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Keller B, Alther B, Jiménez A, Koutroumpa K, Mora-Carrera E, Conti E. Island plants with newly discovered reproductive traits have higher capacity for uniparental reproduction, supporting Baker's law. Sci Rep 2024; 14:11392. [PMID: 38762587 PMCID: PMC11102434 DOI: 10.1038/s41598-024-62065-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 05/13/2024] [Indexed: 05/20/2024] Open
Abstract
Uniparental reproduction is advantageous when lack of mates limits outcrossing opportunities in plants. Baker's law predicts an enrichment of uniparental reproduction in habitats colonized via long-distance dispersal, such as volcanic islands. To test it, we analyzed reproductive traits at multiple hierarchical levels and compared seed-set after selfing and crossing experiments in both island and mainland populations of Limonium lobatum, a widespread species that Baker assumed to be self-incompatible because it had been described as pollen-stigma dimorphic, i.e., characterized by floral morphs differing in pollen-surface morphology and stigma-papillae shape that are typically self-incompatible. We discovered new types and combinations of pollen and stigma traits hitherto unknown in the literature on pollen-stigma dimorphism and a lack of correspondence between such combinations and pollen compatibility. Contrary to previous reports, we conclude that Limonium lobatum comprises both self-compatible and self-incompatible plants characterized by both known and previously undescribed combinations of reproductive traits. Most importantly, plants with novel combinations are overrepresented on islands, selfed seed-set is higher in islands than the mainland, and insular plants with novel pollen-stigma trait-combinations disproportionally contribute to uniparental reproduction on islands. Our results thus support Baker's law, connecting research on reproductive and island biology.
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Affiliation(s)
- Barbara Keller
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland.
| | - Barbara Alther
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland
| | - Ares Jiménez
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland
| | - Konstantina Koutroumpa
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland
- Botanischer Garten und Botanisches Museum Berlin (BGBM), Freie Universität Berlin, Berlin, Germany
| | - Emiliano Mora-Carrera
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland
| | - Elena Conti
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland
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2
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Di Giusto B, Bain A. Local ecological factors, not interference competition, drive the foundress number of two species of fig wasp sharing Ficus septica figs. PLoS One 2024; 19:e0290439. [PMID: 38165887 PMCID: PMC10760673 DOI: 10.1371/journal.pone.0290439] [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: 02/23/2023] [Accepted: 08/08/2023] [Indexed: 01/04/2024] Open
Abstract
Recent studies have challenged assumptions about the classic fig-fig wasp pollination mutualism model, suggesting that further investigation into the receptive phase of fig development is needed. This study assessed the pollination mechanisms of Ficus septica in southern Taiwan and identified two species of wasps as the primary pollinators. Machine learning was used to identify and rank the factors that explain the relative abundance of these wasps. The two wasp species showed the highest level of cohabitation ever reported in the literature, with three-quarters of the figs containing multiple foundresses. The study also reported re-emerged foundresses and a 10% ratio of pollinated figs without foundresses. Local factors, such as the sampling period and tree identity, were the best predictors of the presence and number of each foundress species, with fig size also affecting the number of foundresses. The study highlights the variability in pollinator abundance between figs, crops, and trees. It also shows that the local environment of the trees and the availability of figs are crucial factors in determining which figs the pollinator wasps choose. These findings challenge assumptions about the classic mutualism model and suggest that long-term surveys are needed to estimate the relative contributions of each partner and provide data for evolutionary and ecological models. This study also provides valuable insights into the factors that affect the abundance and interactions of pollinator wasps during the receptive phase of fig development, with implications for understanding the behaviour of pollinating wasps and advancing our knowledge of population dynamics in Ficus species.
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Affiliation(s)
- Bruno Di Giusto
- Journalism and Mass Communication Program, International College, Ming Chuan University, Taipei, Taiwan
| | - Anthony Bain
- Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan
- International Ph.D. Program for Science, National Sun Yat-Sen University, Kaohsiung, Taiwan
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3
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Borges RM. Interactions Between Figs and Gall-Inducing Fig Wasps: Adaptations, Constraints, and Unanswered Questions. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.685542] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The ancient interaction between figs (Ficus, Moraceae) and their pollinating fig wasps is an unusual example of a mutualism between plants and gall-inducing insects. This review intends to offer fresh perspectives into the relationship between figs and the diversity of gall-inducing sycophiles which inhabit their enclosed globular inflorescences that function as microcosms. Besides gall-inducing pollinators, fig inflorescences are also inhabited by other gall-inducing wasps. This review evaluates the state of current knowledge on gall-induction by fig wasps and exposes the many lacunae in this area. This review makes connections between fig and gall-inducing wasp traits, and suggests relatively unexplored research avenues. This manuscript calls for an integrated approach that incorporates such diverse fields as life-history theory, plant mate choice, wasp sexual selection and local mate competition, plant embryology as well as seed and fruit dispersal. It calls for collaboration between researchers such as plant developmental biologists, insect physiologists, chemical ecologists and sensory biologists to jointly solve the many valuable questions that can be addressed in community ecology, co-evolution and species interaction biology using the fig inflorescence microcosm, that is inhabited by gall-inducing mutualistic and parasitic wasps, as a model system.
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4
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Cooper L, Bunnefeld L, Hearn J, Cook JM, Lohse K, Stone GN. Low-coverage genomic data resolve the population divergence and gene flow history of an Australian rain forest fig wasp. Mol Ecol 2020; 29:3649-3666. [PMID: 32567765 DOI: 10.1111/mec.15523] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 06/09/2020] [Accepted: 06/12/2020] [Indexed: 12/16/2022]
Abstract
Population divergence and gene flow are key processes in evolution and ecology. Model-based analysis of genome-wide data sets allows discrimination between alternative scenarios for these processes even in nonmodel taxa. We used two complementary approaches (one based on the blockwise site frequency spectrum [bSFS], the second on the pairwise sequentially Markovian coalescent [PSMC]) to infer the divergence history of a fig wasp, Pleistodontes nigriventris. Pleistodontes nigriventris and its fig tree mutualist Ficus watkinsiana are restricted to rain forest patches along the eastern coast of Australia and are separated into The Northern population is to the north of the Southern populations by two dry forest corridors (the Burdekin and St. Lawrence Gaps). We generated whole genome sequence data for two haploid males per population and used the bSFS approach to infer the timing of divergence between northern and southern populations of P. nigriventris, and to discriminate between alternative isolation with migration (IM) and instantaneous admixture (ADM) models of postdivergence gene flow. Pleistodontes nigriventris has low genetic diversity (π = 0.0008), to our knowledge one of the lowest estimates reported for a sexually reproducing arthropod. We find strongest support for an ADM model in which the two populations diverged ca. 196 kya in the late Pleistocene, with almost 25% of northern lineages introduced from the south during an admixture event ca. 57 kya. This divergence history is highly concordant with individual population demographies inferred from each pair of haploid males using PSMC. Our analysis illustrates the inferences possible with genome-level data for small population samples of tiny, nonmodel organisms and adds to a growing body of knowledge on the population structure of Australian rain forest taxa.
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Affiliation(s)
- Lisa Cooper
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
| | - Lynsey Bunnefeld
- Biological and Environmental Sciences, University of Stirling, Stirling, UK
| | - Jack Hearn
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK.,Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - James M Cook
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
| | - Konrad Lohse
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
| | - Graham N Stone
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
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5
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Greeff JM, Reid K, Gagjee JR, Clift SJ, de Waal PJ. Population genetic structure of the parasitic nematode Spirocerca lupi in South Africa. Vet Parasitol 2018; 258:64-69. [DOI: 10.1016/j.vetpar.2018.06.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 06/05/2018] [Accepted: 06/06/2018] [Indexed: 10/28/2022]
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Duthie AB, Bocedi G, Germain RR, Reid JM. Evolution of precopulatory and post-copulatory strategies of inbreeding avoidance and associated polyandry. J Evol Biol 2018; 31:31-45. [PMID: 28986951 PMCID: PMC5765502 DOI: 10.1111/jeb.13189] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 09/28/2017] [Accepted: 09/28/2017] [Indexed: 01/16/2023]
Abstract
Inbreeding depression is widely hypothesized to drive adaptive evolution of precopulatory and post-copulatory mechanisms of inbreeding avoidance, which in turn are hypothesized to affect evolution of polyandry (i.e. female multiple mating). However, surprisingly little theory or modelling critically examines selection for precopulatory or post-copulatory inbreeding avoidance, or both strategies, given evolutionary constraints and direct costs, or examines how evolution of inbreeding avoidance strategies might feed back to affect evolution of polyandry. Selection for post-copulatory inbreeding avoidance, but not for precopulatory inbreeding avoidance, requires polyandry, whereas interactions between precopulatory and post-copulatory inbreeding avoidance might cause functional redundancy (i.e. 'degeneracy') potentially generating complex evolutionary dynamics among inbreeding strategies and polyandry. We used individual-based modelling to quantify evolution of interacting precopulatory and post-copulatory inbreeding avoidance and associated polyandry given strong inbreeding depression and different evolutionary constraints and direct costs. We found that evolution of post-copulatory inbreeding avoidance increased selection for initially rare polyandry and that evolution of a costly inbreeding avoidance strategy became negligible over time given a lower-cost alternative strategy. Further, fixed precopulatory inbreeding avoidance often completely precluded evolution of polyandry and hence post-copulatory inbreeding avoidance, but fixed post-copulatory inbreeding avoidance did not preclude evolution of precopulatory inbreeding avoidance. Evolution of inbreeding avoidance phenotypes and associated polyandry is therefore affected by evolutionary feedbacks and degeneracy. All else being equal, evolution of precopulatory inbreeding avoidance and resulting low polyandry is more likely when post-copulatory inbreeding avoidance is precluded or costly, and evolution of post-copulatory inbreeding avoidance greatly facilitates evolution of costly polyandry.
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Affiliation(s)
- A. B. Duthie
- Biological and Environmental SciencesUniversity of StirlingStirlingUK
| | - G. Bocedi
- Institute of Biological and Environmental SciencesSchool of Biological SciencesUniversity of AberdeenAberdeenUK
| | - R. R. Germain
- Institute of Biological and Environmental SciencesSchool of Biological SciencesUniversity of AberdeenAberdeenUK
| | - J. M. Reid
- Institute of Biological and Environmental SciencesSchool of Biological SciencesUniversity of AberdeenAberdeenUK
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7
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History Matters: Oviposition Resource Acceptance in an Exploiter of a Nursery Pollination Mutualism. J Chem Ecol 2017; 44:18-28. [PMID: 29250744 DOI: 10.1007/s10886-017-0914-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 11/30/2017] [Accepted: 12/05/2017] [Indexed: 10/18/2022]
Abstract
In the fig-fig wasp nursery pollination system, parasitic wasps, such as gallers and parasitoids that oviposit from the exterior into the fig syconium (globular, enclosed inflorescence) are expected to use a variety of chemical cues for successful location of their hidden hosts. Behavioral assays were performed with freshly eclosed naive galler wasps. Syconia with different oviposition histories, i.e. with or without prior oviposition, were presented to wasps in no-choice assays and the time taken to the first oviposition attempt was recorded. The wasps exhibited a preference for syconia previously exposed to conspecifics for oviposition over unexposed syconia. Additionally, syconia exposed to oviposition by heterospecific wasps were also preferred for oviposition over unexposed syconia indicating that wasps recognise and respond to interspecific cues. Wasps also aggregated for oviposition on syconia previously exposed to oviposition by conspecifics. We investigated chemical cues that wasps may employ in accepting an oviposition resource by analyzing syconial volatile profiles, chemical footprints left by wasps on syconia, and syconial surface hydrocarbons. The volatile profile of a syconium is influenced by the identity of wasps developing within and may be used to identify suitable host syconia at long range whereas close range preference seems to exploit wasp footprints that alter syconium surface hydrocarbon profiles. These cues act as indicators of the oviposition history of the syconium, thereby helping wasps in their oviposition decisions.
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8
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Quaglietti B, Tamisier L, Groussier G, Fleisch A, Le Goff I, Ris N, Kreiter P, Fauvergue X, Malausa T. No inbreeding depression in laboratory-reared individuals of the parasitoid wasp Allotropa burrelli. Ecol Evol 2017; 7:964-973. [PMID: 28168032 PMCID: PMC5288250 DOI: 10.1002/ece3.2643] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 11/03/2016] [Accepted: 11/08/2016] [Indexed: 11/13/2022] Open
Abstract
Inbreeding depression is a major concern in almost all human activities relating to plant and animal breeding. The biological control of pests with natural enemies is no exception, because populations of biocontrol agents experience a series of bottlenecks during importation, rearing, and introduction. A classical biological control program for the Comstock mealybug Pseudococcus comstocki (Hemiptera: Pseudococcidae) was initiated in France in 2008, based on the introduction of an exotic parasitoid, Allotropa burrelli Mues. (Hymenoptera: Platygastridae), a haplodiploid parasitoid imported from Japan. We evaluated the sensitivity of A. burrelli to inbreeding, to optimize rearing and release strategies. We compared several morphological and life‐history traits between the offspring of siblings and the offspring of unrelated parents. We took into account the low level of genetic variability due to the relatively small size of laboratory‐reared populations by contrasting two types of pedigree: one for individuals from a strain founded from a single field population, and the other generated by hybridizing individuals from two strains founded from two highly differentiated populations. Despite this careful design, we obtained no evidence for a negative impact of inbreeding on laboratory‐reared A. burrelli. We discussed the results in light of haplodiploid sex determination and parasitoid mating systems, and classical biological control practices.
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Affiliation(s)
- Bastien Quaglietti
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Lucie Tamisier
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Géraldine Groussier
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Alexandre Fleisch
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Isabelle Le Goff
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Nicolas Ris
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Philippe Kreiter
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Xavier Fauvergue
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
| | - Thibaut Malausa
- UMR 1355-7254 Institut Sophia Agrobiotech CNRS INRA Université Nice Sophia Antipolis Sophia Antipolis France
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9
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Sutton TL, Reuter C, Riegler M, Cook JM. Characterisation of microsatellite markers for fig-pollinating wasps in the Pleistodontes imperialis species complex. AUST J ZOOL 2015. [DOI: 10.1071/zo15011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We characterised a set of nine polymorphic microsatellite loci for Pleistodontes imperialis sp. 1, the pollinator wasp of Port Jackson fig (Ficus rubiginosa) in south-eastern Australia. Characterisation was performed on 30 female individuals collected from a population in Sydney, Australia. The average number of alleles per locus was 7.33, and eight loci were not in Hardy–Weinberg equilibrium. This was expected as fig wasps are known to be highly inbred. A test of genetic differentiation between two natural populations of P. imperialis sp. 1 (Sydney and Newcastle, Australia – some 120 km apart) yielded a very low FST value of 0.012, suggesting considerable gene flow. Bayesian clustering analysis using TESS 2.3.1, which does not assume Hardy–Weinberg equilibrium, however, indicated potential spatial substructuring between the Sydney and Newcastle populations, as well as within the Sydney population. The described loci were also characterised for two other species in the P. imperialis complex: P. imperialis sp. 2 (Townsville, Australia) and P. imperialis sp. 4 (Brisbane, Australia). Seven and six of the nine loci were polymorphic for P. imperialis sp. 2 and P. imperialis sp. 4, respectively.
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10
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Carlson AL, Gong H, Toomajian C, Swanson RJ. Parental genetic distance and patterns in nonrandom mating and seed yield in predominately selfing Arabidopsis thaliana. PLANT REPRODUCTION 2013; 26:317-28. [PMID: 23843176 PMCID: PMC3825607 DOI: 10.1007/s00497-013-0228-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 07/03/2013] [Indexed: 05/09/2023]
Abstract
In this study, we ask two questions: (1) Is reproductive success independent of parental genetic distance in predominately selfing plants? (2) In the absence of early inbreeding depression, is there substantial maternal and/or paternal variation in reproductive success in natural populations? Seed yield in single pollinations and proportion of seeds sired in mixed pollinations were studied in genetically defined accessions of the predominately selfing plant Arabidopsis thaliana by conducting two diallel crosses. The first diallel was a standard, single pollination design that we used to examine variance in seed yield. The second diallel was a mixed pollination design that utilized a standard pollen competitor to examine variance in proportion of seeds sired. We found no correlation between reproductive success and parental genetic distance, and self-pollen does not systematically differ in reproductive success compared to outcross pollen, suggesting that Arabidopsis populations do not experience embryo lethality due to early-acting inbreeding or outbreeding depression. We used these data to partition the contributions to total phenotypic variation from six sources, including maternal contributions, paternal contributions and parental interactions. For seed yield in single pollinations, maternal effects accounted for the most significant source of variance (16.6 %). For proportion of seeds sired in mixed pollinations, the most significant source of variance was paternal effects (17.9 %). Thus, we show that population-level genetic similarities, including selfing, do not correlate with reproductive success, yet there is still significant paternal variance under competition. This suggests two things. First, since these differences are unlikely due to early-acting inbreeding depression or differential pollen viability, this implicates natural variation in pollen germination and tube growth dynamics. Second, this strongly supports a model of fixation of pollen performance genes in populations, offering a focus for future genetic studies in differential reproductive success.
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Affiliation(s)
- Ann L. Carlson
- Department of Biology, Valparaiso University, Valparaiso, IN 46383 USA
| | - Hui Gong
- Department of Mathematics and Computer Science, Valparaiso University, Valparaiso, IN 46383 USA
| | | | - Robert J. Swanson
- Department of Biology, Valparaiso University, Valparaiso, IN 46383 USA
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11
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Sánchez-Molano E, Caballero A, Fernández J. Efficiency of conservation management methods for subdivided populations under local adaptation. ACTA ACUST UNITED AC 2013; 104:554-64. [PMID: 23526788 DOI: 10.1093/jhered/est016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Computer simulations were used to investigate the efficiency of management methods for the conservation of a structured population when local adaptation exists. A subdivided population, with subpopulations adapted to different optima for a quantitative trait under stabilizing selection, was managed in order to maintain the highest genetic diversity in a 10-generation period. Two procedures were compared. For the first, minimum coancestry contributions were carried out independently for each subpopulation, and random migration of individuals was accomplished thereafter. For the second, minimum coancestry contributions from individuals were globally implemented, including an optimal migration design. This optimal method can be adjusted to control local inbreeding to different extents. Adaptation to local optima implies a reduction in the efficiency of the management methods because of the effective failure in the established migrations. For strong selection, the optimal design can be very inefficient, even more than the random migration scheme because the intended migrants have usually low fitness in the recipient subpopulations. However, for more realistic moderate or weak selection, the optimal method is more efficient than random migration, especially if inbreeding depression on fitness is also taken into account. It is concluded that the optimal management method can be recommended in conservation programs with local adaptation of subpopulations, but this issue should be accounted for when designing the management strategies.
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Affiliation(s)
- Enrique Sánchez-Molano
- Departamento de Mejora Genética, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Madrid, Spain
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12
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13
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Nelson RM, Greeff JM. Sex ratio dependent dispersal when sex ratios vary between patches. J Theor Biol 2011; 290:81-7. [PMID: 21893071 DOI: 10.1016/j.jtbi.2011.08.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 08/22/2011] [Accepted: 08/24/2011] [Indexed: 10/17/2022]
Abstract
Female biased sex ratios reduce competition between brothers when mating takes place within local patches. Male dispersal prior to mating is another strategy that reduces competition between brothers. One may thus expect these two traits to co-evolve and this is partially met in that sex ratios becomes less female biased as dispersal increases. However, the evolutionary stable degree of dispersal is unaffected by the sex ratio. The analytical models developed to reach these conclusions ignored variance in sex ratios, since this increases the structural complexity of models. For similar reasons finite clutch sizes are also routinely ignored. To overcome these shortfalls, we developed individual based simulations that allowed us to incorporate realistic clutch sizes and binomial variance in sex ratios between patches. We show that under variable sex ratios, males evolve to more readily disperse away from patches with higher sex ratios than lower sex ratios. We show that, while the dispersal rate is insensitive to the sex ratio when sex ratios are precise, it is affected by the number of males with dispersal decreasing as the number of males decreases.
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Affiliation(s)
- Ronald M Nelson
- Department of Genetics, University of Pretoria, Pretoria, South Africa
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14
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Yamauchi A, Kobayashi Y. Joint evolution of sex ratio and reproductive group size under local mate competition with inbreeding depression. J Theor Biol 2011; 270:127-33. [PMID: 21074542 DOI: 10.1016/j.jtbi.2010.11.008] [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: 06/21/2010] [Revised: 11/05/2010] [Accepted: 11/05/2010] [Indexed: 11/19/2022]
Abstract
Local mate competition (LMC) may involve some amount of inbreeding between siblings. Because sib-mating is generally accompanied by inbreeding depression, natural selection may favor a reduced rate of sib-mating, possibly affecting the evolution of sex ratio and reproductive group size. The present study theoretically investigated the evolution of these traits under LMC in the presence of inbreeding depression. When the reproductive group size evolves, the determination mechanism of sex ratio is important because the timescale of the sex ratio response to reproductive group size can affect the evolutionary process. We consider a spectrum of sex ratio determination mechanisms from purely unconditional to purely conditional, including intermediate modes with various relative strengths of unconditional and conditional effects. This analysis revealed that both the evolutionarily stable reproductive group size and ratio of males increase with higher inbreeding depression and with a larger relative strength of an unconditional effect in sex ratio determination. Unexpectedly, when the sex ratio is controlled purely conditionally, the reproductive group size cannot exceed three even under the severest level of inbreeding depression (i.e., lethal effect). The present study reveals the conditions for LMC to evolve through the analysis of the joint evolution of reproductive group size and sex ratio.
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Affiliation(s)
- Atsushi Yamauchi
- Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu 520-2113, Japan.
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15
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Rousselle Y, Thomas M, Galic N, Bonnin I, Goldringer I. Inbreeding depression and low between-population heterosis in recently diverged experimental populations of a selfing species. Heredity (Edinb) 2011; 106:289-99. [PMID: 20531445 PMCID: PMC3183886 DOI: 10.1038/hdy.2010.72] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Revised: 04/23/2010] [Accepted: 05/05/2010] [Indexed: 11/08/2022] Open
Abstract
In fragmented populations, genetic drift and selection reduce genetic diversity, which in turn results in a loss of fitness or in a loss of evolvability. Genetic rescue, that is, controlled input of diversity from distant populations, may restore evolutionary potential, whereas outbreeding depression might counteract the positive effect of this strategy. We carried out self-pollination and crosses within and between populations in an experimental subdivided population of a selfing species, Triticum aestivum L., to estimate the magnitude of these two phenomena. Surprisingly, for a self-fertilizing species, we found significant inbreeding depression within each population for four of the six traits studied, indicating that mildly deleterious mutations were still segregating in these populations. The progeny of within- and between-population crosses was very similar, indicating low between-population heterosis and little outbreeding depression. We conclude that relatively large population effective sizes prevented fixation of a high genetic load and that local adaptation was limited in these recently diverged populations. The kinship coefficient estimated between the parents using 20 neutral markers was a poor predictor of the progeny phenotypic values, indicating that there was a weak link between neutral diversity and genes controlling fitness-related traits. These results show that when assessing the viability of natural populations and the need for genetic rescue, the use of neutral markers should be complemented with information about the presence of local adaptation in the subdivided population.
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Affiliation(s)
- Y Rousselle
- UMR Génétique Végétale, INRA-CNRS-Univ Paris-Sud-AgroParisTech, Ferme du Moulon, Gif sur Yvette, France.
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16
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Greeff JM, Newman DVK. Testing models of facultative sex ratio adjustment in the pollinating fig wasp Platyscapa awekei. Evolution 2010; 65:203-19. [PMID: 20812975 DOI: 10.1111/j.1558-5646.2010.01116.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Female hymenoptera are renowned for their ability to adjust offspring sex ratio to local mate competition. When two females share a patch, they frequently produce clutches that differ in size, the female with the larger clutch optimally producing a more female-biased sex ratio and vice versa. Females can base their sex allocation on their own clutch size only ("self-knowledge") or on both females' clutch sizes ("complete knowledge"). Few studies have genotyped offspring so that each mother's contribution can be considered separately while none has found that both sources of information are used simultaneously. We genotyped 2489 wasps from 28 figs and assigned their maternity to one of the two foundress females. We argue that likelihood is a very convenient method to compare alternative models, while fitness calculations help to appreciate the cost of maladaptation. We find that the pollinating fig wasp Platyscapa awekei simultaneously uses its own as well as the other females clutch size in allocating sex. Indeed, the complete knowledge model explains the data 36 times better than the self-knowledge model. However, large clutches contained fewer males than the optimal predictions leading to a median selection coefficient of 0.01.
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Affiliation(s)
- Jaco M Greeff
- Department of Genetics, University of Pretoria, Pretoria 0002, South Africa.
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17
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Nelson RM, Greeff JM. Evolutionarily stable mixed mating in a variety of genetic systems. Evol Ecol 2010. [DOI: 10.1007/s10682-010-9418-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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Ouborg NJ, Pertoldi C, Loeschcke V, Bijlsma RK, Hedrick PW. Conservation genetics in transition to conservation genomics. Trends Genet 2010; 26:177-87. [PMID: 20227782 DOI: 10.1016/j.tig.2010.01.001] [Citation(s) in RCA: 216] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Revised: 01/03/2010] [Accepted: 01/04/2010] [Indexed: 11/16/2022]
Affiliation(s)
- N Joop Ouborg
- Molecular Ecology and Ecological Genomics Group, Institute for Water and Wetland Research, Radboud University Nijmegen, 6525 AJ Nijmegen, The Netherlands.
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Puurtinen M, Ketola T, Kotiaho JS. The Good‐Genes and Compatible‐Genes Benefits of Mate Choice. Am Nat 2009; 174:741-52. [PMID: 19772439 DOI: 10.1086/606024] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Mikael Puurtinen
- Centre of Excellence in Evolutionary Research, P.O. Box 35, FI-40014 University of Jyväskylä, Jyväskylä, Finland.
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