Origin and formative process of the Japanese Fauna viewed from molecular phylogeny and fossil records

该项目有一个雄心勃勃的目标，即阐明日本动物群的主要地理起源，以及原始动物群是如何发展成摩登分布和类型的。该项目的一个主要部分是对一些有代表性的陆地和海洋动物进行分子系统发育分析。调查的陆地动物包括野猪属(野猪)、梅花鹿属(鹿)、Selenarctos属(亚洲黑熊)、Diplothrix属(琉球长毛鼠)、Trimeresurus属(哈布蛇属)、Agkistrodon属(马木氏蛇属)、Cynopps属(蝾螈属)、Cobitids属(泥鳅属)、Coreopca属(Percichhyd属)和半球螺属(淡水蜗牛属)。这些海洋生物均为软体动物物种，包括帽贝(PattellogAsterpods)、鲍鱼(Haliotis)、头盖类(Turbinids)、斗鱼(Buccinum)和海鞘属(HelTunea)、双壳类(Anadara)、牡蛎(Crassostrea)和文蛤(Meretrix)。分析使用了大多数相关物种和亚种的样本，分布在整个日本…更多的e岛和亚洲(或者，就海洋生物而言，是整个世界)。这些结果与在日本群岛和亚洲大陆的陆地和海洋沉积物中发现的相关化石的地层学和古生物学研究相结合。这些分子系统发育分析表明，生活在日本的动物物种通常被视为单一物种，实际上通常由两个或两个以上地理分布的亚种或物种组成。分子系统学和化石记录表明，目前许多物种在日本群岛的异地分布最有可能的解释是，基因分离的亚种或物种在不同的地质时期重复从亚洲大陆迁徙，遵循不同的迁徙路线。在海洋软体动物中也观察到了同样的特征，特别是在日本帽贝和白鲸的分子系统学和化石记录中表现得尤为明显。更新世期间从亚洲大陆来到日本群岛的陆地哺乳动物迁徙路线的时间和位置主要是根据日本和中国的大象化石的生物地层分布来估计的。志贺氏恒河猴的产状约为1.2 Ma，东方剑齿虎的产状约为0.6 Ma。九州-四国-本州约为0.35 Ma的古齿虎和北海道约为0.02 Ma的原始哺乳动物强烈表明，当时陆桥的存在使大型陆生哺乳动物得以迁徙。在琉球群岛，本研究揭示了冲绳岛早至中更新世脊椎动物群的丰富多样。直到最近，该地区的更新世化石记录大多局限于晚更新世。对这些脊椎动物化石的古生物学调查表明，一个祖先动物群由前更新世和早更新世大陆的移民组成，今天的中琉球特有动物群和少量物种是在冲绳海槽形成后长期与大陆隔绝的各种祖先动物群的反复灭绝事件中形成的。这项研究还揭示了琉球南部的动物群是由晚更新世和更早的移民组成的。较少

This project had the ambitious goal of clarifying both the dominant geographic origins of Japanese Fauna and how the original fauna developed into the modeen distributions and types. A major part of this project was the molecular phylogenetic analyses of a number of representative land and marine animals. The land animals investigated include the genera Sus (wild boars), Cervus (deer), Selenarctos (Asian black bears), Diplothrix (Ryukyu long-haired rat), Trimeresurus (Habu snakes), Agkistrodon (Mamushi snakes), Cynops (newts), Cobitids (loaches), Coreoperca (Percichthyd) and Semisulcospira (fresh-water snails). The marine organisms were all molluscan species including limpets ((Pattellogastropods), Haliotis (abalones), Turbinids (turban shells), Buccinum and Neptunea (Buccinids), Anadara (arcids), Crassostrea (oysters), and Meretrix (Venerid bibalves). The analyses used samples of most of the relevant species and subspecies of animals with distributions extending throughout the Japanes … More e Islands and Asia (or, in the case of marine organisms, throughout the world.) These results were combined with stratigraphical and paleontological studies of related fossils found in terrestrial and marine deposits throughout the Japanese Islands and Asian continent. Where relevant fossils in other locations throughout the world were also considered.These molecular phylogenetic analyses revealed that an animal species living in Japan generally treated as a single species are in fact commonly composed of two or more allopatrically distributed subspecies or species. Molecular phylogeny and fossil records suggest the most likely explanation for the present-day allopatric distribution of many species in the Japanese Islands is repeated migration of genetically separated subspecies or species from the Asian continent at different geological times following different migration routes. The same features are also observed in marine mollusks, and are particularly clearly exhibited by the molecular phylogeny and fossil records of Japanese limpets and ablones.The timing and location of immigration routes for land mammals that arrived from the Asian continent in the Japanese Islands during the Pleistocene were mainly estimated from the biostratigraphical distribution of elephant fossils in Japan and China. The occurrences of Mammuthus shigensis around 1.2 Ma, Stegodon orientalis around 0.6 Ma. Paleoloxodon naumanni around 0.35 Ma in Kyushu-Shikoku-Honshu, and Mammuthus primigenius around 0.02 Ma in Hokkaido strongly suggest the presence of land bridges at these times that enabled the immigration of the large land-based mammals.In the Ryukyu Islands, the present study revealed the presence of rich and varied Early to Middle Pleistocene vertebrate faunas in Okinawa Island. Until recently Pleistocene fossil records of this area were mostly restricted to the Late Pleistocene. Paleontological investigations of these fossil vertebrate faunas revealed that an ancestral fauna consisted of immigrants from the continents in the pre-Pleistocene and Early Pleistocene periods and also that the present-day endemic fauna of the Middle Ryukyu with a small number of species was formed by repeated extinction events affecting the varied ancestral fauna that has long been isolated from the continent after the formation of the Okinawa trough. This study also revealed that the fauna of the Southern Ryukyu is composed of both Late Pleistocene and much earlier immigrants. Less