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1.
Bandicoots (Peramelemorphia) are a major order of australidelphian marsupials, which despite a fossil record spanning at least the past 25 million years and a pandemic Australasian range, remain poorly understood in terms of their evolutionary relationships. Many living peramelemorphians are critically endangered, making this group an important focus for biological and conservation research. To establish a phylogenetic framework for the group, we compiled a concatenated alignment of nuclear and mitochondrial DNA sequences, comprising representatives of most living and recently extinct species. Our analysis confirmed the currently recognised deep split between Macrotis (Thylacomyidae), Chaeropus (Chaeropodidae) and all other living bandicoots (Peramelidae). The mainly New Guinean rainforest peramelids were returned as the sister clade of Australian dry-country species. The wholly New Guinean Peroryctinae was sister to Echymiperinae. The poorly known and perhaps recently extinct Seram Bandicoot (Rhynchomeles) is sister to Echymipera. Estimates of divergence times from relaxed-clock Bayesian methods suggest that living bandicoots originated in the late Oligocene or early Miocene, much earlier than currently thought based on fossils. Subsequent radiations within Peramelemorphia probably took place on the Australian mainland during the Miocene, with diversification of rainforest taxa on the newly emergent New Guinean landmasses through the middle-late Miocene and complete establishment of modern lineages by the early Pliocene.  相似文献   

2.
We analyzed nucleotide variation at four loci for 75 species to produce a phylogenetic hypothesis for the Meliphagidae, and to examine the evolution and biogeographic history of the Meliphagidae. Both maximum parsimony and Bayesian methods of phylogenetic analysis were employed. The family was found to be monophyletic, though the genera Certhionyx, Anthochaera, and Phylidonyris were not. Four major clades were recovered and the spinebills (Acanthorhynchus) formed the sister clade to the remainder of the family in most analyses. The Australian endemic arid-adapted chats (Epthianura, Ashbyia) were found to be nested deeply within the family Meliphagidae. No evidence was found to support the hypothesis of separate New Guinean and Australian endemic radiations, nor of a close phylogenetic relationship between taxa from the New Guinea highlands and those from Australian northern rainforests.  相似文献   

3.
Bryant, L. M., Donnellan, S. C., Hurwood, D. A. & Fuller, S. J. (2011). Phylogenetic relationships and divergence date estimates among Australo‐Papuan mosaic‐tailed rats from the Uromys division (Rodentia: Muridae). —Zoologica Scripta, 40, 433–447. We inferred phylogenetic relationships and divergence date estimates among four genera of mosaic‐tailed rats from the Uromys division in Australia, New Guinea and the Solomon Islands from both mitochondrial (16S rRNA) and nuclear (AP5 and DHFR introns) nucleotide sequence data. Phylogenetic analysis of our combined data shows that Melomys species from Australia and New Guinea are monophyletic to the exclusion of Paramelomys, which last shared a common ancestor with other members of the Uromys division approximately 3 MYA. However, Melomys was found to be paraphyletic with respect to the Solomon Islands endemic Solomys, suggesting the taxonomic distinction of the latter may need revision. The radiation of this group was estimated to have occurred between 2.1 MYA and 900 000 years ago. A currently undescribed taxon, species nova, which is apparently morphologically indistinguishable from sympatric M. cervinipes, was found to be a highly distinctive lineage and was not monophyletic with Melomys from Australia or New Guinea. Australian Uromys share a sister group relationship with sp. n. and the Melomys/Solomys clade. Australian Melomys were not monophyletic with respect to New Guinean Melomys. The New Guinean M. lutillus and Australian M. burtoni appear to be conspecific, supporting a previous suggestion that M. burtoni has an extralimital distribution encompassing New Guinea as M. lutillus. This also suggests sustained contact between these taxa, most likely enabled through historical landbridges that linked the two landmasses during periods of lower sea level. Melomys rubicola, found only on Bramble Cay, 50 km south of New Guinea, is more closely related to Australian Melomys, particularly M. capensis, than to any of the New Guinean species. Results suggest that M. rubicola and M. capensis last shared a common ancestor in the early Pleistocene, a time when land bridges existed connecting Bramble Cay to Cape York. Finally, polyphyly within M. cervinipes was also detected, corresponding to reciprocally monophyletic northern and southern clades. The northern M. cervinipes clade diverged from the M. capensis/rubicola clade approximately 1.2 MYA, with this split possibly resulting from isolation across the Normanby gap in far north Queensland.  相似文献   

4.
We use approximately 1900bp of mitochondrial (ND2) and nuclear (c-mos and Rag-1) DNA sequence data to recover phylogenetic relationships among 58 species and 26 genera of Eugongylus group scincid lizards from New Caledonia, Lord Howe Island, New Zealand, Australia and New Guinea. Taxon sampling for New Caledonian forms was nearly complete. We find that the endemic skink genera occurring on New Caledonia, New Zealand and Lord Howe Island, which make up the Gondwanan continental block Tasmantis, form a monophyletic group. Within this group New Zealand and New Zealand+Lord Howe Island form monophyletic clades. These clades are nested within the radiation of skinks in New Caledonia. All of the New Caledonian genera are monophyletic, except Lioscincus. The Australian and New Guinean species form a largely unresolved polytomy with the Tasmantis clade. New Caledonian representatives of the more widespread genera Emoia and Cryptoblepharus are more closely related to the non-Tasmantis taxa than to the endemic New Caledonian genera. Using ND2 sequences and the calibration estimated for the agamid Laudakia, we estimate that the diversification of the Tasmantis lineage began at least 12.7 million years ago. However, using combined ND2 and c-mos data and the calibration estimated for pygopod lizards suggests the lineage is 35.4-40.74 million years old. Our results support the hypothesis that skinks colonized Tasmantis by over-water dispersal initially to New Caledonia, then to Lord Howe Island, and finally to New Zealand.  相似文献   

5.
Relationships among the living and recently extinct genera of bandicoots (Marsupialia: Peramelemorphia) have proven difficult to discern. Previous phylogenetic studies have used only morphology or mitochondrial DNA and have reported conflicting results in regards to their relationships. Most phylogenetic reconstructions recognize a basal split between the bilby Macrotis (Thylacomyidae) and the Peramelidae. The Peramelidae is composed of the Peramelinae (Isoodon and Perameles), Echymiperinae (Echymipera and Microperoryctes), and Peroryctinae (Peroryctes). Within Peramelidae, Echymipera and Microperoryctes usually group together to the exclusion of Peroryctes. This clade is sister to the Peramelinae. Placement of the recently extinct pig-footed bandicoot (Chaeropus: Chaeropodidae) has been ambiguous. We address the interrelationships and estimate times of divergence for the living bandicoot genera using a 6 kilobase concatenation consisting of protein-coding regions of five nuclear genes (ApoB, BRCA1, IRBP, Rag1, and vWF). We analyzed this concatenation using maximum parsimony, maximum likelihood, and Bayesian methods and estimated times of divergence using two Bayesian relaxed molecular clock methods. In all concatenated analyses, all nodes associated with the Peramelemorphia were robustly supported (bootstrap support percentages=100; posterior probabilities=1.00). Macrotis was recovered as basal to the remaining living bandicoots. Within the Peramelidae, Echymipera and Microperoryctes grouped to the exclusion of Peroryctes and this clade was sister to the Peramelinae. Only Rag1 amplified for Chaeropus; analyses based on this gene provide moderate support for an association of Chaeropus plus Peramelidae to the exclusion of Macrotis. Both relaxed clock Bayesian methods suggest that the living bandicoots are a relatively recent radiation originating sometime in the late Oligocene or early Miocene with subsequent radiations in the late Miocene to early Pliocene.  相似文献   

6.
Nucleotide sequences from four mitochondrial genes and three nuclear introns were used to examine phylogenetic relationships within the Australo-papuan fairy-wrens (Passeriformes: Maluridae: Malurinae). A well-resolved and well-supported phylogenetic hypothesis of all species in the subfamily was generated. The tree contained three clades corresponding to groups with similar plumages previously identified in earlier studies: the "bi-color," "blue," and "chestnut-shouldered" groups. The genus Malurus was not monophyletic -Malurusgrayi formed a clade with two New Guinean genera Sipodotus and Clytomyias. We recommend M. grayi be reclassified into the genus Chenorhamphus Oustalet 1898. One other taxonomic change is recommended based on the large genetic distance between the two subspecies of Chenorhamphus grayi - the elevation of C. g.campbelli to specific status (= C. campbelli). Although the family Maluridae appears to have had its origins in Australia, the DNA data supports a New Guinean origin for the Malurini (Sipodotus, Clytomyias, Chenorhamphus, Malurus).  相似文献   

7.
Copelatinae is a diverse lineage of diving beetles (Dytiscidae) frequently encountered in wet tropical and subtropical forests, but phylogenetic relationships are very poorly understood. We performed a phylogenetic and biogeographic analysis of this worldwide distributed group based on 50 species including a representative sample of major taxonomic groups and biogeographical regions. DNA sequences were obtained for the mitochondrial genes cytochrome oxidase I, cytochrome b, and 16S rRNA, for a total of 1575 aligned nucleotide positions. We found Copelatinae to be monophyletic, placed in a derived position and not sister to all remaining dytiscids, as had been suggested by earlier authors. The largest genus, Copelatus with some 460 known species was paraphyletic with respect to the smaller genera Lacconectus and Aglymbus. Among the major lineages of Copelatus, the subgenus Papuadytes was consistently recovered as sister to all other species (including Lacconectus and Aglymbus) with the possible exception of two western Palearctic taxa. We propose that the subgenus Papuadytes is removed from Copelatus and assigned generic status. Likewise, the two western Palearctic Copelatus are removed from this genus, and assigned the available genus name Liopterus. Our best phylogenetic hypothesis retrieved Afrotropical and New Guinean plus Australian species of Copelatus as monophyletic. Asian species were paraphyletic with respect to a species from Sulawesi which grouped with the species from New Guinea. Asian species were also paraphyletic with respect to Oriental Lacconectus, which was grouped with a clade of Neotropical species. Neotropical Copelatus form at least two separate lineages. The biogeographical evolution of Papuadytes is consistent with the relative age of the landmasses in the Austral region. Basal species are Australian, and successively derived ones are from New Caledonia and New Guinea. One species apparently dispersed from New Caledonia to China. Assuming a molecular clock and using a standard calibration of 2% divergence/MY the origin of Copelatinae is estimated to be between 85 and 95 MY.  相似文献   

8.
The first cladistic analysis of the relationship of Malagasy vangas (Vangidae) based on morphological characters is presented here. The comparative morphological analysis provides new arguments for the exclusion of several taxa traditionally or recently assigned to Vangidae such as Tylas 'Vanga' ( Tylas eduardi ), Crossley's Babbler ( Mystacornis crossleyi ) and newtonias ( Newtonia spp.), but also for the exclusion of the Red-tailed 'Vanga' ( Calicalicus madagascariensis ) from the Vangidae. It leads also to the hypothesis that vangas sensu stricto , the Australasian woodswallows (Artamidae) and the Australo-Papuan butcherbirds (Cracticidae) form a monophyletic group, with the New Guinean peltops ( Peltops spp.) as its probable sister taxon. Such a relationship implies that the last common ancestor of vangas reached Madagascar from the east by means of a dispersal event across the Indian Ocean. This hypothesis is partly in accordance with that of William Pycraft (1907) published a century ago, but in conflict with contemporary hypotheses based on DNA sequence analysis which favour helmet-shrikes, bush shrikes and relatives as the closest relatives of vangas and therefore an African origin of this group.  相似文献   

9.
The nasute termite genus Nasutitermes is widely distributed over all tropical regions. The phylogenetic relationships among 17 Nasutitermes species from the Pacific tropics were inferred from sequences of mitochondrial cytochrome oxidase II and 16S ribosomal RNA genes. Several methods of analysis yielded phylogenetic trees showing almost the same topology and in good agreement with reconstructions based on morphological or behavioral characters. Neotropical and Australian species came out as separate, apical clades. Asian species split between an apical branch, appearing as sister group to the neotropical clade, and basal taxa. New Guinean species were spread among several clades, suggesting a derivation from multiple origins. A well-supported clade includes the neotropical, Australian, and New Guinean species, with the southeast Asian N. takasagoensis and N. matangensis. It excludes the Asian species N. regularis, N. parvonasutus, and N. longinasus, which might deserve to be removed from Nasutitermes, as well as the long-legged Asian genera Hospitalitermes and Longipeditermes. A Gondwanan origin is proposed for the former clade, although an Old World origin of Nasutitermes followed by dispersal to Australia and South America cannot be excluded.  相似文献   

10.
The bilby (Macrotis lagotis) is a small omnivorous marsupial that was once widespread but is now restricted to the most arid margins of its former range. It feeds on a mixture of invertebrates (mainly ants and termites) and plant material (mainly seeds and bulbs), most of which is below ground. Measurements of the energy and water requirements of free-living bilbies and of the maintenance nitrogen requirements of captive animals provided the basis for an explanation for its continued survival in the Australian arid zone. Measurements of the mean retention times of inert markers for the solute and particulate phases of digesta revealed no selective retention of solutes and small particles in the caecum. Lack of selective digesta retention in the bilby hindgut helps to explain why the plant component of their diet consists predominantly of seeds and bulbs of relatively low fibre content. This is in contrast to the stems and leaves eaten by other bandicoots, all of which appear to have a colonic separation mechanism that not only selectively retains small particles in the caecum but also facilitates the passage of large fibrous particles through the colon. The ability of the bilby to survive in the Australian arid zone is related to low water and nitrogen requirements and the abundance of ants, termites, bulbs and seeds. Foraging efficiency is maximised by exploiting the underground nests of seed-harvesting ants.  相似文献   

11.
We used a multi-gene approach to assess the phylogenetic relationships of New Zealand diplodactylid geckos to their Australian and New Caledonian relatives and to one another. Data from nuclear (RAG-1, PDC) and mitochondrial (ND2, 16S) genes from >180 specimens representing all 19 recognized New Zealand taxa and all but two of 20 putatively new species suggested by previous studies were analyzed using Maximum Parsimony, Maximum Likelihood and Bayesian inference. All analyses retrieved a monophyletic New Zealand clade, most closely related to the Australian Diplodactylidae exclusive of Pseudothecadactylus. Hoplodactylus is paraphyletic and composed of two morphological groups: a broad-toed clade, consisting of the island-restricted, largest extant species, Hoplodactylus duvaucelii, and the species-rich, wide-ranging Hoplodactylus maculatus clade; and a narrow-toed clade, comprising five monophyletic subgroups: Naultinus, the Hoplodactylus pacificus and Hoplodactylus granulatus clades, and the distinctive species Hoplodactylus rakiurae and Hoplodactylus stephensi. Each of these lineages is here recognized at the generic level. Our data support recognition of 16 new species (36 total), and five new or resurrected genera (seven total). The New Zealand diplodactylid radiation split from its Australian relatives 40.2mya (95% highest posterior density estimate 28.9-53.5), after the opening of the Tasman Sea. Their distribution cannot, therefore, be regarded as derived as a result of Gondwanana vicariance. The age of the New Zealand crown group, 24.4mya (95% highest posterior density estimate 15.5-33.8), encompasses the period of the 'Oligocene drowning' of New Zealand and is consistent with the hypothesis that New Zealand was not completely inundated during this period. Major lineages within New Zealand geckos diverged chiefly during the mid- to late Miocene, probably in association with a suite of geological and climatological factors that have characterized the region's complex history.  相似文献   

12.
Archer provided the most recent and comprehensive suprageneric classification of dasyurid marsupials. Five extant subfamilies, two with constituent tribes, were recognized on the basis of morphological, serological, and allozyme data. Phylogenetic relationships among these groups, however, were totally unresolved. Subsequent molecular studies suggested that the endemic New Guinean subfamilies Muricinae and Phascolosoricinae are parts of larger Australian clades. Our objective in this study was to test the monophyly of Archer's seven groups and estimate relationships among them using DNA sequences from the mitochondrial cytochromeb (cyt-b) gene. We report 657 bp ofcyt-b from 32 dasyuroid species. Phylogenetic analysis of these data leads to the following conclusions: (1) muricines form a clade within Phascogalinae that includes endemic New GuineanAntechinus species; (2) the two genera of Phascolosoricinae are part of a more inclusive Dasyurinae; (3) Sminthopsinae is monophyletic, but the tribes Sminthopsini and Planigalini are not; and (4) the dasyurine tribes Dasyurini and Parantechini are probably not monophyletic. Relationships among Sminthopsinae, Dasyurinae (including phascolosoricines), and Phascogalinae (including muricines) remain unresolved.  相似文献   

13.
Pseudocheiridae (Marsupialia: Diprotodontia) is a family of endemic Australasian arboreal folivores, more commonly known as ringtail possums. Seventeen extant species are grouped into six genera (Pseudocheirus, Pseudochirulus, Hemibelideus, Petauroides, Pseudochirops, Petropseudes). Pseudochirops and Pseudochirulus are the only genera with representatives on New Guinea and surrounding western islands. Here, we examine phylogenetic relationships among 13 of the 17 extant pseudocheirid species based on protein-coding portions of the ApoB, BRCA1, ENAM, IRBP, Rag1, and vWF genes. Maximum parsimony, maximum likelihood, and Bayesian methods were used to estimate phylogenetic relationships. Two different relaxed molecular clock methods were used to estimate divergence times. Bayesian and maximum parsimony methods were used to reconstruct ancestral character states for geographic provenance and maximum elevation occupied. We find robust support for the monophyly of Pseudocheirinae (Pseudochirulus + Pseudocheirus), Hemibelidinae (Hemibelideus + Petauroides), and Pseudochiropsinae (Pseudochirops + Petropseudes), respectively, and for an association of Pseudocheirinae and Hemibelidinae to the exclusion of Pseudochiropsinae. Within Pseudochiropsinae, Petropseudes grouped more closely with the New Guinean Pseudochirops spp. than with the Australian Pseudochirops archeri, rendering Pseudochirops paraphyletic. New Guinean species belonging to Pseudochirops are monophyletic, as are New Guinean species belonging to Pseudochirulus. Molecular dates and ancestral reconstructions of geographic provenance combine to suggest that the ancestors of extant New Guinean Pseudochirops spp. and Pseudochirulus spp. dispersed from Australia to New Guinea ∼12.1–6.5 Ma (Pseudochirops) and ∼6.0–2.4 Ma (Pseudochirulus). Ancestral state reconstructions support the hypothesis that occupation of high elevations (>3000 m) is a derived feature that evolved on the terminal branch leading to Pseudochirops cupreus, and either evolved in the ancestor of Pseudochirulus forbesi, Pseudochirulus mayeri, and Pseudochirulus caroli, with subsequent loss in P. caroli, or evolved independently in P. mayeri and P. forbesi. Divergence times within the New Guinean Pseudochirops clade are generally coincident with the uplift of the central cordillera and other highlands. Diversification within New Guinean Pseudochirulus occurred in the Plio-Pleistocene after the establishment of the Central Range and other highlands.  相似文献   

14.
Mitochondrial DNA Evidence and Evolution in Varanoidea (Squamata)   总被引:2,自引:0,他引:2  
Varanoidea is a monophyletic group of anguimorph lizards, comprising the New World helodermatids, the Bornean earless monitor Lanthanotus borneensis , and the Old World monitors ( Varanus ). I use mitochondrial DNA sequences and extensive taxonomic sampling to test alternative hypotheses of varanoid relationships. The most parsimonious hypothesis confirms the monophyly of Varanoidea ( Heloderma, Lanthanotus , and Varanus ) and Varanus , as well as the sister-taxon relationship of Varanus and Lanthanotus . The relationships among Varanus species differ in several respects from previous hypotheses. Three major lineages are recognized within Varanus : an African clade basal to the rest of the group, an Indo-Asian clade, and an Indo-Australian clade. Within the last lineage, the endemic Australian dwarf monitors ( Odatria ) form a clade sister to the large Australian monitors (the gouldii group). Tests of the effects of rate heterogeneity and homoplasy demonstrate that putative process partitions of data are largely congruent with one another and contribute positive support to the overall hypothesis.  相似文献   

15.
Phylogenetic relationships of the Malagasy and Australasian rainbowfishes are investigated using 4394 characters derived from five mitochondrial genes (12S, 16S, tRNA-Valine, ND5, and COI), three nuclear genes (28S, histone H3, and TMO-4c4), and 102 morphological transformations. This study represents the first phylogenetic analysis of the endemic Malagasy family Bedotiidae and includes a nearly complete taxonomic review of all nominal species, as well as numerous undescribed species. Simultaneous analysis of the molecular and morphological datasets results in two equally most parsimonious trees. Results indicate that Bedotiidae (Bedotia+Rheocles) and Bedotia are monophyletic, whereas Rheocles is paraphyletic with the inclusion of two recently described species from northeastern Madagascar, R. vatosoa, and R. derhami. Rheocles vatosoa and R. derhami are sister taxa, and this clade is recovered as the sister group to Bedotia. The remaining species of Rheocles are not sexually dimorphic and comprise a clade that is recovered as the sister group to Bedotia+(R. derhami+R. vatosoa), all of which are sexually dichromatic, and sexually dimorphic for pigmentation and fin development. Three geographically distinct clades are recovered within Bedotia, one comprising species with distributions ranging from mid- to southeastern Madagascar, another including species restricted to eastern drainages north of the Masoala Peninsula, and a third comprising taxa with distributions extending from the Masoala Peninsula south to the Ivoloina River. The Australian/New Guinean melanotaeniids are monophyletic and are recovered as the sister group to Bedotiidae. The Australasian Telmatherinidae and Pseudomugilidae comprise a clade that is recovered as the sister group to the Melanotaeniidae-Bedotiidae clade. This sister-group relationship between Malagasy bedotiids and a clade restricted to Australia-New Guinea, and the absence of a close relationship between bedotiids and African or Mascarene atheriniforms, is congruent with the break-up of Gondwana, not a scenario reliant on Cenozoic trans-oceanic dispersal. Finally, results of the phylogenetic analysis indicate that Atheriniformes is polyphyletic and further corroborate recent morphological hypotheses, which have recovered Bedotiidae in a derived position within Atherinoidei.  相似文献   

16.
We report DNA sequence variation in 861 bp of the mitochondrial cytochromeb gene from 10 species of the dasyurid marsupial subfamily Phascogalinae (including the New Guinean genusMurexia) and an outgroup planigale (Planigale ingrami). Phylogenetic analyses of these sequences indicate that (1) the subfamily consists of three major clades corresponding to (a)Phascogale, (b) AustralianAntechinus, and (c) New Guinean Antechinus andMurexia; (2) Antechinus habbema constitutes the earliest branch of the New Guinean clade; and (3); Antechinus melanurus and A. naso are sister species within the New Guinean clade. Among Australian antechnuses,A. stuartii andA. swainsonii are more closely related to each other than either is toA. flavipes, a result that is seemingly at odds with all previous systematic studies. Although resolution is limited, it appears thatAntechnius andMurexia species form a clade to the exclusion ofPhascogale. This relationship suggests that male semelparity is not a strong synapomorphy for Australian antechinuses and phascogales, despite its apparent physiological similarity in the two groups.To whom correspondence should be addressed.  相似文献   

17.
Green pythons, which are regionally variable in colour patterns, are found throughout the lowland rainforest of New Guinea and adjacent far northeastern Australia. The species is popular in commercial trade and management of this trade and its impacts on natural populations could be assisted by molecular identification tools. We used mitochondrial nucleotide sequences and a limited allozyme data to test whether significantly differentiated populations occur within the species range. Phylogenetic analysis of mtDNA sequences revealed hierarchal phylogeographic structure both within New Guinea and between New Guinea and Australia. Strongly supported reciprocally monophyletic mitochondrial lineages, northern and southern, were found either side of the central mountain range that runs nearly the length of New Guinea. Limited allozyme data suggest that population differentiation is reflected in the nuclear as well as the mitochondrial genome. A previous morphological analysis did not find any phenotypic concordance with the pattern of differentiation observed in the molecular data. The southern mitochondrial lineage includes all of the Australian haplotypes, which form a single lineage, nested among the southern New Guinean haplotypes.  相似文献   

18.
19.
Heterotermes Froggatt is a subterranean termite genus consisting of 30 living described species worldwide, with nine occurring in the New World. Herein we provide a molecular phylogeny, using both mitochondrial and nuclear markers, of all New World species of Heterotermes, including biogeographical analysis, and describe a new species from Paraguay and Bolivia, based on morphological and molecular evidence. Our analysis recovered the New World species as paraphyletic to a monophyletic Australian clade. Within this New World + Australian clade, two monophyletic major groups were formed c. 28 Ma: the aureus- and tenuis-groups. The aureus-group has a disjunct and broad distribution consisting of two clades. The first clade extends into the Nearctic region and a second is composed of a branch in the Caatinga and Cerrado biomes (H. sulcatus Mathews) and a branch in the Chacoan biome (a new species, Heterotermes lauralinearum Carrijo sp.n. ). The tenuis-group is composed of four broadly distributed Neotropical species and the Australian clade. A single dispersion event from South America to Australia probably occurred between 13 and 24 Ma. Heterotermes crinitus Emerson was the first to diverge, being sister group of all other species in the tenuis-group, followed by Heterotermes assu Constantino. An analysis of the historical biogeography of Heterotermes suggests that jump dispersal was the most important cladogenetic process for the genus. This study is the most comprehensive phylogeny of Heterotermes and contributes to the understanding of termite evolution and geographic distribution in the New World, complementing recent studies focused on worldwide patterns. This published work has been registered on Zoobank, http://zoobank.org/urn:lsid:zoobank.org:pub:8951A29B-8B69-4CD5-B9DF-2C70D4628D97 .  相似文献   

20.
Plant-geography of east Malesia   总被引:1,自引:0,他引:1  
A floristic analysis is given of the flora of the Lesser Sunda Islands. It is concluded that their flora must formerly have been richer, especially in rain-forest plants Irom both east and west Malesia. Impoverishment of the flora started at the onset of the Glacial Age, when these islands acted as an important bridge from continental south east Asia through the Philippines, Celebes, to north Australia, facilitating exchange of drought-indifferent or seasonal drought-requiring plants between Asia and Australia. Before the Pliocene the Lesser Sunda Islands contributed little to effective contact and exchange. Two main contacts between the Malesian and Australian floras must have occurred, the first in the Upper Cretaceous to Paleocene, or even earlier, and the second, and final, contact before the end of the Miocene. These contacts were interrupted by a long period, throughout which the Australian flora was isolated. During the first contact Fagoideae and several other taxa of the Laurasian flora attained a bipolar-Antarctic range. Other Laurasian elements, which became thoroughly integrated with the primitive Australian-Gondwanean flora and subsequently evolved with it, probably exist but are difficult to trace. In the Miocene, a further, more abundant influx of the Asian/Malesian element into the Australian flora took place. This influx is more easily traced in the present Australian flora, especially its tropical moiety, a number of endemic species evolving from such immigrant taxa. The New Guinean tract had a rather poor archipelagic Australian-Gondwanean flora from the Oligocene until the Miocene, when this a.chipelago gradually became continuous land. With the developing orogeny over its whole length, it became a colossal expanse, with congenial soils and climate. The diversity of niches thus created allowed an explosive development of the Malesian element. Of the ancient Australian-Gondwanean element already present, part possibly became extinct, while part became integrated. The reciprocal emigration of the Australian element was always impeded because of its adaptation to nutrient-deficient soil types. Such soils are very scarce in New Guinea, Malesia and south-east Asia generally. As a result of this study, the relation between scleromorphy and nutrient-deficient soil types in Australia and South Africa has been reappraised. Scleromorphy can be traced in the tropical rainforest and is exemplarily expressed in the heath forest of west Borneo, and adjacent Banka and Billiton. It is deduced that scleromorphy is bound to soil, not to climate. The poor flora of the primitiae of the New Guinean flora is the result of the dearth of nutrient-“delicient soils and the later competition from the Malesian rain-forest. It also accounts for the proportionally good representation of the Australian element in the mountain flora of New Guinea and other Malesian islands. These botanical interpretations and deductions are in accord with recent tentative geophysical maps and datings. Several hitherto obscure facts are logically explained by this hypothesis: the overwhelming Malesian element of the present New Guinean flora; its explosive development in that island since the Miocene; the presence of the important demarcation between the Asian/Malesian and Australian element in the Torres Strait; the very low percentage of the Australian element in the Malesian flora, and the presence of various Laurasian representatives of different antiquity in the Australian flora.  相似文献   

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