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Species delimitation in recent New Zealand species radiations

Species delimitation in recent New Zealand species radiations. Heidi M. Meudt Museum of New Zealand Te Papa Tongarewa Wellington, New Zealand. http://nzprn.otago.ac.nz/wiki/bin/view/NZPRN/WebHome. Outline – NZ species delimitation. Importance and challenges

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Species delimitation in recent New Zealand species radiations

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  1. Species delimitation in recent New Zealand species radiations Heidi M. Meudt Museum of New Zealand Te Papa Tongarewa Wellington, New Zealand http://nzprn.otago.ac.nz/wiki/bin/view/NZPRN/WebHome

  2. Outline – NZ species delimitation • Importance and challenges • NZ overview – 20 largest genera • Four examples • Outlook Ourisia Veronica Plantago Ranunculus

  3. Delimiting species boundaries Importance Species are fundamental units for description Understanding patterns & processes Assisting effective management Challenges Reproductive isolation not complete Hybridisation & introgression Polyploidy Parallel evolution Conflicts among operational criteria Veronica tetragona

  4. 20 NZ genera with most native spp. • 838 total species • from 14 families • 43% NZ seed plant flora • 26 – 122 species per genus (median = 37, mean = 42) • 55% (11) with revisions since NZ Flora (1961) • Full (9), partial (2) • 73% (8) with explicit criteria or concepts • Operational criteria • Descriptive morphology, geography, cytology, ecology (11) • Statistical morphological analyses (5) • Others (1-5) (Wilton, unpubl., Landcare Research) (Meudt, unpubl.)

  5. Criteria (and concepts) in NZ • Ranunculus (Fisher 1965) • “The only necessary characteristic of a species is that certain attributes should be discontinuous with those of other species… [R]eliable taxonomic distinctions are first applicable at the point where morphological overlaps cease.” • Leptinella (Lloyd 1972) • “A combined biological plus morphological species concept has been used. Groups of populations which are reproductively isolated… have been given the status of taxonomic species if they are also morphologically distinguishable.” • Epilobium (Raven & Raven 1976) • Species are “…morphologically and ecologically definable units that occupy large geographical areas… [and are] important genetic entities with definable physiological characteristics…” • Veronica (Bayly & Kellow 2006) • Species are “…morphologically recognisable… distinct biological entities or lineages” with the underlying assumption that morphological differences “generally reflect underlying reproductive or evolutionary processes.” • Ourisia, Plantago (Meudt et al. 2009, in review) • “Species are separately evolving lineages or metapopulations… This unified [species] concept allows the use of diverse lines of evidence to test species boundaries…” (incl.morphology, AFLPs, cytology, geography, ecology) [e.g., de Quieroz 1998, 2007]

  6. Criteria (and concepts) in NZ • Ranunculus (Fisher 1965) • “The only necessary characteristic of a species is that certain attributes should be discontinuous with those of other species… [R]eliable taxonomic distinctions are first applicable at the point where morphological overlaps cease.” • Leptinella (Lloyd 1972) • “A combined biological plus morphological species concept has been used. Groups of populations which are reproductively isolated… have been given the status of taxonomic species if they are also morphologically distinguishable.” • Epilobium (Raven & Raven 1976) • Species are “…morphologically and ecologically definable units that occupy large geographical areas… [and are] important genetic entities with definable physiological characteristics…” • Veronica (Bayly & Kellow 2006) • Species are “…morphologically recognisable… distinct biological entities or lineages” with the underlying assumption that morphological differences “generally reflect underlying reproductive or evolutionary processes.” • Ourisia, Plantago (Meudt et al. 2009, in review) • “Species are separately evolving lineages or metapopulations… This unified [species] concept allows the use of diverse lines of evidence to test species boundaries…” (incl.morphology, AFLPs, cytology, geography, ecology) [e.g., de Quieroz 1998, 2007]

  7. Criteria (and concepts) in NZ • Ranunculus (Fisher 1965) • “The only necessary characteristic of a species is that certain attributes should be discontinuous with those of other species… [R]eliable taxonomic distinctions are first applicable at the point where morphological overlaps cease.” • Leptinella (Lloyd 1972) • “A combined biological plus morphological species concept has been used. Groups of populations which are reproductively isolated… have been given the status of taxonomic species if they are also morphologically distinguishable.” • Epilobium (Raven & Raven 1976) • Species are “…morphologically and ecologically definable units that occupy large geographical areas… [and are] important genetic entities with definable physiological characteristics…” • Veronica (Bayly & Kellow 2006) • Species are “…morphologically recognisable… distinct biological entities or lineages” with the underlying assumption that morphological differences “generally reflect underlying reproductive or evolutionary processes.” • Ourisia, Plantago (Meudt et al. 2009, in review) • “Species are separately evolving lineages or metapopulations… This unified [species] concept allows the use of diverse lines of evidence to test species boundaries…” (incl.morphology, AFLPs, cytology, geography, ecology) [e.g., de Quieroz 1998, 2007]

  8. OurisiaPlantaginaceae • Operational criteria • Descriptive morphology, geography & ecology • AFLPs congruent • (Cytology uninformative; 2n = 48) • Species limits • 13 NZ species, 2 with subspecies • Evidence for hybridisation • cpDNA geographically structured • May explain unresolved backbone of AFLP phylogeny Meudt 2006; Meudt & Simpson 2006, 2007; Meudt et al. 2009, in prog.

  9. Distance 0.1 Veronica cushions Plantaginaceae V. thomsonii • Operational criteria • Morphology analyses & geography • (Cytology uninformative; 2n = 42) • (Alpine ecology similar: “snow hebes”) • AFLPscongruent or uninformative • Species limits • 4 cushion species • V. ciliolata with 2 subspecies • V. chionohebe = morph, ecol, geog distinct from V. thomsonii • V. myosotoides ≠ ecol, geog distinct (morph intermediate) V. myosotoides V. chionohebe V. ciliolata subsp. fiordensis V. ciliolata subsp. ciliolata AFLP NJ Jaccard (TREECON) tree - 158 indiv V. pulvinaris Meudt 2008, Meudt & Bayly 2008; leaf illustrations by Bobbi Angell.

  10. Plantago Plantaginaceae morphology AFLPs P. lanigera group 2n=12, 24 P. lanigera P. novae-zelandiae lanigera + novae-zelandiae unibracteata P. triandra group 2n=48, 60, 72 P. unibracteata P. triandra triandra + masoniae triantha P. triantha 2n=12 picta P. raoulli group 2n=48, 96 P. raoulli P. sp. nov. P. picta P. spathulata spathulata sp. nov. raoulli P. obconica 2n=12 obconica P. aucklandica 2n=? aucklandica MP tree - 77 indiv, 1443 chars – losses favoured 4:1 (Meudt 2011) NTSYS – SAHN UPGMA clustering - 178 indiv, 56 chars - Gower’s dis. matrix (Meudt in review)

  11. PlantagoPlantaginaceae P. lanigera (2n=12, 24) P. novae-zelandiae (2n=24) P. unibracteata (2n=60) P. unibracteata (2n=72) P. triandra (2n=48) • Operational criteria • Morphology analyses, cytology • (Geography, habitats similar) • AFLPs & molecular cytogenetics congruent or uninformative/complex • Species limits • 4 species in thisgroup • No evidence for P. triandra subspp. • Chromosome races ≠ ecol, morph, geog distinct in P. lanigera, P. unibracteata • P. unibracteata is allopolyploid with complex, multiple origins NTSYS – MDS ordination, 69 indiv, 49 chars - Gower’s dis. matrix (Meudt in review)

  12. Ranunculus Ranunculaceae R. insignis 2n=48 R. nivicola 2n=96 R. verticillatus 2n=48 nrDNA ITS cpDNA JSA (Carter, Lockhart et al. in prep.)

  13. Ranunculus Ranunculaceae • Operational criteria • Morphological data – multivariate analyses • Geography – weak correlation of latitude & morphology • DNA sequences – congruent or uninformative (0 – 2 mutations per lineage) Species limits • 3 species – R. monroi, R. lobulatus, R. insignis • Recognition – floral, leaf, stem characters • Contact zones – hybridisation & introgression Ranunculus insignis 1mm R. insignis 100μm R. lobulatus R. monroi Undet. 1mm (Lehnebach, Lockhart et al. in prep.)

  14. Conclusions and outlook • NZ species delimitation • Downstream effects in research & conservation • Common concepts & criteria • Data congruence (e.g., Ourisia, Veronica) • Challenges underscore evolutionary processes (e.g., Plantago, Ranunculus) • Future developments • More comprehensive treatments (e.g., Myosotis, Aciphylla) • Justification of species limits • Testing limits with new methods • Review & comparative studies

  15. Acknowledgements • NZPRN colleagues • Ilse Breitwieser & fellow symposium speakers • Richard Carter & Carlos Lehnebach for sharing slides of unpublished Ranunculus data • Phil Garnock-Jones for photos http://nzprn.otago.ac.nz/wiki/bin/view/NZPRN/WebHome

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