A New Species of Platymantis (Anura: Ranidae) from Quaternary Deposits On Viti Levu, Fiji

Fossil bones of the frog Platymantis are reported for the first time. Platymantis megabotoniviti sp. nov. is described from fossil bones of late Quaternary age from caves on Viti Levu, Fiji, south-west Pacific, where it was associated with fossils of the extant P. vitianus P. vitiensis . The new species is much larger than any extant congeners, and its robust form indicates that it was a ground-dwelling frog. It appears to have become extinct in the late Holocene after humans arrived on Fiji with commensal rodents.     

Molecular systematics and global phylogeography of angel sharks (genus Squatina)

Angel sharks of the genus Squatina represent a group comprising 22 extant benthic species inhabiting continental shelves and upper slopes. In the present study, a comprehensive phylogenetic reconstruction of 17 Squatina species based on two mitochondrial markers (COI and 16S rRNA) is provided. The phylogenetic reconstructions are used to test biogeographic patterns. In addition, a molecular clock analysis is conducted to estimate divergence times of the emerged clades. All analyses show Squatina to be monophyletic. Four geographic clades are recognized, of which the Europe–North Africa–Asia clade is probably a result of the Tethys Sea closure. A second sister group relationship emerged in the analyses, including S. californica (eastern North Pacific) and S. dumeril (western North Atlantic), probably related to the rise of the Panamanian isthmus. The molecular clock analysis show that both lineage divergences coincide with the estimated time of these two geological events.     

Origin and diversification of the endemic Hawaiian tree snails (Achatinellidae: Achatinellinae) based on molecular evidence

Tree snails of the endemic subfamily Achatinellinae comprise a diverse and important component of the Hawaiian fauna. In recent decades anthropogenic impacts have resulted in devastating extinction rates in Hawaiian tree snails. To address long-standing biogeographic, systematic, and evolutionary questions we used cytochrome c oxidase subunit I (COI) gene sequences to reconstruct the phylogeny of 23 extant species spanning the range of the subfamily from five Hawaiian Islands. To investigate family-level relationships, data were analyzed from 11 terrestrial pulmonate families. Although nodal support for monophyly of the endemic Pacific family Achatinellidae and endemic Hawaiian subfamily Achatinellinae was strong, bifurcation order among deeper ingroup nodes was not well-supported by bootstrap resampling. We hypothesize that lineage extinction and rapidity of lineage formation may have rendered evolutionary reconstruction difficult using a standard phylogenetic approach. Use of an optimized evolutionary model, however, improved resolution and recovered three main clades. The diversification pattern inferred contradicts the traditional biogeographic hypothesis of a Maui origin of the achatinelline lineage. Taxa comprising the basal ingroup clade (Achatinella spp.) and seeding lineages for subsequent clades originated on O'ahu. Therefore it appears that the ancestral colonizing species of achatinellines arrived first on O'ahu from an unknown source, and that O'ahu is the Hawaiian origin of the subfamily. Species previously defined by morphological criteria were generally found to be phylogenetically distinct, and the overall colonization pattern follows the island-age progression rule with several instances of generic polyphyly and back-colonization.     

Molecular phylogenetics and biogeography of transisthmian and amphi-Atlantic needlefishes (Belonidae: Strongylura and Tylosurus): perspectives on New World marine speciation

Phylogenetic relationships among New World and eastern Atlantic species in the belonid genera Strongylura and Tylosurus were hypothesized using 3689bp of nucleotide sequence; including the entire mitochondrial (mtDNA) ATP synthase 6 and 8 genes; partial cytochrome b; 12S and 16S ribosomal genes; and introns and exons, 2 and 3 of the nuclear-encoded creatine kinase B gene. Concordant mtDNA and nuclear genealogies permitted well-supported inference of species relationships within Strongylura and Tylosurus, and of the chronology of diversification in the two genera. Our phylogenetic hypothesis permitted an assessment of Rosen's [Syst. Zool. 24 (1975) 431] model of species diversification across the eastern Atlantic to eastern Pacific marine biogeographic track. The spatial predictions of the Rosen model were generally supported, but not the temporal predictions. Furthermore, long branches leading to terminal Belonidae indicated that many species have persisted for millions of years or that nucleotide substitution rates were elevated for some clades. Though heterogeneity of nucleotide substitution rate was indicated across some belonid lineages, molecular clock estimates were used to hypothesize biogeographic scenarios for Strongylura across the eastern Pacific and Atlantic region. Furthermore, use of a molecular clock indicated; that early diversification among contemporary Strongylura may have been initiated by changes in Atlantic Ocean circulation precipitated by closure of the Tethys Sea; and provided approximate dates for the isolation of the freshwater species on the American continents.     

Molecular phylogeny of new world primates (Platyrrhini) based on beta2-microglobulin DNA sequences

Neotropical primates, traditionally grouped in the infraorder Platyrrhini, comprise 16 extant genera. Cladistic analyses based on morphological characteristics and molecular data resulted in topologic arrangements depicting disparate phylogenetic relationships, indicating that the evolution of gross morphological characteristics and molecular traits is not necessarily congruent. Here we present a phylogenetic arrangement for all neotropical primate genera obtained from DNA sequence analyses of the beta2-microglobulin gene. Parsimony, distance, and maximum likelihood analyses favored two families, Atelidae and Cebidae, each containing 8 genera. Atelids were resolved into atelines and pitheciines. The well-supported ateline clade branched into alouattine (Alouatta) and ateline (Ateles, Lagothrix, Brachyteles) clades. In turn, within the Ateline clade, Lagothrix and Brachyteles were well-supported sister groups. The pitheciines branched into well-supported callicebine (Callicebus) and pitheciine (Pithecia, Cacajao, Chiropotes) clades. In turn, within the pitheciine clade, Cacajao and Chiropotes were well-supported sister groups. The cebids branched into callitrichine (Saguinus, Leontopithecus, Callimico, Callithrix-Cebuella), cebine (Cebus, Saimiri), and aotine (Aotus) clades. While the callitrichine clade and the groupings of species and genera within this clade were all well supported, the cebine clade received only modest support, and the position of Aotus could not be clearly established. Cladistic analyses favored the proposition of 15 rather than 16 extant genera by including Cebuella pygmaea in the genus Callithrix as the sister group of the Callithrix argentata species group. These analyses also favored the sister grouping of Callimico with Callithrix and then of Leontopithecus with the Callithrix-Callimico clade.     

Phylogeography of the Calonectris shearwaters using molecular and morphometric data

We investigated phylogenetic relationships and the biogeographic history of the Calonectris species complex, using both molecular and biometric data from one population of the Cape Verde shearwater Calonectris edwardsii (Cape Verde Islands), one from the streaked shearwater C. leucomelas (western Pacific Ocean) and 26 from Cory's shearwater populations distributed across the Atlantic (C. d. borealis) and the Mediterranean (C. d. diomedea). The streaked shearwater appeared as the most basal and distant clades, whereas the genetic divergences among the three main clades within the Palearctic were similar. Clock calibrations match the first speciation event within Calonectris to the Panama Isthmus formation, suggesting a vicariant scenario for the divergence of the Pacific and the Palearctic clades. The separation between the Atlantic and Mediterranean clades would have occurred in allopatry by range contraction followed by local adaptation during the major biogeographic events of the Pleistocene. The endemic form from Cape Verde probably evolved as a result of ecological divergence from the Mediterranean subspecies. Finally, one Mediterranean population (Almeria) was unexpectedly grouped into the Atlantic subspecies clade, both by genetic and by morphometric analyses, pointing out the Almeria-Oran oceanographic front (AOOF) as the actual divide between the two Cory's shearwater subspecies. Our results highlight the importance of oceanographic boundaries as potentially effective barriers shaping population and species phylogeographical structure in pelagic seabirds.     

Gnathostomulida from Fiji, Tonga and New Zealand

Of 54 species of Gnathostomulida known to date, only six have been reported from the Pacific Ocean. This paper describes 18 species of Gnathostomulida from the Pacific islands of Fiji. Tonga and northern New Zealand. Of these, three are species previously described from the northeastern Atlantic and Mediterranean: Haplognathia ruberrima (Sterrer 1966), or the northwestern Atlantic: Haplognathia rosacea (Sterrer 1970) and Pterognathia ctenifera (Sterrer 1970). Fifteen species are new to science, including three that represent two new genera: Cosmognathia arcus gen. et sp.n., Cosmognathia bastillae sp.n., Pterognathia crocodilus sp.n., Pterognathia vilii sp.n., Agnathiella sp., Tenuignathia vitiensis sp.n., Ratugnathia mukuluvae gen . et sp.n., Gnathostomula salotae sp.n., Gnathostomula raji sp.n., Gnathostomula maorica sp.n., Austrognathia singatokae sp.n., Austrognathia nannulifera sp.n., Austrognathia novaezelandiae sp.n., Austrognatharia homunculus sp.n., and Austrognatharia pecten sp.n.     

Taxonomic revision and phylogenetic analysis of the flightless Mancallinae (Aves, Pan-Alcidae)

Although flightless alcids from the Miocene and Pliocene of the eastern Pacific Ocean have been known for over 100 years, there is no detailed evaluation of diversity and systematic placement of these taxa. This is the first combined analysis of morphological and molecular data to include all extant alcids, the recently extinct Great Auk Pinguinus impennis, the mancalline auks, and a large outgroup sampling of 29 additional non-alcid charadriiforms. Based on the systematic placement of Mancallinae outside of crown clade Alcidae, the clade name Pan-Alcidae is proposed to include all known alcids. An extensive review of the Mancallinae fossil record resulted in taxonomic revision of the clade, and identification of three new species. In addition to positing the first hypothesis of inter-relationships between Mancallinae species, phylogenetic results support placement of Mancallinae as the sister taxon to all other Alcidae, indicating that flightlessness evolved at least twice in the alcid lineage. Convergent osteological characteristics of Mancallinae, the flightless Great Auk, and Spheniscidae are summarized, and implications of Mancallinae diversity, radiation, and extinction in the context of paleoclimatic changes are discussed.     

Systematics of Nothofagus (Nothofagaceae) based on rDNA spacer sequences (ITS): taxonomic congruence with morphology and plastid sequences

Phylogenetic relationships were examined within the southern beech family Nothofagaceae using 22 species representing the four currently recognized subgenera and related outgroups. Nuclear ribosomal DNA sequences encoding the 5.8s rRNA and two flanking internal transcribed spacers (ITS) provided 95 phylogenetically informative nucleotide sites from a single alignment of ~588 bases per species. Parsimony analysis of this variation produced two equally parsimonious trees supporting four monophyletic groups, which correspond to groups designated by pollen type. These topologies were compared to trees from reanalyses of previously reported rbcL sequences and a modified morphological data set. Results from parsimony analysis of the three data sets were highly congruent, with topological differences restricted to the placement of a few terminal taxa. Combined analysis of molecular and morphological data produced six equally parsimonious trees. The consensus of these trees suggests two basal clades within Nothofagus. Within the larger of the two clades, tropical Nothofagus (subgenus Brassospora) of New Guinea and New Caledonia are strongly supported as sister to cool-temperate species of South America (subgenus Nothofagus). Most of the morphological apomorphies of the cupule, fruit, and pollen of Nothofagus are distributed within this larger clade. An area cladogram based on the consensus of combined data supports three trans-Antarctic relationships, two within pollen groups and one between pollen groups. Fossil data support continuous ancestral distributions for all four pollen groups prior to continental drift; therefore, vicariance adequately explains two of these disjunctions. Extinction of trans-Antarctic sister taxa within formerly widespread pollen groups explains the third disjunction; this results in a biogeographic pattern indicative of phylogenetic relationship not vicariance. For the biogeographically informative vicariant clades, area relationships based on total evidence support the recently advanced hypothesis that New Zealand and Australia share a unique common ancestry. Contrary to previous thought, the distribution of extant Nothofagus is informative on the area relationships of the Southern Hemisphere, once precise phylogenetic relationships are placed in the context of fossil data.     

Molecular phylogeny of north mediterranean freshwater barbs (genus Barbus: cyprinidae) inferred from cytochrome b sequences: biogeographic and systematic implications

We investigated phylogenetic relationships among north Mediterranean species of the genus Barbus using sequences of the cytochrome b gene. Our results indicate that the species belong to two major clades that are consistent with those previously defined from morphological features. The first clade includes species ranging from France to the Black Sea. In this clade, there is a well-supported monophyletic group of large-sized fluvio-lacustrine barbs; however, the monophyly of the small-sized rheophilic species is not clear. The second clade comprises species found in Spain, Greece, and Asia Minor and probably represents the oldest group present in the north Mediterranean rivers. In general, there is good concordance between geography and phylogenetic relationships. These results are compared to those from previous morphological- and allozyme-based studies and demonstrate widespread discordance and polyphyly in the traditional taxonomy of the genus Barbus. This study is one of the first reporting the phylogenetic and biogeographic relationships of a genus that is widely distributed in European rivers and contains species that are a major component of the European ichthyofauna.     

A macroevolutionary perspective on species range limits

Understanding the factors that determine the geographic range limits of species is important for many questions in ecology, evolution and conservation biology. These limits arise from complex interactions among ecology and dispersal ability of species and the physical environment, but many of the underlying traits can be conserved among related species and clades. Thus, the range limits of species are likely to be influenced by their macroevolutionary history. Using palaeontological and biogeographic data for marine bivalves, we find that the range limits of genera are significantly related to their constituent species richness, but the effects of age are weak and inconsistent. In addition, we find a significant phylogenetic signal in the range limits at both genus and family levels, although the strength of this effect shows interoceanic variation. This phylogenetic conservatism of range limits gives rise to an evolutionary pattern where wide-ranging lineages have clusters of species within the biogeographic provinces, with a few extending across major boundaries.     

Tectonic blocks and molecular clocks

Evolutionary timescales have mainly used fossils for calibrating molecular clocks, though fossils only really provide minimum clade age constraints. In their place, phylogenetic trees can be calibrated by precisely dated geological events that have shaped biogeography. However, tectonic episodes are protracted, their role in vicariance is rarely justified, the biogeography of living clades and their antecedents may differ, and the impact of such events is contingent on ecology. Biogeographic calibrations are no panacea for the shortcomings of fossil calibrations, but their associated uncertainties can be accommodated. We provide examples of how biogeographic calibrations based on geological data can be established for the fragmentation of the Pangaean supercontinent: (i) for the uplift of the Isthmus of Panama, (ii) the separation of New Zealand from Gondwana, and (iii) for the opening of the Atlantic Ocean. Biogeographic and fossil calibrations are complementary, not competing, approaches to constraining molecular clock analyses, providing alternative constraints on the age of clades that are vital to avoiding circularity in investigating the role of biogeographic mechanisms in shaping modern biodiversity.This article is part of the themed issue ‘Dating species divergences using rocks and clocks’.     

Phylogenetic diversity meets conservation policy: small areas are key to preserving eucalypt lineages

Evolutionary and genetic knowledge is increasingly being valued in conservation theory, but is rarely considered in conservation planning and policy. Here, we integrate phylogenetic diversity (PD) with spatial reserve prioritization to evaluate how well the existing reserve system in Victoria, Australia captures the evolutionary lineages of eucalypts, which dominate forest canopies across the state. Forty-three per cent of remaining native woody vegetation in Victoria is located in protected areas (mostly national parks) representing 48% of the extant PD found in the state. A modest expansion in protected areas of 5% (less than 1% of the state area) would increase protected PD by 33% over current levels. In a recent policy change, portions of the national parks were opened for development. These tourism development zones hold over half the PD found in national parks with some species and clades falling entirely outside of protected zones within the national parks. This approach of using PD in spatial prioritization could be extended to any clade or area that has spatial and phylogenetic data. Our results demonstrate the relevance of PD to regional conservation policy by highlighting that small but strategically located areas disproportionally impact the preservation of evolutionary lineages.     

Phylogenetic relationships and biogeography of Podarcis species from the Balkan Peninsula, by bayesian and maximum likelihood analyses of mitochondrial DNA sequences

Wall lizards of the genus Podarcis (Sauria, Lacertidae) comprise 17 currently recognized species in southern Europe, where they are the predominant nonavian reptile group. The taxonomy of Podarcis is complex and unstable. Based on DNA sequence data, the species of Podarcis falls into four main groups that have substantial geographic coherence (Western island group, southwestern group, Italian group, and Balkan Peninsula group). The Balkan Peninsula species are divided into two subgroups: the subgroup of P. taurica (P. taurica, P. milensis, P. gaigeae, and perhaps P. melisellensis), and the subgroup of P. erhardii (P. erhardii and P. peloponnesiaca). In the present study, the question of phylogenetic relationships among the species of Podarcis encountered in the Balkan Peninsula was addressed using partial mtDNA sequences for cytochrome b (cyt b) and 16S rRNA (16S). The data support the monophyly of Podarcis and suggest that there are three phylogenetic clades: the clade A (P. taurica, P. gaigeae, P. milensis, and P. melisellensis); the clade B (P. erhardii and P. peloponnesiaca), and the clade C (P. muralis and P. sicula). By examining intraspecific relationships it was found that extant populations of P. erhardii are paraphyletic. Furthermore, subspecies previously defined on the basis of morphological characteristics do not correspond to different molecular phylogenetic clades, suggesting that their status should be reconsidered. The distinct geographic distribution of the major clades of the phylogenetic tree and its topology suggest a spatial and temporal sequence of phylogenetic separations that coincide with some major paleogeographic separations during the geological history of the Aegean Sea. The results stress the need for a reconsideration of the evolutionary history of Balkan Podarcis species and help overcome difficulties that classical taxonomy has encountered at both the species and subspecies level.     

Biogeographic diversification in Nolana （Solanaceae）, a ubiquitous member of the Atacama and Peruvian Deserts along the western coast of South America

The present paper reconstructs the biogeographic diversification for Nolana L.f. （Solanaceae）, a genus of 89 endemic species largely restricted to fog-dependent desert lomas formations of coastal Peru and Chile. Previous efforts have reconstructed a phylogenetic estimate for Nolana using a combination of molecular markers. Herein, we expand on those results to examine hypotheses of biogeographic origins and diversification patterns. Nolana occupies habitats within a continuous coastal desert and forms a terrestrial archipelago of discrete ＂islands＂ unique in size, topography, and species composition. Each locality contains at least one Nolana species and many contain multiple species in sympatry. The genus has a Chilean origin, with the basal clades confined to Chile with wide geographic and ecological distributions. Peru contains two strongly supported clades, suggesting two introductions with subsequent radiation. A Chilean clade of shrubby, small-flowered species appears to have had its origins from the same ancestors of the second line that radiated in Peru and northern Chile. Nolana galapagensis is endemic to the Islas Galapagos, with origins traced to Peruvian taxa with a divergence time of 0.35 mya. Rates of diversification over the past 4.02 mya in Nolana, in one of the driest habitats on Earth, suggest rapid adaptive radiation in several clades. Success in Nolana may be attributed to characters that confer a competitive advantage in unpredictable and water-dependent environments, such as succulent leaf anatomy and ecophysiology, and the reproductive mericarp unique to Nolana. The processes affecting or shaping the biota of western South America are discussed.     

Phylogeny and biogeography of the genus Lycium (Solanaceae): inferences from chloroplast DNA sequences

Lycium comprises approximately 70 species and is disjunctly distributed in temperate to subtropical regions in South America, North America, southern Africa, Eurasia, and Australia. Among them, only Lycium sandwicense A. Gray sporadically occurs widely on oceanic islands in the Pacific Ocean. To investigate phylogenetic and biogeographic relationships of the genus with emphasis on L. sandwicense, the coding region of matK, the two intergenic spacers trnT (UGU)-trnL (UAA) and trnL (UAA)-trnF (GAA), and the trnL (UAA) intron of chloroplast DNA (cpDNA) were sequenced. A strict consensus tree resulting from the phylogenetic analysis indicates the following: (1) New World species comprise a potentially paraphyletic assemblage; (2) southern African, Australian, and Eurasian species together are monophyletic; (3) southern African species are a paraphyletic assemblage; and (4) L. sandwicense is in a clade with certain New World species. The estimated biogeographic events based on the cpDNA analysis indicate that (1) Lycium originated in the New World, (2) all southern African, Australian, and Eurasian species have a common ancestor from the New World, (3) Australian and Eurasian species originated once from a southern African progenitor, and (4) L. sandwicense differentiated from the New World species.     

Molecular phylogeny of Banza (Orthoptera: Tettigoniidae), the endemic katydids of the Hawaiian Archipelago

The extant endemic katydids (Orthoptera: Tettigoniidae) of the Hawaiian Archipelago include one to three species per high island and a single species on Nihoa, all currently placed in the genus Banza. These acoustic insects provide an excellent opportunity for investigating the evolution of reproductive isolation and speciation, but such studies require an understanding of phylogenetic relationships within the group. We use maximum parsimony, likelihood-based Bayesian inference, and maximum likelihood to infer phylogenetic relationships among these taxa, based on approximately 2kb of mitochondrial cytochrome oxidase I and cytochrome b. Our results strongly support two distinct high island clades: one clade ("Clade I") composed of species from Kauai, Oahu, Molokai, and Lanai and another clade ("Clade II") composed of species from Maui and Hawaii (Banza unica, from Oahu, may be basal to both these clades, but its placement is not well resolved). Within these clades, some inferred relationships are strongly supported, such as the sister status of B. kauaiensis (Kauai) and B. parvula (Oahu) within Clade I, but other relationships remain more ambiguous, such as the relative position of B. brunnea (Maui) within Clade II. Although a detailed reconstruction of the historical biogeography of the Hawaiian katydids is difficult, we use our genetic data combined with the known geological history of the Hawaiian Islands to set limits on plausible historical scenarios for diversification of this group. Beyond these historical biogeographic inferences, our results indicate possible cryptic speciation on both Oahu and Hawaii, as well as what may be unusually high average rates of nucleotide substitution. The present work sets the stage for future genetic and experimental investigations of this group.     

Deep molluscan phylogeny: synthesis of palaeontological and neontological data

The position of the earliest-derived living molluscs, the Polyplacophora (chitons) and shell-less vermiform Aplacophora, remains highly contentious despite many morphological, developmental and molecular studies of extant organisms. These two groups are thought to represent either a basal molluscan grade or a clade (Aculifera) sister to the 'higher' molluscs (Conchifera). These incompatible hypotheses result in very different predictions about the earliest molluscs. A new cladistic analysis incorporating both Palaeozoic and extant molluscs is presented here. Our results support the monophyly of Aculifera and suggest that extant aplacophorans and polyplacophorans both derive from a disparate group of multivalved molluscs in two major clades. Reanalysis of the critical Ordovician taxon 'Helminthochiton' thraivensis shows that this animal lacks a true foot despite bearing polyplacophoran-like valves. Its position within our phylogenetic reconstruction indicates that many fossil 'polyplacophorans' in the order Palaeoloricata are likely to represent footless stem-group aplacophorans. 'H.' thraivensis and similar forms such as Acaenoplax may be morphological stepping stones between chitons and the shell-less aplacophorans. Our results imply that crown-group molluscan synapomorphies include serial repetition, the presence of a foot, a mineralized scleritome and a creeping rather than worm-like mode of life.     

Multilocus phylogenetic analysis of true morels (Morchella) reveals high levels of endemics in Turkey relative to other regions of Europe

The present study was conducted to better understand how the phylogenetic diversity of true morels (Morchella) in Turkey compares with species found in other regions of the world. The current research builds on our recently published surveys of 10 Turkish provinces and the northern hemisphere in which DNA sequence data from 247 and 562 collections respectively were analyzed phylogenetically. Herein we report on phylogenetic analyses of 243 additional collections made in spring 2009 and 2010 from eight additional provinces in the Aegean, Black Sea, central Anatolia, eastern Anatolia and Marmara regions of Turkey. Our analysis revealed that five species within the Esculenta clade (yellow morels) and 15 species within the Elata clade (black morels) were present in Turkey. Our preliminary results also indicate that M. anatolica, recently described from a collection in Mu?la province in the Aegean region of Turkey, is a closely related sister of M. rufobrunnea; these two species comprise a separate evolutionary lineage from the Esculenta and Elata clades. Nine species of Morchella currently are known only from Turkey, four species were present in Turkey and other European countries and seven species might have been introduced to Turkey anthropogenically. Three of the putatively exotic species in Turkey appear to be endemic to western North America; they are nested within a clade of fire-adapted morels that dates to the late Oligocene, 25 000 000 y ago. Our results indicate that there are roughly twice as many Morchella species in Turkey compared with the other regions of Europe sampled. Knowledge of Morchella species diversity and their biogeographic distribution are crucial for formulating informed conservation policies directed at preventing species loss and ensuring that annual morel harvests are sustainable and ecologically sound.     

Evolution of insular Pacific Pittosporum (Pittosporaceae): origin of the Hawaiian radiation.

We investigated the origin of Hawaiian Pittosporum and their relationship to other South Pacific Pittosporum species using internal transcribed spacer sequences of nuclear ribosomal DNA. We performed both maximum-parsimony and maximum-likelihood analyses, which produced congruent results. Sequence divergence was 0.0% between Hawaiian members of Pittosporum. These taxa formed a strongly supported clade, suggesting a single colonization event followed by phyletic radiation. Sister to the Hawaiian clade were two South Pacific species, P. yunckeri from Tonga and P. rhytidocarpum from Fiji. This result presents convincing evidence for a South Pacific origin of Hawaiian Pittosporum. Our results also identify a monophyletic group comprising three species representing the Fijian Province and East Polynesia, two introductions onto New Caledonia, and at least one (but possibly two) introduction(s) onto New Zealand. Whether the New Zealand taxa form a monophyletic group is unclear from these data. Previous morphologically based hypotheses, however, suggest the presence of four different lineages occupying New Zealand. The nonmonophyly of the New Caledonian species was not surprising based on the extent of their morphological diversity. Although this latter result is not strongly supported, these species are morphologically complex and are currently the subject of taxonomic revision and molecular systematic analyses.