Studies on mass speciation in response to major climatic events in the Cenozoic

根据线粒体12S和16S rRNA基因和细胞色素b基因的核苷酸序列数据，对陆生和海洋哺乳动物(鹿科、牛科、水母、锡里尼亚、鲸类、鳍足纲)、真脊椎动物和海洋腹足类(鞭虫亚科、涡虫科、钾藻科、球螺科和腹足科)进行了分子系统发育分析。系统发育分析表明，物种形成事件在陆地和海洋生态系统中是同步发生的，这种物种分化事件是由海洋生态系统中的主要气候事件引发的结合太平洋新近纪暖海洋气候事件，提出了日本新近纪和第四纪浅海暖水软体动物动物群的化学和地理分布新模式。研究表明，在暖期气候事件期间，许多暖水物种从南部入侵到中纬度地区，并在气候优化导致大量物种形成后，在日本群岛周围定居和地理隔离。反复的暖事件使动物群组成不断更新，最终形成了预设日的黑潮动物群。在这项研究中，我们总结了日本新近纪和第四纪海洋软体动物的极差图，以清楚地显示大量物种形成事件的事实。有关鹿科、鲸类和真脊椎动物的分子系统发育分析的论文发表在国际科学期刊和教科书上。

Molecular phylogenetic analyses were made for a number of animal groups including terrestrial and marine mammals (Cervidae, Bovidae, Suidae, Sirenians, Cetacea, Pinnipedians), euteleostean Perciforms and marine gastropods (Umboniinae, Turbiniidae, Potamididae, Batillariidae and Buccinidae), based on the nucleotide sequence data of mitochondrial 12s and 16s rRNA genes and cytochrome b gene.Our phylogenetic analyses revealed that speciation events occurred synchronously among a number of animal group in both terrestrial and marine ecosystems, suggesting that this mass- speciation events were induced by the major climatic events in the Cenozoic.In this study, a new schema on the chlonological and geographical distribution of the Japanese Neogene and Quaternary shallow marine warm-water molluscan faunas is also presented in relation to the Neogene warmmarine climatic events in the Pacific.The present study revealed that many warm-water species invaded from the south into the mid-latitudes during the warm events and their settlements and geographical isolation around the Japanese Islands after the climatic optima led to mass-speciation. The warm events repeatedly made renewal of the faunal composition and finally have established the preset-day Kuroshio fauna. In this study we summarized the range charts of the Neogene and Quaternary marine molluscs in Japan to show clearly the facts of mass-speciation events. Papers on the molecular phylogenetic analysis of the Cervidae, Cetaceans and euteleostean Perciforms were published on the international scientific journals and text-book.