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Li C, Ohadi S, Mesgaran MB. Asymmetry in fitness-related traits of later-generation hybrids between two invasive species. AMERICAN JOURNAL OF BOTANY 2021; 108:51-62. [PMID: 33316089 DOI: 10.1002/ajb2.1583] [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: 05/05/2020] [Accepted: 09/14/2020] [Indexed: 06/12/2023]
Abstract
PREMISE The importance of hybridization to invasion has been frequently discussed, with most studies focusing on the comparison of fitness-related traits between F1 hybrids and their parents and the consequences of such fitness differences. However, relatively little attention has been given to late-generation hybrids. Different fitness landscapes could emerge in later generations after hybrids cross with each other or backcross with their parents, which may play an important role in plant invasion and subsequent speciation. METHODS In this study, artificial crosses were conducted to generate multiple generations, including F1, F2, and backcrosses between two invasive species: Cakile edentula (self-compatible) and C. maritima (self-incompatible). Putative hybrids were also collected in the sympatric zone and compared with their co-occurring parents for phenotypic and genetic differences. RESULTS Genetic data provided evidence of hybridization happening in the wild, and phenotypic comparisons showed that natural hybrids had intermediate traits between the two species but showed more similarity to C. maritima than to C. edentula. The asymmetry was further identified in artificial generations for several phenotypic characters. Furthermore, backcrosses exhibited different patterns of variation, with backcrosses to C. maritima having higher reproductive output than their counterparts. CONCLUSIONS Our results suggest that hybridization and introgression (backcrossing) in Cakile species is asymmetric and most likely to favor the proliferation of C. maritima genes in the mixed population and thus help its establishment, a finding that could not be predicted by characterizing F1 hybrids.
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Affiliation(s)
- Chengjun Li
- Institute of Environmental Research at Greater Bay Area, Guangzhou University, Guangzhou, 510006, China
- School of BioSciences, the University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Sara Ohadi
- School of BioSciences, the University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Mohsen B Mesgaran
- School of BioSciences, the University of Melbourne, Melbourne, Victoria, 3010, Australia
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2
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Simon A, Arbiol C, Nielsen EE, Couteau J, Sussarellu R, Burgeot T, Bernard I, Coolen JWP, Lamy J, Robert S, Skazina M, Strelkov P, Queiroga H, Cancio I, Welch JJ, Viard F, Bierne N. Replicated anthropogenic hybridisations reveal parallel patterns of admixture in marine mussels. Evol Appl 2020; 13:575-599. [PMID: 32431737 PMCID: PMC7045717 DOI: 10.1111/eva.12879] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 09/27/2019] [Accepted: 10/02/2019] [Indexed: 12/29/2022] Open
Abstract
Human-mediated transport creates secondary contacts between genetically differentiated lineages, bringing new opportunities for gene exchange. When similar introductions occur in different places, they provide informally replicated experiments for studying hybridisation. We here examined 4,279 Mytilus mussels, sampled in Europe and genotyped with 77 ancestry-informative markers. We identified a type of introduced mussels, called "dock mussels," associated with port habitats and displaying a particular genetic signal of admixture between M. edulis and the Mediterranean lineage of M. galloprovincialis. These mussels exhibit similarities in their ancestry compositions, regardless of the local native genetic backgrounds and the distance separating colonised ports. We observed fine-scale genetic shifts at the port entrance, at scales below natural dispersal distance. Such sharp clines do not fit with migration-selection tension zone models, and instead suggest habitat choice and early-stage adaptation to the port environment, possibly coupled with connectivity barriers. Variations in the spread and admixture patterns of dock mussels seem to be influenced by the local native genetic backgrounds encountered. We next examined departures from the average admixture rate at different loci, and compared human-mediated admixture events, to naturally admixed populations and experimental crosses. When the same M. galloprovincialis background was involved, positive correlations in the departures of loci across locations were found; but when different backgrounds were involved, no or negative correlations were observed. While some observed positive correlations might be best explained by a shared history and saltatory colonisation, others are likely produced by parallel selective events. Altogether, genome-wide effect of admixture seems repeatable and more dependent on genetic background than environmental context. Our results pave the way towards further genomic analyses of admixture, and monitoring of the spread of dock mussels both at large and at fine spacial scales.
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Affiliation(s)
- Alexis Simon
- ISEMUniv MontpellierCNRSEPHEIRDMontpellierFrance
| | | | - Einar Eg Nielsen
- Section for Marine Living ResourcesNational Institute of Aquatic ResourcesTechnical University of DenmarkSilkeborgDenmark
| | | | - Rossana Sussarellu
- Ifremer Unité Biogéochimie et ÉcotoxicologieCentre AtlantiqueNantesFrance
| | - Thierry Burgeot
- Ifremer Unité Biogéochimie et ÉcotoxicologieCentre AtlantiqueNantesFrance
| | | | - Joop W. P. Coolen
- Wageningen Marine ResearchDen HelderThe Netherlands
- Aquatic Ecology and Water Quality Management GroupWageningen UniversityWageningenThe Netherlands
| | - Jean‐Baptiste Lamy
- SG2M‐LGPMMLaboratoire de Génétique et Pathologie des Mollusques MarinsIfremerLa TrembladeFrance
| | - Stéphane Robert
- SG2M‐LGPMMLaboratoire de Génétique et Pathologie des Mollusques MarinsIfremerLa TrembladeFrance
| | - Maria Skazina
- St. Petersburg State UniversitySt. PetersburgRussia
- Laboratory of Monitoring and Conservation of Natural Arctic EcosystemsMurmansk Arctic State UniversityMurmanskRussia
| | - Petr Strelkov
- St. Petersburg State UniversitySt. PetersburgRussia
- Laboratory of Monitoring and Conservation of Natural Arctic EcosystemsMurmansk Arctic State UniversityMurmanskRussia
| | | | - Ibon Cancio
- CBET Research GroupDepartment of Zoology and Animal Cell BiologyFaculty Science and Technology and Research Centre for Experimental Marine Biology and Biotechnology (PiE‐UPV/EHU)University of the Basque Country (UPV/EHU)BilbaoSpain
| | - John J. Welch
- Department of GeneticsUniversity of CambridgeCambridgeUK
| | - Frédérique Viard
- Department AD2MUPMC Univ Paris 06CNRSUMR 7144Station BiologiqueSorbonne UniversitésRoscoffFrance
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Gallego-Tévar B, Grewell BJ, Drenovsky RE, Castillo JM. Transgressivity in Key Functional Traits Rather Than Phenotypic Plasticity Promotes Stress Tolerance in A Hybrid Cordgrass. PLANTS (BASEL, SWITZERLAND) 2019; 8:E594. [PMID: 31842356 PMCID: PMC6963473 DOI: 10.3390/plants8120594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 11/30/2019] [Accepted: 12/04/2019] [Indexed: 11/16/2022]
Abstract
Hybridization might promote offspring fitness via a greater tolerance to environmental stressors due to heterosis and higher levels of phenotypic plasticity. Thus, analyzing the phenotypic expression of hybrids provides an opportunity to elucidate further plant responses to environmental stress. In the case of coastal salt marshes, sea level rise subjects hybrids, and their parents, to longer tidal submergence and higher salinity. We analyzed the phenotypic expression patterns in the hybrid Spartina densiflora x foliosa relative to its parental species, native S. foliosa, and invasive S. densiflora, from the San Francisco Estuary when exposed to contrasting salinities and inundations in a mesocosm experiment. 37% of the recorded traits displayed no variability among parents and hybrids, 3% showed an additive inheritance, 37% showed mid-parent heterosis, 18% showed best-parent heterosis, and 5% presented worst-parent heterosis. Transgressivity, rather than phenotypic plasticity, in key functional traits of the hybrid, such as tiller height, conveyed greater stress tolerance to the hybrid when compared to the tolerance of its parents. As parental trait variability increased, phenotypic transgressivity of the hybrid increased and it was more important in response to inundation than salinity. Increases in salinity and inundation associated with sea level rise will amplify the superiority of the hybrid over its parental species. These results provide evidence of transgressive traits as an underlying source of adaptive variation that can facilitate plant invasions. The adaptive evolutionary process of hybridization is thought to support an increased invasiveness of plant species and their rapid evolution.
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Affiliation(s)
- Blanca Gallego-Tévar
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Apartado 1095, 41080 Sevilla, Spain;
| | - Brenda J. Grewell
- USDA-ARS Invasive Species and Pollinator Health Research Unit, Department. of Plant Sciences, University of California, Mail Stop 4, 1 Shields Avenue, Davis, CA 95616, USA;
| | - Rebecca E. Drenovsky
- Department of Biology, John Carroll University, University Heights, OH 44118, USA;
| | - Jesús M. Castillo
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Apartado 1095, 41080 Sevilla, Spain;
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Quilodrán CS, Nussberger B, Montoya‐Burgos JI, Currat M. Hybridization and introgression during density-dependent range expansion: European wildcats as a case study. Evolution 2019; 73:750-761. [PMID: 30815854 PMCID: PMC6594108 DOI: 10.1111/evo.13704] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 02/12/2019] [Indexed: 01/03/2023]
Abstract
Interbreeding between historically allopatric species with incomplete reproductive barriers may result when species expand their range. The genetic consequences of such hybridization depend critically on the dynamics of the range expansion. Hybridization models during range expansion have been developed but assume dispersal to be independent from neighboring population densities. However, organisms may disperse because they are attracted by conspecifics or because they prefer depopulated areas. Here, through spatially explicit simulations, we assess the effect of various density-dependent dispersal modes on the introgression between two species. We find huge introgression from the local species into the invasive one with all dispersal modes investigated, even when the hybridization rate is relatively low. This represents a general expectation for neutral genes even if the dispersal modes differ in colonization times and amount of introgression. Invasive individuals attracted by conspecifics need more time to colonize the whole area and are more introgressed by local genes, whereas the opposite is found for solitary individuals. We applied our approach to a recent expansion of European wildcats in the Jura Mountains and the hybridization with domestic cats. We show that the simulations explained better the observed level of introgression at nuclear, mtDNA, and Y chromosome markers, when using solitary dispersal for wildcats instead of random or gregarious dispersal, in accordance with ecological knowledge. Thus, use of density-dependent dispersal models increases the predictive power of the approach.
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Affiliation(s)
- Claudio S. Quilodrán
- Laboratory of Anthropology, Genetics and Peopling History, Department of Genetics and Evolution, Anthropology UnitUniversity of GenevaGenevaSwitzerland
- Laboratory of Vertebrate Evolution, Department of Genetics and EvolutionUniversity of GenevaGenevaSwitzerland
- Department of ZoologyUniversity of OxfordOxfordUnited Kingdom
| | - Beatrice Nussberger
- Institute of Evolutionary Biology and Environmental StudiesUniversity of ZurichZurichSwitzerland
| | - Juan I. Montoya‐Burgos
- Laboratory of Vertebrate Evolution, Department of Genetics and EvolutionUniversity of GenevaGenevaSwitzerland
- Institute of Genetics and Genomics in Geneva (IGE3)GenevaSwitzerland
| | - Mathias Currat
- Laboratory of Anthropology, Genetics and Peopling History, Department of Genetics and Evolution, Anthropology UnitUniversity of GenevaGenevaSwitzerland
- Institute of Genetics and Genomics in Geneva (IGE3)GenevaSwitzerland
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5
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Development of a Novel Mule Deer Genomic Assembly and Species-Diagnostic SNP Panel for Assessing Introgression in Mule Deer, White-Tailed Deer, and Their Interspecific Hybrids. G3-GENES GENOMES GENETICS 2019; 9:911-919. [PMID: 30670611 PMCID: PMC6404596 DOI: 10.1534/g3.118.200838] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Mule deer (Odocoileus hemionus) are endemic to a wide variety of habitats in western North America, many of which are shared in sympatry with their closely related sister-species white-tailed deer (Odocoileus virginianus), whom they hybridize with in wild populations. Although mule deer meet many ideal conditions for a molecular ecological research species, such as high abundance, ecological importance, and broad dispersal and gene flow, conservation genetic studies have been limited by a relative lack of existing genomic resources and inherent difficulties caused by introgression with white-tailed deer. Many molecular tools currently available for the study of cervids were designed using reference assemblies of divergent model species, specifically cattle (Bos taurus). Bovidae and Cervidae diverged approximately 28 million years ago, therefore, we sought to ameliorate the available resources by contributing the first mule deer whole genome sequence draft assembly with an average genome-wide read depth of 25X, using the white-tailed genome assembly (Ovir.te_1.0) as a reference. Comparing the two assemblies, we identified ∼33 million single nucleotide polymorphisms (SNPs) and insertion/deletion variants. We then verified fixed SNP differences between the two species and developed a 40-loci SNP assay capable of identifying pure mule deer, white-tailed deer, and interspecific hybrids. Assignment capacity of the panel, which was tested on simulated datasets, is reliable up to and including the third backcross hybrid generation. Identification of post-F1 hybrids will be necessary for hybrid zone population studies going forward, and the new mule deer assembly will be a valuable resource for genetic and comparative genomics studies.
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Williams J, Lambert AM, Long R, Saltonstall K. Does hybrid Phragmites australis differ from native and introduced lineages in reproductive, genetic, and morphological traits? AMERICAN JOURNAL OF BOTANY 2019; 106:29-41. [PMID: 30633812 DOI: 10.1002/ajb2.1217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 10/03/2018] [Indexed: 06/09/2023]
Abstract
PREMISE OF THE STUDY Hybridization between previously isolated species or lineages can stimulate invasiveness because of increased genetic diversity and inherited traits facilitating competitive and reproductive potential. We evaluated differences in stand characteristics and sexual and vegetative reproduction among native, introduced, and hybrid Phragmites australis lineages in the southwestern United States. We also assessed the degree of hybridization among lineages and backcrossing of hybrids with parental lineages. METHODS Growth and morphological characteristics were measured in native, introduced, and hybrid Phragmites stands to evaluate relative cover and dominance in associated plant communities. Panicles were collected from stands to evaluate germination, dormancy, and differences in seed traits. Seedlings from germination trials were genotyped to determine frequency of crossing and backcrossing among lineages. KEY RESULTS Introduced and hybrid Phragmites stands had significantly greater stem and panicle densities than native stands and were more likely to be dominant members of their respective plant communities. Hybrid seed outputs were significantly greater, but hybrid seeds had lower germination rates than those from native and introduced lineages. We detected a novel hybridization event between native and introduced lineages, but found no strong evidence of hybrids backcrossing with parental lineages. CONCLUSIONS Hybrid Phragmites in the Southwest exhibits reproductive, genetic, and morphological characteristics from both parental lineages that facilitate dispersal, establishment, and aggressive growth, including high reproductive output, rhizome viability, and aboveground biomass, with smaller seeds and greater genetic diversity than its progenitors. Our results show hybrids can inherit traits that confer invasiveness and provide insight for managing this species complex and other cryptic species with native and introduced variants with potential for intraspecific hybridization.
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Affiliation(s)
- Jared Williams
- Marine Science Institute and Cheadle Center for Biodiversity and Ecological Restoration, University of California, Santa Barbara, CA, 93106-6150, USA
| | - Adam M Lambert
- Marine Science Institute and Cheadle Center for Biodiversity and Ecological Restoration, University of California, Santa Barbara, CA, 93106-6150, USA
| | - Randy Long
- Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Kristin Saltonstall
- Smithsonian Tropical Research Institute, Apartado, 0843-03092, Balboa, Ancon, Republic of Panama
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7
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Gallego-Tévar B, Curado G, Grewell BJ, Figueroa ME, Castillo JM. Realized niche and spatial pattern of native and exotic halophyte hybrids. Oecologia 2018; 188:849-862. [DOI: 10.1007/s00442-018-4251-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 08/20/2018] [Indexed: 11/28/2022]
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8
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Becher C, Gumm JM. The roles of inter- and intra-sexual selection in behavioral isolation between native and invasive pupfishes. Curr Zool 2018; 64:135-144. [PMID: 29492046 PMCID: PMC5809032 DOI: 10.1093/cz/zox068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 11/18/2017] [Indexed: 11/14/2022] Open
Abstract
Male-male competition and female mate choice may both play important roles in driving and maintaining reproductive isolation between species. When previously allopatric species come into secondary contact with each other due to introductions, they provide an opportunity to evaluate the identity and strength of reproductive isolating mechanisms. If reproductive isolation is not maintained, hybridization may occur. We examined how reproductive isolating mechanisms mediate hybridization between endemic populations of the Red River pupfish Cyprinodon rubrofluviatilis and the recently introduced sheepshead minnow C. variegatus. In lab-based dominance trials, males of both species won the same number of competitions. However, male C. rubrofluviatilis that won competitions were more aggressive than C. variegatus winners, and more aggression was needed to win against competitor C. variagatus than allopatric C. rubrofluviatilis. Duration of fights also differed based on the relatedness of the competitor. In dichotomous mate choice trials, there were no conspecific or heterospecific preferences expressed by females of either species. Our findings that male-male aggression differs between closely and distantly related groups, but female choice does not suggest that male-male competition may be the more likely mechanism to impede gene flow in this system.
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Affiliation(s)
- Cory Becher
- Department of Biology, Stephen F. Austin State University, Nacogdoches, TX 75962, USA and.,Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Jennifer M Gumm
- Department of Biology, Stephen F. Austin State University, Nacogdoches, TX 75962, USA and
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Hybridization can facilitate species invasions, even without enhancing local adaptation. Proc Natl Acad Sci U S A 2018; 113:10210-4. [PMID: 27601582 DOI: 10.1073/pnas.1605626113] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The founding population in most new species introductions, or at the leading edge of an ongoing invasion, is likely to be small. Severe Allee effects-reductions in individual fitness at low population density-may then result in a failure of the species to colonize, even if the habitat could support a much larger population. Using a simulation model for plant populations that incorporates demography, mating systems, quantitative genetics, and pollinators, we show that Allee effects can potentially be overcome by transient hybridization with a resident species or an earlier colonizer. This mechanism does not require the invocation of adaptive changes usually attributed to invasions following hybridization. We verify our result in a case study of sequential invasions by two plant species where the outcrosser Cakile maritima has replaced an earlier, inbreeding, colonizer Cakile edentula (Brassicaceae). Observed historical rates of replacement are consistent with model predictions from hybrid-alleviated Allee effects in outcrossers, although other causes cannot be ruled out.
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Pieper SJ, Nicholls AA, Freeland JR, Dorken ME. Asymmetric Hybridization in Cattails (Typha spp.) and Its Implications for the Evolutionary Maintenance of Native Typha latifolia. J Hered 2017; 108:479-487. [DOI: 10.1093/jhered/esx036] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 04/12/2017] [Indexed: 12/11/2022] Open
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Bouhours J, Mesgaran MB, Cousens RD, Lewis MA. Neutral hybridization can overcome a strong Allee effect by improving pollination quality. THEOR ECOL-NETH 2017. [DOI: 10.1007/s12080-017-0333-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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14
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Lee AK, Ayres DR, Pakenham-Walsh MR, Strong DR. Responses to salinity of Spartina hybrids formed in San Francisco Bay, California (S. alterniflora × foliosa and S. densiflora × foliosa ). Biol Invasions 2016. [DOI: 10.1007/s10530-015-1011-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Saltonstall K, Lambert AM, Rice N. What happens in Vegas, better stay in Vegas: Phragmites australis hybrids in the Las Vegas Wash. Biol Invasions 2016. [DOI: 10.1007/s10530-016-1167-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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16
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Glotzbecker GJ, Walters DM, Blum MJ. Rapid movement and instability of an invasive hybrid swarm. Evol Appl 2016; 9:741-55. [PMID: 27330551 PMCID: PMC4908461 DOI: 10.1111/eva.12371] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Accepted: 02/08/2016] [Indexed: 12/15/2022] Open
Abstract
Unstable hybrid swarms that arise following the introduction of non‐native species can overwhelm native congeners, yet the stability of invasive hybrid swarms has not been well documented over time. Here, we examine genetic variation and clinal stability across a recently formed hybrid swarm involving native blacktail shiner (Cyprinella venusta) and non‐native red shiner (C. lutrensis) in the Upper Coosa River basin, which is widely considered to be a global hot spot of aquatic biodiversity. Examination of phenotypic, multilocus genotypic, and mitochondrial haplotype variability between 2005 and 2011 revealed that the proportion of hybrids has increased over time, with more than a third of all sampled individuals exhibiting admixture in the final year of sampling. Comparisons of clines over time indicated that the hybrid swarm has been rapidly progressing upstream, but at a declining and slower pace than rates estimated from historical collection records. Clinal comparisons also showed that the hybrid swarm has been expanding and contracting over time. Additionally, we documented the presence of red shiner and hybrids farther downstream than prior studies have detected, which suggests that congeners in the Coosa River basin, including all remaining populations of the threatened blue shiner (Cyprinella caerulea), are at greater risk than previously thought.
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Affiliation(s)
| | - David M Walters
- U.S. Geological Survey Fort Collins Science Center Fort Collins CO USA
| | - Michael J Blum
- Department of Ecology and Evolutionary BiologyTulane UniversityNew OrleansLAUSA; Tulane - Xavier Center for Bioenvironmental ResearchTulane UniversityNew OrleansLAUSA
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Todesco M, Pascual MA, Owens GL, Ostevik KL, Moyers BT, Hübner S, Heredia SM, Hahn MA, Caseys C, Bock DG, Rieseberg LH. Hybridization and extinction. Evol Appl 2016; 9:892-908. [PMID: 27468307 PMCID: PMC4947151 DOI: 10.1111/eva.12367] [Citation(s) in RCA: 339] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 01/28/2016] [Indexed: 01/29/2023] Open
Abstract
Hybridization may drive rare taxa to extinction through genetic swamping, where the rare form is replaced by hybrids, or by demographic swamping, where population growth rates are reduced due to the wasteful production of maladaptive hybrids. Conversely, hybridization may rescue the viability of small, inbred populations. Understanding the factors that contribute to destructive versus constructive outcomes of hybridization is key to managing conservation concerns. Here, we survey the literature for studies of hybridization and extinction to identify the ecological, evolutionary, and genetic factors that critically affect extinction risk through hybridization. We find that while extinction risk is highly situation dependent, genetic swamping is much more frequent than demographic swamping. In addition, human involvement is associated with increased risk and high reproductive isolation with reduced risk. Although climate change is predicted to increase the risk of hybridization‐induced extinction, we find little empirical support for this prediction. Similarly, theoretical and experimental studies imply that genetic rescue through hybridization may be equally or more probable than demographic swamping, but our literature survey failed to support this claim. We conclude that halting the introduction of hybridization‐prone exotics and restoring mature and diverse habitats that are resistant to hybrid establishment should be management priorities.
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Affiliation(s)
- Marco Todesco
- Department of Botany and Biodiversity Research Centre University of British Columbia Vancouver BC Canada
| | - Mariana A Pascual
- Department of Botany and Biodiversity Research Centre University of British Columbia Vancouver BC Canada
| | - Gregory L Owens
- Department of Botany and Biodiversity Research Centre University of British Columbia Vancouver BC Canada
| | - Katherine L Ostevik
- Department of Botany and Biodiversity Research Centre University of British Columbia Vancouver BC Canada
| | - Brook T Moyers
- Department of Botany and Biodiversity Research Centre University of British Columbia Vancouver BC Canada; Department of Bioagricultural Sciences and Pest Management Colorado State University Ft Collins CO USA
| | - Sariel Hübner
- Department of Botany and Biodiversity Research Centre University of British Columbia Vancouver BC Canada
| | - Sylvia M Heredia
- Department of Botany and Biodiversity Research Centre University of British Columbia Vancouver BC Canada
| | - Min A Hahn
- Department of Botany and Biodiversity Research Centre University of British Columbia Vancouver BC Canada
| | - Celine Caseys
- Department of Botany and Biodiversity Research Centre University of British Columbia Vancouver BC Canada
| | - Dan G Bock
- Department of Botany and Biodiversity Research Centre University of British Columbia Vancouver BC Canada
| | - Loren H Rieseberg
- Department of Botany and Biodiversity Research Centre University of British Columbia Vancouver BC Canada; Department of Biology Indiana University Bloomington IN USA
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Genetic characterization of hybridization between native and invasive bittersweet vines (Celastrus spp.). Biol Invasions 2015. [DOI: 10.1007/s10530-015-0926-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Strong DR, Ayres DR. Ecological and Evolutionary Misadventures of Spartina. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2013. [DOI: 10.1146/annurev-ecolsys-110512-135803] [Citation(s) in RCA: 144] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Spartina species of the mid-low intertidal areas are powerful ecological engineers that are highly valued where they are native. Elsewhere, they overgrow native salt marsh and open intertidal mudflats, diminish biota, increase costs of managing wildlife, and interfere with human uses of estuaries. Huge efforts have been mounted to kill some populations of invading Spartina. All large Spartina invasions are by S. densiflora (2n = 7x = 70) or S. alterniflora (2n = 6x = 62) or hybrids between the hexaploid species (2n = 6x). Hybridization is a recurrent theme in Spartina; the allododecaploid S. anglica (2n = 12x = 120) and the hybrid swarm in San Francisco Bay arose through the introductions of S. alterniflora into the range of native Spartina species. The ancient hybrid S. densiflora also hybridized with native Spartina species. Hybridization promotes the evolution of highly invasive populations and hampers control efforts. Whether Spartina, native and not, would protect the shore as sea levels rise depends upon unimpeded areas for upward marsh growth and sufficient sediment, conditions that are often not satisfied.
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Affiliation(s)
- Donald R. Strong
- Section of Evolution and Ecology, University of California, Davis, California 95616;,
| | - Debra R. Ayres
- Section of Evolution and Ecology, University of California, Davis, California 95616;,
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Ward JL, Blum MJ. Exposure to an environmental estrogen breaks down sexual isolation between native and invasive species. Evol Appl 2012; 5:901-12. [PMID: 23346234 PMCID: PMC3552407 DOI: 10.1111/j.1752-4571.2012.00283.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 05/15/2012] [Indexed: 11/30/2022] Open
Abstract
Environmental change can increase the likelihood of interspecific hybridization by altering properties of mate recognition and discrimination between sympatric congeners. We examined how exposure to an environmentally widespread endocrine-disrupting chemical (EDC), bisphenol A (BPA), affected visual communication signals and behavioral isolation between an introduced freshwater fish and a native congener (genus: Cyprinella). Exposure to BPA induced changes in the expression of male secondary traits as well as male and female mate choice, leading to an overall reduction in prezygotic isolation between congeners. Changes in female mate discrimination were not tightly linked to changes in male phenotypic traits, suggesting that EDC exposure may alter female choice thresholds independently of the effects of exposure on males. These findings indicate that environmental exposure to EDCs can lead to population declines via the erosion of species boundaries and by promoting the establishment and spread of non-native species via hybridization.
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Affiliation(s)
- Jessica L Ward
- Department of Ecology and Evolutionary Biology, Tulane UniversityNew Orleans, LA, USA
- Department of Fisheries, Wildlife and Conservation Biology and Department of Ecology, Evolution and Behavior, University of MinnesotaSaint Paul, MN, USA
| | - Michael J Blum
- Department of Ecology and Evolutionary Biology, Tulane UniversityNew Orleans, LA, USA
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Ghosh A, Meirmans PG, Haccou P. Quantifying introgression risk with realistic population genetics. Proc Biol Sci 2012; 279:4747-54. [PMID: 23055068 DOI: 10.1098/rspb.2012.1907] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Introgression is the permanent incorporation of genes from the genome of one population into another. This can have severe consequences, such as extinction of endemic species, or the spread of transgenes. Quantification of the risk of introgression is an important component of genetically modified crop regulation. Most theoretical introgression studies aimed at such quantification disregard one or more of the most important factors concerning introgression: realistic genetical mechanisms, repeated invasions and stochasticity. In addition, the use of linkage as a risk mitigation strategy has not been studied properly yet with genetic introgression models. Current genetic introgression studies fail to take repeated invasions and demographic stochasticity into account properly, and use incorrect measures of introgression risk that can be manipulated by arbitrary choices. In this study, we present proper methods for risk quantification that overcome these difficulties. We generalize a probabilistic risk measure, the so-called hazard rate of introgression, for application to introgression models with complex genetics and small natural population sizes. We illustrate the method by studying the effects of linkage and recombination on transgene introgression risk at different population sizes.
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Affiliation(s)
- Atiyo Ghosh
- Institute of Environmental Sciences (CML), Leiden University, PO Box 9518, 2300 RA Leiden, The Netherlands.
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SCHULTE ULRICH, VEITH MICHAEL, HOCHKIRCH AXEL. Rapid genetic assimilation of native wall lizard populations (Podarcis muralis) through extensive hybridization with introduced lineages. Mol Ecol 2012; 21:4313-26. [DOI: 10.1111/j.1365-294x.2012.05693.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Ward JL, Blum MJ, Walters DM, Porter BA, Burkhead N, Freeman B. Discordant introgression in a rapidly expanding hybrid swarm. Evol Appl 2012; 5:380-92. [PMID: 25568058 PMCID: PMC3353357 DOI: 10.1111/j.1752-4571.2012.00249.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 12/09/2011] [Indexed: 12/01/2022] Open
Abstract
The erosion of species boundaries can involve rapid evolutionary change. Consequently, many aspects of the process remain poorly understood, including the formation, expansion, and evolution of hybrid swarms. Biological invasions involving hybridization present exceptional opportunities to study the erosion of species boundaries because timelines of interactions and outcomes are frequently well known. Here, we examined clinal variation across codominant and maternally inherited genetic markers as well as phenotypic traits to characterize the expansion and evolution of a hybrid swarm between native Cyprinella venusta and invasive Cyprinella lutrensis minnows. Discordant introgression of phenotype, microsatellite multilocus genotype, and mtDNA haplotype indicates that the observable expansion of the C. venusta × C. lutrensis hybrid swarm is a false invasion front. Both parental and hybrid individuals closely resembling C. lutrensis are numerically dominant in the expansion wake, indicating that the non-native parental phenotype may be selectively favored. These findings show that cryptic introgression can extend beyond the phenotypic boundaries of hybrid swarms and that hybrid swarms likely expand more rapidly than can be documented from phenotypic variation alone. Similarly, dominance of a single parental phenotype following an introduction event may lead to instances of species erosion being mistaken for species displacement without hybridization.
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Affiliation(s)
- Jessica L Ward
- Department of Ecology, Evolution and Behavior, University of Minnesota St. Paul, MN, USA
| | - Mike J Blum
- Department of Ecology and Evolutionary Biology, Tulane University New Orleans, LA, USA
| | - David M Walters
- U.S. Geological Survey, Fort Collins Science Center Fort Collins, CO, USA
| | - Brady A Porter
- Department of Biological Sciences, Duquesne University Pittsburgh, PA, USA
| | - Noel Burkhead
- U.S. Geological Survey, Southeast Ecological Science Center Gainesville, FL, USA
| | - Byron Freeman
- Georgia Museum of Natural History and Odum School of Ecology, University of Georgia Athens, GA, USA
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Baskett ML, Gomulkiewicz R. Introgressive hybridization as a mechanism for species rescue. THEOR ECOL-NETH 2011. [DOI: 10.1007/s12080-011-0118-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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YIN MINGBO, WOLINSKA JUSTYNA, GIEßLER SABINE. Clonal diversity, clonal persistence and rapid taxon replacement in natural populations of species and hybrids of the Daphnia longispina complex. Mol Ecol 2010; 19:4168-78. [DOI: 10.1111/j.1365-294x.2010.04807.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Castillo JM, Ayres DR, Leira-Doce P, Bailey J, Blum M, Strong DR, Luque T, Figueroa E. The production of hybrids with high ecological amplitude between exotic Spartina densiflora and native S. maritima in the Iberian Peninsula. DIVERS DISTRIB 2010. [DOI: 10.1111/j.1472-4642.2010.00673.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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27
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Gallien L, Münkemüller T, Albert CH, Boulangeat I, Thuiller W. Predicting potential distributions of invasive species: where to go from here? DIVERS DISTRIB 2010. [DOI: 10.1111/j.1472-4642.2010.00652.x] [Citation(s) in RCA: 249] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Hooftman DAP, Hartman Y, Oostermeijer JGB, Den Nijs HJCM. Existence of vigorous lineages of crop-wild hybrids in Lettuce under field conditions. ENVIRONMENTAL BIOSAFETY RESEARCH 2009; 8:203-17. [PMID: 20883659 DOI: 10.1051/ebr/2010001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2010] [Accepted: 06/20/2010] [Indexed: 01/27/2023]
Abstract
Plant to plant gene flow is a route of environmental exposure for GM plants specifically since crosses with wild relatives could lead to the formation of more vigorous hybrids, which could increase the rate of introgression and the environmental impact. Here, we test the first step in the process of potential transgene introgression: whether hybrid vigor can be inherited to the next generation, which could lead to fixation of altered, i.e., elevated, quantitative traits. The potential for a permanent elevated fitness was tested using individual autogamous progeny lineages of hybrids between the crop Lactuca sativa (Lettuce) and the wild species Lactuca serriola (Prickly Lettuce). We compared progeny from motherplants grown under either greenhouse or field conditions. The survival of young plants depended strongly on maternal environment. Furthermore, we observed that offspring reproductive fitness components were correlated with maternal fitness. Our study demonstrates that post-zygotic genotypic sorting at the young plants stage reduces the number of genotypes non-randomly, leading to inheritance of high levels of reproductive traits in the surviving hybrid lineages, compared to the pure wild relatives. Consequently, directional selection could lead to displacement of the pure wild relative and fixation of more vigorous genome segments originating from crops, stabilizing plant traits at elevated levels. Such information can be used to indentify segments which are less likely to introgress into wild relative populations as a target for transgene insertion.
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Affiliation(s)
- Danny A P Hooftman
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, The Netherlands.
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Spatial deployment of gene-for-gene resistance governs evolution and spread of pathogen populations. THEOR ECOL-NETH 2009. [DOI: 10.1007/s12080-009-0045-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Hooftman DAP, Oostermeijer JGB, Marquard E, den Nijs H(JC. Modelling the consequences of cropwild relative gene flow: a sensitivity analysis of the effects of outcrossing rates and hybrid vigour breakdown inLactuca. J Appl Ecol 2008. [DOI: 10.1111/j.1365-2664.2008.01508.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Currat M, Ruedi M, Petit RJ, Excoffier L. The hidden side of invasions: massive introgression by local genes. Evolution 2008; 62:1908-20. [PMID: 18452573 DOI: 10.1111/j.1558-5646.2008.00413.x] [Citation(s) in RCA: 276] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Despite hundreds of reports involving both plants and animals, the mechanisms underlying introgression remain obscure, even if some form of selection is frequently invoked. Introgression has repeatedly been reported in species that have recently colonized a new habitat, suggesting that demographic processes should be given more attention for understanding the mechanisms of introgression. Here we show by spatially explicit simulations that massive introgression of neutral genes takes place during the invasion of an occupied territory if interbreeding is not severely prevented between the invading and the local species. We also demonstrate that introgression occurs almost exclusively from the local to the invading species, especially for populations located far away from the source of the invasion, and this irrespective of the relative densities of the two species. This pattern is strongest at markers experiencing reduced gene flow, in keeping with the observation that organelle genes are often preferentially introgressed across species boundaries. A survey of the literature shows that a majority of published empirical studies of introgression during range expansions, in animals and in plants, follow the predictions of our model. Our results imply that speciation genes can be identified by comparing genomes of interfertile native and invading species pairs.
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Affiliation(s)
- Mathias Currat
- Computational and Molecular Population Genetics Laboratory, Institute of Zoology, University of Bern, Baltzerstrasse 6, 3012 Berne, Switzerland.
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Ayres DR, Zaremba K, Sloop CM, Strong DR. Sexual reproduction of cordgrass hybrids (Spartina foliosa x alterniflora) invading tidal marshes in San Francisco Bay. DIVERS DISTRIB 2007. [DOI: 10.1111/j.1472-4642.2007.00414.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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