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Baird HP, Moon KL, Janion‐Scheepers C, Chown SL. Springtail phylogeography highlights biosecurity risks of repeated invasions and intraregional transfers among remote islands. Evol Appl 2020; 13:960-973. [PMID: 32431746 PMCID: PMC7232766 DOI: 10.1111/eva.12913] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 12/08/2019] [Accepted: 12/13/2019] [Indexed: 12/13/2022] Open
Abstract
Human-mediated transport of species outside their natural range is a rapidly growing threat to biodiversity, particularly for island ecosystems that have evolved in isolation. The genetic structure underpinning island populations will largely determine their response to increased transport and thus help to inform biosecurity management. However, this information is severely lacking for some groups, such as the soil fauna. We therefore analysed the phylogeographic structure of an indigenous and an invasive springtail species (Collembola: Poduromorpha), each distributed across multiple remote sub-Antarctic islands, where human activity is currently intensifying. For both species, we generated a genome-wide SNP data set and additionally analysed all available COI barcodes. Genetic differentiation in the indigenous springtail Tullbergia bisetosa is substantial among (and, to a lesser degree, within) islands, reflecting low dispersal and historic population fragmentation, while COI patterns reveal ancestral signatures of postglacial recolonization. This pronounced geographic structure demonstrates the key role of allopatric divergence in shaping the region's diversity and highlights the vulnerability of indigenous populations to genetic homogenization via human transport. For the invasive species Hypogastrura viatica, nuclear genetic structure is much less apparent, particularly for islands linked by regular shipping, while diverged COI haplotypes indicate multiple independent introductions to each island. Thus, human transport has likely facilitated this species' persistence since its initial colonization, through the ongoing introduction and inter-island spread of genetic variation. These findings highlight the different evolutionary consequences of human transport for indigenous and invasive soil species. Crucially, both outcomes demonstrate the need for improved intraregional biosecurity among remote island systems, where the policy focus to date has been on external introductions.
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Affiliation(s)
- Helena P. Baird
- School of Biological SciencesMonash UniversityClaytonVictoriaAustralia
| | - Katherine L. Moon
- School of Biological SciencesMonash UniversityClaytonVictoriaAustralia
| | - Charlene Janion‐Scheepers
- Iziko Museums of South AfricaCape TownSouth Africa
- Department of Zoology & EntomologyUniversity of the Free StateBloemfonteinSouth Africa
| | - Steven L. Chown
- School of Biological SciencesMonash UniversityClaytonVictoriaAustralia
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Chau JH, Born C, McGeoch MA, Bergstrom D, Shaw J, Terauds A, Mairal M, Le Roux JJ, Jansen van Vuuren B. The influence of landscape, climate and history on spatial genetic patterns in keystone plants (Azorella) on sub-Antarctic islands. Mol Ecol 2019; 28:3291-3305. [PMID: 31179588 DOI: 10.1111/mec.15147] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 05/13/2019] [Accepted: 05/14/2019] [Indexed: 11/30/2022]
Abstract
The distribution of genetic variation in species is governed by factors that act differently across spatial scales. To tease apart the contribution of different processes, especially at intermediate spatial scales, it is useful to study simple ecosystems such as those on sub-Antarctic oceanic islands. In this study, we characterize spatial genetic patterns of two keystone plant species, Azorella selago on sub-Antarctic Marion Island and Azorella macquariensis on sub-Antarctic Macquarie Island. Although both islands experience a similar climate and have a similar vegetation structure, they differ significantly in topography and geological history. We genotyped six microsatellites for 1,149 individuals from 123 sites across Marion Island and 372 individuals from 42 sites across Macquarie Island. We tested for spatial patterns in genetic diversity, including correlation with elevation and vegetation type, and clines in different directional bearings. We also examined genetic differentiation within islands, isolation-by-distance with and without accounting for direction, and signals of demographic change. Marion Island was found to have a distinct northwest-southeast divide, with lower genetic diversity and more sites with a signal of population expansion in the northwest. We attribute this to asymmetric seed dispersal by the dominant northwesterly winds, and to population persistence in a southwestern refugium during the Last Glacial Maximum. No apparent spatial pattern, but greater genetic diversity and differentiation between sites, was found on Macquarie Island, which may be due to the narrow length of the island in the direction of the dominant winds and longer population persistence permitted by the lack of extensive glaciation on the island. Together, our results clearly illustrate the implications of island shape and geography, and the importance of direction-dependent drivers, in shaping spatial genetic structure.
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Affiliation(s)
- John H Chau
- Department of Zoology, Centre for Ecological Genomics and Wildlife Conservation, University of Johannesburg, Auckland Park, South Africa
| | - Céline Born
- Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa
| | - Melodie A McGeoch
- Ecology Research Group, School of Biological Sciences, Monash University, Melbourne, Vic., Australia
| | - Dana Bergstrom
- Australian Antarctic Division, Kingston, Tas., Australia.,Global Challenges Program, University of Wollongong, Wollongong, NSW, Australia
| | - Justine Shaw
- Environmental Decision Group, School of Biological Sciences, University of Queensland, Brisbane, Qld., Australia
| | - Aleks Terauds
- Australian Antarctic Division, Kingston, Tas., Australia
| | - Mario Mairal
- Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa
| | - Johannes J Le Roux
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Bettine Jansen van Vuuren
- Department of Zoology, Centre for Ecological Genomics and Wildlife Conservation, University of Johannesburg, Auckland Park, South Africa
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Pahad G, Montgelard C, Jansen van Vuuren B. Phylogeography and niche modelling: reciprocal enlightenment. MAMMALIA 2019. [DOI: 10.1515/mammalia-2018-0191] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Phylogeography examines the spatial genetic structure of species. Environmental niche modelling (or ecological niche modelling; ENM) examines the environmental limits of a species’ ecological niche. These two fields have great potential to be used together. ENM can shed light on how phylogeographical patterns develop and help identify possible drivers of spatial structure that need to be further investigated. Specifically, ENM can be used to test for niche differentiation among clades, identify factors limiting individual clades and identify barriers and contact zones. It can also be used to test hypotheses regarding the effects of historical and future climate change on spatial genetic patterns by projecting niches using palaeoclimate or future climate data. Conversely, phylogeographical information can populate ENM with within-species genetic diversity. Where adaptive variation exists among clades within a species, modelling their niches separately can improve predictions of historical distribution patterns and future responses to climate change. Awareness of patterns of genetic diversity in niche modelling can also alert conservationists to the potential loss of genetically diverse areas in a species’ range. Here, we provide a simplistic overview of both fields, and focus on their potential for integration, encouraging researchers on both sides to take advantage of the opportunities available.
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Affiliation(s)
- Govan Pahad
- Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology , University of Johannesburg , PO Box 524 , Auckland Park, Johannesburg 2000 , South Africa
| | - Claudine Montgelard
- Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology , University of Johannesburg , PO Box 524 , Auckland Park, Johannesburg 2000 , South Africa
- PSL Research University, CEFE UMR 5175, CNRS, Université de Montpellier, Université Paul-Valéry Montpellier , EPHE, Biogéographie et Ecologie des Vertébrés , 1919 route de Mende , 34293 Montpellier , France
| | - Bettine Jansen van Vuuren
- Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology , University of Johannesburg , PO Box 524 , Auckland Park, Johannesburg 2000 , South Africa
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Leihy RI, Duffy GA, Nortje E, Chown SL. High resolution temperature data for ecological research and management on the Southern Ocean Islands. Sci Data 2018; 5:180177. [PMID: 30179229 PMCID: PMC6122169 DOI: 10.1038/sdata.2018.177] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 07/13/2018] [Indexed: 11/09/2022] Open
Abstract
Southern Ocean Islands are globally significant conservation areas. Predicting how their terrestrial ecosystems will respond to current and forecast climate change is essential for their management and requires high-quality temperature data at fine spatial resolutions. Existing datasets are inadequate for this purpose. Remote-sensed land surface temperature (LST) observations, such as those collected by satellite-mounted spectroradiometers, can provide high-resolution, spatially-continuous data for isolated locations. These methods require a clear sightline to measure surface conditions, however, which can leave large data-gaps in temperature time series. Using a spatio-temporal gap-filling method applied to high-resolution (~1 km) LST observations for 20 Southern Ocean Islands, we compiled a complete monthly temperature dataset for a 15-year period (2001-2015). We validated results using in situ measurements of microclimate temperature. Gap-filled temperature observations described the thermal heterogeneity of the region better than existing climatology datasets, particularly for islands with steep elevational gradients and strong prevailing winds. This dataset will be especially useful for terrestrial ecologists, conservation biologists, and for developing island-specific management and mitigation strategies for environmental change.
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Affiliation(s)
- Rachel I. Leihy
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
| | - Grant A. Duffy
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
| | - Erika Nortje
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Steven L. Chown
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
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Visser JH, Bennett NC, Jansen van Vuuren B. Spatial genetic diversity in the Cape mole-rat, Georychus capensis: Extreme isolation of populations in a subterranean environment. PLoS One 2018; 13:e0194165. [PMID: 29543917 PMCID: PMC5854370 DOI: 10.1371/journal.pone.0194165] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 02/26/2018] [Indexed: 11/18/2022] Open
Abstract
The subterranean niche harbours animals with extreme adaptations. These adaptations decrease the vagility of taxa and, along with other behavioural adaptations, often result in isolated populations characterized by small effective population sizes, high inbreeding, population bottlenecks, genetic drift and consequently, high spatial genetic structure. Although information is available for some species, estimates of genetic diversity and whether this variation is spatially structured, is lacking for the Cape mole-rat (Georychus capensis). By adopting a range-wide sampling regime and employing two variable mitochondrial markers (cytochrome b and control region), we report on the effects that life-history, population demography and geographic barriers had in shaping genetic variation and population genetic patterns in G. capensis. We also compare our results to information available for the sister taxon of the study species, Bathyergus suillus. Our results show that Georychus capensis exhibits low genetic diversity relative to the concomitantly distributed B. suillus, most likely due to differences in habitat specificity, habitat fragmentation and historical population declines. In addition, the isolated nature of G. capensis populations and low levels of population connectivity has led to small effective population sizes and genetic differentiation, possibly aided by genetic drift. Not surprisingly therefore, G. capensis exhibits pronounced spatial structure across its range in South Africa. Along with geographic distance and demography, other factors shaping the genetic structure of G. capensis include the historical and contemporary impacts of mountains, rivers, sea-level fluctuations and elevation. Given the isolation and differentiation among G. capensis populations, the monotypic genus Georychus may represent a species complex.
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Affiliation(s)
- Jacobus H. Visser
- Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology, University of Johannesburg, Auckland Park, South Africa
- * E-mail:
| | - Nigel C. Bennett
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Bettine Jansen van Vuuren
- Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology, University of Johannesburg, Auckland Park, South Africa
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Moon KL, Chown SL, Fraser CI. Reconsidering connectivity in the sub-Antarctic. Biol Rev Camb Philos Soc 2017; 92:2164-2181. [DOI: 10.1111/brv.12327] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 02/09/2017] [Accepted: 02/15/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Katherine L. Moon
- School of Biological Sciences; Monash University; Clayton 3800 Australia
- Fenner School of Environment and Society; Australian National University; Acton 2601 Australia
| | - Steven L. Chown
- School of Biological Sciences; Monash University; Clayton 3800 Australia
| | - Ceridwen I. Fraser
- Fenner School of Environment and Society; Australian National University; Acton 2601 Australia
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Rastorgueff PA, Arnal V, Montgelard C, Monsanto DM, Groenewald CW, Haddad WA, Dubois MP, Jansen van Vuuren B. Characterization of 21 polymorphic microsatellite loci for the collembolan Cryptopygus antarcticus travei from the sub-Antarctic Prince Edward Islands. BIOCHEM SYST ECOL 2016. [DOI: 10.1016/j.bse.2015.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Convey P, Chown SL, Clarke A, Barnes DKA, Bokhorst S, Cummings V, Ducklow HW, Frati F, Green TGA, Gordon S, Griffiths HJ, Howard-Williams C, Huiskes AHL, Laybourn-Parry J, Lyons WB, McMinn A, Morley SA, Peck LS, Quesada A, Robinson SA, Schiaparelli S, Wall DH. The spatial structure of Antarctic biodiversity. ECOL MONOGR 2014. [DOI: 10.1890/12-2216.1] [Citation(s) in RCA: 232] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Gutiérrez-García TA, Vázquez-Domínguez E. Biogeographically dynamic genetic structure bridging two continents in the monotypic Central American rodentOtotylomys phyllotis. Biol J Linn Soc Lond 2012. [DOI: 10.1111/j.1095-8312.2012.01966.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Tania A. Gutiérrez-García
- Departamento de Ecología de la Biodiversidad; Instituto de Ecología; Universidad Nacional Autónoma de México; Ap. Postal 70-275 Ciudad Universitaria México DF 04510 México
- Posgrado en Ciencias Biológicas; Universidad Nacional Autónoma de México; Av. Universidad 3000 Coyoacán México DF 04510 México
| | - Ella Vázquez-Domínguez
- Departamento de Ecología de la Biodiversidad; Instituto de Ecología; Universidad Nacional Autónoma de México; Ap. Postal 70-275 Ciudad Universitaria México DF 04510 México
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Fraser CI, Nikula R, Ruzzante DE, Waters JM. Poleward bound: biological impacts of Southern Hemisphere glaciation. Trends Ecol Evol 2012; 27:462-71. [DOI: 10.1016/j.tree.2012.04.011] [Citation(s) in RCA: 140] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 04/23/2012] [Accepted: 04/24/2012] [Indexed: 10/28/2022]
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Terauds A, Chown SL, Morgan F, J. Peat H, Watts DJ, Keys H, Convey P, Bergstrom DM. Conservation biogeography of the
A
ntarctic. DIVERS DISTRIB 2012. [DOI: 10.1111/j.1472-4642.2012.00925.x] [Citation(s) in RCA: 172] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
- Aleks Terauds
- Centre for Invasion Biology Department of Botany and Zoology Stellenbosch University Private Bag X1 Matieland 7602 South Africa
- Australian Antarctic Division Department of the Sustainability, Environment, Water, Population and Communities 203 Channel Highway Kingston 7050 Tas. Australia
| | - Steven L. Chown
- Centre for Invasion Biology Department of Botany and Zoology Stellenbosch University Private Bag X1 Matieland 7602 South Africa
| | - Fraser Morgan
- Landcare Research New Zealand, Private Bag 92170 Auckland Mail Centre Auckland 1142 New Zealand
| | - Helen J. Peat
- British Antarctic Survey Natural Environment Research Council High Cross, Madingley Road Cambridge CB3 0ET UK
| | - David J. Watts
- Australian Antarctic Division Department of the Sustainability, Environment, Water, Population and Communities 203 Channel Highway Kingston 7050 Tas. Australia
| | - Harry Keys
- Department of Conservation Private Bag Turangi 3335 New Zealand
| | - Peter Convey
- British Antarctic Survey Natural Environment Research Council High Cross, Madingley Road Cambridge CB3 0ET UK
| | - Dana M. Bergstrom
- Australian Antarctic Division Department of the Sustainability, Environment, Water, Population and Communities 203 Channel Highway Kingston 7050 Tas. Australia
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