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1.
The Australian fauna is composed of several major biogeographical elements reflecting different spatial and temporal histories. Two groups of particular interest are the Gondwanan Element, reflecting an ancient origin in Gondwana or southern Gondwana (southern vicariance hypothesis), and the Asian Element, reflecting a more recent origin in Asia, Eurasia or Laurasia (northern dispersal hypothesis). Theories regarding the origin and evolution of butterflies (Hesperioidea, Papilionoidea) in Australia are controversial, with no clear consensus. Here, we investigate the phylogenetic and historical biogeographical relationships of the subtribe Aporiina, a widespread taxon with disjunct distributions in each of the major zoogeographical regions. Attention is paid to origins of the subtribe in the Australian Region for which several conflicting hypotheses have been proposed for the Old World genus Delias Hübner. Our phylogenetic reconstruction was based on analysis of fragments of two nuclear genes (elongation factor‐1α, wingless) and one mitochondrial gene (cytochrome oxidase subunit I) for 30 taxa. Phylogenetic analyses based on maximum parsimony, maximum likelihood and Bayesian inference of the combined data set (2729 bp; 917 parsimony informative characters) recovered six major lineages within the monophyletic Aporiina, with the following topology: (Cepora + Prioneris + (Mylothris + (Aporia + Delias group + Catasticta group))). Given a probable age of origin of the stem‐group near the Cretaceous/Tertiary boundary (69–54 Mya), followed by diversification of the crown‐group in the early to mid Tertiary (57–45 Mya), we show that an origin of the Aporiina in either southern Gondwana or Laurasia is equally parsimonious, and that dispersal has played a major role in shaping the underlying phylogenetic pattern. We tentatively conclude that an origin in southern Gondwanan is more likely; however, neither hypothesis satisfactorily explains the present‐day distribution, and additional lower‐level phylogenies are needed to determine the directionality of dispersal events of several taxa and to reject one hypothesis over the other. Dispersal is inferred to have occurred primarily during cooler periods when land bridges or stepping‐stones were available between many of the zoogeographical regions. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 90 , 413–440.  相似文献   

2.
The origin of biodiversity in the Neotropics predominantly stems either from Gondwana breakup or late dispersal events from the Nearctic region. Here, we investigate the biogeography of a diving beetle clade whose distribution encompasses parts of the Oriental region, the Indo‐Australian archipelago (IAA) and the Neotropics. We reconstructed a dated molecular phylogeny, inferred diversification dynamics and estimated ancestral areas under different biogeographic assumptions. For the Oriental region and the IAA, we reveal repeated and complex colonization patterns out of Australia, across the major biogeographic lines in the region (e.g. Wallace's Line). The timing of colonization events across the IAA broadly coincides with the proposed timing of the formation of major geographic features in the region. Our phylogenetic hypothesis recovers Neotropical species nested in two derived clades. We recover an origin of the group in the early Eocene about 55 million yr ago, long after the break‐up of Gondwana initiated, but before a complete separation of Australia, Antarctica and the Neotropics. When allowing an old Gondwanan ancestor, we reconstruct an intricate pattern of Gondwanan vicariance and trans‐Pacific long‐distance dispersal from Australia toward the Neotropics. When restricting the ancestral range to more plausible geological area combinations in the Eocene, we infer an Australian origin with two trans‐Pacific long‐distance dispersal events toward the Neotropics. Our results support on one hand a potential Gondwanan signature associated with regional extinctions in the Cenozoic and with Antarctica serving as a link between Australia and the Neotropics. On the other hand, they also support a trans‐Pacific dispersal of these beetles toward the Andean coast in the Oligocene.  相似文献   

3.
Aim To analyse the historical biogeography of the lichen genus Chroodiscus using a phenotype‐based phylogeny in the context of continental drift and evolution of tropical rain forest vegetation. Location All tropical regions (Central and South America, Africa, India, Southeast Asia, north‐east Australia). Methods We performed a phenotype‐based phylogenetic analysis and ancestral character state reconstruction of 14 species of the lichen genus Chroodiscus, using paup * and mesquite ; dispersal–vicariance analysis (DIVA) and dispersal–extinction–cladogenesis (DEC) modelling to trace the geographical origin of individual clades; and ordination and clustering by means of pc‐ord , based on a novel similarity index, to visualize the biogeographical relationships of floristic regions in which Chroodiscus occurs. Results The 14 species of Chroodiscus show distinctive distribution patterns, with one pantropical and one amphi‐Pacific taxon and 12 species each restricted to a single continent. The genus comprises four clades. DIVA and DEC modelling suggest a South American origin of Chroodiscus in the mid to late Cretaceous (120–100 Ma), with subsequent expansion through a South American–African–Indian–Southeast Asian–Australian dispersal route and late diversification of the argillaceus clade in Southeast Asia. Based on the abundance of extant taxa, the probability of speciation events in Chroodiscus is shown to be extremely low. Slow dispersal of foliicolous rain forest understorey lichens is consistent with estimated phylogenetic ages of individual species and with average lengths of biological species intervals in fungi (10–20 Myr). Main conclusions The present‐day distribution of Chroodiscus can be explained by vicariance and mid‐distance dispersal through the interconnection or proximity of continental shelves, without the need for recent, trans‐oceanic long‐distance dispersal. Phylogenetic reconstruction and age estimation for Chroodiscus are consistent with the ‘biotic ferry’ hypothesis: a South American origin and subsequent eastward expansion through Africa towards Southeast Asia and north‐eastern Australia via the Indian subcontinent. The present‐day pantropical distributions of many clades and species of foliicolous lichens might thus be explained by eastward expansion through continental drift, along with the evolution of modern rain forests starting 120 Ma, rather than by the existence of a hypothetical continuous area of pre‐modern rain forest spanning South America, Africa and Southeast Asia during the mid and late Cretaceous.  相似文献   

4.
Aims Insular Southeast Asia and adjacent regions are geographically complex, and were dramatically affected by both Pliocene and Pleistocene changes in climate, sea level and geology. These circumstances allow the testing of several biogeographical hypotheses regarding species distribution patterns and phylogeny. Avian species in this area present a challenge to biogeographers, as many are less hindered by barriers that may block the movements of other species. Widely distributed Southeast Asian avian lineages, of which there are many, have been generally neglected. Ficedula flycatchers are distributed across Eurasia, but are most diverse within southern Asia and Southeast Asian and Indo‐Australian islands. We tested the roles of vicariance, dispersal and the evolution of migratory behaviours as mechanisms of speciation within the Ficedula flycatchers, with a focus on species distributed in insular Southeast Asia. Methods Using a published molecular phylogeny of Ficedula flycatchers, we reconstructed ancestral geographical areas using dispersal vicariance analysis, weighted ancestral area analysis, and a maximum likelihood method. We evaluated the evolution of migratory behaviours using maximum likelihood ancestral character state reconstruction. Speciation timing estimates were calculated via local molecular clock methods. Results Ficedula originated in southern mainland Asia, c. 6.5 Ma. Our analyses indicate that two lineages within Ficedula independently and contemporaneously colonized insular Southeast Asia and Indo‐Australia, c. 5 Ma. The potential impact of vicariance due to rising sea levels is difficult to assess in these early colonization events because the ancestral areas to these clades are reconstructed as oceanic islands. Within each of these clades, inter‐island dispersal was critical to species’ diversification across oceanic and continental islands. Furthermore, Pliocene and Pleistocene climatic change may have caused the disjunct island distributions between several pairs of sister taxa. Both vicariance and dispersal shaped the distributions of continental species. Main conclusions This study presents the first evaluation, for Ficedula, of the importance of vicariance and dispersal in shaping distributions, particularly across insular Southeast Asia and Indo‐Australia. Although vicariant speciation may have initially separated the island clades from mainland ancestors, speciation within these clades was driven primarily by dispersal. Our results contribute to the emerging body of literature concluding that dynamic geological processes and climatic change throughout the Pliocene and Pleistocene have been important factors in faunal diversification across continental and oceanic islands.  相似文献   

5.
Aim The biogeography of the tropical plant family Monimiaceae has long been thought to reflect the break‐up of West and East Gondwana, followed by limited transoceanic dispersal. Location Southern Hemisphere, with fossils in East and West Gondwana. Methods We use phylogenetic analysis of DNA sequences from 67 of the c. 200 species, representing 26 of the 28 genera of Monimiaceae, and a Bayesian relaxed clock model with fossil prior constraints to estimate species relationships and divergence times. Likelihood optimization is used to infer switches between biogeographical regions on the highest likelihood tree. Results Peumus from Chile, Monimia from the Mascarenes and Palmeria from eastern Australia/New Guinea form a clade that is sister to all other Monimiaceae. The next‐deepest split is between the Sri Lankan Hortonia and the remaining genera. The African Monimiaceae, Xymalos monospora, then forms the sister clade to a polytomy of five clades: (I) Mollinedia and allies from South America; (II) Tambourissa and allies from Madagascar and the Mascarenes; (III) Hedycarya, Kibariopsis and Leviera from New Zealand, New Caledonia and Australia; (IV) Wilkiea, Kibara, Kairoa; and (V) Steganthera and allies, all from tropical Australasia. Main conclusions Tree topology, fossils, inferred divergence times and ances‐tral area reconstruction fit with the break‐up of East Gondwana having left a still discernible signature consisting of sister clades in Chile and Australia. There is no support for previous hypotheses that the break‐up of West Gondwana (Africa/South America) explains disjunctions in the Monimiaceae. The South American Mollinedia clade is only 28–16 Myr old, and appears to have arrived via trans‐Pacific dispersal from Australasia. The clade apparently spread in southern South America prior to the Andean orogeny, fitting with its first‐diverging lineage (Hennecartia) having a southern‐temperate range. The crown ages of the other major clades (II–V) range from 20 to 29 Ma, implying over‐water dispersal between Australia, New Caledonia, New Zealand, and across the Indian Ocean to Madagascar and the Mascarenes. The endemic genus Monimia on the Mascarenes provides an interesting example of an island lineage being much older than the islands on which it presently occurs.  相似文献   

6.
Dawkins  Kathryn L.  Furse  James M.  Hughes  Jane M. 《Hydrobiologia》2021,848(2):403-420

Biogeographic investigations of Gondwanan mesic Australian fauna are scarce. The burrowing clade of Australian freshwater crayfish represent an ideal group to provide biogeographic inferences, due to their extensive distribution across the continent and their presumed ancient origin. This study tested the competing hypotheses of a ‘early’ versus ‘late’ origin of this clade, coinciding with the early or late fragmentation of Gondwana, respectively. The biogeographic history of this group was investigated through: (a) examination of the phylogenetic relationships between the seven extant taxon groups; (b) reconstruction of four species trees, each using a different calibration method; and (c) reconstruction of ancestral ranges and correlation of estimated dispersal and vicariance events with historical geological data to propose plausible mechanisms responsible for driving diversification. The phylogenetic relationships between the taxon groups were generally well supported (although some uncertainty exists for the oldest genera), and all calibration methods produced concordant results. The hypothesis that the clade arose during the early fragmentation of Gondwana in southern Australia is supported. Divergence between the extant taxa likely resulted from a combination of both short- and long-distance dispersal events (often followed by later vicariance), coincident with phases of sea level oscillation and changing climate continuing into the Eocene.

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7.
The moss bugs of the Peloridiidae, a small group of cryptic and mostly flightless insects, is the only living family in Coleorrhyncha (Insecta: Hemiptera). Today 37 species in 17 genera are known from eastern Australia, New Zealand, New Caledonia and Patagonia, and the peloridiids are thereby a group with a classical southern Gondwanan distribution. To explicitly test whether the present-day distribution of the Peloridiidae actually results from the sequential breakup of southern Gondwana, we provide the first total-evidence phylogenetic study based on morphological and molecular characters sampled from about 75% of recognized species representing 13 genera. The results largely confirm the established morphological phylogenetic context except that South American Peloridium hammoniorum constitutes the sister group to the remaining peloridiids. A timescale analysis indicates that the Peloridiidae began to diversify in the land mass that is today's Patagonia in the late Jurassic (153 Ma, 95% highest posterior density: 78–231 Ma), and that splitting into the three extant well-supported biogeographical clades (i.e. Australia, Patagonia and New Zealand/New Caledonia) is consistent with the sequential breakup of southern Gondwana in the late Cretaceous, indicating that the current transoceanic disjunct distributions of the Peloridiidae are best explained by a Gondwanan vicariance hypothesis.  相似文献   

8.
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   

9.
Aim To investigate distributional patterns and derivation of skates in the Australasian realm. Location Australasia. Methods Genus‐group skate taxa were defined for this region for the first time and new systematic information, as well as bathymetric and geographical data, used to identify distribution patterns. Results The extant skate fauna of Australasia (Australia, New Zealand, New Caledonia and adjacent subAntarctic dependencies) is highly diverse and endemic with sixty‐two species from twelve currently recognized, nominal genus‐group taxa. These include the hardnose skate (rajin) groups Anacanthobatis, Amblyraja, Dipturus, Okamejei, Rajella and Leucoraja, and softnose skate (arhynchobatin) genera Arhynchobatis, Bathyraja, Insentiraja, Irolita, Pavoraja and Notoraja. Additional new and currently unrecognized nominal taxa of both specific and supraspecific ranks also occur in the region. The subfamily Arhynchobatinae is particularly speciose in Australasia, and the New Zealand/New Caledonian fauna is dominated by undescribed supraspecific taxa and species. The Australian fauna, although well represented by arhynchobatins, is dominated by Dipturus‐like skates and shows little overlap in species composition with the fauna of New Zealand and New Caledonia. Similarly, these faunas exhibit no overlap with the polar faunas of the Australian subAntarctic dependencies (Heard and Macdonald Islands) to the south. Skates appear to be absent from the Macquarie Ridge at the southern margin of the New Zealand Plateau. Their absence off New Guinea probably reflects inadequate sampling and the subsequent poor knowledge of that region's deepwater fish fauna. Main conclusions Skates appear to have existed in the eastern, Australasian sector of Gondwana before fragmentation in the late Cretaceous. The extant fauna appears to be derived from elements of Gondwanan origin, dispersal from the eastern and western Tethys Sea, and intraregional vicariance speciation.  相似文献   

10.
《Systematic Entomology》2018,43(4):798-809
The origins, evolutionary history and diversification of the Australian butterfly fauna are poorly known and uncertain. Two competing hypotheses have been proposed to explain the occurrence of butterflies on this isolated continental landmass. The common view is that all Australian butterflies entered the continent relatively recently from the northern hemisphere via Southeast Asia and/or mainland New Guinea (i.e. northern dispersal origin hypothesis). The alternative view is that part or all of the Australian butterfly fauna ultimately evolved in remnant or Southern Gondwana when Australia was connected to South America through Antarctica (i.e. Southern Gondwanan origin hypothesis). However, robust phylogenies with strong support for monophyly are lacking for the majority of Australian endemic butterfly lineages, thereby precluding determination of their systematic relationships and hence their geographic origins. Here, we use molecular data to reconstruct phylogenetic relationships of the globally distributed butterfly subtribe Coenonymphina (Satyrinae: Satyrini). This group represents a major component of the butterfly fauna of the wider Australasian region, with 19 genera and 71 species endemic to the region. Dating estimates extrapolated from secondary calibration sources indicate that the subtribe arose c . 48 Ma (95% credibility interval, 52–42 Ma), and the crown group first diverged in the Eocene (c . 44 Ma, 95% credibility interval 51–37 Ma). Rapid speciation events subsequently followed around the Eocence–Oligocene boundary, resulting in a near‐hard polytomy comprising short basal branches with nodes that are difficult to resolve. Based on strongly supported phylogenetic relationships and estimates of divergence times, we conclude that the group probably had its origin in the fragment of Southern Gondwana consisting of Australia, Antarctica and South America. However, we are unable to rule out the northern dispersal scenario, particularly as Coenonymphina are closely related to a set of predominantly Asian lineages. Dispersal and extinction events following the final break‐up of Gondwana have played a pivotal role in shaping the extant distributions of the group.  相似文献   

11.
Previous phylogenetic studies of the bee tribe Allodapini suggested a puzzling biogeographic problem: one of the key basal divergences involved separation of the southern African and southern Australian clades at a very early stage in allodapine evolution, but no taxa occur in the Palaearctic or Asian regions that might suggest a Laurasian dispersal route. However, these studies lacked sufficient sequence data and appropriate maximum likelihood partition models to provide reliable phylogenetic estimates and enable alternative biogeographic hypotheses to be distinguished. Using Bayesian and penalized likelihood approaches and an expanded sequence and taxon set we examine phylogenetic relationships between the Australian, African, and Malagasy groups and estimate divergence times for key nodes. We show that divergence of the three basal Australian clades (known as the exoneurines) occurred at least 25 Mya following a single colonization event, and that this group diverged from the African + Madagascan clade at least 30 Mya, but actual divergence dates are likely to be much older than these very conservative limits. The bifurcation order of the exoneurine clades was not resolved and analyses could not rule out the existence of a hard polytomy, suggesting rapid radiation after colonization of Australia. Their divergence involved major transitions in life history traits and these placed constraints on the kinds of social organization that subsequently evolved in each lineage. Early divergence between the African, Malagasy, and Australian clades presents a major puzzle for historical biogeography: node ages are too recent for Gondwanan vicariance hypotheses, but too early for Laurasian dispersal scenarios. We suggest a scenario involving island hopping across the Indian Ocean via a series of now largely submerged elements of the Kergulen Plateau and Broken Ridge provinces, both of which are known to have had subaerial formations during the Cenozoic. [Bayesian; biogeography; dispersal; Gondwana; Kerguelen Plateau; penalized likelihood.].  相似文献   

12.
The gastropod genus Cominella Gray, 1850 consists of approximately 20 species that inhabit a wide range of marine environments in New Zealand and Australia, including its external territory, the geographically isolated Norfolk Island. This distribution is puzzling, however, with apparently closely‐related species occurring either side of the Tasman Sea, even though all species are considered to have limited dispersal abilities. To determine how Cominella attained its current distribution, we derived a dated molecular phylogeny, which revealed a clade comprising all the Australian and Norfolk Island species nested within four clades of solely New Zealand species. This Australian clade diverged well after the vicariant separation of New Zealand from Australia, and implies two long‐distance dispersal events: a counter‐current movement across the Tasman Sea from New Zealand to Australia, occurring at the origination of the clade, followed by the colonization of Norfolk Island. The biology of Cominella suggests that the most likely method of long‐distance dispersal is rafting as egg capsules. Our robust phylogeny also means that the current Cominella classification requires revision. We propose that our clades be recognized as subgenera: Cominella (s.s.), Cominista, Josepha, Cominula, and Eucominia, with each subgenus comprising only of New Zealand or Australian species. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 115 , 315–332.  相似文献   

13.
Aim The sequential break‐up of Gondwana is thought to be a dominant process in the establishment of shared biota across landmasses of the Southern Hemisphere. Yet similar distributions are shared by taxa whose radiations clearly post‐date the Gondwanan break‐up. Thus, determining the contribution of vicariance versus dispersal to seemingly Gondwanan biota is complex. The southern freshwater crayfishes (family Parastacidae) are distributed on Australia and New Guinea, South America, Madagascar and New Zealand and are unlikely to have dispersed via oceans, owing to strict freshwater limitations. We test the hypotheses that the break‐up of Gondwana has led to (1) a predominately east–west (((Australia, New Zealand: 80 Ma) Madagascar: 160–121 Ma) South America: 165–140 Ma), or (2) a southern (((Australia, South America: 52–35 Ma) New Zealand: 80 Ma) Madagascar: 160–121 Ma) pattern for parastacid crayfish. Further, we examine the evidence for a complete drowning of New Zealand and subsequent colonization by freshwater crayfish. Location Southern Hemisphere. Methods The evolutionary relationships among the 15 genera of Parastacidae were reconstructed using mitochondrial [16S, cytochrome c oxidase subunit I (COI)] and nuclear (18S, 28S) sequence data and maximum likelihood and Bayesian methods of phylogenetic reconstruction. A Bayesian (multidivtime ) molecular dating method using six fossil calibrations and phylogenetic inference was used to estimate divergence time among crayfish clades on Gondwanan landmasses. Results The South American crayfish are monophyletic and a sister group to all other southern crayfish. Australian crayfish are not monophyletic, with two Tasmanian genera, Spinastacoides and Ombrastacoides, forming a clade with New Zealand and Malagasy crayfish (both monophyletic). Divergence of crayfish among southern landmasses is estimated to have occurred around the Late Jurassic to Early Cretaceous (109–178 Ma). Main conclusions The estimated phylogenetic relationships and time of divergence among the Southern Hemisphere crayfishes were consistent with an east–west pattern of Gondwanan divergence. The divergence between Australia and New Zealand (109–160 Ma) pre‐dated the rifting at around 80 Ma, suggesting that these lineages were established prior to the break‐up. Owing to the age of the New Zealand crayfish, we reject the hypothesis that there was a complete drowning of New Zealand crayfish habitat.  相似文献   

14.
Aim Twentieth century biogeographers developed intriguing hypotheses involving West Wind Drift dispersal of Southern Hemisphere biota, but such models were largely abandoned in favour of vicariance following the development of plate tectonic theory. Here I present a synthesis of southern temperate marine biogeography, and suggest some new directions for phylogeographic research. Location The southern continents, formerly contiguous components of Gondwana, are now linked only by ocean currents driven by the West Wind Drift. Methods While vicariance theory certainly facilitates the development of testable hypotheses, it does not necessarily follow that vicariance explains much of contemporary southern marine biogeography. To overcome the limitations of narratives that simply assume vicariance or dispersal, it is essential for analyses to test biogeographic hypotheses by incorporating genetic, ecological and geological data. Results Recent molecular studies have provided strong evidence for dispersal, but relatively little evidence for the biogeographic role of plate tectonics in distributing southern marine taxa. Despite confident panbiogeographic claims to the contrary, molecular and ecological studies of buoyant macroalgae, such as Macrocystis, indicate that dispersal predominates. Ironically, some of the better supported evidence for marine vicariance in southern waters has little or nothing to do with plate tectonics. Rather, it involves far more localized and recent vicariant models, such as the isolating effect of the Bassian Isthmus during Pleistocene low sea‐level stands (Nerita). Main conclusions Recent phylogeographic studies of southern marine taxa (e.g. Diloma and Parvulastra) imply that passive rafting cannot be ignored as an important mechanism of long‐distance dispersal. I outline a new direction for southern hemisphere phylogeography, involving genetic analyses of bull‐kelp (Durvillaea) and its associated holdfast invertebrate communities.  相似文献   

15.
The Empis macrorrhyncha group (Diptera: Empididae) from cool to warm temperate areas of South America and Australia is diagnosed and cladistically analysed, and five new species, Empis animosa sp.n. , E. austera sp.n. , E. maculosa sp.n. , E. occidentalis sp.n. and E. pedivillosula sp.n. , are described. Cladistic analysis of 23 adult morphological characters for 14 species of the group generated a single tree of 28 steps (CI = 0.82; RI = 0.93). Monophyly was established on the basis of a single apomorphy, possession of a bilobed cercus of the male hypopygium. Three main clades were inferred: clade 1 included three Patagonian and a single southwestern Australian species; clade 2 included two species from southeastern Australia; clade 3 included a large Patagonian group of five species and a single southeastern Australian species. The E. fulvicollis complex (clade 1) is a sister‐group of the E. macrorrhyncha complex (clades 2 + 3). A provisional historical biogeographic hypothesis is advanced correlating the appearance of the South American and Australian sister lineages with the timing of the break‐up of Gondwana.  相似文献   

16.
The southern coast of Australia is composed of three distinct biogeographic provinces distinguished primarily by intertidal community composition. Several ecological mechanisms have been proposed to explain their formation and persistence, but no consensus has been reached. The marine clam Lasaea australis is arguably the most common bivalve on southern Australian rocky shores and occurs in all three provinces. Here, we tested if this species exhibits cryptic genetic structuring corresponding to the provinces and if so, what mechanisms potentially drove its divergence. Variation in two mitochondrial genes (16S and COIII) and one nuclear gene (ITS2) was assayed to test for genetic structuring and to reconstruct the clam's phylogenetic history. Our results showed that L. australis is comprised of three cryptic mitochondrial clades, each corresponding almost perfectly to one of the three biogeographic provinces. Divergence time estimates place their cladogenesis in the Neogene. The trident‐like topology and Neogene time frame of L. australis cladogenesis are incongruent with Quaternary vicariance predictions: a two‐clade topology produced by Pleistocene Bass Strait land bridge formation. We hypothesize that the interaction of the Middle Miocene Climate Transition with the specific geography of the southern coastline of Australia was the primary cladogenic driver in this clam lineage. Additional in‐depth studies of the endemic southern Australian marine biota across all three provinces are needed to establish the generality of this proposed older framework for regional cladogenesis.  相似文献   

17.
Phylogenetic analysis of nrDNA ITS and trnL (UAA) 5 exon-trnF (GAA) chloroplast DNA sequences from 17 species ofPelargonium sect.Peristera, together with nine putative outgroups, suggests paraphyly for the section and a close relationship between the highly disjunct South African and Australian species of sect.Peristera. Representatives fromPelargonium sectt.Reniformia, Ligularia s. l. andIsopetalum (the St. Helena endemicP. cotyledonis) appear to be nested within thePeristera clade. The close relationship between the South African and AustralianPeristera is interpreted as being caused by long-range dispersal to Australia, probably as recent as the late Pliocene.  相似文献   

18.
A phylogenetic hypothesis for the patellid limpets is reconstructed by cladistic analysis of morphological characters from 37 species, representing all but one of the living members of the family. Characters included in the analysis are derived from shell shape and microstructure, headfoot and pallial complex, radula and sperm. The species fall into four clades, providing the basis for a new phylogenetic classification into four monophyletic genera: Helcion (four species; southern Africa), Cymbula (eight species; southern Africa, eastern Atlantic, southern Indian Ocean), Scutellastra (17 species; southern and southwestern Africa, Australia, Indo-West Pacific, Eastern Pacific) and Patella (nine species; northeastern Atlantic and Mediterranean). The analysis suggests sister-group relationships between Helcion and Cymbula, and between Scutellastra and Patella. In combination with present-day patterns of geographical distribution, this phylogenetic hypothesis is used to discuss the historical biogeography of the Patellidae. Scutellastra may have originated in southern Africa and dispersed across the Pacific, or alternatively may be a primitively Tethyan group. Both Helcion and Cymbula appear to have originated in southern Africa, but three Cymbula species have dispersed respectively to northwest Africa, St Helena and the southern Indian Ocean. The patellids of the northeastern Atlantic form a single clade, Patella (including P. pellucida), which may have arrived by northward dispersal of an ancestor from southern Africa, or possibly by vicariance of a widespread ancestral Tethyan distribution. The known fossil record of patellids is too fragmentary to permit choice between these alternatives.  相似文献   

19.
Aim To test the congruence of phylogeographic patterns and processes between a woodland agamid lizard (Diporiphora australis) and well‐studied Australian wet tropics fauna. Specifically, to determine whether the biogeographic history of D. australis is more consistent with a history of vicariance, which is common in wet tropics fauna, or with a history of dispersal with expansion, which would be expected for species occupying woodland habitats that expanded with the increasingly drier conditions in eastern Australia during the Miocene–Pleistocene. Location North‐eastern Australia. Methods Field‐collected and museum tissue samples from across the entire distribution of D. australis were used to compile a comprehensive phylo‐geographic dataset based on c. 1400 bp of mitochondrial DNA (mtDNA), incorporating the ND2 protein‐coding gene. We used phylogenetic methods to assess biogeographic patterns within D. australis and relaxed molecular clock analyses were conducted to estimate divergence times. Hierarchical Shimodaira–Hasegawa tests were used to test alternative topologies representing vicariant, dispersal and mixed dispersal/vicariant biogeographic hypotheses. Phylogenetic analyses were combined with phylogeographic analyses to gain an insight into the evolutionary processes operating within D. australis. Results Phylogenetic analyses identified six major mtDNA clades within D. australis, with phylogeographic patterns closely matching those seen in many wet tropics taxa. Congruent phylogeographic breaks were observed across the Black Mountain Corridor, Burdekin and St Lawrence Gaps. Divergence amongst clades was found to decrease in a north–south direction, with a trend of increasing population expansion in the south. Main conclusions While phylogeographic patterns in D australis reflect those seen in many rain forest fauna of the wet tropics, the evolutionary processes underlying these patterns appear to be very different. Our results support a history of sequential colonization of D. australis from north to south across major biogeographic barriers from the late Miocene–Pleistocene. These patterns are most likely in response to expanding woodland habitats. Our results strengthen the data available for this iconic region in Australia by exploring the understudied woodland habitats. In addition, our study shows the importance of thorough investigations of not only the biogeographic patterns displayed by species but also the evolutionary processes underlying such patterns.  相似文献   

20.
Abrotanella is the basal genus in the large tribe Senecioneae (Asteraceae) and has a disjunct distribution in Australasia and South America. A recent molecular phylogeny of the genus was used to investigate whether the main biogeographical patterns in the group could be related to the region's tectonic history in a coherent way. The phylogenetic/biogeographical breaks and overlaps in the genus imply a series of vicariance and range expansion events. Each of these can be related to one of the main tectonic events in the region, including assembly of the New Zealand terranes, crustal extension, and magmatism in Gondwana that preceded seafloor spreading, opening of the Tasman and Pacific basins, and transcurrent movement on the New Zealand Alpine fault. The coincident sequence indicates that pre‐drift tectonics and magmatism have been more important for the origin of trans‐Tasman and trans‐Pacific groups than the final rifting of Gondwana that led to their disjunction. For example, during the pre‐drift phase of break‐up, the Whitsunday volcanic province of Australia and the Median Batholith of New Zealand formed a large, active igneous belt. Its distribution is aligned with the break between New Zealand–south‐eastern Australia clades, and New Zealand–New Guinea clades. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ??, ??–??.  相似文献   

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