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1.
An antitropical distribution represents an intriguing disjunction, in which a given species or sister lineages occupy regions north and south of the tropics but are absent from the intervening areas. Solenogyne mikadoi endemic to the Ryukyu Archipelago is regarded as an Australian element. Testing the phylogenetic relationship with Australian congeners and discussing the onset timing and causes of the disjunction would potentially enhance the understanding of antitropical distribution. A nuclear ribosomal DNA phylogeny was reconstructed using Bayesian and most parsimonious criteria with allied genera. Solenogyne was monophyletic and clustered with Lagenophora huegelii endemic to Australia, indicating the antitropical distribution and Australian origin of Solenogyne. Multispecies coalescent analysis based on nuclear ribosomal DNA and chloroplast DNA indicated the divergence of S. mikadoi and Australian congeners in the Plio‐Pleistocene. Phylogenetic network analyses suggested that the ancestral lineage of S. mikadoi first colonized the southernmost island in the archipelago and then dispersed northward. The migration to the archipelago likely followed the flourishing of Solenogyne in open vegetation communities that radiated in south‐eastern Australia during the late Pliocene. This disjunction might arise through long‐distance dispersal across the tropics or, alternatively, through extinction in the tropics as a result of unsuitably high temperatures during climate oscillation and/or competitions from diverse tropical flora surviving since the early Tertiary. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105 , 197–217.  相似文献   

2.
We present a comprehensively sampled three‐gene phylogeny of the monophyletic Forcipulatacea, one of three major lineages within the crown‐group Asteroidea. We present substantially more Southern Hemisphere and deep‐sea taxa than were sampled in previous molecular studies of this group. Morphologically distinct groups, such as the Brisingida and the Zoroasteridae, are upheld as monophyletic. Brisingida is supported as the derived sister group to the Asteriidae (restricted), rather than as a basal taxon. The Asteriidae is paraphyletic, and is broken up into the Stichasteridae and four primary asteriid clades: (1) a highly diverse boreal clade, containing members from the Arctic and sub‐Arctic in the Northern Hemisphere; (2) the genus Sclerasterias; (3) and (4) two sister clades that contain asteriids from the Antarctic and pantropical regions. The Stichasteridae, which was regarded as a synonym of the Asteriidae, is resurrected by our results, and represents the most diverse Southern Hemisphere forcipulatacean clade (although two deep‐sea stichasterid genera occur in the Northern Hemisphere). The Labidiasteridae is artificial, and should be synonymized into the Heliasteridae. The Pedicellasteridae is paraphyletic, with three separate clades containing pedicellasterid taxa emerging among the basal Forcipulatacea. Fossils and timing estimates from species‐level phylogeographic studies are consistent with prior phylogenetic hypotheses for the Forcipulatacea, suggesting diversification of basal taxa in the early Mesozoic, with some evidence for more widely distributed ranges from Cretacous taxa. Our analysis suggests a hypothesis of an older fauna present in the Antarctic during the Eocene, which was succeeded by a modern Antarctic fauna that is represented by the recently derived Antarctic Asteriidae and other forcipulatacean lineages. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 162 , 646–660.  相似文献   

3.
Recent mtDNA phylogenies of Australasian agamid lizards are highly incongruent with existing morphological views. To resolve this discrepancy we sequenced two nuclear gene regions, c- mos and brain-derived neurotrophic factor (BDNF). These were highly concordant with each other and the mtDNA phylogeny, but not the morphology. A combined molecular analysis reveals substantial hidden support (additional phylogenetic signal that emerges only when the data sets interact in a combined analysis). Bayesian posteriors, and a partitioned bootstrap procedure introduced here, indicate strong support for most nodes. The resultant tree implies extensive morphological homoplasy, with many genera emerging as non-monophyletic ( Amphibolurus , Rankinia , Ctenophorus , Physignathus , Diporiphora ). The water and forest dragons ( Physignathus and Hypsilurus ) form a paraphyletic basal assemblage to the more derived Australian forms such as Amphibolurus and Ctenophorus , which include almost all the xeric taxa. However, the thorny devil Moloch horridus is a basal lineage and not closely related to the other arid forms. Tree topology, inferred divergence dates, palaeogeographical and palaeoclimatic data are all consistent with Miocene immigration into Australia from the north by mesic forest ecomorphs, followed by initial diversification in mesic habitats before radiation into xeric habitats facilitated by increasing aridity.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 93 , 343–358.  相似文献   

4.
5.
The evolutionary history and biogeography of freshwater-dependent taxa in Australia is of intrinsic interest given the present-day aridity of this continent. Cherax is the most widespread and one of the most species-rich of Australia's nine freshwater crayfish genera. The phylogenetic relationships amongst 19 of the 23 Australian Cherax were established from mitochondrial DNA sequences representing the 12S rRNA and 16S rRNA gene regions. The relationships among species support an initial east–west separation, followed by a north–south divergence in eastern Australia. Molecular clock estimations suggest that these divergences date back to the Miocene. The phylogenetic relationships support endemic speciation within geographical regions and indicate that long-distance dispersal has not led to recent speciation as previously hypothesized. This new evolutionary scenario is consistent with the climatic history of Australia and the evolutionary history of other similarly distributed freshwater-dependent organisms in Australia.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 81 , 553–563.  相似文献   

6.
Not all butterflies are innocuous plant‐feeders. A small number of taxa in the family Lycaenidae have graduated from mutualistic partnerships with ants to predatory or parasitic associations. These highly‐specialized life histories, involving butterfly larvae living inside ant colonies, are often associated with rarity and vulnerability to extinction. In the present study, we examined the evolutionary relationships of a poorly‐known group of seven taxa herein referred to as the idmo‐group within the Australian lycaenid genus Ogyris. The idmo‐group has a relictual distribution across southern Australia and includes taxa with highly‐specialized phytophagous and myrmecophagous life histories. A phylogeny based on mitochondrial DNA (cytochrome oxidase I and cytochrome b] and the nuclear DNA locus elongation factor 1α (EF1α), generally agrees with current taxonomy and supports the recent elevation of endangered taxon Ogyris halmaturia to full species status. The transition to myrmecophagy was dated to the mid‐Miocene (approximately 16 Mya), when southern Australia experienced a humid climate and extensive mesic biome. The arid Nullarbor Plain, a major biogeographical feature of central southern Australia, divides the remnants of this mesic biome into south‐eastern and south‐western isolates. Late‐Miocene to Pliocene divergence estimates for polytypic Ogyris species across the Nullarbor were older than estimates made for similarly distributed birds, butterflies, mammals, and reptiles, which mostly date to the Pleistocene. The concept of highly‐specialized life histories as evolutionary dead‐end strategies is well exemplified by the idmo‐group. Data compiled on the known extant subpopulations for idmo‐group taxa show that all of these extraordinary butterflies are scarce and several face imminent threat of extinction. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111 , 473–484.  相似文献   

7.
Aim Deciphering the complex colonization history of island archipelagos is greatly facilitated by comprehensive phylogenies. In this study we investigate the phylogeny and biogeography of the insular reed‐warblers (genus Acrocephalus) of the tropical Pacific Ocean, from Australia to eastern Polynesia. Location Oceania. Methods We used sequences of mitochondrial DNA (cytochrome b, ND2 and ATP8 genes) to infer the colonization patterns of reed‐warblers endemic to Pacific islands and Australia. We sampled all known taxa of Acrocephalus in the Pacific except A. luscinius nijoi, for which no sample was available. Most taxa were represented by toe‐pad samples from museum specimens collected in the 19th and 20th centuries. With a few exceptions, several specimens per taxon were sequenced independently in two institutions (Smithsonian Institution and Natural History Museum of Geneva). Results Our data indicate that Pacific reed‐warblers do not form a monophyletic group, because A. luscinius luscinius from Guam falls outside the main Pacific radiation. The remaining Pacific taxa are divided into two clades: one clade includes all the reed‐warblers from Micronesia (except Guam) and Australia, and two Polynesian taxa from the Line Islands and the southern Marquesas; the other clade includes all remaining Polynesian taxa. The taxa endemic to three archipelagos (Mariana, Marquesas and Society islands) are polyphyletic, suggesting several independent colonizations. Main conclusions Our results provide evidence for a complex pattern of colonization of the Pacific by reed‐warblers. Calibration analyses suggest that reed‐warbler lineages are much younger than the ages of the islands they occupy. Several remote archipelagos were colonized independently more than once. Consequently, we infer that the colonization of reed‐warblers in the Pacific did not follow a regular, stepping‐stone‐like pattern. The phylogeny also suggests a previously undetected case of reverse colonization (from island to continent) for the Australian lineage and indicates that A. luscinius, as currently defined, is not monophyletic. We discuss the supertramp strategy of reed‐warblers in the Pacific and show that, although Pacific reed‐warblers meet some of the supertramp criteria in their aptitude for colonizing remote archipelagos, their life history characteristics do not fit the model.  相似文献   

8.
The monophyly and phylogeny of the adaptive radiation of Hawaiian finches (Fringillidae: Drepanidini; honeycreepers, auct.) were studied using parsimony analysis of comparative osteology, combined with Templeton (Wilcoxon signed‐ranks) tests of alternative phylogenetic hypotheses. Eighty‐four osteological characters were scored in 59 terminal taxa of drepanidines, including 24 fossil forms, and in 30 outgroup species. The optimal phylogenetic trees show considerable agreement, and some conflict, with independently derived ideas about drepanidine evolution. The monophyly of a large Hawaiian radiation was upheld, although one fossil taxon from Maui fell outside the drepanidine clade. The finch‐billed species were placed as basal drepanidine taxa, and continental cardueline finches (Carduelini) were identified as the radiation's closest outgroups. The study found anatomical as well as phylogenetic evidence that the radiation had a finch‐billed ancestor. The optimal trees identify the red‐and‐black plumage group as a clade, and suggest that the tubular tongue evolved only once in the radiation. Because comparative osteology provides too few characters to strongly support all the nodes of the tree, it was helpful to evaluate statistical support for alternative hypotheses about drepanidine relationships using the Templeton test. Among the alternatives that received significant statistical support are a relationship of the drepanidines with cardueline finches rather than with the Neotropical honeycreepers (Thraupini), classification of the controversial genera Paroreomyza and Melamprosops as drepanidines, and a secondary loss of the tubular tongue in Loxops mana. The hypothesis of monophyly for all the Hawaiian taxa in the study was not rejected statistically. The study provides a framework for incorporating morphological and palaeontological information in evolutionary studies of the Drepanidini. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society, 2004, 141 , 207–255.  相似文献   

9.
Skinks of the genus Sphenomorphus are the most diverse clade of squamates in the Philippine Archipelago. Morphological examination of these species has defined six phenotypic groups that are commonly used in characterizations of taxonomic hypotheses. We used a molecular phylogeny based on four mitochondrial and two nuclear genes to assess the group's biogeographical history in the archipelago and examine the phylogenetic validity of the currently recognized Philippine species groups. We re‐examined traditional characters used to define species groups and used multivariate statistics to quantitatively evaluate group structure in morphometric space. Clustering analyses of phenotypic similarity indicate that some (but not all) members of previously defined species groups are phenotypically most similar to other members of the same group. However, when species group membership was mapped on our partitioned Bayesian phylogenetic hypothesis, only one species group corresponds to a clade; all other species group arrangements are strongly rejected by our phylogeny. Our results demonstrate that (1) previously recognized species group relationships were misled by phenotypic convergence; (2) Sphenomorphus is widely paraphyletic; and (3) multiple lineages have independently invaded the Philippines. Based on this new perspective on the phylogenetic relationships of Philippine Sphenomorphus, we revise the archipelago's diverse assemblage of species at the generic level, and resurrect and/or expand four previously recognized genera, and describe two new genera to accommodate the diversity of Philippine skinks of the Sphenomorphus group. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163 , 1217–1243.  相似文献   

10.
Polyphenism has been suggested as an accelerator for morphological evolution and speciation. In the dung beetles of the genus Onthophagus, horn expression is polyphenic: large males develop horns whereas smaller males express greatly reduced or no horns. Horn static allometries seem to diverge rapidly amongst extant taxa, a process which might trigger changes in the male genital morphology, thus possibly promoting speciation as a by‐product. It can therefore be hypothesized that interspecific distances in allometries and, possibly, in other morphological traits mirror phylogenetic distances. In this study we first assessed the phylogenetic relationships amongst three closely related taxa belonging to the so‐called ‘Onthophagus fracticornis‐similis‐opacicollis’ species‐complex by sequencing the mitochondrial gene cytochrome oxidase subunit 1 (cox1). Biomolecular results indicated three independent lineages, the closest relationships being found between Onthophagus similis and Onthophagus opacicollis. Then we assessed the extent to which divergence pattern of horn static allometries and size and shape divergence patterns of one genital (paramere) and two nongenital (head and epipharynx) structures mirrored the phylogenetic relationships. Interspecific divergence patterns of horn static allometries, paramere, and head shape were found to be congruent with the evolutionary relationships inferred from biomolecular data. Nevertheless, paramere size and epipharynx shape showed patterns not consistent with the phylogeny. Furthermore, the relative size of nongenital structures showed little interspecific divergence compared to their shapes. Our results suggest that size and shape interspecific divergence mirror phylogeny only in part; they also indicate that distinct morphological traits may differ in their tendency to evolve in concert, and that size and shape of the same trait can evolve independently across species. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 162 , 482–498.  相似文献   

11.
The interrelationships within ant subfamilies remain elusive, despite the recent establishment of the phylogeny of the major ant lineages. The tribe Myrmicini belongs to the subfamily Myrmicinae, and groups morphologically unspecialized genera. Previous research has struggled with defining Myrmicini, leading to considerable taxonomic instability. Earlier molecular phylogenetic studies have suggested the nonmonophyly of Myrmicini, but were based on limited taxon sampling. We investigated the composition of Myrmicini with phylogenetic analyses of an enlarged set of taxa, using DNA sequences of eight gene fragments taken from 37 representatives of six of the seven genera (Eutetramorium, Huberia, Hylomyrma, Manica, Myrmica, and Pogonomyrmex), and eight outgroups. Our results demonstrate the invalidity of Myrmicini as currently defined. We recovered sister‐group relationships between the genera Myrmica and Manica, and between Pogonomyrmex and Hylomyrma. This study illustrates that to understand the phylogeny of over 6000 myrmicine species, comprehensive taxon sampling and DNA sequencing are an absolute requisite. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 160 , 482–495.  相似文献   

12.
Recent advances in molecular phylogenetics are continuously changing our perception of decapod phylogeny. Although the two suborders Dendrobranchiata and Pleocyemata within the Decapoda are widely accepted, this taxonomic view is now challenged when using mitochondrial protein‐coding genes to investigate the decapod phylogeny, especially for the basal pleocyematan groups. Here, we enhanced taxonomic coverage by sequencing the genomes of two basal decapod taxa Alpheus distinguendus and Panulirus ornatus, representing two infraorders, Caridea and Achelata, respectively. Based on these two and other available mitochondrial genomes, we evaluated the usefulness of protein‐coding genes in resolving deep phylogenetic relationships of the Decapoda using maximum likelihood and Bayesian analyses. The mt genomic results revealed a novel gene order because of the reverse transposition of trnE (transfer, trn for Glutamate) and a pseudogene‐like trnS (AGN) [trn for Serine (S1, AGN)] in the mitochondrial genome of A. distinguendus, and a duplicate of 89 bp sequences in the putative noncoding region of P. ornatus. Our phylogenetic inferences suggest monophyly of the Decapoda and its two suborders, and that several lineages within the Reptantia are consistently recovered with high nodal supports. Our findings suggest that the best mitochondrial genome phylogeny can be found on the premise that systematic errors should be minimized as much as possible. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 162 , 471–481.  相似文献   

13.
Abstract The Acacia acuminata complex includes three taxa, A. acuminata ssp. acuminata, A. acuminata ssp. burkittii and A. oldfieldii, along with several informal variants of A. acuminata. It is widespread throughout southern Australia with the centre of diversity in south‐west Western Australia. Phylogeographical patterns in the complex were investigated using a nested clade analysis of cpDNA RFLPs from 25 populations in Western Australia. Except for A. oldfieldii that was clearly identified as a distinct entity, haplotypes were not restricted to sub‐specific taxa or variants within A. acuminata. There was significant association between phylogenetic position of many haplotypes and their geographical distribution. The fine‐scale phylogeographical patterns were complex but at deeper levels in the phylogeny there was evidence of divergence between two lineages. The pattern of shared haplotypes between lineages suggests retention of ancestral polymorphism as a result of incomplete lineage sorting. The divergence of these lineages is consistent with fragmentation caused by climatic instability during the Pleistocene.  相似文献   

14.
Aim To compare the phylogeny of the eucalypt and melaleuca groups with geological events and ages of fossils to discover the time frame of clade divergences. Location Australia, New Caledonia, New Guinea, Indonesian Archipelago. Methods We compare published molecular phylogenies of the eucalypt and melaleuca groups of the plant family Myrtaceae with geological history and known fossil records from the Cretaceous and Cenozoic. Results The Australasian eucalypt group includes seven genera, of which some are relictual rain forest taxa of restricted distribution and others are species‐rich and widespread in drier environments. Based on molecular and morphological data, phylogenetic analyses of the eucalypt group have identified two major clades. The monotypic Arillastrum endemic to New Caledonia is related in one clade to the more species‐rich Angophora, Corymbia and Eucalyptus that dominate the sclerophyll vegetation of Australia. Based on the time of rifting of New Caledonia from eastern Gondwana and the age of fossil eucalypt pollen, we argue that this clade extends back to the Late Cretaceous. The second clade includes three relictual rain forest taxa, with Allosyncarpia from Arnhem Land the sister taxon to Eucalyptopsis of New Guinea and the eastern Indonesian archipelago, and Stockwellia from the Atherton Tableland in north‐east Queensland. As monsoonal, drier conditions evolved in northern Australia, Arnhem Land was isolated from the wet tropics to the east and north during the Oligocene, segregating ancestral rain forest biota. It is argued also that the distribution of species in Eucalyptopsis and Eucalyptus subgenus Symphyomyrtus endemic in areas north of the stable edge of the Australian continent, as far as Sulawesi and the southern Philippines, is related to the geological history of south‐east Asia‐Australasia. Colonization (dispersal) may have been aided by rafting on micro‐continental fragments, by accretion of arc terranes onto New Guinea and by land brought into closer proximity during periods of low sea‐level, from the Late Miocene and Pliocene. The phylogenetic position of the few northern, non‐Australian species of Eucalyptus subgenus Symphyomyrtus suggests rapid radiation in the large Australian sister group(s) during this time frame. A similar pattern, connecting Australia and New Caledonia, is emerging from phylogenetic analysis of the Melaleuca group (Beaufortia suballiance) within Myrtaceae, with Melaleuca being polyphyletic. Main conclusion The eucalypt group is an old lineage extending back to the Late Cretaceous. Differentiation of clades is related to major geological and climatic events, including rifting of New Caledonia from eastern Gondwana, development of monsoonal and drier climates, collision of the northern edge of the Australian craton with island arcs and periods of low sea level. Vicariance events involve dispersal of biota.  相似文献   

15.
Studies of major switches by parasites between highly divergent host lineages are important for understanding new opportunities for parasite diversification. One such major host switch is inferred for avian feather lice (Ischnocera) in the family Goniodidae, which parasitize two distantly‐related groups of birds: Galliformes (pheasants, quail, partridges, etc.) and Columbiformes (pigeons and doves). Although there have been several cophylogenetic studies of lice at the species level, few studies have focused on such broad evolutionary patterns and major host‐switching events. Using a phylogeny based on DNA sequences for goniodid feather lice, we investigated the direction of this major host switch. Unexpectedly, we found that goniodid feather lice have switched host orders, not just once, but twice. A primary host switch occurred from Galliformes to Columbiformes, leading to a large radiation of columbiform body lice. Subsequently, there was also a host switch from Columbiformes back to Galliformes, specifically to megapodes in the Papua–Australasian region. The results of the present study further reveal that, although morphologically diagnosable lineages are supported by molecular data, many of the existing genera are not monophyletic and a revision of generic limits is needed. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 614–625.  相似文献   

16.
The rainforests, wet sclerophyll forests and temperate heathlands of the Australian mesic zone are home to a diverse and highly endemic biota, including numerous old endemic lineages restricted to refugial, mesic biomes. A growing number of phylogeographic studies have attempted to explain the origins and diversification of the Australian mesic zone biota, in order to test and better understand the mode and tempo of historical speciation within Australia. Assassin spiders (family Archaeidae) are a lineage of iconic araneomorph spiders, characterised by their antiquity, remarkable morphology and relictual biogeography on the southern continents. The Australian assassin spider fauna is characterised by a high diversity of allopatric species, many of which are restricted to individual mountains or montane systems, and all of which are closely tied to mesic and/or refugial habitats in the east and extreme south-west of mainland Australia. We tested the phylogeny and vicariant biogeography of the Australian Archaeidae (genus Austrarchaea Forster & Platnick), using a multi-locus molecular approach. Fragments from six mitochondrial genes (COI, COII, tRNA-K, tRNA-D, ATP8, ATP6) and one nuclear protein-coding gene (Histone H3) were used to infer phylogenetic relationships and to explore the phylogeographic origins of the diverse Australian fauna. Bayesian analyses of the complete molecular dataset, along with differentially-partitioned Bayesian and parsimony analyses of a smaller concatenated dataset, revealed the presence of three major Australian lineages, each with non-overlapping distributions in north-eastern Queensland, mid-eastern Australia and southern Australia, respectively. Divergence date estimation using mitochondrial data and a rate-calibrated relaxed molecular clock revealed that major lineages diverged in the early Tertiary period, prior to the final rifting of Australia from East Antarctica. Subsequent speciation occurred during the Miocene (23-5.3 million years ago), with tropical and subtropical taxa diverging in the early-mid Miocene, prior to southern and temperate taxa in the mid-late Miocene. Area cladograms reconciled with Bayesian chronograms for all known Archaeidae in southern and south-eastern Australia revealed seven potentially vicariant biogeographic barriers in eastern Queensland, New South Wales and southern Australia, each proposed and discussed in relation to other mesic zone taxa. Five of these barriers were inferred as being of early Miocene age, and implicated in the initial vicariant separation of endemic regional clades. Phylogeographic results for Australian Archaeidae are congruent with a model of sequential allopatric speciation in Tertiary refugia, as driven by the contraction and fragmentation of Australia’s mesic biomes during the Miocene. Assassin spiders clearly offer great potential for further testing historical biogeographic processes in temperate and eastern Australia, and are a useful group for better understanding the biology and biogeography of the Australian mesic zone.  相似文献   

17.
18.
Clades that predate the origin of biomes that they inhabit provide unique opportunities to examine both when major environmental transitions occurred, and how lineages adapted to these changes. The isolated island continent Australia has undergone a profound environmental transition through the Miocene, from relatively mesic to predominantly arid; however, we have much to learn about both the timing of this change, and how organisms may have responded to it. The family Carphodactylidae is an ancient Gondwanan group of geckos that occurs across all major Australian biomes. A multilocus (ND2, Rag-1, c-mos) phylogenetic and dating analysis of the most ecologically diverse clade within this group, the genus Nephrurus (sensuBauer, 1990) reveals that two of three morphological taxa historically recognized (the 'spiny knob-tails' and 'Underwoodisaurus') are relatively species depauperate, pleisomorphic basal grades that diversified through the late Oligocene and early Miocene, and are now absent from most of the arid biome. Based on their deep divergence and morphological distinctiveness we recognize two lineages (milii and sphyrurus) as monotypic genera, the later of which is named herein (Uvidicolus nov. gen). In contrast, a third morphological group, the 'smooth knob-tails,' is a monophyletic group of five exclusively arid zone burrowing species that has radiated relatively recently (mid-Miocene). Our phylogeny indicates that successful colonization of this novel and challenging biome by Nephrurus correlates with an initial shift to terrestriality and adaptation to at least seasonally arid conditions around the early Miocene, and the eventual evolution and subsequent mid-Miocene radiation of a lineage specialized for burrowing.  相似文献   

19.
This study produces a nearly comprehensive phylogeny for the marine gastropod group Cypraeidae (cowries) and uses this topology to examine diversification patterns in the tropics. The dataset is based on molecular sequence data from two mitochondrial genes and includes 210 evolutionary significant units (ESUs) from 170 recognized species (>80%). Systematics for the group is revised based on well‐supported clades, and tree topology is generally consistent with previously proposed classification schemes. Three new genera are introduced ( Cryptocypraea gen. nov , Palmulacypraea gen. nov , and Contradusta gen. nov ) and two previous genera are resurrected (Perisserosa and Eclogavena). One new tribe is proposed (Bistolidini). Topologies produced by a range of transition:transversion (Ti:Tv) weighting schemes in parsimony are pooled and evaluated using maximum likelihood criteria. Extensive geographical coverage shows persistent, large‐scale geographical structure in sister‐groups. Genetic divergence between subspecies is often equivalent or even greater than that between recognized species. Using ESUs as a metric, diversity throughout the Indo‐West Pacific (IWP) increases by 38%. Intra‐ and inter‐regional diversification patterns show that the IWP is the centre for speciation in cowries. The other major tropical regions of the world are inhabited by a predominantly relictual fauna; from a cowrie's eye‐view. Good dispersal ability begets larger ranges, increased extinction resistance and morphological stasis; whereas shorter larval duration results in smaller ranges, higher speciation rates, but also higher turnover. Larval duration and dispersal ability appear correlated with ocean productivity as taxa with longer‐lived larvae are associated with oligotrophic conditions; whereas taxa with shorter larval durations are associated with eutrophic, continental conditions. This tendency is carried to the extreme in temperate or upwelling regions where a planktonic phase is completely lost and crawl‐away larvae evolve multiple times. A strong phylogenetic trend supports these observations as lineages leading up to and including the derived Indo‐West Pacific Erroneinae clade contain taxa predominantly restricted to continental habitats and have undergone the greatest evolutionary radiations in their respective regions. © 2003 The Linnean Society of London, Biological Journal of the Linnean Society, 2003, 79, 401– 459.  相似文献   

20.
Comparative phylogeography is underpinned by the assumption that sympatrically‐distributed taxa will have experienced similar environmental histories, resulting in broadly congruent spatial structuring of phylogenetic lineages, particularly if they inhabit similar niches. However, divergent local conditions, specifically those related to microhabitat, may produce significantly divergent systematic signatures of demographic histories. In the present study, we compare the phylogenetic and population genetic spatial patterns displayed by two species of niche‐separated (but sympatrically distributed) Australian funnel web spiders (Mygalomorphae: Hexathelidae). We demonstrate that an apparently minor disparity in habitat niche has led to divergent experiences of a common environmental history in the saproxylic Hadronyche cerberea and the ground‐burrowing Atrax sutherlandi. Furthermore, we take a crucial first step in documenting the molecular systematics of a group that has traditionally suffered from a dearth of research interest. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 805–819.  相似文献   

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