Synergistic effects of Pleistocene geological and climatic events on complex phylogeographic history of widespread sympatric species of Megaloptera in East Asia

Unraveling the phylogeographic histories of species remains a key endeavor for comprehending the evolutionary processes contributing to the rich biodiversity and high endemism found in East Asia.In this study,we explored the phylogeographic patterns and demographic histories of three endemic fishfly and dobsonfly species(Neochauliodes formosanus,Protohermes costalis,and Neoneuromus orientalis)belonging to the holometabolan order Megaloptera.These species,which share a broad and largely overlapping distribution,were analyzed using comprehensive mitogenomic data.Our findings revealed a consistent influence of vicariance on the population isolation of Neoc.formosanus and P.costalis between Hainan,Taiwan,and the East Asian mainland during the early Pleistocene,potentially hindering subsequent colonization of the later diverged Neon.orientalis to these islands.Additionally,we unveiled the dual function of the major mountain ranges in East Asia,serving both as barriers and conduits,in shaping the population structure of all three species.Notably,we demonstrated that these co-distributed species originated from Southwest,Southern,and eastern Central China,respectively,then subsequently migrated along multi-directional routes,leading to their sympatric distribution on the East Asian mainland.Furthermore,our results highlighted the significance of Pleistocene land bridges along the eastern coast of East Asia in facilitating the dispersal of mountain-dwelling insects with low dispersal ability.Overall,this study provides novel insight into the synergistic impact of Pleistocene geological and climatic events in shaping the diversity and distribution of aquatic insects in East Asia.

Phylogeography of the Phrynocephalus vlangalii Species Complex in the Upper Reaches of the Yellow River Inferred from mtDNA ND4-tRNA^(LEU) Segments

The Ching Hai Toad-headed Agama(Phrynocephalus vlangalii) complex is a small toad-headed viviparous lizard that is endemic to the Qinghai-Tibetan Plateau. A fragment of mtDNA ND4-tRNALEU from 189 samples in 26 populations was used to infer the phylogeographic history of this species complex in the upper reaches of the Yellow River. Phylogenetic analyses revealed that P. vlangalii and another proposed species(P. putjatia) do not form a monophyletic mtDNA clade,which in contrast with a previous study,includes P. theobaldi and P. forsythii. Lineage diversification occurred in the Middle Pleistocene for P. vlangali(ca. 0.95 Ma) and in the Early Pleistocene for P. putjatia(ca. 1.78 Ma). The uplift of the A’nyemaqen Mountains and glaciations since the mid-late Pleistocene,especially during the Kunlun Glaciation,are considered to have promoted the allopartric divergence of P. vlangalii. The diversification of P. putjatia may be triggered by the tectonic movement in the Huangshui River valley during the C phase of Qingzang Movement. Subsequently,the glacial climate throughout the Pleistocene may have continued to impede the gene flow of P. putjatia,eventually resulting in the genetic divergence of P. putjatia in the allopatric regions. Demographic estimates revealed weak population expansion in one lineage of P. vlangalii(A2,the Qaidam Basin lineage) and one lineage of P. putjatia(B2,the north Qinghai Lake lineage) after approximately 42 000 years before present. However,constant population size through time was inferred for two lineages(A1 and B1),the source of Yellow River lineage of P. vlangalii and the southeast of Qinghai Lake lineage of P. putjatia,possibly due to stable populations persisting in areas unaffected by glacial advances. Our results also suggest: 1) at least four differentiated lineages of P. vlangalii complex may have evolved allopatrically in different regions during the Pleistocene glaciation events; 2) in support of several recent studies,P. putjatia is a valid species,having a more wide distribution than previously considered; and 3) a hypothesis referring to P. v. hongyuanensis,inhabiting in the source region of the Yellow River,being synonymous with P. v. pylozwi is supported.

Mountain evolution and environmental changes of Huangshan(Yellowmountain),China

Huangshan (Yellow Mountain) is located in southern part of the lower reaches of the Yangtze River. The highest Lotus Flower peak is 1864 m above sea level. Formative ages of the Huangshan and its granite,process of mountain geomorphic evolution from the Eocene to Quaternary,environmental changes of Quaternary, formative origin of beautiful peaks and fascinating rocks were studied and the questionable 'Pleistocene glaciation' was also discussed in this paper.

Species diversification and phylogeographical patterns of birds in response to the uplift of the Qinghai-Tibet Plateau and Quaternary glaciations

The Qinghai-Tibet Plateau （QTP） is well known for being of great importance in the evolution of montane species due to its unique geological history and landform configuration, climate complexity, and diversified habitats. The effect of environmental changes since the Quaternary on species diversification, population genetic structure, and demography under environmental change can be studied using phylogenetic and phylogeographieal approaches. Birds are the most well-studied group of all terrestrial vertebrates with regard to their response to climatic changes over time. Herein, we briefly review the species diversification of birds in response to the uplift of the QTP, focusing on summarizing the different phylogeographical patterns of birds on the Plateau, its southeastern margin, and the Eastern Himalayas and the reasons underlying these patterns. Speciation was found to be closely related to the uplift of the QTP, with different patterns of intraspecific processes： （1） no divergence within a single refuge was identified in a restricted semi-continuous area of the eastern margin of the Plateau; （2） two divergent lineages with separated refugia were located at the south-eastern and north-eastern margins of the plateau; and （3） multiple divergent lineages within subregions were found in the Eastern Himalayas. Glacial movements and induced climate change are considered to be key factors in shaping these different patterns. The species distributed mainly in the heavily ice-covered platform regions of the Plateau experienced population expansion following the retreat of the extensive glaciations, whereas the species distributed on the ice-free edges of the plateau maintained their population size at a stable level. Demographic stresses on the edge species might have been mitigated by the milder climate in comparison to their platform-distributed counterparts. Various behavioral and ecological characteristics, including dispersal capacity, habitat preference, and elevation specificity, along with evolutionary history might have helped to shape these different phylogeographical patterns [Current Zoology 60 （2）： 149-161, 2014].

The potential drivers in forming avian biodiversity hotspots in the East Himalaya Mountains of Southwest China

Little has been published to describe or interpret Asian biodiversity hotspots,including those in the East Himalayan Mountains of Southwest China(HMSC),thus making necessary a review of the current knowledge.The Pliocene and Pleistocene geological and glacial histories of the Asian continent differ from those of Europe and North America,suggesting different mechanisms of speciation and extinction,and,thus,different responses to climate changes during the Quaternary glaciations.This short review summarizes potential drivers in shaping and maintaining high species richness and endemism of birds in the HMSC.The geographical location at the junction of different biogeographical realms,the wide range of habitats and climates along the extensive elevational range,the complex topography and the distinct geological history of this region have probably contributed to the evolution of an exceptionally species-rich and endemic-rich,specialized montane avian fauna.The Mountain systems in the HMSC may have provided refugia where species survived during the glacial periods and barriers for preventing species dispersal after the glacial periods.More studies are required to further test this refugia hypothesis by comparing more cold-tolerent and warm-tolerent species.