锦鸡儿属(豆科)祖先分布区分析

锦鸡儿属(Caragana)是一个温带亚洲分布属.在我们对这一属系统发育树以及13个分布区的基础上,重点采用Bremer(1992),Ronquist(1994)和Hausdorf(1997)提出的方法,进行本属祖先分布区的分析和探讨.结果表明,3种方法均表明远东-我国东北,阿尔泰-萨彦岭以及华北-秦岭是可能的祖先分布区.结合北温带植物类群属的北方起源学说,认为远东-我国东北为原始分布区的可能性更大一些.同时这三个分布区彼此地理上是隔离的,也恰是本属内一个较原始种树锦鸡儿(Caragana arborescens)的分布区,结合我们以前的分析生物地理学研究,认为隔离分化是本属最重要的物种形成方式,扩散是次要的而且是短距离的扩散.     

锦鸡儿属植物在鄂尔多斯高原区系和植被中的作用

锦鸡儿属植物在鄂尔多斯高原分布有9种。是物种多样性相对丰富的一个地区。其中中间锦鸡儿Caragana korshinskii var. intermedia,在鄂尔多斯高原东部和毛乌素沙地被当作优选的、广泛栽培的、习见的固沙和水土保持灌木树种。从植物区系成分上分析,主要是中亚成分和东亚成分,中亚成分有蒙古高原分布,阿拉善分布,戈壁-蒙古分布,内蒙古草原-黄土高原分布;东亚成分有华北分布,华北-青藏高原分布,以及蒙古高原南部-青藏高原成分。这些成分充分反映出这一地区与相邻地区的联系和过渡性。形成明显替代现象是本区东部的C. korshinskii var. intermedia与西部的C. korshinskii之间的替代。灌木种类是鄂尔多斯高原的优势生活型植物。在鄂尔多斯高原分布的14个主要灌木群落中,其中有4个重要的锦鸡儿群落,即中间锦鸡儿群系Form. Caragana korshinskii var. intermedia,狭叶锦鸡儿群系Form. Caragana stenophylla,柠条锦鸡儿群系Form. Caragana korshinskii,藏锦鸡儿群系Form. Caragana tibetica。中间锦鸡儿群系为优良的固沙和水土保持灌木。藏锦鸡儿群系则主要分布在西鄂尔多斯,为自然分布。在硬地及覆沙梁地形成高达40~80 cm的小沙丘包,在灌丛中占绝对优势,是锦鸡儿属植物在鄂尔多斯高原最典型的景观之一。这些锦鸡儿属植物群落对于揭示植被从东到西典型草原-荒漠化草原-荒漠的地带性分布具有典型的表征意义。     

锦鸡儿属(豆科)祖先分布区分析(英文)

锦鸡儿属(Caragana)是一个温带亚洲分布属。在我们对这一属系统发育树以及13个分布区的基础上,重点采用Bremer(1992),Ronquist(1994)和Hausdorf(1997)提出的方法,进行本属祖先分布区的分析和探讨。结果表明,3种方法均表明远东-我国东北,阿尔泰-萨彦岭以及华北-秦岭是可能的祖先分布区。结合北温带植物类群属的北方起源学说,认为远东-我国东北为原始分布区的可能性更大一些。同时这三个分布区彼此地理上是隔离的,也恰是本属内一个较原始种树锦鸡儿(Caraganaarborescens)的分布区,结合我们以前的分析生物地理学研究,认为隔离分化是本属最重要的物种形成方式,扩散是次要的而且是短距离的扩散。     

Ancestral Area Analysis of the Genus Caragara （Leguminosae）

Caragana has a temperate Asian distribution. Based on the phylogeny and 13 distributionalareas of this genus, its ancestral area was studied via the ancestral area analysis suggested by Bremer(1992), Ronquist (1994) and Hausdorf (1997). The results indicate that three areas, Far East-NortheastChina, Altai-Sayan and North China-Qinling Mountains (Mts) are likely the ancestral areas. Linking to theviewpoints of the Holarctic origin for north temperate flora, Far East-Northeast China seems more likely tobe the ancestral area. According to the three ancestral areas isolated geographically and the analysis inthe present study, as well as former biogeographical analysis of this genus, it is suggested that Caraganaspeciation is mainly in the mode of vicariance rather than dispersal, and dispersed is often in shortdistance.     

Partitioned Bayesian analyses, dispersal-vicariance analysis, and the biogeography of Chinese toad-headed lizards (Agamidae: Phrynocephalus): a re-evaluation

The toad-headed lizards of genus Phrynocephalus are distributed from northwestern China to Turkey and are one of the major components of the central Asian desert fauna. To date, published morphological and molecular phylogenetic hypotheses of Phrynocephalus are only partially congruent, and the relationships within the genus are still far from clear. We re-analyzed published mitochondrial gene sequence data (12S, 16S, cyt b, ND4-tRNA(Leu)) by employing partition-specific modeling in a combined DNA analysis to clarify existing gaps in the phylogeny of Chinese Phrynocephalus. Using this phylogenetic framework, we inferred the genus' historical biogeography by using weighted ancestral-area analysis and dispersal-vicariance analysis in combination with a Bayesian relaxed molecular-clock approach and paleogeographical data. The partitioned Bayesian analyses support the monophyly of Phrynocephalus and its sister-group relationship with Laudakia. An earlier finding demonstrating the monophyly of the viviparous group is corroborated. However, our hypothesis of internal relationships of the oviparous group differs from a previous hypothesis as our results do not support monophyly of the oviparous taxa. Instead, the viviparous taxa form a clade with many oviparous taxa exclusive of P. helioscopus and P. mystaceus. Our results also suggest that: (1) P. putjatia is a valid species, comprising populations from Guide, Qinghai Province and Tianzhu, Gansu Province; (2) P. hongyuanensis is not a valid species, synonymized instead with P. vlangalii; (3) P. zetangensis is not a valid species and should be included in P. theobaldi; (4) the population occurring in Kuytun, Xinjiang Uygur Autonomous Region is recognized as P. guttatus instead of P. versicolor; and (5) the Lanzhou population of P. frontalis is part of P. przewalskii. Congruent with previous hypotheses, the uplift of the Tibetan Plateau played a fundamental role in the diversification of Phrynocephalus. An evolutionary scenario combining aspects of vicariance and dispersal is necessary to explain the distribution of Phrynocephalus. Bayesian divergence-time estimation suggests that Phrynocephalus originated at the Middle-Late Miocene boundary (15.16-10.4 Ma), and diversified from Late Miocene to Pleistocene from a center of origin in Central Asia, Tarim Basin, and Junggar Basin temperate desert, followed by several rapid speciation events in a relatively short time. The proposed biogeographic scenarios also indicate that the Tarim Basin desert may be the secondary diversification center, followed by Junggar Basin temperate desert and Alashan Plateau temperate desert. In the viviparous group, the allopatric speciation of P. theobaldi and P. vlangalii may have been caused by the uplifting of Tanggula Mountain Ranges. In addition, the results of this study make an important contribution to understanding the uplift of the Tibetan Plateau and Tian Shan Mountains and the biogeography of the entire region.     

Multiple intercontinental dispersals shaped the distribution area of Hordeum (Poaceae)

The grass genus Hordeum (Poaceae, Triticeae), comprising 31 species distributed in temperate and dry regions of the world, was analysed to determine the relative contributions of vicariance and long-distance dispersal to the extant distribution pattern of the genus. Sequences from three nuclear regions (DMC1, EF-G and ITS) were combined and analysed phylogenetically for all diploid (20 species) and two tetraploid Hordeum species and the outgroup Psathyrostachys. Ages of clades within Hordeum were estimated using a penalized likelihood analysis of sequence divergence. The sequence data resulted in an almost fully resolved phylogenetic tree that allowed the reconstruction of intrageneric migration routes. Hordeum evolved c. 12 million years ago in South-west Asia and spread into Europe and Central Asia. The colonization of the New World and South Africa involved at least six intercontinental exchanges during the last 4 million years (twice Eurasia-North America, North America-South America, twice South America-North America and Europe-South Africa). Repeated long-distance dispersal between the northern and southern hemisphere were important colonization mechanisms in Hordeum.     

北温带水青冈属的间断分布及其泛生物地理学解释

水青冈属(Fagus L.)在北温带呈间断分布, 已发现的丰富的第三纪化石为讨论其起源和演化提供了证据。该文采用泛生物地理学的轨迹分析方法对水青冈属的分布进行了研究, 试图分析水青冈属的分布格局, 进而讨论其进化问题。结果表明, 水青冈属在中国、日本、北美、欧洲的分布是完全间断的, 没有一个共有轨迹连接它们, 即使在毗邻的、且有植物亲缘关系的中国和日本, 也没有一个共有轨迹连接。完全间断的轨迹对分析水青冈属的起源、演化和扩散学说, 没有提供任何信息。仅有两条共有轨迹分别分布在中国东南部和日本, 分别代表了中国4种和日本3种水青冈属种类的连接, 说明水青冈属经历了漫长的历史演化, 扩散能力是有局限性的, 仅在分化和多样性中心进行了一些分化和演化, 整个属并未进行长距离的扩散, 或者长距离扩散早已销声匿迹了, 现代的分布格局完全是以间断为最主要特征的。间断分布的动力解释为古地中海西撤、青藏高原隆起、东亚季风活动等地质历史事件, 第三纪以来特别是第四纪冰期活动等气候波动, 以及水青冈属植物的生物学特性(特别是喜温喜湿)。     

The formation and differentiation of the Leguminosae flora in Xizang (Tibet)

Xizang (Tibet) is rich in Leguminosae flora, comprising 41 genera and 254 species so far known, exclusive of the commonly cultivated taxa (including 11 genera and 16 species). There are 4 endemic genera (with 8 species), 10 temperate genera (with 175 species) and 19 tropical genera (with 46 species) as well as the representatives of those genera whose distribution centers are in East Asia-North America, Mediterranean and Central Asia. 1. There are altogether 4 endemic genera of Leguminosae in this region. According to their morphological characters, systematic position and geographical distribution, it would appear that Salweenia and Piptanthus are Tertiary paleo-endemics, while Straceya and Cochlianths are neo-endemics. Salweenia and Piptanthus may be some of more primitive members in the subfamily Papilionasae and their allies are largely distributed in the southern Hemisphere. The other two genera might have been derived from the northern temperate genus Hedysarum and the East Asian-North American genus Apios respectively, because of their morphological resemblance. They probably came into existanc during the uplifting of the Himalayas. 2. An analysis of temperate genera There are twelve temperate genera of Leguminosae in the region, of which the more important elements in composition of flora, is Astragalus, Oxytropis and Caragana. Astragalus is a cosmopolitan genus comprising 2000 species, with its center distribution in Central Asia. 250 species, are from China so far known, in alpine zone of Southwest and Northwest, with 70 species extending farther to the Himalayas and Xizang Plateau. Among them, there are 7 species (10%) common to Central Asia, 12 species (15.7%) to Southwest China and 40 species (60%) are endemic, it indicates that the differentiation of the species of the genus in the region is very active, especially in the subgenus Pogonophace with beards in stigma. 27 species amounting to 78.5% of the total species of the subgenus, are distributed in this region. The species in the region mainly occur in alpine zone between altitude of 3500—300 m. above sea-level. They have developed into a member of representative of arid and cold alpine regions. The endemic species of Astragalus in Xizang might be formed by specialization of the alien and native elements. It will be proved by a series of horizontal and vertical vicarism of endemic species. For example, Astragalus bomiensis and A. englerianus are horizontal and vertical vicarism species, the former being distributed in southeast part of Xizang and the latter in Yunnan; also A. arnoldii and A. chomutovii, the former being an endemic on Xizang Plateau and latter in Central Asia. The genus Oxytropis comprises 300 species which are mainly distributed in the north temperate zone. About 100 species are from China so far known, with 40 species extending to Himalayas and Xizang Plateau. The distribution, formation and differentiation of the genus in this region are resembled to Astragalus. These two genera are usually growing together, composing the main accompanying elements of alpine meadow and steppe. Caragana is an endemic genus in Eurasian temperate zone and one of constructive elements of alpine bush-wood. About 100 species are from China, with 16 species in Xizang. According to the elements of composition, 4 species are common to Inner Mongolia and Kausu, 4 species to Southwest of China, the others are endemic. This not only indicates that the species of Caragana in Xizang is closely related to those species of above mentioned regions, but the differentiation of the genus in the region is obviously effected by the uplifting of Himalayas, thus leading to the formations of endemic species reaching up to 50%. 3. An Analysis of Tropical Genera There are 19 tropical genera in the region. They concentrate in southeast of Xizang and southern flank of the Himalayas. All of them but Indigofera and Desmodium are represented by a few species, especially the endemic species. Thus, it can be seen that they are less differentiated than the temperate genera. However, the genus Desmodium which extends from tropical southeast and northeast Asia to Mexio is more active in differentiation than the other genera. According to OhaShi_,s system about the genus in 1973, the species of Desmodium distributed in Sino-Himalaya region mostly belong to the subgenus Dollinera and subgenus Podocarpium. The subgenus Dollinera concentrates in both Sino-Himalaya region and Indo-China with 14 species, of which 7 species are endemic in Sino-Himalaya. They are closely related to species of Indo-China, southern Yunnan and Assam and shows tha tthey have close connections in origin and that the former might be derived from the latter. Another subgenus extending from subtropical to temperate zone is Podocarpium. Five out of the total eight species belonging to the subgenus are distributed in Sino-Himalaya and three of them are endemic. An investigation on interspecific evolutionary relationship and geographic distribution of the subgenus shows that the primary center of differentiation of Podocarpium is in the Sino-Himalaya region. Finally, our survey shows that owing to the uplifting of the Himalayas which has brought about complicated geographic and climatic situations, the favorable conditions have been provided not only for the formation of the species but also for the genus in cer-tain degree.     

基于序列trnL-trnF和ITS的榉属系统发育与地理分布格局的初步分析

榉属(Zelkova)是包含6个种的榆科小属, 呈东亚、西亚和南欧间断分布。该文基于DNA序列trnL-trnF和ITS构建了榉属的分子系统发育树, 大体上把此属分为3个分支, 分别对应东亚、西亚和南欧的种类, 与前人仅依据ITS序列的结果不同。生物地理的扩散和隔离分化分析(DIVA)表明, 榉属的原始祖先分布区可能是欧亚北温带, 包括了东亚、西亚和南欧的某个大的区域。分化过程以隔离分化为主要特征, 即3个分布区域是逐步隔离分化的。由于东亚的物种多样性, 北太平洋有可能是起源中心。榉属的现代分布格局可能主要是由于渐新世发生的古地中海西退、中新世发生的青藏高原大范围隆升, 以及第四纪冰川活动引起的分布区的收缩。     

Out-of-Africa origin and dispersal-mediated diversification of the butterfly genus Junonia (Nymphalidae: Nymphalinae)

The relative importance of dispersal and vicariance in the diversification of taxa has been much debated. Within butterflies, a few studies published so far have demonstrated vicariant patterns at the global level. We studied the historical biogeography of the genus Junonia (Nymphalidae: Nymphalinae) at the intercontinental level based on a molecular phylogeny. The genus is distributed over all major biogeographical regions of the world except the Palaearctic. We found dispersal to be the dominant process in the diversification of the genus. The genus originated and started diversifying in Africa about 20 Ma and soon after dispersed into Asia possibly through the Arabian Peninsula. From Asia, there were dispersals into Africa and Australasia, all around 5 Ma. The origin of the New World species is ambiguous; the ancestral may have dispersed from Asia via the Beringian Strait or from Africa over the Atlantic, about 3 Ma. We found no evidence for vicariance at the intercontinental scale. We argue that dispersal is as important as vicariance, if not more, in the global diversification of butterflies.     

A dated phylogeny of Lardizabalaceae reveals an unusual long-distance dispersal across the Pacific Ocean and the rapid rise of East Asian subtropical evergreen broadleaved forests in the late Miocene

Temperate South American–Asian disjunct distributions are the most unusual in organisms, and challenging to explain. Here, we address the origin of this unusual disjunction in Lardizabalaceae using explicit models and molecular data. The family (c.40 species distributed in ten genera) also provides an opportunity to explore the historical assembly of East Asian subtropical evergreen broadleaved forests, a typical and luxuriant vegetation in East Asia. DNA sequences of five plastid loci of 42 accessions representing 23 species of Lardizabalaceae (c. 57.5% of estimated species diversity), and 19 species from the six other families of Ranunculales, were used to perform phylogenetic analyses. By dating the branching events and reconstructing ancestral ranges, we infer that extant Lardizabalaceae dated to the Upper Cretaceous of East Asia and that the temperate South American lineage might have split from its East Asian sister group at c. 24.4 Ma. A trans-Pacific dispersal possibly by birds from East Asia to South America is plausible to explain the establishment of the temperate South American–East Asian disjunction in Lardizabalaceae. Diversification rate analyses indicate that net diversification rates of Lardizabalaceae experienced a significant increase around c. 7.5 Ma. Our findings suggest that the rapid rise of East Asian subtropical evergreen broadleaved forests occurred in the late Miocene, associated with the uplift of the Tibetan Plateau and the intensified East Asian monsoon, as well as the higher winter temperature and atmospheric CO₂ levels.     

Molecular phylogeny and historical biogeography of the Holarctic wetland leaf beetle of the genus Plateumaris

Leaf beetles of the genus Plateumaris inhabit wetlands across the temperate zone of the Holarctic region. To explore the phylogeographic relationships among North American, East Asian, and European members of this genus and the origin of the species endemic to Japan, we studied the molecular phylogeny of 20 of the 27 species in this genus using partial sequences of mitochondrial cytochrome oxidase subunit I (COI) and the 16S and nuclear 28S rRNA genes. The molecular phylogeny revealed that three species endemic to Europe are monophyletic and sister to the remaining 11 North American and six Asian species. Within the latter clade, North American and Asian species did not show reciprocal monophyly. Dispersal-vicariance analysis and divergence time estimation revealed that the European and North America-Asian lineages diverged during the Eocene. Moreover, subsequent differentiation occurred repeatedly between North American and Asian species, which was facilitated by three dispersal events from North America to Asia and one in the opposite direction during the late Eocene through the late Miocene. Two Japanese endemics originated from different divergence events; one differentiated from the mainland lineage after differentiation from the North American lineage, whereas the other showed a deep coalescence from the North American lineage with no present-day sister species on the East Asian mainland. This study of extant insects provides molecular phylogenetic evidence for ancient vicariance between Europe and East Asia-North America, and for more recent (but pre-Pleistocene) faunal exchanges between East Asia and North America.     

Out of Asia: Mitochondrial DNA Evidence for an Oriental Origin of Tiger Frogs, Genus Hoplobatrachus

Most examples of intercontinental dispersal events after the Miocene contact between Africa and Asia involve mammal lineages. Among amphibians, a number of probably related groups are known from both continents, but their phylogenies are so far largely unresolved. To test the hypothesis of Miocene dispersal against a Mesozoic vicariance scenario in the context of Gondwana fragmentation, we analyzed fragments of the mitochondrial 16S rRNA gene (572 bp) in 40 specimens of 34 species of the anuran family Ranidae. Results corroborated the monophyly of tiger frogs (genus Hoplobatrachus), a genus with representatives in Africa and Asia. The African H. occipitalis was the sister group of the Asian H. crassus, H. chinensis, and H. tigerinus. Hoplobatrachus was placed in a clade also containing the Asian genera Euphlyctis and Nannophrys. Combined analysis of sequences of 16S and 12S rRNA genes (total 903 bp) in a reduced set of taxa corroborated the monophyly of the lineage containing these three genera and identified the Asian genus Fejervarya as its possible sister group. The fact that the African H. occipitalis is nested within an otherwise exclusively Asian clade indicates its probable Oriental origin. Rough molecular clock estimates did not contradict the assumption that the dispersal event took place in the Miocene. Our data further identified a similar molecular divergence between closely related Asian and African species of Rana (belonging to the section Hylarana), indicating that Neogene intercontinental dispersal also may have taken place in this group and possibly in rhacophorid treefrogs.     

Historical biogeography and phenotype‐phylogeny of Chroodiscus (lichenized Ascomycota: Ostropales: Graphidaceae)

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

青藏高原杨属化石概述

杨属是北半球温带森林生态系统中一个重要的乔木属。文中概述了青藏高原古近纪和新近纪的杨属化石记录,并根据最新的地层学和年代学数据,对化石的时代进行厘定。化石记录显示杨属在青藏高原最早出现于始新世最晚期。在渐新世和中新世杨属在青藏高原的南部和北部都有较多的化石,但在高原中部尚未见记录。青藏高原具有杨属的化石植物群大多数都是温带落叶阔叶的河岸植被,进一步证实杨属在其演化历史早期就偏好温带近河岸的环境。青藏高原北部的早渐新世植物群中杨属多样性较高,并占据显著优势,表明这一地区在杨属早期分化中具有重要作用。     

Snakehead (Teleostei: Channidae) diversity and the Eastern Himalaya biodiversity hotspot

The collision of the Indian and Eurasian landmasses in the Cenozoic was a decisive factor in shaping biodiversity patterns in Southern and Southeastern Asia. While most studies thus far have focused on the biotic interchange between India and Eurasia and evolutionary diversification on or around the Tibetan Plateau, little attention has been paid to the biodiversity buildup in the Eastern Himalaya biodiversity hotspot (EHH) which harbors over 540 freshwater fish species with a high degree of endemicity. An important component of the regional ichthyofauna are snakehead fishes of the family Channidae comprising throughout their African-Asian distribution 47 valid species, but a poorly known species-level diversity. In order to evaluate channid intrarelationships and biogeography, a temporal and geographic framework of channid evolution in conjunction with a critical reevaluation of the channid fossil record is warranted. Based on molecular data, we provide a comprehensive species-level phylogeny based on 223 channid individuals belonging to 37 species and one additional currently undescribed species. The first split within channids separates the African genus Parachanna from the Asian genus Channa which can be divided into eight distinct species groups (Argus, Asiatica, Gachua, Lucius, Marulius, Micropeltes, Punctata, and Striata groups). Large intraspecific divergences were observed within several species and potentially indicate additional species-level diversity. Almost 40% of the channid species are narrow-range endemics belonging to the Gachua group. These are found in the EHH making this area an outstanding hotspot for endemic channid diversity. The large majority of the EHH endemics are restricted to the southern foothills of the Eastern Himalaya and the Shillong-Mikir Hills Plateau, areas west of the Indoburman Ranges. Our results reveal complex and difficult to interpret biogeographic patterns indicating that both vicariance and dispersal events have potentially been responsible in shaping current distribution patterns in Asian channids. We recognize †Parachanna fayumensis as the oldest reliable channid fossil and argue that the three oldest so-called channid fossils (i.e., †Eochanna chlorakkiensis, †Anchichanna kuldanensis, and †Ophiocephalus lydekkeri) lack clear diagnostic features that would allow them to be unequivocally placed within Channidae.     

A unique record of Cercis from the late early Miocene of interior Asia and its significance for paleoenvironments and paleophytogeography

The climatic impacts of the Tibetan Plateau since the Neogene and the phytogeographic pattern changes of formerly widely-distributed forest communities on the plateau remain poorly constrained. Today, Cercis L. (Fabaceae) is a well-known arborescent genus typically distributed in subtropical to warm temperate zones of the Northern Hemisphere, and Paleogene fossil occurrences from Eurasia and North America show a long history of the genus in mid-low latitudes of the Northern Hemisphere. Here, we describe a fossil species, Cercis zekuensis sp. nov. based on well-preserved fruits from the early Miocene of the northeastern Tibetan Plateau. Detailed morphological comparison (e.g., ventral margin with a veinless wing) of extant and fossil members of Cercis and other genera confirmed validity of the present taxonomic identity. Based on the comparison with extant relatives and their climate preferences, this unexpected occurrence of thermophilic Cercis in northeastern Tibetan Plateau indicates this area had higher temperature and precipitation in the Miocene than today. Integrated with inferred (paleo-)temperature lapse rates, this indicates a low paleoelevation of less than 2.4 km. In contrast with the present-day alpine climate here (~3.7 km), such a low elevation facilitated a more favorable habitat with comparatively high biodiversity and warm temperate forests at that time, as were evidenced by co-occurring megafossils. Moreover, the present existence of Cercis implies the genus was widespread in interior Asia during the early Neogene and shows its modern disjunction or diversification between eastern and central Asia was possibly shaped by the late Cenozoic regional tectonic uplift and consequential environmental deterioration.     

Intraspecific phylogeography of Percina evides (Percidae: Etheostomatinae): an additional test of the Central Highlands pre-Pleistocene vicariance hypothesis

North America exhibits the most diverse freshwater fish fauna among temperate regions of the world. Species diversity is concentrated in the Central Highlands, drained by the Mississippi, Gulf Slope and Atlantic Slope river systems. Previous investigations of Central Highlands biogeography have led to conflicting hypotheses involving dispersal and vicariance to explain the diversity and distribution of the freshwater fish fauna. In this investigation predictions of the Central Highlands pre-Pleistocene vicariance hypothesis are tested with a phylogeographic analysis of the percid species Percina evides, which is widely distributed in several disjunct areas of the Central Highlands. Phylogenetic analysis of complete gene sequences of mitochondrially encoded cytochrome b recover three phylogroups, with very low levels of sequence polymorphism within groups. The two western phylogroups are monophyletic with respect to the eastern phylogroup. The recovery of two monophyletic lineages with an eastern and western distribution in the disjunct highland areas is a pattern expected from vicariance, but is not predicted by the Central Highlands pre-Pleistocene vicariance hypothesis. The recovery of very limited mitochondrial DNA polymorphism and lack of phylogeographic structuring across the entire range of the eastern clade, very shallow polymorphism between the disjunct Missouri River and upper Mississippi River populations, and lack of sequence polymorphism in the upper Mississippi River populations, support a hypothesis of dispersal during or following the Pleistocene. The present distribution of P. evides is best explained by both vicariant and dispersal events.     

Phylogeny of spiny frogs Nanorana (Anura: Dicroglossidae) supports a Tibetan origin of a Himalayan species group

Recent advances in the understanding of the evolution of the Asian continent challenge the long‐held belief of a faunal immigration into the Himalaya. Spiny frogs of the genus Nanorana are a characteristic faunal group of the Himalaya–Tibet orogen (HTO). We examine the phylogeny of these frogs to explore alternative biogeographic scenarios for their origin in the Greater Himalaya, namely, immigration, South Tibetan origin, strict vicariance. We sequenced 150 Nanorana samples from 62 localities for three mitochondrial (1,524 bp) and three nuclear markers (2,043 bp) and complemented the data with sequence data available from GenBank. We reconstructed a gene tree, phylogenetic networks, and ancestral areas. Based on the nuDNA, we also generated a time‐calibrated species tree. The results revealed two major clades (Nanorana and Quasipaa), which originated in the Lower Miocene from eastern China and subsequently spread into the HTO (Nanorana). Five well‐supported subclades are found within Nanorana: from the East, Central, and Northwest Himalaya, the Tibetan Plateau, and the southeastern Plateau margin. The latter subclade represents the most basal group (subgenus Chaparana), the Plateau group (Nanorana) represents the sister clade to all species of the Greater Himalaya (Paa). We found no evidence for an east–west range expansion of Paa along the Himalaya, nor clear support for a strict vicariance model. Diversification in each of the three Himalayan subclades has probably occurred in distinct areas. Specimens from the NW Himalaya are placed basally relative to the highly diverse Central Himalayan group, while the lineage from the Tibetan Plateau is placed within a more terminal clade. Our data indicate a Tibetan origin of Himalayan Nanorana and support a previous hypothesis, which implies that a significant part of the Himalayan biodiversity results from primary diversification of the species groups in South Tibet before this part of the HTO was uplifted to its recent heights.     

青藏高原和喜马拉雅地区锦鸡儿属植物的地理分布

锦鸡儿属Caragana是一个典型的温带亚洲分布属。本属在青藏高原和喜马拉雅约有24种1变种,约占整个属的1／3。这些种类几乎全部处于演化高级阶段,且既有叶轴宿存类群,也有假掌状叶类群。反映出种的分化很活跃,在横断山地区形成本属的分布中心、分化中心。本区内绝大多数种类是特有分布。替代现象主要受气候、植被变化作用,沿横断山和喜马拉雅分布的长齿系Ser. Bracteolatae Kom．是一个典型的替代分布类群。锦鸡儿属植物生态适应性很强,可在其生长的灌丛中形成优势种。 寒化和旱化现象十分突出,它们有一系列森林种、草原种和荒漠种及相关的形态变异。用锦鸡儿属植物进行青藏高原和喜马拉雅区域内的分布区关系分析及最小生成树MST和特有性简约性分析(PAE),表明横断山地区特别是其北部是本属植物的一个地理结点。以此沿横断山向北部唐古特和西部藏东南适应性辐射。横断山和西喜马拉雅联系微弱,看不出植物长距离扩散的踪迹,大多是由于生态因子限制而产生的隔离。虽然本区不可能是锦鸡儿属的起源地,然而,通过本区与邻近地区的地理联系,可推测它们在我国适应性辐射方向是从东北向西南。结合豆科蝶形花亚科其它属化石记录及其分布区局限在温带亚洲等现象,认为锦鸡儿植物是一组特化、晚近衍生的类群,起源于北方东西伯利亚晚第三纪中新世后期至上新世。