Deep mtDNA subdivision within Linnean species in an endemic radiation of tiger beetles from New Zealand (genus Neocicindela) Joan Pons a,b , Tomochika Fujisawa a,c , Elin M. Claridge a,1 , R. Anthony Savill d , Timothy G. Barraclough c , Alfried P. Vogler a,c,⇑ a Department of Entomology, Natural History Museum, Cromwell Road, London SW7 5BD, UK b IMEDEA (CSIC-UIB), Miquel Marqués, 21 Esporles, 07190 Illes Balears, Spain c Division of Biology, Imperial College London, Silwood Park Campus, Ascot SL5 7PY, UK d Canterbury Museum, Rolleston Avenue, Christchurch, New Zealand article info Article history: Received 19 January 2010 Revised 15 November 2010 Accepted 14 February 2011 Available online 19 February 2011 Keywords: Biogeography New Zealand Invertebrates Species delimitation GMYC groups DNA taxonomy abstract The invertebrate fauna of New Zealand is of great interest as a geologically tractable model for the study of species diversification, but direct comparisons with closely related lineages elsewhere are lacking. Integrating population-level analyses with studies of taxonomy and clade diversification, we performed mtDNA analysis on Neocicindela (Cicindelidae, tiger beetles) for a broad sample of populations from 11 of 12 known species and 161 specimens (three loci, 1883 nucleotides), revealing 123 distinct haplotypes. Phylogenetic reconstruction recovered two main lineages, each composed of 5–6 Linnean species whose origin was dated to 6.66 and 7.26 Mya, while the Neocicindela stem group was placed at 10.82 ± 0.48 Mya. Species delimitation implementing a character-based (diagnostic) species concept recognized 19 species- level groups that were in general agreement with Linnean species but split some of these into mostly allopatric subgroups. Tree-based methods of species delimitation using a mixed Yule-coalescence model were inconclusive, and recognized 32–51 entities (including singletons), splitting existing species into up to 8 partially sympatric groups. These findings were different from patterns in the Australian sister genus Rivacindela, where character-based and tree-based methods were previously shown to produce highly congruent groupings. In Neocicindela, the pattern of mtDNA variation was characterized by high intra- population and intra-species haplotype divergence, the coexistence of divergent haplotypes in sympatry, and a poor correlation of genetic and geographic distance. These observations combined suggest a sce- nario of phylogeographic divergence and secondary contact driven by orogenetic and climatic changes of the Pleistocene/Pliocene. The complex evolutionary history of most species of Neocicindela due to the relative instability of the New Zealand biota resulted in populations of mixed ancestry but not in a general loss of genetic variation. Ó 2011 Elsevier Inc. All rights reserved. 1. Introduction The invertebrate fauna of New Zealand has recently been subjected to numerous studies of historical biogeography and phy- logeography (Wallis and Trewick, 2009). This surge of interest re- sulted in a better understanding of the origin of extant lineages and the role of paleoclimatic and geological changes in the diversi- fication process. New Zealand is geologically derived from a frag- ment of continental crust that was part of the Gondwanan supercontinent, i.e. is expected to harbour an ancient fauna and flora, but instead most groups show patterns of species composi- tion and radiation usually attributed to young oceanic islands. This may be explained by the geographical isolation and extensive sub- mergence of New Zealand in the Oligocene (Landis et al., 2008) which caused the extirpation of most lineages. Phylogenetic anal- yses now have established that most endemic invertebrate lin- eages are derived from post-Oligocene colonizations (Goldberg et al., 2008). However, many questions remain about the processes of diversification within New Zealand (Wallis and Trewick, 2009). Recent work addressed the closely linked issues of population divergence and geographic distributions which have been influ- enced by the complex orogeny (King, 2000; Landis et al., 2008), as well as Pleistocene glacial cycles (Buckley and Simon, 2007; Emerson and Wallis, 1995). Surveys of mtDNA variation now exist for a large number of species or genera, in particular for arthro- pods. These have attempted to infer the location of glacial refugia 1055-7903/$ - see front matter Ó 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.ympev.2011.02.013 ⇑ Corresponding author at: Department of Entomology, Natural History Museum, Cromwell Road, London SW7 5BD, UK. E-mail address: apv@nhm.ac.uk (A.P. Vogler). 1 Present address: University of California Berkeley, Gump Research Station, Moorea, French Polynesia, United States. Molecular Phylogenetics and Evolution 59 (2011) 251–262 Contents lists available at ScienceDirect Molecular Phylogenetics and Evolution journal homepage: www.elsevier.com/locate/ympev