Role of ancient lakes in genetic and phenotypic diversification of freshwater snails

Endemic organisms of ancient lakes have been studied as models to understand processes of speciation and adaptive radiation. However, it remains unclear how ancient lakes play roles in genetic and phenotypic diversity of freshwater mollusks. In the present study, we focus on viviparid freshwater snails in the ancient lakes of East and Southeast Asia (Japan and China) to address this question. Using molecular phylogenetic analyses based on mitochondrial (COI, 16S) and nuclear genes (18S, 28S, H3), we show that patterns of species diversification in viviparid lineages. Colonization to ancient lake occurred independently in China and Japan at least four times, with subsequent diversification into more than two species within each lake group. Morphological analyses of fossil related viviparids suggest parallel phenotypic evolution occurred in the different lakes and ages. Each lake contained a single lineage, which was phenotypically diversified relative to those from other sites. Using gen...古湖特有生物已被作为模式生物，用于解析物种形成与适应性辐射的演化过程。然而，目前学界仍未明确古湖如何塑造淡水软体动物的遗传与表型多样性。本研究聚焦东亚及东南亚（日本与中国）古湖中的胎生淡水螺类（viviparid），旨在解答这一科学问题。本研究基于线粒体基因（COI、16S）与核基因（18S、28S、H3）开展分子系统发育分析，揭示了胎生螺类支系的物种分化模式。研究发现，中国与日本的古湖殖民事件至少独立发生四次，且每个湖泊类群后续均分化出2个以上的物种。对相关胎生螺类化石的形态学分析表明，不同湖泊与地质年代中均出现了平行的表型演化现象。每个古湖仅包含单一支系，相较于其他生境的类群，该支系的表型已产生显著分化。本研究采用基因