Averaging v. outlier removal. Decrypting variance among cryptic Lejeunea species (Lejeuneaceae: Jungermanniopsida) using geometric morphometrics
Matt A. M. Renner A C , Elizabeth A. Brown A and Glenda M. Wardle B
+ Author Affiliations
- Author Affiliations
A National Herbarium of New South Wales, Mrs Macquaries Road, Sydney, NSW 2000, Australia.
B School of Biological Sciences, Heydon-Laurence Building A08, University of Sydney, Sydney, NSW 2006, Australia.
C Corresponding author. Email: matt.renner@rbgsyd.nsw.gov.au
Australian Systematic Botany 26(1) 13-30 https://doi.org/10.1071/SB12016
Submitted: 16 May 2012 Accepted: 10 December 2012 Published: 12 April 2013
Abstract
Molecular data have revealed many morphologically cryptic species. More surprising than lack of difference, however, is that morphological variation and complex patterns of overlapping features can mask cryptic species. We employ geometric morphometric methods (GMM) to explore patterns of variation within four liverwort species, three of which were previously attributed to Lejeunea tumida Mitt. Each species exhibited considerable variation within, and overlap among, species in size and shape, independent of degree of relatedness. Most variation was expressed within individuals, suggesting that the observed breadth of variation was within the developmental capacity of single genotypes. Size and shape variation within, and consequently overlap among, individuals resulted primarily from variance in growth of shoots. Inter-specific differences were swamped by intra- and inter-individual variation. We coupled GMM with multivariate methods for outlier removal, and simple averaging of individuals to explore whether intra-individual variation could be reconciled to maximise the inter-species difference, facilitating resolution of cryptic species despite extensive morphological continuity and overlap. Unfortunately, outlier removal did not achieve separation among species, because removing extremes failed to eliminate overlap resulting from within-species variation. Individual averaging was partially successful in extracting L. tumida as a discrete entity but did not segregate the remaining three species. Although the challenges for morphology-based identification of cryptic species are significant, GMM provide one of the best sets of methods for identifying and communicating any subtle morphological differences that may exist.
References
Adams DC (1999) Methods for shape analysis of landmark data from articulated structures. Evolutionary Ecology Research 1, 959–970.Adams DC, Slice DE, Rohlf FJ (2004) Geometric morphometrics: ten years of progress following the ‘revolution’. The Italian Journal of Zoology 71, 5–16.
| Geometric morphometrics: ten years of progress following the ‘revolution’.Crossref | GoogleScholarGoogle Scholar |
Albrecht G (1992) Assessing the affinities of fossils using canonical variates and generalized differences. Journal of Human Evolution 7, 49–69.
| Assessing the affinities of fossils using canonical variates and generalized differences.Crossref | GoogleScholarGoogle Scholar |
Bickford D, Lohman DJ, Sodhi NS, Ng PKL, Meier R, Winker K, Ingram KK, Das I (2007) Cryptic species as a window on diversity and conservation. Trends in Ecology & Evolution 22, 148–155.
| Cryptic species as a window on diversity and conservation.Crossref | GoogleScholarGoogle Scholar |
Bischler H, Boisselier-Dubayle MC, Fontinha S, Lambourdière J (2006) Species boundaries in European and Macaronesian Porella L. (Jungermanniales, Porellaceae). Cryptogamie Bryologie 27, 35–57.
Boisselier-Dubayle MC, Lambourdière J, Bischler H (1998) The leafy liverwort Porella baueri (Porellaceae) is an allopolyploid. Plant Systematics and Evolution 210, 175–197.
| The leafy liverwort Porella baueri (Porellaceae) is an allopolyploid.Crossref | GoogleScholarGoogle Scholar |
Bookstein FL (1996) Biometrics, biomathematics and the morphometric synthesis. Bulletin of Mathematical Biology 58, 313–365.
| Biometrics, biomathematics and the morphometric synthesis.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK28zkt1SnsA%3D%3D&md5=9e7f9d0bb1c4425e543b618ab5c4054bCAS | 8713662PubMed |
Buczkowska K (2004) Genetic differentiation of Calypogeia fissa Raddi (Hepaticae, Jungermanniales) in Poland. Plant Systematics and Evolution 247, 187–201.
| Genetic differentiation of Calypogeia fissa Raddi (Hepaticae, Jungermanniales) in Poland.Crossref | GoogleScholarGoogle Scholar |
Burghardt M, Gradstein SR (2008) A revision of Tylimanthus (Acrobolbaceae, Marchantiophyta) in tropical America, Africa, and Macaronesia. Fieldiana Botany 47, 199–210.
| A revision of Tylimanthus (Acrobolbaceae, Marchantiophyta) in tropical America, Africa, and Macaronesia.Crossref | GoogleScholarGoogle Scholar |
Cardini A, Elton S (2007) Sample size and sampling error in geometric morphometric studies of size and shape. Zoomorphology 126, 121–134.
| Sample size and sampling error in geometric morphometric studies of size and shape.Crossref | GoogleScholarGoogle Scholar |
Cooper ED, Shaw AJ, Shaw B, Henwood MJ, Heslewood MM, Brown EA (2011) A multi-locus molecular phylogeny of the Lepidoziaceae: laying the foundations for a stable classification. Molecular Phylogenetics and Evolution 59, 489–509.
| A multi-locus molecular phylogeny of the Lepidoziaceae: laying the foundations for a stable classification.Crossref | GoogleScholarGoogle Scholar | 21316477PubMed |
Cooper ED, Henwood MJ, Brown EA (2012) A molecular phylogeny of the Lepidozia generic complex supports re-circumscription of the Lepidozioidea. Molecular Phylogenetics and Evolution 65, 10–22.
| A molecular phylogeny of the Lepidozia generic complex supports re-circumscription of the Lepidozioidea.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XnvFCltLg%3D&md5=e5a39078f316000085f8ba499ffabf6aCAS | 22705399PubMed |
Coyne JA, Orr HA (2004) ‘Speciation.’ (Sinauer Associates: Sunderland, MA)
Cracraft J (2000) Species concepts in theoretical and applied biology: a systematic debate with consequences. In ‘Species Concepts and Phylogenetic Theory: a Debate’. (Eds QD Wheeler, R Meier) pp. 30–43. (Columbia University Press: New York)
Cronquist A (1988) ‘The evolution and classification of flowering plants’, 2nd edn. (The New York Botanic Gardens Press: New York)
Davis JI, Nixon KC (1992) Populations, genetic variation, and the de-limitation of phylogenetic species. Systematic Biology 41, 421–435.
de Queiroz K (1998) The general lineage concept of species. In ‘Endless Forms: Species and Speciation’. (Eds DJ Howard, SH Berlocher) pp. 57–75. (Oxford University Press: Oxford, UK)
Devos N, Vanderpoorten A (2009) Range disjunctions, speciation, and morphological transformation rates in the liverwort genus Leptoscyphus. Evolution 63, 779–792.
| Range disjunctions, speciation, and morphological transformation rates in the liverwort genus Leptoscyphus.Crossref | GoogleScholarGoogle Scholar | 19154356PubMed |
Devos N, Renner MAM, Gradstein SR, Shaw AJ, Vanderpoorten A (2011) Molecular data challenge traditional subgeneric divisions in the leafy liverwort Radula. Taxon 60, 1623–1632.
Dimitriadou E, Hornik K, Leisch F, Meyer D, Weingessel A (2011) Miscellaneous functions of the Department of Statistics (e1071). Version 1.5–26. RCRAN repository. Available at http://cran.r-project.org/web/packages/e1071/index.html [Verified 4 March 2012]
Dryden I (2009) Statistical shape analysis. Version 1.1–3. Available at http://www.maths.nott.ac.uk/~ild/shapes [Verified 15 September 2010]
Dryden IL, Mardia KV (1998) ‘Statistical Shape Analysis.’ (Wiley: Chichester, UK)
Feldberg K, Vána J, Schulze C, Bombosch A, Heinrichs J (2011) Morphologically similar but genetically distinct: on the differentiation of Syzygiella concreta and S. perfoliata (Adelanthaceae subfam. Jamesonielloideae). The Bryologist 114, 686–695.
| Morphologically similar but genetically distinct: on the differentiation of Syzygiella concreta and S. perfoliata (Adelanthaceae subfam. Jamesonielloideae).Crossref | GoogleScholarGoogle Scholar |
Felsenstein J (1988) Phylogenies and quantitative characters. Annual Review of Ecology and Systematics 19, 445–471.
| Phylogenies and quantitative characters.Crossref | GoogleScholarGoogle Scholar |
Fife AJ (1995) Checklist of the mosses of New Zealand. The Bryologist 98, 313–337.
| Checklist of the mosses of New Zealand.Crossref | GoogleScholarGoogle Scholar |
Filzmoser P (2005) Identification of multivariate outliers: a performance study. Austrian Journal of Statistics 34, 127–138.
Filzmoser P, Gschwandtner M (2011) Multivariate outlier detection based on robust methods. Version 1.9.1. Available at http://www.statistik.tuwien.ac.at/public/filz/ [Verified 4 July 2011]
FitzJohn RG (2010) Quantitative traits and diversification. Systematic Biology 59, 619–633.
| Quantitative traits and diversification.Crossref | GoogleScholarGoogle Scholar | 20884813PubMed |
Forrest LL, Davis EC, Long DG, Crandall-Stotler BJ, Clarck A, Hollingsworth ML (2006) Unraveling the evolutionary history of the liverworts (Marchantiophyta): multiple taxa, genomes and analyses. The Bryologist 109, 303–334.
| Unraveling the evolutionary history of the liverworts (Marchantiophyta): multiple taxa, genomes and analyses.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XhtVWksLvL&md5=47816fbd449ebf61cc18440b686632e6CAS |
Fraley C, Raferty AE (2002) Model-based clustering, discriminant analysis and density estimation. Journal of the American Statistical Association 97, 611–631.
| Model-based clustering, discriminant analysis and density estimation.Crossref | GoogleScholarGoogle Scholar |
Fuselier L, Davison PG, Clements M, Shaw B, Devos N, Heinrichs J, Hentschel J, Sabobljevic M, Szövenyi P, Schütte S, Hofbauer W, Shaw AJ (2009) Phylogenetic analyses reveal distinct lineages of Metzgeria furcata and M. conjugata (Metzgeriaceae) in Europe and North America. Biological Journal of the Linnean Society. Linnean Society of London 98, 745–756.
| Phylogenetic analyses reveal distinct lineages of Metzgeria furcata and M. conjugata (Metzgeriaceae) in Europe and North America.Crossref | GoogleScholarGoogle Scholar |
Gómez A, Serra M, Carvalho GR, Lunt DH (2002) Speciation in ancient cryptic species complexes: evidence from the molecular phylogeny of Brachionus plicatilis (Rotifera). Evolution 56, 1431–1444.
Gómez JM, Perfectti F, Camacho JPM (2006) Natural selection on Erysimum mediohispanicum flower shape: insights into the evolution of zygomorphy. American Naturalist 168, 531–545.
| Natural selection on Erysimum mediohispanicum flower shape: insights into the evolution of zygomorphy.Crossref | GoogleScholarGoogle Scholar | 17004224PubMed |
Gradstein SR (1975) A taxonomic monograph of the genus Acrolejeunea (Hepaticae). Bryophytorum Bibliotheca 4, 1–162.
Gradstein SR, Pinheiro da Costa D (2003) The Hepaticae and Anthocerotae of Brazil. Memoirs of the New York Botanical Garden 87, 1–318.
Gradstein SR, Churchill SP, Salazar-Allen N (2001) ‘Guide to the Bryophytes of Tropical America.’ (The New York Botanical Gardens Press: New York)
Hammer Ø, Harper DAT, Ryan PD (2001) PAST: paleontological statistics software package for education and data analysis. Palaeontologia Electronica 4, 9
| PAST: paleontological statistics software package for education and data analysis.Crossref | GoogleScholarGoogle Scholar |
Hartmann FA, Wilson R, Gradstein SR, Schneider H, Heinrichs J (2006) Testing hypotheses on species delimitations and disjunctions in the liverwort Bryopteris (Jungermanniopsida: Lejeuneaceae). International Journal of Plant Sciences 167, 1205–1214.
| Testing hypotheses on species delimitations and disjunctions in the liverwort Bryopteris (Jungermanniopsida: Lejeuneaceae).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXhtFylurg%3D&md5=094f070273dda15b15aae01055c61daeCAS |
Hedenäs L (1996) On the interdependence of some leaf characters within the Drepanocladus aduncus-polycarpus complex. Journal of Bryology 19, 311–324.
Hedenäs L, Eldenäs P (2008) Relationship in Scorpidium (Calliergonaceae, Bryophyta), especially between S. cossonii and S. scorpioides. Taxon 57, 121–130.
Heinrichs J, Klugmann F, Hentschel J, Schneider H (2009) DNA taxonomy, cryptic speciation and diversification of the Neotropical-African liverwort, Marchesinia brachiata (Lejeuneaceae, Porellales). Molecular Phylogenetics and Evolution 53, 113–121.
| DNA taxonomy, cryptic speciation and diversification of the Neotropical-African liverwort, Marchesinia brachiata (Lejeuneaceae, Porellales).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXptlyksLw%3D&md5=9d0cc96eee2487412c6555d18444755cCAS | 19501177PubMed |
Heinrichs J, Hentschel J, Bombosch A, Fiebig A, Reise J, Edelmann M, Kreier H-P, Schäfer-Verwimp A, Caspari S, Schmidt AR, Zhu R-L, von Konrat MJ, Shaw B, Shaw AJ (2010) One species or at least eight? Delimitation and distribution of Frullania tamarisci (l.) Dumort. s.l. (Jungermanniopsida, Porellales) inferred from nuclear and chloroplast DNA markers. Molecular Phylogenetics and Evolution 56, 1105–1114.
| One species or at least eight? Delimitation and distribution of Frullania tamarisci (l.) Dumort. s.l. (Jungermanniopsida, Porellales) inferred from nuclear and chloroplast DNA markers.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXos1Cjs7g%3D&md5=184540cf87636a6a643798196676a020CAS | 20460161PubMed |
Heinrichs J, Kreier HP, Feldberg K, Schmidt AR, Zhu R-L, Shaw B, Shaw AJ, Wissemann V (2011) Formalizing morphologically cryptic biological entities: new insights from DNA taxonomy, hybridization, and biogeography in the leafy liverwort Porella platyphylla (Jungermanniopsida, Porellales). American Journal of Botany 98, 1252–1262.
| Formalizing morphologically cryptic biological entities: new insights from DNA taxonomy, hybridization, and biogeography in the leafy liverwort Porella platyphylla (Jungermanniopsida, Porellales).Crossref | GoogleScholarGoogle Scholar | 21788532PubMed |
Henderson A (2005) The methods of herbarium taxonomy. Systematic Botany 30, 456–459.
| The methods of herbarium taxonomy.Crossref | GoogleScholarGoogle Scholar |
Hentschel J, Zhu R-L, Long DG, Davison PG, Schneider H, Gradstein SR, Heinrichs J (2007) A phylogeny of Porella (Porellaceae, Jungermanniopsida) based on nuclear and chloroplast DNA sequences. Molecular Phylogenetics and Evolution 45, 693–705.
| A phylogeny of Porella (Porellaceae, Jungermanniopsida) based on nuclear and chloroplast DNA sequences.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXhtFKhsr7I&md5=ebd3ee8645681fb7d516ad56cc6372a9CAS | 17600732PubMed |
Hentschel J, von Konrat MJ, Pócs T, Schäfer-Verwimp A, Shaw AJ, Schneider H, Heinrichs J (2009) Molecular insights into the phylogeny and subgeneric classification of Frullania raddii (Frullaniaceae, Porellales). Molecular Phylogenetics and Evolution 52, 142–156.
| Molecular insights into the phylogeny and subgeneric classification of Frullania raddii (Frullaniaceae, Porellales).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXlvF2ks7k%3D&md5=1e5fb24ef4120a4278d59c0fa5203276CAS | 19166952PubMed |
Hebert PDN, Penton EH, Burns JM, Janzen DH, Hallwachs W (2004) Ten species in one: DNA barcoding reveals cryptic species in the neotropical skipper butterfly Astrapetes fulgerator. Proceedings of the National Academy of Sciences of the United States of America 101, 14 812–14 817.
| Ten species in one: DNA barcoding reveals cryptic species in the neotropical skipper butterfly Astrapetes fulgerator.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXovVyju7g%3D&md5=40b63c91ff301e288343f91fbb391637CAS |
Hutsemékers V, Vieira CC, Ros RM, Huttunen S, Vanderpoorten A (2012) Morphology informed by phylogeny reveals unexpected patterns of species differentiation in the aquatic moss Rhynchostegium riparioides s.l. Molecular Phylogenetics and Evolution 62, 748–755.
| Morphology informed by phylogeny reveals unexpected patterns of species differentiation in the aquatic moss Rhynchostegium riparioides s.l.Crossref | GoogleScholarGoogle Scholar | 22138204PubMed |
Jensen RJ, Hokanson SC, Isebrands JG, Hancock JF (1993) Morphometric variation in oaks of the Apostle Islands in Wisconsin: evidence of hybridization between Q. rubra and Q. ellipsoidalis (Fagaceae). American Journal of Botany 80, 1358–1366.
| Morphometric variation in oaks of the Apostle Islands in Wisconsin: evidence of hybridization between Q. rubra and Q. ellipsoidalis (Fagaceae).Crossref | GoogleScholarGoogle Scholar |
Jensen RJ, Ciofani KM, Miramontes LC (2002) Lines, outlines, and landmarks: morphometric analyses of leaves of Acer rubrum, A. saccharinum (Aceraceae) and their hybrid. Taxon 51, 475–492.
| Lines, outlines, and landmarks: morphometric analyses of leaves of Acer rubrum, A. saccharinum (Aceraceae) and their hybrid.Crossref | GoogleScholarGoogle Scholar |
Jones G, Vanparijs SM (1993) Bimodal echolocation in Pipistrelle bats – are cryptic species present. Proceedings of the Royal Society B – Biological Sciences 251, 119–125.
| Bimodal echolocation in Pipistrelle bats – are cryptic species present.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK3s3gsFKqtQ%3D%3D&md5=70af4f1b0f7cbd629d56d657e6d6daefCAS |
Klingenberg CP (2011) MorphoJ: an integrated software package for geometric morphometrics. Molecular Ecology Resources 11, 353–357.
| MorphoJ: an integrated software package for geometric morphometrics.Crossref | GoogleScholarGoogle Scholar | 21429143PubMed |
Klingenberg CP, Leamy LJ (2001) Quantitative genetics of geometric shape in the mouse mandible. Evolution 55, 2342–2352.
Klingenberg CP, Monteiro LR (2005) Distances and directions in multidimensional shape spaces: implications for morphometric applications. Systematic Biology 54, 678–688.
| Distances and directions in multidimensional shape spaces: implications for morphometric applications.Crossref | GoogleScholarGoogle Scholar | 16126663PubMed |
Klingenberg CP, Barluenga M, Meyer A (2002) Shape analysis of symmetric structures: quantifying variation among individuals and asymmetry. Evolution 56, 1909–1920.
Laenen B, Désamoré A, Devos N, Shaw AJ, González-Mancebo JM, Carine MA, Vanderpoorten A (2011) Macaronesia: a source of hidden genetic diversity for post-glacial recolonisation of western Europe in the leafy liverwort R. lindenbergiana. Journal of Biogeography 38, 631–639.
| Macaronesia: a source of hidden genetic diversity for post-glacial recolonisation of western Europe in the leafy liverwort R. lindenbergiana.Crossref | GoogleScholarGoogle Scholar |
Lande R (1976) Natural selection and random genetic drift in phenotypic evolution. Evolution 30, 314–334.
| Natural selection and random genetic drift in phenotypic evolution.Crossref | GoogleScholarGoogle Scholar |
Lexer C, Joseph J, van Loo M, Prenner G, Heinze B, Chase MW, Kirkup D (2009) The use of digital image-based morphometrics to study the phenotypic mosaic in taxa with porous genomes. Taxon 58, 349–364.
Liem KF (1974) Evolutionary strategies and morphological innovations: cichlid pharyngeal jaws. Systematic Biology 22, 425–441.
MacLeod N (1999) Generalizing and extending the eigenshape method of shape visualization and analysis. Paleobiology 25, 107–138.
| Generalizing and extending the eigenshape method of shape visualization and analysis.Crossref | GoogleScholarGoogle Scholar |
MacNair MR, Gardner M (1998) The evolution of edaphic endemics. In ‘Endless Forms: Species and Speciation’. (Eds DJ Howard, SH Berlocher) pp. 157–171. (Oxford University Press: Oxford, UK)
MacNair MR, MacNair VE, Martin BE (1989) Adaptive speciation in Mimulus: an ecological comparison of M. cupriphilus with its presumed progenitor, M. guttatus. New Phytologist 112, 269–279.
| Adaptive speciation in Mimulus: an ecological comparison of M. cupriphilus with its presumed progenitor, M. guttatus.Crossref | GoogleScholarGoogle Scholar |
Manly BFJ (1997) ‘Randomisation, Bootstrap and Monte Carlo Methods in Biology.’ (Chapman and Hall Press: New York)
Marcus LF (1990) Traditional morphometrics. In ‘Proceedings of the Michigan Morphometrics Workshop’; 16–28 May 1990, Ann Arbor, MI. (Eds FJ Rohlf, FL Bookstein) Special Publication Number 2, pp. 77–122. (University of Michigan Museum Zoology: Ann Arbor, MI).
Mayr E (1963) ‘Animal Species and Evolution.’ (Belknap Press of Harvard University Press: Cambridge, MA)
McDaniel SF, Shaw AJ (2003) Phylogeographic structure and cryptic speciation in the trans-Antarctic moss Pyrrhobryum mnioides. Evolution 57, 205–215.
Molbo D, Machado CA, Sevenster JG, Keller L, Herre EA (2003) Cryptic species of fig-pollinating wasps: implications for the evolution of the fig-wasp mutualism, sex allocation, and precision of adaptation. Proceedings of the National Academy of Sciences, USA 100, 5867–5872.
| Cryptic species of fig-pollinating wasps: implications for the evolution of the fig-wasp mutualism, sex allocation, and precision of adaptation.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXjvFOlsb0%3D&md5=80be41a70c78c53fafa1d02cbe2ab7e2CAS |
Neff NA, Marcus LF (1980) ‘A survey of multivariate methods for systematics.’ (American Museum of Natural History Press: New York)
Oksanen J, Blanchet G, Kindt R, Legendre P, O’Hara RB, Simpson GL, Solymos P, Stevens MHH, Wagner H (2010) Community ecology package. Version 1.17–4. Available at http://vegan.r-forge.r-project.org/ [Verified 18 September 2010]
Orr MR, Smith TB (1998) Ecology and speciation. Trends in Ecology & Evolution 13, 502–506.
| Ecology and speciation.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC3M7it1SgsA%3D%3D&md5=674b1dddd56064f8ee178fbed847ccf7CAS |
Pätsch R, Hentschel J, Linares-Palomino R, Zhu R-L, Heinrichs J (2010) Diversification and taxonomy of the liverwort Jubula Dumort. (Jungermanniopsida: Porellales) inferred from nuclear and chloroplast DNA sequences. Systematic Botany 35, 6–12.
| Diversification and taxonomy of the liverwort Jubula Dumort. (Jungermanniopsida: Porellales) inferred from nuclear and chloroplast DNA sequences.Crossref | GoogleScholarGoogle Scholar |
Patterson C (1982) Morphological characters and homology. In ‘Problems of Phylogenetic Reconstruction’. (Eds KA Joysey, AE Friday) pp. 21–74. (Academic Press: London)
Pokorny L, Oliván G, Shaw AJ (2011) Phylogeographic patterns in two southern hemisphere species of Calyptrochaeta (Daltoniaceae, Bryophyta). Systematic Botany 36, 542–553.
| Phylogeographic patterns in two southern hemisphere species of Calyptrochaeta (Daltoniaceae, Bryophyta).Crossref | GoogleScholarGoogle Scholar |
Prendini L, Wheeler WC (2005) Scorpion higher phylogeny and classification, taxonomic anarchy, and standards for peer review in online publishing. Cladistics 21, 446–494.
| Scorpion higher phylogeny and classification, taxonomic anarchy, and standards for peer review in online publishing.Crossref | GoogleScholarGoogle Scholar |
Ramaiya M, Johnston M, Shaw B, Heinrichs J, Hentschel J, von Konrat M, Davison P, Shaw AJ (2010) Morphologically cryptic biological species within the liverwort, Frullania asagrayana. American Journal of Botany 97, 1707–1718.
| Morphologically cryptic biological species within the liverwort, Frullania asagrayana.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhsVaqtb7E&md5=4d9ff16f73294b42605b37a557558cc3CAS | 21616804PubMed |
Reiner-Drehwald ME (2005) On Lejeunea rotundifolia and Dicladolejeunea (Lejeuneaceae, Jungermanniopsida). Systematic Botany 30, 687–692.
| On Lejeunea rotundifolia and Dicladolejeunea (Lejeuneaceae, Jungermanniopsida).Crossref | GoogleScholarGoogle Scholar |
Reiner-Drehwald ME (2010) A taxonomic revision of Lejeunea deplanata (Lejeuneaceae, Marchantiophyta) from tropical America. Nova Hedwigia 91, 519–532.
| A taxonomic revision of Lejeunea deplanata (Lejeuneaceae, Marchantiophyta) from tropical America.Crossref | GoogleScholarGoogle Scholar |
Renner MAM (2012) Further insight into lobule teeth homology in Lejeuneaceae subf. Lejeuneoideae from Cheilolejeunea oscilla, a new species from Australia. The Bryologist 115, 536–556.
Renner MAM, Brown EA, Wardle GM (2009a) Lejeunea pocsii R.M.Schust. is a heterotypic synonym of L. helmsiana (Steph.) Steph. (Lejeuneaceae: Jungermanniopsida). Nova Hedwigia 89, 335–348.
| Lejeunea pocsii R.M.Schust. is a heterotypic synonym of L. helmsiana (Steph.) Steph. (Lejeuneaceae: Jungermanniopsida).Crossref | GoogleScholarGoogle Scholar |
Renner MAM, Brown EA, Wardle GM (2009b) Evidence for species recognition on the basis of a single specimen: Nephelolejeunea carcharias sp. nov. (Lejeuneaceae: Jungermanniopsida). Systematic Botany 34, 615–624.
| Evidence for species recognition on the basis of a single specimen: Nephelolejeunea carcharias sp. nov. (Lejeuneaceae: Jungermanniopsida).Crossref | GoogleScholarGoogle Scholar |
Renner MAM, Brown EA, Wardle GM (2010a) The Lejeunea tumida species group in New Zealand. Australian Systematic Botany 23, 443–462.
| The Lejeunea tumida species group in New Zealand.Crossref | GoogleScholarGoogle Scholar |
Renner MAM, Devos N, Shaw AJ (2010b) Radula splendida sp. nov. (Radulaceae: Marchantiophyta), a polymorphic species from New Zealand. Nova Hedwigia 90, 105–122.
| Radula splendida sp. nov. (Radulaceae: Marchantiophyta), a polymorphic species from New Zealand.Crossref | GoogleScholarGoogle Scholar |
Renner MAM, Brown EA, Wardle GM (2011) The Lejeunea tumida species group is positively polyphyletic (Lejeuneaceae: Jungermanniopsida). Australian Systematic Botany 24, 10–18.
| The Lejeunea tumida species group is positively polyphyletic (Lejeuneaceae: Jungermanniopsida).Crossref | GoogleScholarGoogle Scholar |
Rieppel OC, Kearney M (2002) Similarity. Biological Journal of the Linnean Society. Linnean Society of London 75, 59–82.
| Similarity.Crossref | GoogleScholarGoogle Scholar |
Rieppel OC, Kearney M (2007) The poverty of taxonomic characters. Biology and Philosophy 22, 95–113.
| The poverty of taxonomic characters.Crossref | GoogleScholarGoogle Scholar |
Rohlf FJ (1986) Relationships among eigenshape analysis, Fourier analysis, and analysis of coordinates. Mathematical Geology 18, 845–854.
| Relationships among eigenshape analysis, Fourier analysis, and analysis of coordinates.Crossref | GoogleScholarGoogle Scholar |
Rohlf FJ (1993) Relative-warp analysis and an example of its application to mosquito wings. In ‘Contributions to Morphometrics. Vol. 8’. (Eds LF Marcus, E Bello, A Garcia-Valdecasas) pp. 131–159. (Museo Nacional de Ciencias Naturales: Madrid)
Rohlf FJ (2003a) Bias and error in estimates of mean shape in geometric morphometrics. Journal of Human Evolution 44, 665–683.
| Bias and error in estimates of mean shape in geometric morphometrics.Crossref | GoogleScholarGoogle Scholar | 12799158PubMed |
Rohlf FJ (2003b) ‘tpsSmall. Version 1.20.’ (Department of Ecology and Evolution, Stony Brook University: New York) Available at www.lie.bio.sunysb.edu/morph/ [Verified 10 April 2012]
Rohlf FJ (2003c) ‘tpsRelw. Version 1.36.’ (Department of Ecology and Evolution, Stony Brook University: New York) Available at www.lie.bio.sunysb.edu/morph/ [Verified 20 September 2009]
Rohlf FJ (2010a) ‘tpsUTIL. Version 1.46.’ (Department of Ecology and Evolution, Stony Brook University: New York) Available at www.lie.bio.sunysb.edu/morph/ [Verified 12 November 2010]
Rohlf FJ (2010b) ‘tpsDIG2. Version 2.16.’ (Department of Ecology and Evolution, Stony Brook University: New York) Available at www.lie.bio.sunysb.edu/morph/ [Verified 12 November 2010]
Rohlf FJ (2011) ‘tpsREGR. Version 2.38.’ (Department of Ecology and Evolution, Stony Brook University: New York) Available at www.lie.bio.sunysb.edu/morph/ [Verified 14 April 2012]
Rohlf FJ, Marcus LF (1993) A revolution in morphometrics. Trends in Ecology & Evolution 8, 129–132.
Rohlf FJ, Slice DE (1990) Extensions of the Procrustes method for the optimal superimposition of landmarks. Systematic Zoology 39, 40–59.
| Extensions of the Procrustes method for the optimal superimposition of landmarks.Crossref | GoogleScholarGoogle Scholar |
Schluter D (2001) Ecology and the origin of species. Trends in Ecology & Evolution 16, 372–380.
| Ecology and the origin of species.Crossref | GoogleScholarGoogle Scholar |
Schuster RM (1980) ‘The Hepaticae and Anthocerotae of North America, Vol. 4.’ (Field Museum of Natural History: Chicago, IL)
Shaw AJ (2000) Molecular phylogeography and cryptic speciation in the mosses Mielichhoferia elongata and M. mielichhoferiana (Bryaceae). Molecular Ecology 9, 595–608.
| Molecular phylogeography and cryptic speciation in the mosses Mielichhoferia elongata and M. mielichhoferiana (Bryaceae).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXjsFCqu7k%3D&md5=2fd8567744f7ddb5eb42fcb78d626e50CAS | 10792702PubMed |
Shaw AJ, Allen B (2000) Phylogenetic relationships, morphological incongruence, and geographic speciation in the Fontinalaceae (Bryophyta). Molecular Phylogenetics and Evolution 16, 225–237.
| Phylogenetic relationships, morphological incongruence, and geographic speciation in the Fontinalaceae (Bryophyta).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXls1antLo%3D&md5=0c79471752fdc61293c98544fd84b50fCAS | 10942609PubMed |
Shaw AJ, Andrus RE, Shaw B (2008) Sphagnum beringiense sp. nov. (Bryophyta) from Arctic Alaska, based on morphological and molecular data. Systematic Botany 33, 469–477.
| Sphagnum beringiense sp. nov. (Bryophyta) from Arctic Alaska, based on morphological and molecular data.Crossref | GoogleScholarGoogle Scholar |
Sidlauskas B (2008) Continuous and arrested morphological diversification in sister clades of characiform fishes: a phylomorphospace approach. Evolution 62, 3135–3156.
| Continuous and arrested morphological diversification in sister clades of characiform fishes: a phylomorphospace approach.Crossref | GoogleScholarGoogle Scholar | 18786183PubMed |
Sites JW, Marshall JC (2004) Operational criteria for delimiting species. Annual Review of Ecology and Systematics 35, 199–227.
| Operational criteria for delimiting species.Crossref | GoogleScholarGoogle Scholar |
Sokal RR, Crovello TJ (1970) Biological species concept – a critical evaluation. American Naturalist 104, 127–153.
| Biological species concept – a critical evaluation.Crossref | GoogleScholarGoogle Scholar |
Spagnuolo V, Terracciano S, Cobianchi RC, Giordano S (2008) Taxonomy of the Hypnum cupressiforme complex in Italy based on ITS and trnL sequences and ISS markers. Journal of Bryology 30, 283–289.
| Taxonomy of the Hypnum cupressiforme complex in Italy based on ITS and trnL sequences and ISS markers.Crossref | GoogleScholarGoogle Scholar |
Stearns SC (1989) The evolutionary significance of phenotypic plasticity. Bioscience 39, 436–445.
| The evolutionary significance of phenotypic plasticity.Crossref | GoogleScholarGoogle Scholar |
Szweykowski J, Buczkowska K, Odrzykoski IJ (2005) Conocephalum salebrosum (Marchantiopsida, Conocephalaceae) – a new Holarctic liverwort species. Plant Systematics and Evolution 253, 133–158.
| Conocephalum salebrosum (Marchantiopsida, Conocephalaceae) – a new Holarctic liverwort species.Crossref | GoogleScholarGoogle Scholar |
Therrien JP, Crandall-Stotler BJ, Stotler RE (1998) Morphological and genetic variation in Porella platyphylla and P. platyphylloidea and their systematic implications. The Bryologist 101, 1–19.
Tobias JA, Seddon N, Spottiswoode CN, Pilgrim JD, Fishpool LDC, Collar NJ (2010) Quantitative criteria for species delimitation. The Ibis 152, 724–746.
| Quantitative criteria for species delimitation.Crossref | GoogleScholarGoogle Scholar |
Vanderpoorten A, Goffinet B (2006) Mapping uncertainty and phylogenetic uncertainty in ancestral character state reconstruction: an example in the moss genus Brachytheciastrum. Systematic Biology 55, 957–971.
| Mapping uncertainty and phylogenetic uncertainty in ancestral character state reconstruction: an example in the moss genus Brachytheciastrum.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2s7ks1WgtA%3D%3D&md5=34ade90c863f3652d79fe379830ed3b7CAS | 17345677PubMed |
Vanderpoorten A, Jacquemart A-L (2004) Evolutionary mode, tempo, and phylogenetic association of continuous morphological traits in the aquatic moss genus Amblystegium. Journal of Evolutionary Biology 17, 279–287.
| Evolutionary mode, tempo, and phylogenetic association of continuous morphological traits in the aquatic moss genus Amblystegium.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2c7hvFyrtg%3D%3D&md5=388e284f2e46f062ed879cf6da6e2694CAS | 15009261PubMed |
Vanderpoorten A, Shaw AJ (2010) The application of molecular data to the phylogenetic delimitation of species in bryophytes: a note of caution. Phytotaxa 9, 229–237.
Vanderpoorten A, Goffinet B, Hedenäs L, Cox C, Shaw AJ (2003) A taxonomic reassessment of the Vittiaceae (Hypnales, Bryopsida): evidence from phylogenetic analyses of combined chloropast and nuclear sequence data. Plant Systematics and Evolution 241, 1–12.
| A taxonomic reassessment of the Vittiaceae (Hypnales, Bryopsida): evidence from phylogenetic analyses of combined chloropast and nuclear sequence data.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXotleitLg%3D&md5=7ae4b944ff2b8af0164d95f66ed3d0baCAS |
Vanderpoorten A, Schäfer-Verwimp A, Heinrichs J, Devos N, Long DG (2010) The taxonomy of the leafy liverwort genus Leptoscyphus (Lophocoleaceae) revisited. Taxon 59, 176–186.
Viscosi V, Cardini A (2011) Leaf morphology, taxonomy and geometric morphometrics: a simplified protocol for beginners. PLoS ONE 6, e25630
| Leaf morphology, taxonomy and geometric morphometrics: a simplified protocol for beginners.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhtlGmtLrP&md5=22fc784a0fdbaddcc51f9f64f3c868cbCAS | 21991324PubMed |
Viscosi V, Fortini P, Slice DE, Loy A, Blasi C (2009a) Geometric morphometric analyses of leaf variation in four oak species of the subgenus Quercus (Fagaceae). Plant Biosystems 143, 575–587.
| Geometric morphometric analyses of leaf variation in four oak species of the subgenus Quercus (Fagaceae).Crossref | GoogleScholarGoogle Scholar |
Viscosi V, Lepais O, Gerber S, Fortini P (2009b) Leaf morphological analyses in four European oak species (Quercus) and their hybrids: a comparison of traditional and geometric morphometric methods. Plant Biosystems 143, 564–574.
| Leaf morphological analyses in four European oak species (Quercus) and their hybrids: a comparison of traditional and geometric morphometric methods.Crossref | GoogleScholarGoogle Scholar |
von Konrat MJ, Braggins JE, Asakawa Y, Toyota M (2006) Recognition of Frullania congesta: a case study to present a species concept and a synthesis of significant taxonomic characters for the large liverwort genus Frullania (Frullaniaceae). The Journal of the Hattori Botanical Laboratory 100, 553–576.
von Konrat MJ, Söderström L, Renner MAM, Hagborg A, Briscoe L, Engel JJ (2010) Early land plants today (ELPT): how many liverwort species are there? Phytotaxa 9, 22–40.
von Konrat MJ, de Lange PJ, Greif M, Strozier L, Hentschel J, Heinrichs J (2012) Frullania knightbridgei, a new liverwort (Frullaniaceae, Marchantiophyta) species from the deep south of Aotearoa–New Zealand based on an integrated evidence-based approach. Phytokeys 8, 13–36.
| Frullania knightbridgei, a new liverwort (Frullaniaceae, Marchantiophyta) species from the deep south of Aotearoa–New Zealand based on an integrated evidence-based approach.Crossref | GoogleScholarGoogle Scholar |
West-Eberhard MJ (1989) Phenotypic plasticity and the origins of diversity. Annual Review of Ecology and Systematics 20, 249–278.
| Phenotypic plasticity and the origins of diversity.Crossref | GoogleScholarGoogle Scholar |
Wheeler QD (2004) Taxonomic triage and the poverty of phylogeny. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 359, 571–583.
| Taxonomic triage and the poverty of phylogeny.Crossref | GoogleScholarGoogle Scholar | 15253345PubMed |
Wilson R, Heinrichs J, Hentschel J, Gradstein SR, Schneider H (2007a) Steady diversification of derived liverworts under Tertiary climatic fluctuations. Biology Letters 3, 566–569.
| Steady diversification of derived liverworts under Tertiary climatic fluctuations.Crossref | GoogleScholarGoogle Scholar | 17686755PubMed |
Wilson R, Gradstein SR, Schneider H, Heinrichs J (2007b) Unravelling the phylogeny of Lejeuneaceae (Jungermanniopsida): evidence for four main lineages. Molecular Phylogenetics and Evolution 43, 270–282.
| Unravelling the phylogeny of Lejeuneaceae (Jungermanniopsida): evidence for four main lineages.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXjslGrs7s%3D&md5=0aba84eb12589416025e6a156bbe3e2aCAS | 17157036PubMed |
Wu C-I (2001) The genic view of the process of speciation. Journal of Evolutionary Biology 14, 851–865.
| The genic view of the process of speciation.Crossref | GoogleScholarGoogle Scholar |
Wyatt R, Lane DM, Stoneburner A (1982) The misuse of mixed collections in bryophyte taxonomy. Taxon 31, 698–704.
| The misuse of mixed collections in bryophyte taxonomy.Crossref | GoogleScholarGoogle Scholar |
Zander R (1997) On mounting delicate bryophytes in glycerol. The Bryologist 100, 380–382.
Zapata F, Jiménez I (2012) Species delimitation: inferring gaps in morphology across geography. Systematic Biology 61, 179–194.
| Species delimitation: inferring gaps in morphology across geography.Crossref | GoogleScholarGoogle Scholar | 21840841PubMed |
Zelditch M, Swiderske D, Sheets D (2004) ‘Geometric Morphometrics for Biologists: a Primer.’ (Elsevier Academic Press: San Diego, CA)
