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1.
The Hydrachnidia (water mites) represent the most important group of the Arachnida in fresh water. Over 6,000 species have been described worldwide, representing 57 families, 81 subfamilies and more than 400 genera. The article analyzes extant water mite diversity and biogeography. Data on distribution and species richness of water mites are substantial but still far from complete. Many parts of the world are poorly investigated, Oriental and Afrotropical regions in particular. Moreover, information among different freshwater habitats is unbalanced with springs and interstitial waters disproportionately unrepresented. Therefore, more than 10,000 species could be reasonably expected to occur in inland waters worldwide. Based on available information, the Palaearctic region represents one of the better investigated areas with the highest number of species recorded (1,642 species). More than 1,000 species have been recorded in each of the Neotropical (1,305 species) and Nearctic regions (1,025 species). Known species richness is lower in Afrotropical (787 species) and Australasian (694 species) regions, and lowest in the Oriental region (554 species). The total number of genera is not correlated with species richness and is distinctly higher in the Neotropical (164 genera); genus richness is similar in the Palaearctic, Nearctic and Australasian regions (128–131 genera) and is lower in the Afrotropical and Oriental regions with 110 and 94 genera, respectively. A mean number of about three genera per family occur in the Palaeartic, Nearctic and Oriental while an average of more than four genera characterizes the families of Australasian and Afrotropical regions and more than five genera those of the Neotropical. Australasian fauna is also characterized by the highest percentage of endemic genera (62%), followed by Neotropical (50.6%) and Afrotropical (47.2%) regions. Lower values are recorded for the Palaearctic (26.9%), Oriental (24.4%) and Nearctic (21.4%). The Palaearctic and Nearctic have the highest faunistic similarity, some minor affinities are also evident for the generic diversification of Holarctic and Oriental families. The faunas of Southern Hemisphere bioregions are more distinct and characterized by the presence of ancient Gondwanan clades with a regional diversification particularly evident in the Neotropics and Australasia. This scenario of water mite diversity and distribution reflect the basic vicariance pattern, isolation, phylogenetic diversification, recent climatic vicissitudes and episodes of dispersal between adjacent land masses together with extant ecological factors can be evoked to explain distribution patterns at a global scale. Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens Freshwater Animal Diversity Assessment  相似文献   

2.
Historical biogeography of scarabaeine dung beetles   总被引:1,自引:0,他引:1  
Abstract Aim (1) To review briefly global biogeographical patterns in dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae), a group whose evolutionary history has been dominated by ecological specialization to vertebrate dung in warmer climates. (2) To develop hypotheses accounting for the evolution of these patterns. Location Six principal biogeographical regions: Palaearctic, Oriental, Afrotropical, Australasia, Neotropical, Nearctic and five outlying islands or island groups harbouring endemic genera: Caribbean, Madagascar, Mauritius, New Caledonia, New Zealand. Methods Major patterns of tribal, generic and species distribution are investigated using cluster analysis, ordination, parsimony analysis of endemism and track analysis. Attempts are made to resolve biogeographical patterns with findings in the fields of plate tectonics, fossil and evolutionary history, plus phylogeny of both mammals and dung beetles. Results Because of conflict between published findings, it is uncertain at what point in time density of dinosaur dung, mammal dung or both became sufficiently great to select for specialized habits in dung beetles. However, biogeographical evidence would suggest a Mesozoic origin followed by further taxonomic radiation during the Cenozoic, possibly in response to the increasing size and diversity of mammalian dung types in South America and Afro‐Eurasia. Proportional generic distribution in fourteen tribes and subtribes showed four principal biogeographical patterns: (1) southerly biased Gondwanaland distribution, (2) Americas or (3) Madagascar endemism, and (4) northerly biased, Afro‐Eurasian‐centred distribution with limited numbers of genera also widespread in other regions. Proportional composition of faunas in eleven geographical regions indicated three principal distributional centres, East Gondwanaland fragments, Afro‐Eurasia and the Americas. These patterns probably result from three principal long‐term range expansion and vicariance events (Mesozoic: Gondwanaland interchange and fragmentation, Cenozoic: Afro‐Eurasian/Nearctic interchange and the Great American interchange). It is suggested that old vicariance caused by the Mesozoic fragmentation of Gondwanaland leads to a high degree of regional endemism at generic or tribal level across one or more Gondwanaland tracks. In contrast, it is suggested that the more recent Cenozoic range expansions occurred primarily towards northern regions leading to endemism primarily at species level. These Cenozoic radiations were facilitated by the re‐linking of continents, either because of tectonic plate movements (Africa to Eurasia in Miocene), climatically induced sea‐level change (Afro‐Eurasia to Nearctic in Miocene and Pleistocene), or similar coupled with orogenics (Nearctic to Neotropical in Pliocene). Speciation has followed vicariance either because of climatic change or physical barrier development. These recent range expansions probably occurred principally along an Afro‐Eurasian land track to the Nearctic and Neotropical and an Americas land track northwards from the Neotropics to the Nearctic, with limited dispersal from Eurasia to Australia, probably across a sea barrier. This accounts for the overall, spatially constrained, biogeographical pattern comprising large numbers of species‐poor genera endemic to a single biogeographical region and fewer more species‐rich genera, many of which show wider biogeographical distributions. In most southerly regions (Australasia, Madagascar, Neotropical), faunal composition and generic endemism is primarily dominated by elements with Gondwanaland ancestry, which is consistent with the Gondwanaland origin claimed for Scarabaeinae. In Afro‐Eurasia (Palaearctic, Oriental, Afrotropical), generic endemism of monophyletically derived Afro‐Eurasian and widespread lineages is centred in the Afrotropical region and faunal composition is numerically dominated by Afro‐Eurasian and widespread elements. In the Nearctic region, the fauna is jointly dominated by widespread elements, derived from Afro‐Eurasia, and Gondwanaland and Americas elements derived from the Neotropical region. Main conclusions Global biogeographical patterns in scarabaeine dung beetles primarily result from Mesozoic and Cenozoic range expansion events followed by vicariance, although recent dispersal to Australia may have occurred across sea barriers. Detailed phylogenetics research is required to provide data to support dispersal/vicariance hypotheses.  相似文献   

3.
The World fauna of the tribe Eupitheciini is the most species-rich in the family Geometridae. This tribe includes about 1900 species (almost 3000 species-group names) from 47 genera; about one third of the genera (15) are monotypic. The generic diversity of Eupitheciini is the highest in the Australian (38 genera, 11 of them endemic) and Oriental regions (32 genera, 4 endemic) and the lowest in the Neotropical Region (possibly one genus only). The faunas of different biogeographic regions can be arranged in following order by their species richness: the Palaearctic (487 species), Oriental (397), Neotropical (346), Australian (251), Afrotropical (198), and Nearctic Regions (166 species). Eupithecia is the most species-rich genus in the family Geometridae and the entire order Lepidoptera, and one of the largest genera in the whole World fauna of insects. The greatest number of species of this genus is recorded in the Palaearctic Region (466 species), where Eupithecia accounts for about 95% of the tribe Eupitheciini. The mainland of the Oriental Region (especially the Himalayas) is also very species-rich; however the proportion of the Eupithecia representatives decreases towards Malaysia, Sundaland, and the Australian Region (about 2% of the tribe). The Eupitheciini faunas have the greatest similarity at the generic level between the Oriental and Australian Regions (the Jaccard and Sørensen coefficient values being 0.62 and 0.77, respectively). The Palaearctic fauna is more similar to the Afrotropical and Oriental faunas at the genus-group level. On the whole, the fauna of the Nearctic Region is similar to that the West Palaearctic, with the exception of the fact that representatives of the genera Gymnoscelis and Chloroclystis are absent in North America, although two endemic genera Nasusina and Prorella are present. At the genus-group level, the Nearctic fauna of Eupitheciini is more similar to the Neotropical (the Jaccard and Sørensen coefficients 0.20 and 0.33, respectively) than to the Palaearctic fauna (0.17 and 0.29). The number of synonymies is very high in the tribe Eupitheciini because of the homogeneity of this group, whose species are difficult to identify without the use of elaborate anatomical techniques. Modern revisions, catalogues, surveys, and atlases on Eupitheciini are absent for many countries and large geographic regions. Revisions of pugs of the tribe Eupitheciini for some biogeographic regions are extremely difficult because of fragmentation of entomological collections including the type specimens of many species-group taxa. A large fraction of synonyms is characteristic of parts of the World with the best known faunas: Europe (64% of synonyms) and North America (39%). On the contrary, the lowest levels of synonymy are typical of the less known faunas of the regions situated at the equatorial latitudes, namely the Neotropical (9%) and Afrotropical (8%) ones.  相似文献   

4.
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   

5.
西双版纳热带雨林蚁科昆虫区系分析   总被引:9,自引:1,他引:8  
徐正会 《动物学研究》1999,20(5):379-384
在西双版纳热带雨林已鉴定蚊科昆虫9亚科76属267种。西双版纳地区的蚂蚁区系以热带至亚热带分布的东洋界成分最为丰富。在属级水平上,与马来西亚界关系最为密切。与澳洲界关系较密切;与非洲界和马拉加西界的关系知中。与新北界,新热带界和古北界的关系最为疏远。可见西双版纳的蚂蚁区系具有典型的热带亚洲起源特征,同时与澳洲和非洲的热带区系有一定的渊源关系。  相似文献   

6.
申效诚  张保石  张锋  刘新涛 《生态学报》2013,33(21):6795-6802
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。  相似文献   

7.
本文就科昆虫的起源,各亚科、族及属的分布特点进行了分析和总结;并根据各属的世界分布情况,将其分为8种类型。文中还就中国科昆虫的地理分布及特点作了初步的探讨,结果表明:在我国已知的2亚科4族20个属中,东洋区分布的有10个属,其中有3个属仅分布于我国;古北区分布的有1个属;东洋-古北区分布的有3个属;东洋-新北区分布的有1个属;东洋-古北-新北区分布的有4个属;东洋-古北-新北-非洲区分布的有1个属。此外,科昆虫在中国的一个主要分布特点就是多数种类集中分布于华中区、华南区和西南区;而华中区则很可能是科种类的分化中心,并以此为中心向其他区扩散。  相似文献   

8.
本文系统分析了叶蜂总科广布属的地理分布特性。叶蜂总科广布属被分为12个主要的分布类型,其中全北界分布型69属,可再分为6种次类型。在各分布型下列举了全部具有该类分布特征的叶蜂总科属名,并提出了一些有关起源与扩散的设想和推论。在广布型属的地理分布研究基础上,对各大生物地理界之间的关系也提出了一些看法。  相似文献   

9.
We have inferred the most comprehensive phylogenetic hypothesis to date of butterflies in the tribe Satyrini. In order to obtain a hypothesis of relationships, we used maximum parsimony and model‐based methods with 4435 bp of DNA sequences from mitochondrial and nuclear genes for 179 taxa (130 genera and eight out‐groups). We estimated dates of origin and diversification for major clades, and performed a biogeographic analysis using a dispersal–vicariance framework, in order to infer a scenario of the biogeographical history of the group. We found long‐branch taxa that affected the accuracy of all three methods. Moreover, different methods produced incongruent phylogenies. We found that Satyrini appeared around 42 Mya in either the Neotropical or the Eastern Palaearctic, Oriental, and/or Indo‐Australian regions, and underwent a quick radiation between 32 and 24 Mya, during which time most of its component subtribes originated. Several factors might have been important for the diversification of Satyrini: the ability to feed on grasses; early habitat shift into open, non‐forest habitats; and geographic bridges, which permitted dispersal over marine barriers, enabling the geographic expansions of ancestors to new environments that provided opportunities for geographic differentiation, and diversification.
相似文献   

10.
A phylogeny of the 37 known species and subspecies of the micropterous snow fly genus Chionea Dalman is presented using adult morphological characters. The genus contains two major clades: a strictly Palaearctic clade, and a combined Nearctic‐Palaearctic clade with representatives in the Nearctic and Western Palaearctic regions. As there is little congruence between the recovered phylogeny of Chionea and the currently used subgeneric division in Chionea s.s. and Sphaeconophilus Becker, we propose to abandon the use of subgeneric taxa in Chionea. A strictly morphological analysis appears to be insufficient to fully resolve the phylogeny of the genus at the species level, and future molecular work should provide additional evidence for the establishment of relationships among the members of Chionea. The large‐scale historical biogeography of Chionea was analysed using dispersal‐vicariance analysis. The initial distribution area of the genus probably extended in the Eastern Palaearctic, and the Nearctic and the origin of Chionea could be dated in the Late Cretaceous. The various dispersal and vicariance events that led to the major speciation events in the genus are set against major paleogeographic developments. The ancestor of the Western Palaearctic group in the second major clade originated from the Nearctic. The presence of the cold‐adapted Chionea in currently temperate to warm climatic zones in the southern parts of its distribution was analysed using ecological niche modelling. It appears that prolonged periods of climate cooling, as occurred during the Last Glacial Maximum, enabled Chionea to cover large parts of central and southern Europe and reach the southern distribution areas where the genus is present today. A similar biogeographic pattern was less evident in the Nearctic region.  相似文献   

11.
中国夜蛾科昆虫的物种多样性及分布格局   总被引:5,自引:0,他引:5  
申效诚  孙浩  赵华东 《昆虫学报》2007,50(7):709-719
本文在收集整理中国夜蛾全部种类名录和分布资料的数据库基础上,对其分布格局进行了分析。结果表明:中国夜蛾共有20个亚科845个有效属3 751个有效种,占世界种类的13.66%,其中1 734种模式产地在中国。这些种类主要归属4种区系成分,其中东亚成分占优势,占总数的51.35%,东洋成分占25.51%,古北成分占18.45%,广布成分仅2.26%。夜蛾在全国七个动物地理区中的分布,是不同类群不同分布特点的复合体,84种广布种分布广泛而均匀,七区之间的多元相似性系数达显著水平。 957种东洋种类和692种古北种类随纬度呈阶梯状分布,各区间无显著相似性。 1 926种东亚种类中,南中国型1 363种,分别较为孤立地分布在华南、华中、西南三区,各区之间联系微弱; 北中国型290种,零星分散地分布在东北、蒙新、华北、青藏四区; 中中国型273种遍布全国,但主要分布在我国中部的华北、华中、西南、青藏四区,以跨界分布为特点,四区之间具有显著的多元相似性。特有种的简约性分析结果表明,特有分布区的分布和划分基本和中国动物地理区划相一致,但台湾和华中区关系密切。关键区系分析显示,台湾、云南、新疆、西藏等11个省区包含了中国夜蛾物种的90%,是物种保护的优先区域。  相似文献   

12.
Previous hypotheses of phylogenetic relationships among Nearctic toads (Bufonidae) and their congeners suggest contradictory biogeographic histories. These hypotheses argue that the Nearctic Bufo are: (1) a polyphyletic assemblage resulting from multiple colonizations from Africa; (2) a paraphyletic assemblage resulting from a single colonization event from South America with subsequent dispersal into Eurasia; or (3) a monophyletic group derived from the Neotropics. We obtained approximately 2.5 kb of mitochondrial DNA sequence data for the 12S, 16S, and intervening valine tRNA gene from 82 individuals representing 56 species and used parametric bootstrapping to test hypotheses of the biogeographic history of the Nearctic Bufo. We find that the Nearctic species of Bufo are monophyletic and nested within a large clade of New World Bufo to the exclusion of Eurasian and African taxa. This suggests that Nearctic Bufo result from a single colonization from the Neotropics. More generally, we demonstrate the utility of parametric bootstrapping for testing alternative biogeographic hypotheses. Through parametric bootstrapping, we refute several previously published biogeographic hypotheses regarding Bufo. These previous studies may have been influenced by homoplasy in osteological characters. Given the Neotropical origin for Nearctic Bufo, we examine current distributional patterns to assess whether the Nearctic-Neotropical boundary is a broad transition zone or a narrow boundary. We also survey fossil and paleogeographic evidence to examine potential Tertiary and Cretaceous dispersal routes, including the Paleocene Isthmian Link, the Antillean and Aves Ridges, and the current Central American Land Bridge, that may have allowed colonization of the Nearctic.  相似文献   

13.
Studies of Neotropical birds, and their distributions and areas of endemism, in particular, have been central in the formulation of hypotheses proposed to explain the high species diversity in the Neotropics. We used mtDNA sequence data (ATPase 6 and 8, COI, and cyt b) to reconstruct the species-level phylogenies for two genera, Pionopsitta (Aves: Psittacidae) and Pteroglossus (Aves: Ramphastidae), compare our results with previous morphology-based phylogenetic analyses, and estimate the absolute timing of lineage and biogeographic divergences. Both the Pionopsitta and Pteroglossus phylogenies support a hypothesis of area relationships in which a divergence of the Serra do Mar (Atlantic Forest, Brazil) region of endemism is followed by the divergence of cis- and trans-Andean regions, then a split between the upper and lower Amazon basin, next the divergence of the Guyana area, and finally diversification of taxa in the upper Amazon basin's areas of endemism. Phylogenies of both genera support a hypothesis of area relationships that is similar to that proposed by Prum [XIX International Ornithological Congress (1988), 2562] for high-vagility species, but while they agree on the relative timing of area divergence (vicariance) events, they yield different absolute time estimates for those divergences when the typical avian mtDNA clock calibration is used. Taken at face value, the time estimates indicate that both genera began to diversify before the start of the Pleistocene, and that climatic and habitat shifts alone do not account for the diversification of these taxa.  相似文献   

14.
The not yet uploaded Trichoptera World Checklist (TWC) [], as at July 2006, recorded 12,627 species, 610 genera and 46 families of extant and in addition 488 species, 78 genera and 7 families of fossil Trichoptera. An analysis of the 2001 TWC list of present-day Trichoptera diversity at species, generic/subgeneric and family level along the selected Afrotropical, Neotropical, Australian, Oriental, Nearctic and Palaearctic (as a unit or assessed as Eastern and Western) regions reveals uneven distribution patterns. The Oriental and Neotropical are the two most species diverse with 47–77% of the species in widespread genera being recorded in these two regions. Five Trichoptera families comprise 55% of the world’s species and 19 families contain fewer than 30 species per family. Ten out of 620 genera contain 29% of the world’s known species. Considerable underestimates of Trichoptera diversity for certain regions are recognised. Historical processes in Trichoptera evolution dating back to the middle and late Triassic reveal that the major phylogenetic differentiation in Trichoptera had occurred during the Jurrasic and early Cretaceous. The breakup of Gondwana in the Cretaceous led to further isolation and diversification of Trichoptera. High species endemism is noted to be in tropical or mountainous regions correlated with humid or high rainfall conditions. Repetitive patterns of shared taxa between biogeographical regions suggest possible centres of origin, vicariant events or distribution routes. Related taxa associations between different regions suggest that an alternative biogeographical map reflecting Trichoptera distribution patterns different from the Wallace (The Geographical Distribution of Animals: With a Study of the Relations of Living and Extinct Faunas as Elucidating the Past Changes of the Earth’s Surface, Vol. 1, 503 pp., Vol. 2, 607 pp., Macmillan, London, 1876) proposed biogeography patterns should be considered. Anthropogenic development threatens biodiversity and the value of Trichoptera as important functional components of aquatic ecosystems, indicator species of deteriorating conditions and custodians of environmental protection are realised.  相似文献   

15.
蚊科的区系分布及其演变的初步探讨:双翅目:蚊科   总被引:4,自引:0,他引:4  
  相似文献   

16.
The aquatic and semi-aquatic Heteroptera, consisting of the infraorders Leptopodomorpha, Gerromorpha, and Nepomorpha, comprise a significant component of the world’s aquatic insect biota. Within these three infraorders as a whole there are currently 23 families, 343 genera and 4,810 species group taxa considered valid, of which 20 families, 326 genera and 4,656 species inhabit freshwater. In addition, more than 1,100 unequivocally diagnosed species remain to be described. Aquatic Heteroptera occur on all continents except Antarctica, and are most numerous in the tropical regions, although there are many distinctly cold-adapted genera. Overall species richness is highest in the Neotropical and Oriental regions, which harbor 1,289 and 1,103 species, respectively. In comparison to these core tropical regions, species richness is significantly lower in the Afrotropical (799 species), Australasian (654 species), Palearctic (496 species), Nearctic (424 species) and Pacific (37 species) regions. Aquatic Heteroptera are notable for utilizing an exceptionally broad range of habitats, from marine and intertidal to arctic and high alpine, across a global altitudinal range of 0–4,700 m. Species may be found in almost every freshwater biotope, and many exhibit striking morphological adaptations to their aquatic environment, making them excellent subjects for ecological and biogeographic studies. Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens Freshwater Animal Diversity Assessment  相似文献   

17.
Many tropical tree species occupy continental expanses of rainforest and flank dispersal barriers such as oceans and mountains. The role of long-distance dispersal in establishing the range of such species is poorly understood. In this study, we test vicariance hypotheses for range disjunctions in the rainforest tree Ceiba pentandra, which is naturally widespread across equatorial Africa and the Neotropics. Approximate molecular clocks were applied to nuclear ribosomal [ITS (internal transcribed spacer)] and chloroplast (psbB-psbF) spacer DNA sampled from 12 Neotropical and five West African populations. The ITS (N=5) and psbB-psbF (N=2) haplotypes exhibited few nucleotide differences, and ITS and psbB-psbF haplotypes were shared by populations on both continents. The low levels of nucleotide divergence falsify vicariance explanations for transatlantic and cross-Andean range disjunctions. The study shows how extreme long-distance dispersal, via wind or marine currents, creates taxonomic similarities in the plant communities of Africa and the Neotropics.  相似文献   

18.
Thirty-three termite species have been recorded from the Arabian peninsula (from Saudi Arabia, North and South Yemen, Oman, Bahrain, Abu Dhabi, Qatar and Kuwait). The fauna is predominantly Afro-tropical (Ethiopian) but with a major Palaearctic (Eremic) element. The greatest diversity occurs in the south-west where mountainous regions provide greater habitat diversity than elsewhere. The Afro-tropical influence decreases towards the north and east, the Palaearctic influence increasing correspondingly; the Oriental influence is negligible and the level of endemism is high.  相似文献   

19.

Background

Rutaceae subfamily Rutoideae (46 genera, c. 660 species) is diverse in both rainforests and sclerophyll vegetation of Australasia. Australia and New Caledonia are centres of endemism with a number of genera and species distributed disjunctly between the two regions. Our aim was to generate a high-level molecular phylogeny for the Australasian Rutoideae and identify major clades as a framework for assessing morphological and biogeographic patterns and taxonomy.

Methodology/Principal Findings

Phylogenetic analyses were based on chloroplast genes, rbcL and atpB, for 108 samples (78 new here), including 38 of 46 Australasian genera. Results were integrated with those from other molecular studies to produce a supertree for Rutaceae worldwide, including 115 of 154 genera. Australasian clades are poorly matched with existing tribal classifications, and genera Philotheca and Boronia are not monophyletic. Major sclerophyll lineages in Australia belong to two separate clades, each with an early divergence between rainforest and sclerophyll taxa. Dehiscent fruits with seeds ejected at maturity (often associated with myrmecochory) are inferred as ancestral; derived states include woody capsules with winged seeds, samaras, fleshy drupes, and retention and display of seeds in dehisced fruits (the last two states adaptations to bird dispersal, with multiple origins among rainforest genera). Patterns of relationship and levels of sequence divergence in some taxa, mostly species, with bird-dispersed (Acronychia, Sarcomelicope, Halfordia and Melicope) or winged (Flindersia) seeds are consistent with recent long-distance dispersal between Australia and New Caledonia. Other deeper Australian/New Caledonian divergences, some involving ant-dispersed taxa (e.g., Neoschmidia), suggest older vicariance.

Conclusions/Significance

This comprehensive molecular phylogeny of the Australasian Rutoideae gives a broad overview of the group’s evolutionary and biogeographic history. Deficiencies of infrafamilial classifications of Rutoideae have long been recognised, and our results provide a basis for taxonomic revision and a necessary framework for more focused studies of genera and species.  相似文献   

20.
A cladistic biogeographic analysis for the Holarctic and Indo-Chinese regions was undertaken based on seven genera of the tribe Cidariini: Cidaria Treitschke, Thera Stephens, Pennithera Viidalepp, Heterothera Inoue, Callabraxas Butler, Gandaritis Moore and Eulithis Httbner. Smallest coincident ranges of two species recognized 11 endemic areas. The study has two aims: to construct a hierarchical structure of those areas, and to recognize dispersal events. Under two assumptions [widespread taxa mapped (identical as assumption 0) and widespread taxa not mapped (identical as assumption 1)] the 11 endemic areas were mapped with 72 taxa. The best resolved area cladograms under the two assumptions differ in the placement of one endemic area, northern Europe. Area relationships found in this present analysis are congruent with the current landmass configurations: (North America, (Europe, (northern India, (southwestern Asia, (Baikal area, (south China, (Taiwan, (Russian Far East, Japan)))))))). These area cladograms postulate at least three vicariance events: (1) between North America and the Palaearctic; (2) western-eastern Palaearctic; (3) northern India–the rest of Asia. The approach to recognize dispersed taxa by pruning each taxon suggests that most dispersal events occurred in East Asia: from the Baikal area or south China to the Russian Far East; and from the Russian Far East to Japan. Relationships among endemic areas are briefly discussed.  相似文献   

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