of seahorses because larvae are extremely difficult to obtain in the wild and breeding in captivity is rarely successful. Here we compare the developmental osteology of Hippocampus reidi over an ontogenetic series spanning the first 93 days after release from the brood pouch to that of a smaller series of Hippocampus; namely H. subelongatus. Results We compare the osteology in these two species over growth to the published description of the dwarf species, H. zosterae. We show that ossification onset in H. subelongatus is earlier than in H. reidi, despite similar sizes at parturition. Interestingly, the timing of development of the bony skeleton in H. zosterae is similar to that of the larger species, H. subelongatus. Furthermore, we show that the growth rate of all three species is similar up until about 30 days post pouch release. From this stage onwards in the life history, the size of the dwarf species H. zosterae remains relatively constant whilst the other two species continue growing with an accelerated growth phase. Conclusion This data together with a phylogenetic assessment suggests that there has been a heterochronic shift (a delay) in the timing of ossification in H. reidi and accelerated bonedevelopment in H. zosterae. That is, H. zosterae is not a developmentally truncated dwarf species but rather a smaller version of its larger ancestor, “a proportioned dwarf” species. Furthermore, we show that caudal fin loss is incomplete in Hippocampus seahorses. This study shows that these three species of Hippocampus seahorses have evolved (either directly or indirectly) different osteogenic strategies over the last 20–30 million years of seahorse evolution.
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Mobley KB, Abou Chakra M, Jones AG. No evidence for size-assortative mating in the wild despite mutual mate choice in sex-role-reversed pipefishes. Ecol Evol 2013; 4:67-78. [PMID: 24455162 PMCID: PMC3894889 DOI: 10.1002/ece3.907] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 11/05/2013] [Accepted: 11/10/2013] [Indexed: 11/30/2022] Open
Abstract
Size-assortative mating is a nonrandom association of body size between members of mating pairs and is expected to be common in species with mutual preferences for body size. In this study, we investigated whether there is direct evidence for size-assortative mating in two species of pipefishes, Syngnathus floridae and S. typhle, that share the characteristics of male pregnancy, sex-role reversal, and a polygynandrous mating system. We take advantage of microsatellite-based “genetic-capture” techniques to match wild-caught females with female genotypes reconstructed from broods of pregnant males and use these data to explore patterns of size-assortative mating in these species. We also develop a simulation model to explore how positive, negative, and antagonistic preferences of each sex for body size affect size-assortative mating. Contrary to expectations, we were unable to find any evidence of size-assortative mating in either species at different geographic locations or at different sampling times. Furthermore, two traits that potentially confer a fitness advantage in terms of reproductive success, female mating order and number of eggs transferred per female, do not affect pairing patterns in the wild. Results from model simulations demonstrate that strong mating preferences are unlikely to explain the observed patterns of mating in the studied populations. Our study shows that individual mating preferences, as ascertained by laboratory-based mating trials, can be decoupled from realized patterns of mating in the wild, and therefore, field studies are also necessary to determine actual patterns of mate choice in nature. We conclude that this disconnect between preferences and assortative mating is likely due to ecological constraints and multiple mating that may limit mate choice in natural populations.
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Affiliation(s)
- Kenyon B Mobley
- Max Planck Institute of Evolutionary Biology August-Thienemann Str. 2, Plön, 24306, Germany
| | - Maria Abou Chakra
- Max Planck Institute of Evolutionary Biology August-Thienemann Str. 2, Plön, 24306, Germany
| | - Adam G Jones
- Department of Biology, Texas A&M University 3258 TAMU, College Station, Texas, 77843, USA
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Sanna D, Biagi F, Alaya HB, Maltagliati F, Addis A, Romero A, De Juan J, Quignard JP, Castelli A, Franzoi P, Torricelli P, Casu M, Carcupino M, Francalacci P. Mitochondrial DNA variability of the pipefish Syngnathus abaster. JOURNAL OF FISH BIOLOGY 2013; 82:856-876. [PMID: 23464548 DOI: 10.1111/jfb.12027] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Accepted: 11/15/2012] [Indexed: 06/01/2023]
Abstract
This study provides data on the genetic structuring of the pipefish Syngnathus abaster in the western Mediterranean and Adriatic Seas. A total of 109 specimens were collected in brackish-water biotopes. The control region and three other regions of the mitochondrial genome were analysed. The most relevant result was the high genetic structuring found by Bayesian inference (BI), maximum likelihood (ML) and network analyses, which were consistent in showing three well-separated clusters of S. abaster populations. Furthermore, BI and ML did not support the monophyly of the taxon S. abaster. These results suggest the occurrence of a species complex in the study area, whose differentiation may have occurred since the Pleistocene. The results also show a very high genetic variability at the inter-population level, with no shared haplotypes among sites. Evolutionary forces due to the fragmented nature of the brackish-water habitats may account for the high genetic divergence found among the groups and populations. Finally, although dispersal by rafting over long distances may occasionally occur, this study suggests linear stepping-stone model of colonization to be most likely. The complexity of the results obtained suggests that further studies are needed to elucidate the phylogeny of S. abaster.
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Affiliation(s)
- D Sanna
- Dipartimento di Scienze della Natura e del Territorio - Sezione di Zoologia, Archeozoologia e Genetica, Università di Sassari, Via Francesco Muroni 25, 07100, Sassari, Italy
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DiBattista JD, Rocha LA, Craig MT, Feldheim KA, Bowen BW. Phylogeography of two closely related Indo-Pacific butterflyfishes reveals divergent evolutionary histories and discordant results from mtDNA and microsatellites. ACTA ACUST UNITED AC 2012; 103:617-29. [PMID: 22888133 DOI: 10.1093/jhered/ess056] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Marine biogeographic barriers can have unpredictable consequences, even among closely related species. To resolve phylogeographic patterns for Indo-Pacific reef fauna, we conducted range-wide surveys of sister species, the scrawled butterflyfish (Chaetodon meyeri; N = 134) and the ornate butterflyfish (Chaetodon ornatissimus; N = 296), using mitochondrial DNA cytochrome b sequences and 10 microsatellite loci. The former is distributed primarily in the Indian Ocean but also extends to the Line Islands in the Central Pacific, whereas the latter is distributed primarily in the Central-West Pacific (including Hawaii and French Polynesia) but extends to the eastern margin of the Indian Ocean. Analyses of molecular variance and Bayesian STRUCTURE results revealed 1 range-wide group for C. meyeri and 3 groups for C. ornatissimus: 1) eastern Indian Ocean and western Pacific, 2) Central Pacific, and 3) Hawaii. Estimates of the last population expansion were much more recent for C. meyeri (61 500 to 95 000 years) versus C. ornatissimus (184 700 to 286 300 years). Despite similarities in ecology, morphology, life history, and a broadly overlapping distribution, these sister species have divergent patterns of dispersal and corresponding evolutionary history. The mtDNA and microsatellite markers did not provide concordant results within 1 of our study species (C. meyeri), or in 7 out of 12 other cases of marine fishes in the published literature. This discordance renews caution in relying on one or a few markers for reconstructing historical demography.
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Servedio MR, Van Doorn GS, Kopp M, Frame AM, Nosil P. Magic traits in speciation: ‘magic’ but not rare? Trends Ecol Evol 2011; 26:389-97. [PMID: 21592615 DOI: 10.1016/j.tree.2011.04.005] [Citation(s) in RCA: 372] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 04/05/2011] [Accepted: 04/11/2011] [Indexed: 12/29/2022]
Affiliation(s)
- Maria R Servedio
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA.
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Eble JA, Rocha LA, Craig MT, Bowen BW. Not All Larvae Stay Close to Home: Insights into Marine Population Connectivity with a Focus on the Brown Surgeonfish ( Acanthurus nigrofuscus). JOURNAL OF MARINE BIOLOGY 2011; 2011:518516. [PMID: 25505914 PMCID: PMC4260469 DOI: 10.1155/2011/518516] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Recent reports of localized larval recruitment in predominately small-range fishes are countered by studies that show high genetic connectivity across large oceanic distances. This discrepancy may result from the different timescales over which genetic and demographic processes operate or rather may indicate regular long-distance dispersal in some species. Here, we contribute an analysis of mtDNA cytochrome b diversity in the widely distributed Brown Surgeonfish (Acanthurus nigrofuscus; N = 560), which revealed significant genetic structure only at the extremes of the range (ΦCT = 0.452; P < .001). Collections from Hawaii to the Eastern Indian Ocean comprise one large, undifferentiated population. This pattern of limited genetic subdivision across reefs of the central Indo-Pacific has been observed in a number of large-range reef fishes. Conversely, small-range fishes are often deeply structured over the same area. These findings demonstrate population connectivity differences among species at biogeographic and evolutionary timescales, which likely translates into differences in dispersal ability at ecological and demographic timescales. While interspecific differences in population connectivity complicate the design of management strategies, the integration of multiscale connectivity patterns into marine resource planning will help ensure long-term ecosystem stability by preserving functionally diverse communities.
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Affiliation(s)
- Jeff A. Eble
- Hawaii Institute of Marine Biology, University of Hawaii at Manoa, P.O. Box 1346, Kaneohe, HI 96744, USA
| | - Luiz A. Rocha
- Marine Science Institute, University of Texas at Austin, Port Aransas, TX 78373, USA
| | - Matthew T. Craig
- Department of Marine Sciences, University of Puerto Rico Mayagüez, P.O. Box 9000, Mayagüez, PR 00681, USA
| | - Brian W. Bowen
- Hawaii Institute of Marine Biology, University of Hawaii at Manoa, P.O. Box 1346, Kaneohe, HI 96744, USA
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25
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Kisdi É, Priklopil T. Evolutionary branching of a magic trait. J Math Biol 2010; 63:361-97. [DOI: 10.1007/s00285-010-0377-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 10/12/2010] [Indexed: 10/18/2022]
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Abstract
Sympatric speciation has been contentious since its inception, yet is increasingly recognized as important based on accumulating theoretical and empirical support. Here, we present a compelling case of sympatric speciation in a taxon of marine reef fishes using a comparative and mechanistic approach. Hexagrammos otakii and H. agrammus occur in sympatry throughout their ranges. Molecular sequence data from six loci, with complete sampling of the genus, support monophyly of these sister species. Although hybridization occurs frequently with an allopatric congener in an area of slight distributional overlap, we found no F(1) hybrids between the focal sympatric taxa throughout their coextensive ranges. We present genetic evidence for complete reproductive isolation based on SNP analysis of 382 individuals indicating fixed polymorphisms, with no shared haplotypes or genotypes, between sympatric species. To address questions of speciation, we take a mechanistic approach and directly compare aspects of reproductive isolation between allopatric and sympatric taxa both in nature and in the laboratory. We conclude that the buildup of reproductive isolation is strikingly different in sympatric vs. allopatric taxa, consistent with theoretical predictions. Lab reared hybrids from allopatric species crosses exhibit severe fitness effects in the F(1) or backcross generation. No intrinsic fitness effects are observed in F(1) hybrids from sympatric species pairs, however these treatments exhibited reduced fertilization success and complete pre-mating isolation is implied in nature because F(1) hybrid adults do not occur. Our study addresses limitations of previous studies and supports new criteria for inferring sympatric speciation.
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Affiliation(s)
- Karen D Crow
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA.
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Abstract
Absolute barriers to dispersal are not common in marine systems, and the prevalence of planktonic larvae in marine taxa provides potential for gene flow across large geographic distances. These observations raise the fundamental question in marine evolutionary biology as to whether geographic and oceanographic barriers alone can account for the high levels of species diversity observed in marine environments such as coral reefs, or whether marine speciation also operates in the presence of gene flow between diverging populations. In this respect, the ecological hypothesis of speciation, in which reproductive isolation results from divergent or disruptive natural selection, is of particular interest because it may operate in the presence of gene flow. Although important insights into the process of ecological speciation in aquatic environments have been provided by the study of freshwater fishes, comparatively little is known about the possibility of ecological speciation in marine teleosts. In this study, the evidence consistent with different aspects of the ecological hypothesis of speciation is evaluated in marine fishes. Molecular approaches have played a critical role in the development of speciation hypotheses in marine fishes, with a role of ecology suggested by the occurrence of sister clades separated by ecological factors, rapid cladogenesis or the persistence of genetically and ecologically differentiated species in the presence of gene flow. Yet, ecological speciation research in marine fishes is still largely at an exploratory stage. Cases where the major ingredients of ecological speciation, namely a source of natural divergent or disruptive selection, a mechanism of reproductive isolation and a link between the two have been explicitly documented are few. Even in these cases, specific predictions of the ecological hypothesis of speciation remain largely untested. Recent developments in the study of freshwater fishes illustrate the potential for molecular approaches to address specific questions related to the ecological hypothesis of speciation such as the nature of the genes underlying key ecological traits, the magnitude of their effect on phenotype and the mechanisms underlying their differential expression in different ecological contexts. The potential provided by molecular studies is fully realized when they are complemented with alternative (e.g. ecological, theoretical) approaches.
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Affiliation(s)
- O Puebla
- Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Balboa, Ancon, Republic of Panama.
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28
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Scobell SK, Fudickar AM, Knapp R. Potential reproductive rate of a sex-role reversed pipefish over several bouts of mating. Anim Behav 2009. [DOI: 10.1016/j.anbehav.2009.05.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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29
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Mattle B, Wilson AB. Body size preferences in the pot-bellied seahorse Hippocampus abdominalis: choosy males and indiscriminate females. Behav Ecol Sociobiol 2009; 63:1403-1410. [PMID: 19633734 PMCID: PMC2714888 DOI: 10.1007/s00265-009-0804-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 05/12/2009] [Accepted: 05/31/2009] [Indexed: 11/26/2022]
Abstract
Male seahorses (genus Hippocampus) provide all post-fertilization parental care, yet despite high levels of paternal investment, these species have long been thought to have conventional sex roles, with female mate choice and male–male competition. Recent studies of the pot-bellied seahorse (Hippocampus abdominalis) have shown that sex-role reversal occurs in high-density female-biased populations, indicating that male mating preferences may lead to sexual selection on females in this species. Egg size, egg number, and offspring size all correlate positively with female body size in Hippocampus, and by choosing large mating partners, male seahorses may increase their reproductive success. While male brood size is also positively correlated with body size, small H. abdominalis males can carry exceptionally large broods, suggesting that the fecundity benefits of female preference for large partners may be limited. We investigated the importance of body size in reproductive decisions of H. abdominalis, presenting focal individuals of both sexes with potential mating partners of different sizes. Mating preferences were quantified in terms of time spent courting each potential partner. Male seahorses were highly active throughout the mate-choice trials and showed a clear behavioral preference for large partners, while females showed significantly lower levels of activity and equivocal mating preferences. The strong male preferences for large females demonstrated here suggest that sexual selection may act strongly on female body size in wild populations of H. abdominalis, consistent with predictions on the importance of female body size for reproductive output in this species.
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Affiliation(s)
- Beat Mattle
- Zoological Museum, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Anthony B. Wilson
- Zoological Museum, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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MACCOLL ANDREWDC. Parasites may contribute to ‘magic trait’ evolution in the adaptive radiation of three-spined sticklebacks, Gasterosteus aculeatus (Gasterosteiformes: Gasterosteidae). Biol J Linn Soc Lond 2009. [DOI: 10.1111/j.1095-8312.2008.01123.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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31
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Anthony CD, Venesky MD, Hickerson CAM. Ecological separation in a polymorphic terrestrial salamander. J Anim Ecol 2008; 77:646-53. [PMID: 18479343 DOI: 10.1111/j.1365-2656.2008.01398.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1. When studying speciation, researchers commonly examine reproductive isolation in recently diverged populations. Polymorphic species provide an opportunity to examine the role of reproductive isolation in populations that may be in the process of divergence. 2. We examined a polymorphic population of Plethodon cinereus (red-backed salamanders) for evidence of sympatric ecological separation by colour morphology. Recent studies have correlated temperature and climate with colour morphology in this species, but no studies have looked at differences in diet or mate choice between colour morphs. We used artificial cover objects to assess salamander diet, mating preference and surface activity over a 2-year period at a field site in north-eastern Ohio. 3. We detected differences in diet between two colour morphs, striped and unstriped. The diets of striped individuals were significantly more diverse and were made up of more profitable prey than the diets of unstriped salamanders. 4. Opposite sex pairs were made up of individuals of the same colour morph and striped males were found more often with larger females than were unstriped males. 5. We corroborate findings of earlier studies suggesting that the unstriped form is adapted to warmer conditions. Unstriped individuals were the first to withdraw from the forest floor as temperatures fell in the late fall. We found no evidence that the colour morphs responded differently to abiotic factors such as soil moisture and relative humidity, and responses to surface temperatures were also equivocal. 6. We conclude that the two colour morphs exhibit some degree of ecological separation and tend to mate assortatively, but are unlikely to be undergoing divergence given the observed frequency of intermorph pairings.
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Affiliation(s)
- Carl D Anthony
- Department of Biology, John Carroll University, University Heights, OH 44118, USA.
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Silva K, Vieira MN, Almada VC, Monteiro NM. Can the limited marsupium space be a limiting factor for Syngnathus abaster females? Insights from a population with size-assortative mating. J Anim Ecol 2008; 77:390-4. [DOI: 10.1111/j.1365-2656.2007.01346.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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33
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Kelly RP, Eernisse DJ. Reconstructing a radiation: the chiton genus Mopalia in the north Pacific. INVERTEBR SYST 2008. [DOI: 10.1071/is06021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The chiton genus Mopalia Gray, 1847 is highly speciose despite showing little morphological differentiation. Many of the 24 extant species are conspicuous, large-bodied and ecologically important today, but pre-Pleistocene fossils for the genus are rare. Here, we use a combined analysis of four gene regions (16S and COI mtDNA, 18S and 28S rDNA) to estimate the phylogenetic relationships for Mopalia species and use the inferred phylogeny to analyse the group’s biogeography and patterns of speciation. We then use these molecular data to distinguish between two alternative interpretations of the fossil record, as there is a large temporal gap between the oldest fossils tentatively identified as Mopalia and the next oldest fossils (Miocene versus Plio-Pleistocene). Based on the estimated substitution rates from a wide variety of other marine animals, we conclude that the observed rates in Mopalia are consistent with a Miocene origin for the genus. Given this age for the group and assuming a molecular clock, most speciation events in Mopalia are inferred to have occurred on average ~5 Mya. The phylogenetic results indicate that most of the speciation events leading to extant species must have occurred along the western North American coast, though there appear to have been multiple spreading events across the Pacific. When considered along with results for the many other near-shore taxa that have similar distributions to Mopalia, our findings suggest the emergence of a coherent historical biogeography of the northern Pacific.
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Kvarnemo C, Moore GI, Jones AG. Sexually selected females in the monogamous Western Australian seahorse. Proc Biol Sci 2007; 274:521-5. [PMID: 17476772 PMCID: PMC1766380 DOI: 10.1098/rspb.2006.3753] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Studies of sexual selection in monogamous species have hitherto focused on sexual selection among males. Here, we provide empirical documentation that sexual selection can also act strongly on females in a natural population with a monogamous mating system. In our field-based genetic study of the monogamous Western Australian seahorse, Hippocampus subelongatus, sexual selection differentials and gradients show that females are under stronger sexual selection than males: mated females are larger than unmated ones, whereas mated and unmated males do not differ in size. In addition, the opportunity for sexual selection (variance in mating success divided by its mean squared) for females is almost three times that for males. These results, which seem to be generated by a combination of a male preference for larger females and a female-biased adult sex ratio, indicate that substantial sexual selection on females is a potentially important but under-appreciated evolutionary phenomenon in monogamous species.
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Serrano-Meneses M, Córdoba-Aguilar A, Méndez V, Layen S, Székely T. Sexual size dimorphism in the American rubyspot: male body size predicts male competition and mating success. Anim Behav 2007. [DOI: 10.1016/j.anbehav.2006.08.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Abstract
Evolutionary theory predicts that sexual selection may increase taxonomic diversity when emergent mating preferences result in reproductive isolation and therefore speciation. This theory has been invoked to explain patterns of diversity in ray-finned fishes (most notably in the cichlids), but the theory has not been tested comparatively in fish. Additionally, several other unrelated factors have been identified as promoters of cladogenesis, so it is unclear how important sexual selection might be in diversification. Using sister-clade analysis, I tested the relationship between the presence of sexually selected traits and taxonomic diversification in actinopterygiian fishes, a large clade that shows substantial diversity in mating preferences and related sexually selected traits. In all identified sister-families that differed with regard to the proportion of species manifesting sexually selected traits, sexual selection was correlated with increased diversification, and this association was significant across all sister clades (P=0.02). This suggests that sexual selection, when present, is a substantial driver of diversification in the ray-finned fishes, and lends further empirical support to the theoretical link between mating preferences and accelerated cladogenesis.
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Affiliation(s)
- J E Mank
- Evolutionary Biology Centre, Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden.
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37
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Bürger R, Schneider KA, Willensdorfer M. THE CONDITIONS FOR SPECIATION THROUGH INTRASPECIFIC COMPETITION. Evolution 2006. [DOI: 10.1111/j.0014-3820.2006.tb01857.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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38
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Bolnick DI. Multi-species outcomes in a common model of sympatric speciation. J Theor Biol 2006; 241:734-44. [PMID: 16483610 DOI: 10.1016/j.jtbi.2006.01.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2005] [Revised: 01/04/2006] [Accepted: 01/10/2006] [Indexed: 10/25/2022]
Abstract
While models of sympatric speciation are motivated in part by multi-species adaptive radiations such as the Cameroon crater lake cichlids, existing models have focused on bifurcation into a single pair of daughter species. This paper shows that a familiar model of sympatric speciation, driven by intraspecific competition and assortative mating based on ecological characters values, can yield multiple daughter species if individual niche widths are sufficiently restricted. Surprisingly, the multi-species outcome is not produced by successive bifurcation events, but by simultaneous divergence resulting in a hard polytomy. This result is sensitive to a number of assumptions, whose violation may prevent speciation. In some cases when speciation fails, the population instead ends in a state that closely resembles incipient species pairs, with an ecological polymorphism and partial reproductive isolation. However, this polymorphism is stable and does not lead to complete reproductive isolation, suggesting that empirical cases of incipient species pairs may not always end in speciation.
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Affiliation(s)
- Daniel I Bolnick
- Integrative Biology, University of Texas at Austin, 1 University Station C0930, Austin, TX 78712, USA.
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Singh SR, Rashkovetsky E, Iliadi K, Nevo E, Korol A. Assortative mating in Drosophila adapted to a microsite ecological gradient. Behav Genet 2006; 35:753-64. [PMID: 16273320 DOI: 10.1007/s10519-005-6119-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2004] [Accepted: 05/25/2005] [Indexed: 10/25/2022]
Abstract
Elucidating the causes of population divergence, and ultimately speciation, is a central objective of evolutionary biology. A number of previous studies of Drosophila populations from the Nahal Oren canyon (Mt Carmel, Israel) revealed significant interslope differences for a complex of fitness and behavioral traits. Peculiarities in courtship song patterns and nonrandom mating were observed, despite a small interslope distance. Single and multiple mate choice tests with D. melanogaster from the opposite slopes displayed highly significant assortative mating, with preference for sexual partners from the same slope. Here we report the results on mate choice in the sibling species D. melanogaster and D. simulans inhabiting Nahal Oren canyon. Significant assortative mating was found in both species. Genetic heterogeneity in mate choice was found among the isofemale lines of D. melanogaster. Samples of isofemale lines established from females collected in spring and fall seasons show the same mating patterns.
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Affiliation(s)
- Shree Ram Singh
- Institute of Evolution, University of Haifa, Mount Carmel, Haifa 31905, Israel.
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40
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Yukilevich R, True JR. Divergent outcomes of reinforcement speciation: the relative importance of assortative mating and migration modification. Am Nat 2006; 167:638-54. [PMID: 16671009 DOI: 10.1086/503120] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2005] [Accepted: 01/05/2006] [Indexed: 11/03/2022]
Abstract
Most studies of reinforcement speciation focus on the evolution of assortative mating, but R. A. Fisher argued that migration modification is likely to be a common alternative mechanism. Despite previous models showing that assortative mating and migration modification may both be involved in reinforcement, no one has determined their relative evolutionary importance. This is surprising because understanding the biological conditions favoring these mechanisms may explain why certain pairs of species exhibit abutting, nonoverlapping geographical ranges with habitat fidelity while other pairs coexist in sympatry with sexual isolation. In this article, we explicitly model the evolution of both mechanisms simultaneously. First, we explore how these mechanisms differ in their evolutionary dynamics. Second, we ask how they affect each other's evolution and whether the interaction alters their relative importance in reinforcement. Our results reveal that assortative mating may evolve faster and under a broader range of biological conditions than migration modification. However, direct evolutionary interactions favor migration modification when populations experience strong divergent selection. Depending on the nature of postmating isolation, these mechanisms may either interfere with each other's evolution or coevolve in the same system. These results illustrate the importance of studying multiple mechanisms of speciation simultaneously in future speciation models.
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Affiliation(s)
- Roman Yukilevich
- Department of Ecology and Evolution, State University of New York, Stony Brook, New York 11794, USA.
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Abstract
Most models of sympatric speciation have assumed that assortative mating has no costs. A few studies, however, have shown that the costs for being choosy can prevent such speciation. Here, we investigate the role of the strength of assortment and of the costs for being choosy for a simple genetic model of a single ('magic') trait that mediates both intraspecific competition for a continuum of resources and assortative mating, which is induced by choosy females who preferentially mate with males of similar phenotype. Choosiness may be costly if it is difficult to find a mating partner. Such magic trait models are considered to be most conducive of sympatric speciation. We consider a sexually reproducing population of haploid individuals that is density regulated. The trait is determined by a single locus with multiple alleles. The strength of stabilizing selection (caused by a unimodal resource distribution), the strength of competition, the degree of assortment and the costs for being choosy are independent parameters. We investigate analytically and numerically how these parameters determine the equilibrium and stability structure. In particular, we identify conditions under which no polymorphism at all is maintained as well as conditions under which strong competitive divergence occurs, or the population even splits into two reproductively isolated classes of highly diverse phenotypes. If costs are absent or moderate, genetic variability tends to be minimized at intermediate strengths of assortment, and reproductively isolated classes of phenotypes are a likely result of evolution only for intermediate or strong competition and for very strong assortment. The likelihood of divergence depends relatively weakly on the costs as long as they are not high. With high costs, however, increasingly strong assortment rapidly depletes all genetic variation, and strong competitive divergence is prevented.
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Affiliation(s)
- K A Schneider
- Department of Mathematics, University of Vienna, Wien, Austria
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Affiliation(s)
- R K Butlin
- School of Biology, The University of Leeds, Leeds, UK.
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Whiteman HH, Krenz JD, Semlitsch RD. Intermorph breeding and the potential for reproductive isolation in polymorphic mole salamanders (Ambystoma talpoideum). Behav Ecol Sociobiol 2006. [DOI: 10.1007/s00265-005-0139-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bürger R, Schneider KA. Intraspecific Competitive Divergence and Convergence under Assortative Mating. Am Nat 2006; 167:190-205. [PMID: 16670980 DOI: 10.1086/499375] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2005] [Accepted: 09/23/2005] [Indexed: 11/03/2022]
Abstract
Ecologically driven sympatric speciation has received much attention recently. We investigate a multilocus model of a quantitative trait that is under frequency-dependent selection caused by intraspecific competition and acts as mating character for assortment. We identify the conditions that lead to the establishment of reproductively isolated clusters. This may be interpreted as evolutionary splitting or sympatric speciation. In our model, there are parameters that independently determine the strength of assortment, the costs for being choosy, and the strength of frequency-dependent natural selection. Sufficiently strong frequency dependence leads to disruptive selection on the phenotypes. The population consists of (sexual) haploid individuals. If frequency dependence is strong enough to induce disruptive selection and costs are absent or low, the result of evolution depends in a distinctive nonlinear way on the strength of assortment: under moderately strong assortment, less genetic variation is maintained than under weak or strong assortment, and sometimes there is none at all. Evolutionary splitting occurs only if frequency dependence and assortment are both strong enough and costs are low. Even then, the evolutionary outcome depends on the genetics and the initial conditions. The roles of the number of loci, of linkage, and of asymmetric selection are also explored.
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Affiliation(s)
- Reinhard Bürger
- Department of Mathematics, University of Vienna, Nordbergstrasse 15, 1090 Vienna, Austria.
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Bürger R, Schneider KA, Willensdorfer M. THE CONDITIONS FOR SPECIATION THROUGH INTRASPECIFIC COMPETITION. Evolution 2006. [DOI: 10.1554/06-321.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Rocha LA, Robertson DR, Roman J, Bowen BW. Ecological speciation in tropical reef fishes. Proc Biol Sci 2005; 272:573-9. [PMID: 15817431 PMCID: PMC1564072 DOI: 10.1098/2004.3005] [Citation(s) in RCA: 251] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2004] [Accepted: 11/08/2004] [Indexed: 11/12/2022] Open
Abstract
The high biodiversity in tropical seas provides a long-standing challenge to allopatric speciation models. Physical barriers are few in the ocean and larval dispersal is often extensive, a combination that should reduce opportunities for speciation. Yet coral reefs are among the most species-rich habitats in the world, indicating evolutionary processes beyond conventional allopatry. In a survey of mtDNA sequences of five congeneric west Atlantic reef fishes (wrasses, genus Halichoeres) with similar dispersal potential, we observed phylogeographical patterns that contradict expectations of geographical isolation, and instead indicate a role for ecological speciation. In Halichoeres bivittatus and the species pair Halichoeres radiatus/brasiliensis, we observed strong partitions (3.4% and 2.3% divergence, respectively) between adjacent and ecologically distinct habitats, but high genetic connectivity between similar habitats separated by thousands of kilometres. This habitat partitioning is maintained even at a local scale where H. bivittatus lineages are segregated between cold- and warm-water habitats in both Bermuda and Florida. The concordance of evolutionary partitions with habitat types, rather than conventional biogeographical barriers, indicates parapatric ecological speciation, in which adaptation to alternative environmental conditions in adjacent locations overwhelms the homogenizing effect of dispersal. This mechanism can explain the long-standing enigma of high biodiversity in coral reef faunas.
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Affiliation(s)
- Luiz A Rocha
- Department of Fisheries and Aquatic Sciences, University of Florida, 7922, NW 71st Street, Gainesville, FL 32653, USA.
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Doebeli M, Dieckmann U, Metz JAJ, Tautz D. WHAT WE HAVE ALSO LEARNED: ADAPTIVE SPECTIATION IS THEORETICALLY PLAUSIBLE. Evolution 2005. [DOI: 10.1111/j.0014-3820.2005.tb01028.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Doebeli M, Dieckmann U, Metz JAJ, Tautz D. WHAT WE HAVE ALSO LEARNED: ADAPTIVE SPECIATION IS THEORETICALLY PLAUSIBLE. Evolution 2005. [DOI: 10.1554/04-154] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Teske PR, Cherry MI, Matthee CA. The evolutionary history of seahorses (Syngnathidae: Hippocampus): molecular data suggest a West Pacific origin and two invasions of the Atlantic Ocean. Mol Phylogenet Evol 2004; 30:273-86. [PMID: 14715220 DOI: 10.1016/s1055-7903(03)00214-8] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sequence data derived from four markers (the nuclear RP1 and Aldolase and the mitochondrial 16S rRNA and cytochrome b genes) were used to determine the phylogenetic relationships among 32 species belonging to the genus Hippocampus. There were marked differences in the rate of evolution among these gene fragments, with Aldolase evolving the slowest and the mtDNA cytochrome b gene the fastest. The RP1 gene recovered the highest number of nodes supported by >70% bootstrap values from parsimony analysis and >95% posterior probabilities from Bayesian inference. The combined analysis based on 2317 nucleotides resulted in the most robust phylogeny. A distinct phylogenetic split was identified between the pygmy seahorse, Hippocampus bargibanti, and a clade including all other species. Three species from the western Pacific Ocean included in our study, namely H. bargibanti, H. breviceps, and H. abdominalis occupy basal positions in the phylogeny. This and the high species richness in the region suggests that the genus evolved somewhere in the West Pacific. There is also fairly strong molecular support for the remaining species being subdivided into three main evolutionary lineages: two West Pacific clades and a clade of species present in both the Indo-Pacific and the Atlantic Ocean. The phylogeny obtained herein suggests at least two independent colonization events of the Atlantic Ocean, once before the closure of the Tethyan seaway, and once afterwards.
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Affiliation(s)
- Peter R Teske
- Zoology Department, University of Stellenbosch, Private Bag X1, 7602, Matieland, South Africa.
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Abstract
While it now appears likely that sympatric speciation is possible, its generality remains contentious. If it really is rare, then most natural populations must not fit the assumptions of sympatric speciation theory. A better understanding of these assumptions may help identify when sympatric speciation is or is not likely. This paper investigates two such assumptions: that genetic variation for stringent assortative mating is not limiting and that females are not penalized for mating assortatively. Simulations demonstrate that the speed of sympatric speciation is very sensitive to the population's capacity for stringent assortative mating and is potentially extremely slow. The rapid divergence often thought to be a hallmark of sympatric speciation may only occur in a restricted area of parameter space.
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Affiliation(s)
- Daniel I Bolnick
- Center for Population Biology, Section of Evolution and Ecology, Storer Hall, University of California at Davis, Davis, California 95616, USA.
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