Panbiogeography of New Caledonia,south‐west Pacific: basal angiosperms on basement terranes,ultramafic endemics inherited from volcanic island arcs and old taxa endemic to young islands

Aim To investigate areas of endemism in New Caledonia and their relationship with tectonic history. Location New Caledonia, south‐west Pacific. Methods Panbiogeographical analysis. Results Biogeographical patterns within New Caledonia are described and illustrated with reference to eight terranes and ten centres of endemism. The basement terranes make up a centre of endemism for taxa including Amborella, the basal angiosperm. Three of the terranes that accreted to the basement in the Eocene (high‐pressure metamorphic terrane, ultramafic nappe and Loyalty Ridge) have their own endemics. Main conclusions New Caledonia is not simply a fragment of Gondwana but, like New Zealand and New Guinea, is a complex mosaic of allochthonous terranes. The four New Caledonian basement terranes were all formed from island arc‐derived and arc‐associated material (including ophiolites) which accumulated in the pre‐Pacific Ocean, not in Gondwana. They amalgamated and were accreted to Gondwana (eastern Australia) in the Late Jurassic/Early Cretaceous, but in the Late Cretaceous they separated from Australia with the opening of the Tasman Sea and break‐up of Gondwana. An Eocene collision of the basement terranes with an island arc to the north‐east – possibly the Loyalty Ridge – is of special biogeographical interest in connection with New Caledonia–central Pacific affinities. The Loyalty–Three Kings Ridge has had a separate history from that of the Norfolk Ridge/New Caledonia, although both now run in parallel between Vanuatu and New Zealand. The South Loyalty Basin opened between Grande Terre and the Loyalty Ridge in the Cretaceous and attained a width of 750 km. However, it was almost completely destroyed by subduction in the Eocene which brought the Loyalty Ridge and Grande Terre together again, after 30 Myr of separation. The tectonic history is reflected in the strong biogeographical differences between Grande Terre and the Loyalty Islands. Many Loyalty Islands taxa are widespread in the Pacific but do not occur on Grande Terre, and many Grande Terre/Australian groups are not on the Loyalty Islands. The Loyalty Islands are young (2 Myr old) but they are merely the currently emergent parts of the Loyalty Ridge whose ancestor arcs have a history of volcanism dating back to the Cretaceous. Old taxa endemic to the young Loyalty Ridge islands persist over geological time as a dynamic metapopulation surviving in situ on the individually ephemeral islands and atolls found around subduction zones. The current Loyalty Islands, like the Grande Terre terranes, have inherited their biota from previous islands. On Grande Terre, the ultramafic terrane was emplaced on Grande Terre in the Eocene (about the same time as the collision with the island arc). The very diverse endemic flora on the ultramafics may have been inherited by the obducting nappe from prior base‐rich habitat in the region, including the mafic Poya terrane and the limestones typical of arc and intraplate volcanic islands.     

Globally basal centres of endemism: the Tasman-Coral Sea region (south-west Pacific), Latin America and Madagascar/South Africa

The New Zealand wrens (Acanthisittidae) are basal in passerine birds and in New Caledonia, the closest country to New Zealand, Amborella is basal in angiosperms. A review of molecular studies indicates that 29 other locally or regionally endemic clades around the Tasman and Coral Sea basins have cosmopolitan or globally widespread sister groups. Other areas that have local endemics basal to diverse global groups include Borneo, Madagascar/South Africa/Tanzania, southern China–Taiwan–Japan, and different parts of Latin America, especially the Guayana Plateau and western Mexico. Basal clades are widely interpreted as ancestral and their location is generally taken to represent a centre of origin for the group as a whole. In the present study, basal groups are treated simply as small (less speciose) sister groups. The Tasman and western Mexico/Caribbean regions have important biogeographic and tectonic ties with each other and with the central Pacific. Large igneous provinces (Ontong Java, Hikurangi‐Manihiki, and Gorgona Plateaus) formed in the central Pacific in the Cretaceous. Fossil wood is found on the Ontong Java Plateau, and formerly emergent seamounts up to 24 km across occur on Hikurangi Plateau. Many terranes in New Zealand, New Caledonia, New Guinea and western America represent former island arcs (or their products) that formed in the central Pacific and later accreted to the Pacific margins. Long‐term survival of taxa as metapopulations on the ephemeral volcanic islands and atolls of plate margins and fissures may explain the biogeographical connections among the Tasman region, the central Pacific, and the accreted terranes of western America. Branching sequences in cladograms and phylogenetic trees have been interpreted as dispersal events, but instead probably indicate the sequence of differentiation in an already widespread ancestor. Major disjunctions of tens of thousands of kilometres often occur between taxa at consecutive nodes on a tree and dispersal by physical movement is unlikely. The break between the globally basal centres and the rest of the world marks the initial site of differentiation of a widespread ancestor, with subsequent or more or less simultaneous differentiation occurring in other areas. Differentiation of the modern angiosperms, passerines and other groups first took place around the Tasman region, or at least the terranes now accumulated there, and then around other centres, especially Madagascar–South Africa and Mexico–north‐west South America. Angiosperms are now recognized as basal to extant gymnosperms and major tectonic dynamism around the globally basal centres during the Mesozoic, involving terrane accretion, orogeny, and rifting could have been involved with the last important modernization of angiosperms, birds and other groups. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96 , 222–245.     

Contemporary genetic structure of an endemic freshwater turtle reflects Miocene orogenesis of New Guinea

The island of New Guinea lies in one of the most tectonically active regions in the world and has long provided outstanding opportunity for studies of biogeography. Several chelid turtles, of clear Gondwanal origin, occur in New Guinea; all species except one, the endemic Elseya novaeguineae, are restricted to the lowlands south of the Central Ranges. Elseya novaeguineae is found throughout New Guinea. We use mitochondrial and nuclear gene variation among populations of E. novaeguineae throughout its range to test hypotheses of recent extensive dispersal versus more ancient persistence in New Guinea. Its genetic structure bears the signature of Miocene vicariance events. The date of the divergence between a Birds Head (Kepala Burung) clade and clades north and south of the Central Ranges is estimated to be 19.8 Mya [95% highest posterior density (HPD) interval of 13.3–26.8 Mya] and the date between the northern and southern clades is estimated to be slightly more recent at 17.4 Mya (95% HPD interval of 11.0–24.5 Mya). The distribution of this endemic species is best explained by persistent occupation (or early invasion and dispersal) and subsequent isolation initiated by the dramatic landform changes that were part of the Miocene history of the island of New Guinea, rather than as a response to the contemporary landscape of an exceptionally effective disperser. The driving influence on genetic structure appears to have been isolation arising from a combination of: (1) the early uplift of the Central Ranges and establishment of a north‐south drainage divide; (2) development of the Langguru Fold Belt; (3) the opening of Cenderawasih Bay; and (4) the deep waters of the Aru Trough and Cenderawasih Bay that come close to the current coastline to maintain isolation of the Birds Head through periods of sea level minima (?135 m). The dates of divergence of turtle populations north and south of the ranges predate the telescopic uplift of the central ranges associated with oblique subduction of the Australian Plate beneath the Pacific Plate. Their isolation was probably associated with earlier uplift and drainage isolation driven by the accretion of island terranes to the northern boundary of the Australian craton that occurred earlier than the oblique subduction. The opening of Cenderawasih Bay is too recent (6 Mya) to have initiated the isolation of the Birds Head populations from those of the remainder of New Guinea, although its deep waters will have served to sustain the isolation through successive sea level changes. The molecular evidence suggests that the Birds Head docked with New Guinea some time before the Central Ranges emerged as a barrier to turtle dispersal. Overall, deep genetic structure of the species complex reflects events and processes that occurred during Miocene, whereas structure within each clade across the New Guinea landscape relates to Pliocene and Pleistocene times. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111 , 192–208.     

Australian biogeographical connections and the phylogeny of large genera in the plant family Myrtaceae

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.     

Do biodiversity hotspots match with rodent conservation hotspots?

Biodiversity hotspots are used widely to designate priority regions for conservation efforts. It is unknown, however, whether the current network of hotspots adequately represents globally threatened taxonomic diversity for whole plant and animal groups. We used a mammalian group traditionally neglected in terms of conservation efforts, the rodents, in order to test whether biodiversity hotspots match the current distribution of threatened taxa (genera and species). Significantly higher numbers of threatened rodent genera and species fell within biodiversity hotspots; nonetheless over 25% of the total threatened genera and species did not occur in any biodiversity hotspot. This was particularly true for the Australian region, where 100% of the threatened genera and species fell outside biodiversity hotspots, with many threatened taxa found in Papua-New Guinea. We suggest to officially including Papua New Guinea among biodiversity hotspots for rodents, and also the steppic/semidesert areas of central Asia.     

Infrequent and unidirectional colonization of hyperdiverse Papuadytes diving beetles in New Caledonia and New Guinea

We present a molecular phylogenetic analysis of 2808 aligned bp of rrnL, cox1, cob, H3 and 18S rRNA of all major morphological groups of Papuadytes diving beetles (Coleoptera: Dytiscidae) which are diverse in running water habitats throughout the Australian region. We focus on the origin of the fauna of the megadiverse islands of New Guinea and New Caledonia. Parsimony as well as Bayesian analyses suggest a basal position of Australian species in a paraphyletic series, with more recent nested radiations in New Caledonia and New Guinea. According to molecular clock analyses, both landmasses were colonized during the Miocene, which matches geological data and corroborates similar findings in other taxonomic groups. Our analyses suggest that dispersal played an important role in the formation of these large insular faunas, although successful colonization appears to be a rare event, and, in this case, is unidirectional. Whether or not a lineage is present on an island is due to chance: Papuadytes are absent from Fiji, where related Copelatus have radiated extensively in the same habitats occupied by Papuadytes in New Caledonia and New Guinea, while Copelatus are absent from New Caledonia. Lineages of Papuadytes apparently colonized New Caledonia twice, around 14 and 9 MYA according to the molecular calibration, and both lineages are derived from an Australian ancestor. The older clade is represented only by two apparently relictual mountain species (one morphologically strongly adapted to highly ephemeral habitats), while the younger clade contains at least 18 species exhibiting a great morphological diversity. The 150+ species in New Guinea are monophyletic, apparently derived from an Australian ancestor, and constitute a morphologically rather homogenous group. The tree backbone remains insufficiently supported under parsimony and Bayesian analyses, where shorter branches suggest a rapid sequence of major branching events.     

New Guinea: A Correlation between Accreting Areas and Dispersing Sapindaceae

A correlation between accreting (hybridizing) areas and dispersing taxa (several genera of Southeast Asian/Australian Sapindaceae) is theoretically impossible in cladistic biogeography. However, in particular circumstances (primitive absence followed by colonization and speciation) cladistic methods can reconstruct (part of) the historical sequence of accretion. In this example, the phases in the accretion history of more than 30 terranes of the northern half of New Guinea correspond reasonably well with the generalized area cladogram of the Sapindaceae.     

Biogeography of the world: a case study from cyphophthalmid Opiliones, a globally distributed group of arachnids

Aim To test the hypothesis that continental drift drives diversification of organisms through vicariance, we selected a group of primitive arachnids which originated before the break‐up of Pangaea and currently inhabits all major landmasses with the exception of Antarctica, but lacks the ability to disperse across oceanic barriers. Location Major continental temperate to tropical landmasses (North America, South America, Eurasia, Africa, Australia) and continental islands (Bioko, Borneo, Japan, Java, New Caledonia, New Guinea, New Zealand, Sri Lanka, Sulawesi, Sumatra). Methods Five kb of sequence data from five gene regions for more than 100 cyphophthalmid exemplars were analysed phylogenetically using different methods, including direct optimization under parsimony and maximum likelihood under a broad set of analytical parameters. We also used geological calibration points to estimate gross phylogenetic time divergences. Results Our analyses show that all families except the Laurasian Sironidae are monophyletic and adhere to clear biogeographical patterns. Pettalidae is restricted to temperate Gondwana, Neogoveidae to tropical Gondwana, Stylocellidae to Southeast Asia, and Troglosironidae to New Caledonia. Relationships between the families inhabiting these landmasses indicate that New Caledonia is related to tropical Gondwana instead of to the Australian portion of temperate Gondwana. The results also concur with a Gondwanan origin of Florida, as supported by modern geological data. Main conclusions By studying a group of organisms with not only an ancient origin, low vagility and restricted habitats, but also a present global distribution, we have been able to test biogeographical hypotheses at a scale rarely attempted. Our results strongly support the presence of a circum‐Antarctic clade of formerly temperate Gondwanan species, a clade restricted to tropical Gondwana and a Southeast Asian clade that originated from a series of early Gondwanan terranes that rifted off northwards from the Devonian to the Triassic and accreted to tropical Laurasia. The relationships among the Laurasian species remain more obscure.     

Three new species of Oreophryne (Anura,Microhylidae) from Papua New Guinea

I describe three new species of the diverse microhylid frog genus Oreophryne from Papua New Guinea. Two of these occur in two isolated mountain ranges along the northern coast of Papua New Guinea; the third is from Rossel Island in the very southeasternmost part of the country. All three are the first Oreophryne known from these areas to have a cartilaginous connection between the procoracoid and scapula, a feature usually seen in species far to the west or from the central cordillera of New Guinea. Each of the new species also differs from the many other Papuan Oreophryne in a variety of other morphological, color-pattern, and call features. Advertisement-call data for Oreophryne species from the north-coast region suggest that they represent only two of the several call types seen in regions further south, consistent with the relatively recent derivation of these northern regions as accreted island-arc systems. The distinctively different, whinnying, call type of the new species from Rossel Island occurs among other Oreophryne from southeastern Papua New Guinea but has been unreported elsewhere, raising the possibility that it may characterize a clade endemic to that region.     

The Australian monsoon tropics as a barrier for exchange of dragonflies (Insecta: Odonata) between New Guinea and Australia

Recent studies show a remarkable scarcity of faunal exchange events between Australia and New Guinea in the Pleistocene despite the presence of a broad land connection for long periods. This is attributed to unfavourable conditions in the connecting area associated with the long established northern Australian Monsoon Climate. This would be expected to have impacted strongly on freshwater faunas with the following results: (1) limited overlap in species, (2) most higher taxonomic groups present in both areas sharing no species or even genera and (3) shared species dominated by lentic species with high dispersal capacity. Testing these predictions for dragonflies showed the turnover in the family, genus and species composition between Australia and New Guinea to be higher than anywhere in the world with only 50% of families and subfamilies, 33% of the genera and 8% of the species being shared. Only one of the 53 shared species favors lotic waters compared with 64% of the 652 combined Australian–New Guinean species. These results agree with our predictions and indicate that the dragonfly fauna of Australia and New Guinea have effectively been separated during the Pleistocene probably due to the prolonged unfavourable climatic conditions in the intervening areas.     

Continental shelf as potential retreat areas for Austral‐Asian estrildid finches (Passeriformes: Estrildidae) during the Pleistocene

Studies dealing with changes of biodiversity in time and space constitute an important part of biogeography, ecology and conservation biology. Areas of long‐term climate stability are particularly interesting as they might have facilitated the survival of species over historical times and thus are crucial for understanding contemporary diversity patterns. In this study, we assessed the potential distribution of 23 estrildid finch species in order to analyse stability in recent and past diversity patterns and diversity centres in the Austral‐Asiatic region. We used Maxent to predict recent distributions of each species and to project them onto the climatic conditions of the Last Glacial Maximum (LGM, 21 000 yr BP) using two different scenarios (CCSM, MIROC). The resulting diversity patterns were tested on presence and possible shifts of distribution centres. Diversity patterns of forest‐ and savannah‐living species were considered combined and separately. During the LGM, potential diversity patterns of forest‐living species corroborated well with postulated rainforest refuges situated on the eastern coast of Cape York Peninsula. Our results indicate a remarkably high stability of existing diversity centres. Although projections into the past show some differences in detail in the extent and exact position of the diversity centres, they reveal largely congruent large scale patterns in both time slices. However, the models suggest a northward shift towards exposed continental shelf areas that where dry during the LGM. Clearly, centres of diversity were situated on this land bridge between Australia and New Guinea, highlighting their importance as areas of retreat for estrildid finches and maybe other savannah species in times of changing climatic conditions and associated sea‐level fluctuations.     

Holocene palynology and sea-level change in two estuaries in Southern Irian Jaya

Southern New Guinea leads the continental Australian plate into convergence to form the New Guinea Highlands. Extensive inter-tidal deltas are typical of much of this low gradient equatorial coastline. In two adjacent estuaries in Irian Jaya (West Papua), this study uses present elevations of mangrove species zones as a finite indicator of Holocene sea levels from pollen diagrams of estuarine cores. All cores showed mangroves at levels well below the present tidal range, with landward species zones being replaced over time by seaward zones. Results show tectonic subsidence in the recent period, with Late Holocene relative sea-level rise of 0.67 mm year⁻¹.     

Exocelina baliem sp. n., the only known pond species of New Guinea Exocelina Broun, 1886 (Coleoptera,Dytiscidae, Copelatinae)

Exocelina baliem sp. n. is described from the Baliem Valley in the Central Mountain Range of New Guinea (Papua Province, Indonesia). Having striolate elytra, different structure and setation of the male and female genitalia and tarsomeres, and inhabiting swampy ponds, the new species differs from all known New Guinea species, which have smooth elytra and are stream associated. It forms a monophyletic group with the Australian Exocelina ferruginea (Sharp, 1882) and New Caledonian Exocelina inexspectata Wewalka, Balke & Hendrich, 2010, based on shape of the paramere and structure of the male tarsi. Habitus, protarsomeres, and male and female genitalia are illustrated, comparing some structures with Exocelina ferruginea and two New Guinea stream species. We briefly discuss the biogeographic relevance of this discovery.     

Phytogeography, range size and richness of Australian endemic Sauropus (Euphorbiaceae)

Aim To investigate the distribution of Australian species of Sauropus. The information obtained is used to (1) identify areas of highest richness and centres of endemism, (2) investigate latitudinal gradients of richness and range size, (3) determine the types of rarity shown, and (4) provide hypotheses on historical biogeography of the genus within Australia. Location Australia. Methods Specimens from 17 herbaria and field searches were examined and label and field information collated on distribution, habit and habitat. Distribution information was used to map all species within 784 grid cells of 1° × 1° and within the 97 Australian ‘ecological regions’. Morphometric cluster analysis of species was conducted using Kulczynski association and flexible UPGMA on 23 character states. Simple regression was used to correlate species richness, density and range size to changes in latitude. CLIMEX is used to match the climate of the region of highest richness in Australia with other areas of the world. Results Species richness was highest within the tropical north of Australia, and most species were associated with tropical savanna woodlands. Two areas were identified as centres of endemism and these corresponded closely to areas of high species richness. Four morphological groups were identified. One species (Sauropus trachyspermus) was found to be widespread, however all other species had small geographical ranges. Species richness and range size were significantly correlated with changes in latitude. Ten species were found to be of the rarest type, warranting conservation initiatives. Main conclusions Two regions of high richness and endemism of Sauropus occur, Thailand and Australia. Within Australia, the Kakadu‐Alligator River and the Cairns‐Townsville areas were identified as centres of endemism and high species richness for Sauropus. Australian Sauropus in general occur in similar communities and climates as other members of the genus elsewhere. Ten of the 27 species of Australian endemic Sauropus are extremely rare and warrant conservation initiatives. Correlations of latitude to species richness are potentially due to Sauropus radiating from the climatically stable top end of Australia. Increasing range size in more southern latitudes may also be due to stability of climates in the top end or because there is more available land area at these latitudes. Sauropus micranthus, the only non‐endemic species, is probably a more recent invader from the Tertiary period when tropical rain forests where more extensive and congruent with those of New Guinea.     

A structural comparison of New Zealand and south-east Australian rain forests and their tropical affinities

An ecological comparison, with special reference to tropical affinities, is made between the rain forests of New Zealand and south-east Australia, based on the distribution of seventy physiognomic-structural attributes in mature forests at selected sites (ten in New Zealand, twenty in Australia, and four in New Guinea to represent authentic humid tropical lowland rain forest). The structural data were recorded in a standard pro forma and subjected to classification, ordination and two-parameter analysis. In the classification, the Australian and New Zealand sites, with two exceptions, separated at the four-group level. The more complex (cool subtropical) Australian types were the least related to the New Zealand forests, which are closest to Australian simple (submontane) types. There was a similar distinction in the ordination, in which the trend along the first two vectors was latitudinal, correlated with extremes of temperature and with moisture availability. The relative contributions of the structural attributes to the various site groupings in the classification and ordination are enumerated, and provide an objective scale of comparison of the forests. Structural attributes designated by analysis as exclusively or preferentially tropical by reference to the New Guinea sites are then used to assess degree of tropical affinity. The simplified cool temperate (montane) forests dominated by one species of Notho-fagus in New Zealand and Australia are closely related. The Australian forests of the sub-montane zone (mean annual temperature 12–15° C) which are typically dominated by Ceratopetalum apetalum, Nothofagus moorei or Doryphora sassafras, are similar to the podocarp-broadleaf forests, with or without kauri, of New Zealand. The Australian forests of the cool subtropical zone (mean annual temperature 15–17°C) which have mixed dominants, have some affinities with the kauri-podocarp-broadleaf forests of North Auckland. In New Zealand, a broadleaf type in which kauri is absent or rare on basalt in North Auckland (lat. 35° S) was the most complex forest sampled and is marginally subtropical.     

世界蜘蛛的分布格局及其多元相似性聚类分析

蜘蛛是一类种类繁多、数量巨大、分布广泛的捕食性生物。至2012年底,全世界共有蜘蛛43678种（包括亚种）,隶属于112科3898属。科、属、种3个分类阶元的分布域非常悬殊,90%的种分布在一个界内,90%的科是跨界分布或全球分布。按行政区域,亚洲种类较多,欧洲较少,南极洲没有蜘蛛记录;按动物地理区域,古北界和新热带界较多,新北界较少。根据地理条件、生态条件和蜘蛛的分布状况,将全球陆地分为53个基础地理单元,用申效诚等新近提出的相似性通用公式和据此创立的多元相似性聚类分析方法,分别对属、种两级的分布进行分析,得到两个聚类结构相同、聚类关系合理的支序图,而且属级的支序图层次更为分明,在相似性水平为0.32时,53个基础地理单元聚为17个小单元群,在0,22水平上,又聚为8个大单元群。这些大、小单元群的组成单元地域相邻相连,生态条件相对一致,可以作为蜘蛛地理区划的界、亚界两个层级。和华莱士主要以哺乳动物建立的世界动物地理区划相比,主要差异是：1、古北界东、西两部分差异显著,可分设两界;2、新西兰和澳洲大陆相似性较低,可单独设界;3、新几内亚和太平洋岛屿与澳洲大陆的关系远于和东洋界的关系,华莱士线在两界间的作用似乎不存在; 4、新热带界的中美地区似乎属于新北界更为合适,并由此产生了南北美洲间的紧密联系;5、新北界与古北界的相似性关系弱于与新热带界的关系,全北界的概念几近消失。前两点差异可以从地球板块构造的变动得到解释,第3、5个差异已在植物和其它生物类群得到佐证,第4个差异尚不稳定,需要更多类群的比较与分析。使用多元相似性聚类分析方法对于如此典型的点状分布的生物类群和如此海量的数据,能够得到如此精细的,既符合地理学、统计学的逻辑,又符合生物学、生态学逻辑的定量分析结果,这在国内外都是首次成功尝试,其简便性和合理性将会促使在其它类群中的应用。     

The endemic plant families and the palms of New Caledonia: a biogeographical analysis

This paper provides a panbiogeographical analysis of the endemic plant families and the palms of New Caledonia. There are three endemic plant families in New Caledonia and several genera that were previously recognized as endemic families. Of these taxa, some are sister to widespread Northern Hemisphere or global groups (Canacomyrica, Austrotaxus, Amborella). The others belong to trans‐Indian Ocean groups (Strasburgeria), trans‐tropical Pacific groups (Oncotheca) or Tasman Sea/Coral Sea groups (Phelline, Paracryphia) that are sister to widespread Northern Hemisphere or global groups. In palms, the four clades show allopatric regional connections in, respectively: (1) western Indonesia, Malaysia and Thailand; (2) Vanuatu/Fiji and the southern Ryukyu Islands near Taiwan; (3) the western Tasman/Coral Sea (eastern Australia, New Guinea and the Solomon Islands); and (4) the eastern Tasman/Coral Sea (Lord Howe and Norfolk Islands, New Zealand, Vanuatu, Fiji and the Solomon Islands). The four clades thus belong to different centres of endemism that overlap in New Caledonia. The patterns are attributed not to chance dispersal and adaptive radiation but to the different histories of the eight terranes that fused to produce modern New Caledonia. Trans‐tropical Pacific connections can be related to the Cretaceous igneous plateaus that formed in the central Pacific and were carried, with plate movement, west to the Solomon Islands and New Zealand, and east to Colombia and the Caribbean.     

Panbiogeography of Nothofagus (Nothofagaceae): analysis of the main species massings

Aim The aim of this paper is to analyse the biogeography of Nothofagus and its subgenera in the light of molecular phylogenies and revisions of fossil taxa. Location Cooler parts of the South Pacific: Australia, Tasmania, New Zealand, montane New Guinea and New Caledonia, and southern South America. Methods Panbiogeographical analysis is used. This involves comparative study of the geographic distributions of the Nothofagus taxa and other organisms in the region, and correlation of the main patterns with historical geology. Results The four subgenera of Nothofagus have their main massings of extant species in the same localities as the main massings of all (fossil plus extant) species. These main massings are vicariant, with subgen. Lophozonia most diverse in southern South America (north of Chiloé I.), subgen. Fuscospora in New Zealand, subgen. Nothofagus in southern South America (south of Valdivia), and subgen. Brassospora in New Guinea and New Caledonia. The main massings of subgen. Brassospora and of the clade subgen. Brassospora/subgen. Nothofagus (New Guinea–New Caledonia–southern South America) conform to standard biogeographical patterns. Main conclusions The vicariant main massings of the four subgenera are compatible with largely allopatric differentiation and no substantial dispersal since at least the Upper Cretaceous (Upper Campanian), by which time the fossil record shows that the four subgenera had evolved. The New Guinea–New Caledonia distribution of subgenus Brassospora is equivalent to its total main massing through geological time and is explained by different respective relationships of different component terranes of the two countries. Global vicariance at family level suggests that Nothofagaceae/Nothofagus evolved largely as the South Pacific/Antarctic vicariant in the breakup of a world‐wide Fagales ancestor.     

The phylogenetic relationships of the bilby, Macrotis lagotis (Peramelimorphia: Thylacomyidae), to the bandicoots- DNA sequence evidence

Partial sequencing of the 12S ribosomal RNA gene was used to test two competing hypotheses concerning the phylogenetic relationship of the bilby (Macrotis lagotis) to the Australian and New Guinean species of bandicoot. The first hypothesis proposes that the Australian and New Guinean bandicoots are in a monophyletic clade to the exclusion of the bilbies, whereas the second hypothesis proposes that the bilby is monophyletic with the Australian bandicoots to the exclusion of the New Guinean bandicoots. Phylogenies determined by both maximum-likelihood and neighbour-joining approaches supported the first hypothesis in which the bilby is excluded from the clade represented by the Australian and New Guinean bandicoots. Monophyly of the Australian and New Guinean bandicoots is consistent with the biogeographical scenario in which Australia and Papua New Guinea have undergone repeated connection and disconnection over the last 20 million years.     

The spermatozoon of the Old Endemic Australo‐Papuan and Philippine rodents – its morphological diversity and evolution

Breed, W.G. and Leigh, C.M. 2010. The spermatozoon of the Old Endemic Australo‐Papuan and Philippine rodents – its morphological diversity and evolution.—Acta Zoologica (Stockholm) 91 : 279–294 The spermatozoon of most murine rodents contains a head in which there is a characteristic apical hook, whereas most old endemic Australian murines, which are part of a broader group of species that also occur in New Guinea and the Philippines, have a far more complex sperm form with two additional ventral processes. Here we ask the question: what is the sperm morphology of the New Guinea and Philippines species and what are the trends in evolutionary changes of sperm form within this group? The results show that, within New Guinea, most species have a highly complex sperm morphology like the Australian rodents, but within the Pogonomys Division some species have a simpler sperm morphology with no ventral processes. Amongst the Philippines species, many have a sperm head with a single apical hook, but in three Apomys species the sperm head contains two additional small ventral processes, with two others having cockle‐shaped sperm heads. When these findings are plotted on a molecular phylogeny, the results suggest that independent and convergent evolution of highly complex sperm heads containing two ventral processes has evolved in several separate lineages. These accessory structures may support the sperm head apical hook during egg coat penetration.