Abstract
Amidst a worldwide decline in amphibian populations, those species endemic to islands remain an important focus for conservation efforts. The Sooglossidae are a family of frog species endemic to the Seychelles islands that are believed to have evolved in isolation for approximately 75 million years. Formerly thought to inhabit just two Seychelles islands (Mahé and Silhouette), a third population was discovered on Praslin in 2009. Phylogenetic analysis based on 438 bp of mitochondrial 16S rRNA suggests that the Praslin population is most closely related to Sooglossus sechellensis from Silhouette, and identifies these as two separate clades which together sit distinct from the population on Mahé. An average of 4.06% uncorrected pairwise sequence divergence between the Praslin and Silhouette populations suggests substantial evolutionary divergence rather than recent introduction. Discriminant function analysis also revealed differences in morphology in frogs from Praslin and Mahé. DNA sequences of two Praslin specimens group more closely with the Mahé population, indicating some shared haplotypes that suggest recent secondary contact. Tests for a genetic signature of recent population expansion on either island were not significant. Our results suggest substantial evolutionary divergence between the three populations of S. sechellensis, most likely following isolation due to changes in sea level in the Indian Ocean. Whilst further genetic sampling and ecological studies are needed, our initial phylogenetic analyses suggest that the sooglossid population on Praslin should be managed as an evolutionarily significant unit to retain the uniqueness of its genetic diversity and its evolutionary trajectory within this ancient family of amphibians.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Badyukov D, Demidenko DEL, Kaplin PA (1989) Paleogeography of the Seychelles bank and the North West Madagascar shelf during the last glacio-eutastic regression (18,000 a B.P.). Chin J Oceanol Limnol 7:89–92
Biju SD, Bossuyt F (2003) New frog family from India reveals an ancient biogeographical link with the Seychelles. Nature 425:711–714
Brown RM, Linkem CW, Siler CD, Sukumaran J, Esselstyn JA, Diesmos AC, Iskandar DT, Bickford D, Evans BJ, McGuire JA, Grismer L, Supriatna J and Andayani N (2010) Phylogeography and historical demography of Polypedates leucomystax in the islands of Indonesia and the Philippines: evidence for recent human-mediated range expansion? Mol Phylogenet Evol. doi:10.1016/j.ympev.2010.06.015
Camoin GF, Montaggioni LF, Braithwaite CJR (2004) Late glacial to post glacial sea levels in the Western Indian Ocean. Mar Geol 206:119–146
Cheke AS, Hume JP (2008) Lost land of the Dodo: the ecological history of the Mascarene Islands. A & C. Black publishers, London (Poyser imprint)
Crandall KA, Bininda-Emonds ORP, Mace GM, Wayne RK (2000) Considering evolutionary processes in conservation biology. Trends Ecol Evol 17:390–395
Doak N (2005) Saving rare island frogs: a project to investigate and conserve the endemic frog family Sooglossidae in the Seychelles Islands. Nature Seychelles, Unpublished report
Edgar P (2003) The sooglossid frogs of Mahé Island, Seychelles: a report for nature Seychelles and The RSPB. The Herpetological Conservation Trust Unpublished report
Emerson BC (2002) Evolution on oceanic islands: molecular phylogenetic approaches to understanding process and pattern. Mol Ecol 11:951–966
Evolutionarily Distinct and Globally Endangered (EDGE) (2010) Amphibian species information, London. www.edgeofexistance.org/amphibians/species_info.php. Accessed Feb 2010
Felsenstein J (1981) Evolutionary trees from DNA sequences: a maximum likelihood approach. J Mol Evol 17:368–376
Felsenstein J (1985) Confidence limits on phylogenies: an approach using the bootstrap. Evolution 39:783–791
Fouquet A, Gilles A, Vences M, Marty C, Blanc M, Gemmell NJ (2007) Underestimation of species richness in Neotropical frogs revealed by mtDNA analyses. PLoS One 10:1–10
Frankham R (1998) Inbreeding and extinction: island populations. Conserv Biol 12:665–675
Frankham R, Ballou JD, Briscoe DA (2002) Introduction to conservation genetics, 2nd edn. Cambridge University Press, Cambridge
Fraser DJ, Bernatchez L (2001) Adaptive evolutionary conservation: towards a unified concept for defining conservation units. Mol Ecol 10:2741–2752
Gelman A, Rubin DB (1992) Inference from iterative stimulation using multiple sequences. Stat Sci 7:457–472
Gerlach J (2007) Distribution and status of the Seychelles frogs (Amphibia: Anura: Sooglossidae). Herpetol J 17:115–122
Gerlach J, Willi J (2002) A new species of frog, genus Sooglossus (Anura: Sooglossidae) from Silhouette Island, Seychelles. Amphib Reptil 23:445–458
Goldstein PZ, DeSalle R, Amato G, Vogler AP (2000) Conservation genetics at the species boundary. Conserv Biol 14:120–131
Green DM, Nussbaum RA, Yang D (1988) Genetic divergence and heterozygosity among frogs of the family Sooglossidae. Herpetologica 44:113–119
Griffiths I (1959) The phylogenetic status of the Sooglossinae. Annu Mag Nat Hist 13:626–640
Halliday T (2008) Why amphibians are important. Int Zoo Yearb 42:7–14
Haq BU, Hardenbol J, Vail PR (1987) Chronology of fluctuating sea levels since the Triassic. Science 235:1156–1167
Hartl DL, Clark AG (1997) Principles of population genetics, 3rd edn. Sinauer Associates, Sunderland
Hasegawa M, Kishino H, Yano T (1985) Dating of the human-ape splitting by a molecular clock of mitochondrial DNA. J Mol Evol 22:160–174
Hoegg S, Vences M, Brinkmann H, Meyer A (2004) Phylogeny and comparative substitution rates of frogs inferred from sequences of three nuclear genes. Mol Biol Evol 21:1188–1200
International Union of Conservation and Nature (IUCN) (2009) IUCN red list of threatened species, Version 2009.2, Gland. www.iucnredlist.org. Accessed Jan 2010
Kass RE, Raftery AE (1995) Bayes factors. J Am Stat Assoc 90:773–791
Köhler J, Vieites DR, Bonett RM, Garcia FH, Glaw F, Steinke D, Vences M (2005) New amphibians and global conservation: a boost in species discoveries in a highly endangered vertebrate group. Bioscience 55:693–696
Larkin MA, Blackshields G, Brown NP, Chenna R, McGettigan PA, McWilliam H, Valentin F, Wallace IM, Wilm A, Lopez R, Thompson JD, Gibson TJ, Higgins DG (2007) CLUSTAL W and CLUSTAL X version 2.0. Bioinformatics 23:2947–2948
Librado P, Rozas J (2009) DNASP v5: a software for comprehensive analysis of DNA polymorphism data. Bioinformatics 25:1451–1452
Mace GM (2004) The role of taxonomy in species conservation. Philos Trans R Soc Lond 359:711–719
Measey JG, Vences M, Drewes RC, Chiari Y, Melo M, Bourles B (2007) Freshwater paths across the ocean: molecular phylogeny of the frog Ptychadena newtoni gives insights into amphibian colonization of oceanic islands. J Biogeogr 34:7–20
Moritz C (1994) Defining ‘evolutionarily significant units’ for conservation. Trends Ecol Evol 9:373–375
Moritz C (2002) Strategies to protect biological diversity and the evolutionary processes that sustain it. Syst Biol 51:238–254
Myers N, Mittermeier RA, Mittermeier CG, da Fonseca GAB, Kent J (2000) Biodiversity hotspots for conservation priorities. Nature 403:853–858
Nicholas KB, Nicholas Jr HB (1997) GENEDOC: a tool for editing and annotating multiple sequence alignments. Multiple sequence alignment and shading utility, version 2.6. 002
Nussbaum RA, Wu S-H (2007) Morphological assessments and phylogenetic relationships of the Seychellean frogs of the family Sooglossidae (Amphibia: Anura). Zool Stud 46:322–335
Palumbi SR, Martin A, Romano S, McMillan WO, Stice L, Grabowski G (1991) A simple fool’s guide to PCR, Version 2.0. University of Hawaii, Honolulu
Parra GR et al (2005) Systematics and conservation. In: Gascon C, Collins JP, Moore RD, Church DR, McKay JE, Mendelson III JR (eds) Amphibian conservation action plan. Proceedings: IUCN/SSC amphibian conservation summit. The World Conservation Union (IUCN), Gland, pp 44–48
Posadas P, Esquivel DRM, Crisci JV (2001) Using phylogenetic diversity measures to set priorities in conservation: an example from southern South America. Conserv Biol 15:1325–1334
Ronquist F, Huelsenbeck JP (2003) MrBayes 3: Bayesian phylogenetic inference under mixed models. Bioinformatics 19:1572–1574
Sambrook J, Russell DW (2001) Molecular cloning: a laboratory manual. Cold Spring Harbour Laboratory Press, Cold Spring Harbour
San Mauro DM, Vences M, Alcobendas M, Zardoya R, Meyer A (2005) Initial diversification of living amphibians predated the breakup of Pangaea. Am Nat 165:590–599
Seychelles Islands Foundation (2010) Survey and initial population estimate of a newly discovered population of Sooglossid frog on Praslin, Seychelles. Unpublished report to the Seychelles Science Committee and Seychelles Bureau of Standards, Government of Seychelles
SPSS (2010) PASW Base 18.0 for Windows User’s Guide. SPSS Inc., Chicago
Stuart SN, Chanson JS, Cox NA, Young BE, Rodrigues ASL, Fischman DL, Waller RW (2004) Status and trends of amphibian declines and extinctions worldwide. Science 306:1783–1786
Swofford J (2000) PAUP *.Phylogenetic analysis using Parsimony (*and other methods) version 4. Sinauer Associates, Sunderland
Tajima F (1989) Statistical method for testing the neutral mutation hypothesis by DNA polymorphism. Genetics 123:585–595
van der Meijden A, Boistel R, Gerlach J, Ohler A, Vences M, Meyer A (2007) Molecular phylogenetic evidence for paraphyly of the genus Sooglossus, with the description of a new genus of Seychellean frogs. Biol J Linn Soc 91:347–359
Vences M, Glaw F (2002) Molecular phylogeography of Boophis tephraeomystax: a test case for east-west vicariance in Malagasy anurans. Spixiana 25:79–84
Vences M, Wake DB (2007) Speciation, species, boundaries and phylogeography of amphibians. In: Heatwole H (ed) Amphibian biology: volume 7: Systematics. Surry Beatty & Sons, Chipping Norton, pp 2613–2672
Vences M, Thomas M, van der Meijden A, Chiari Y, Vieites RD (2005) Comparative performance of the 16S rRNA gene in DNA barcoding of amphibians. Frontiers Zool 2:1–12
Weins JJ (2008) Systematics and herpetology in the age of genomics. Bioscience 58:297–307
Acknowledgments
We thank SIF staff and associated colleagues on Praslin and Mahé for their support, help and advice, including F. Fleischer-Dogley, W. Accouche, M. Pierre, D. Esther, N. Victor, U. Samedi and C. Kaiser-Bunbury. Samples were collected in the Seychelles with permission from the Seychelles Bureau of Standards and we thank R. Fanchette of the Department of Environment for issuing the Material Transfer Agreement. M.L.T. was funded by the Seychelles Islands Foundation (SIF) and the Durrell Institute of Conservation and Ecology (DICE) at the University of Kent.
Author information
Authors and Affiliations
Corresponding author
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Taylor, M.L., Bunbury, N., Chong-Seng, L. et al. Evidence for evolutionary distinctiveness of a newly discovered population of sooglossid frogs on Praslin Island, Seychelles. Conserv Genet 13, 557–566 (2012). https://doi.org/10.1007/s10592-011-0307-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10592-011-0307-9