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Integrative taxonomy. Gustav Paulay Florida Museum of Natural History University of Florida. Integrative taxonomy. Use of multiple lines of evidence Field - museum - lab Ecology - behavior - morphology - genetics - geography Distinguishing between morphs and species - PowerPoint PPT Presentation

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  • Integrative taxonomyGustav PaulayFlorida Museum of Natural HistoryUniversity of Florida

  • Integrative taxonomyUse of multiple lines of evidenceField - museum - labEcology - behavior - morphology - genetics - geographyDistinguishing between morphs and speciesTwo or more independent characters showing distinction between species

  • Integrative taxonomy: Actinopyga mauritiana - guamensis

  • Integrative taxonomy: Actinopyga mauritiana - guamensis

  • Not seeing species where there arecukes vs. primates different foci for sensory perception

    unequal rates of evolutionphenotype: morphology, behavior, color pattern...genotype: sequence divergencereproductive isolation

  • Supposed distribution of Scutellastra flexuosa and exustaPowell, 1968

  • but what is really going on...

    NJ K2P COI

  • Seeing species where there arentecophenotypic variationontogenetic variationgeographic variationecological variation - depth, habitat, etcpolymorphismparalogous lociformer divergence now united

  • Paralogous loci:mitochondrial genes gone nuclear in AlpheusWilliams & Knowlton 2001 Mol Biol Evol

  • Cypraea tigris a species differentiated, then united

  • ESU - reciprocal monophylyDNA - gene flow - BSCreciprocal monophyly implies lack of recent genetic connectionsneed several samples of each form to testreliability of conclusion depends on depth of intra- vs. inter-specific variationin sympatry - separate biological speciesin allopatry - separate ESUs, species status subjective

  • Basinal/subbasinal speciation commonperceived as other dominant mode of speciation by past studiespredominant mode in Cypraeidae, Aspidochirotida, Diogenidae, Parribacus

    Cypraea punctata complex

  • Where are the species limits?

  • Lack of reciprocal monophylymorphs rather than speciesdistinct species, but:introgressioninsufficient time for sortingdeep coalescentrapid speciation

  • Introgression in Astralium

  • Introgression in Bohadschia argus?Unusual form only in W Pacific; never seen in Polynesia, etc.Need compare independent markers to test

  • Insufficient time for sorting

    Gene trees vs. species trees:coalescence theoryAvise 1999 Phylogeography

  • Evolution of reproductive isolationSlowmost gastropoddeep divergence among allopatric ESUsclear reciprocal monophylyslow to secondary sympatry / biological speciesRapidechinoids, holothuroidsshallow divergence among sympatric speciespotential paraphyletic speciesrapid to secondary sympatry / biological species

  • Astralium rhodostomum complexTwo deeply divergent clades: A & B sympatric on 8 island groups 30 ESUs so farPigmentation separates major and minor clades.

  • Geographic signalno signal94% divergences < 10 Maretain signal (115 of 122)Persistence of allopatry - Cypraeidae94% divergences < 10 Maretain allopatry (115 of 122)

  • Echinometra mathaei complex Rapid secondary sympatryFacilitated by rapid evolution of fertilization proteins? ~1 MaCOIBindinLandry et al. 2003 Proc Roy SocCOIBindin

  • Cukes like urchins:Actinopyga obesa complex

  • Stichopus variegatus complex

  • Advantages of sequence dataDirectly test genetic connectionsVery large number of charactersIndependent markers - independent sourcesIndependent of morphology - so can trace evolution of form, etc on gene tree without circularity

  • Potential problems with sequence datadepth of coalescent vs. interspecific divergenceparalogous sequencesintrogressionselective sweepshomogenization through drift

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