Hirano Takahiro, Saito Takumi, Ito Shun, Ye Bin, Linscott T Mason, Do Van Tu, Dong Zhengzhong, Chiba Satoshi
Center for Northeast Asian Studies, Tohoku University, Miyagi, Japan; Graduate School of Life Sciences, Tohoku University, Miyagi, Japan; Biology Program, Faculty of Science, University of the Ryukyus, Okinawa, Japan.
Center for Northeast Asian Studies, Tohoku University, Miyagi, Japan; Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic.
Mol Phylogenet Evol. 2023 May;182:107728. doi: 10.1016/j.ympev.2023.107728. Epub 2023 Feb 16.
Fossils provide important insight into our understanding of phylogenetic history by serving as calibration points for divergence time estimation. However, uncertainties in the fossil record due to parallel evolution and convergent evolution can critically affect estimates of node ages. Here, we compare and contrast estimates of phylogenetic divergence with geologic and fossil history for two freshwater snail genera of the family Viviparidae in East Asia (Cipangopaludina and Margarya). Cipangopaludina species are commonly widely distributed species in East Asia, but extant Margarya species are endemic to the ancient lakes in Yunnan, China. According to some previous studies, parallel evolution or convergent evolution of shell morphology has occurred in the family several times which may affect divergence time estimation using fossil records. In this study, we used SNP data derived from ddRAD-seq loci to investigate population demographic history of both genera. Our results show a common pattern of lake endemic lineages diversifying from widely distributed lineages in the Miocene, and multiple colonization to a single ancient lake occurred in the Pleistocene. Our results indicate substantial incongruence among estimated phylogenomic divergence times, some fossil records, and formation ages of ancient lakes. These findings suggest some fossil records may be misidentified in these groups and highlight the need to carefully evaluate geological evidence and fossil records when using these for divergence time estimation.
化石通过作为分歧时间估计的校准点，为我们理解系统发育历史提供了重要的见解。然而，由于平行进化和趋同进化导致的化石记录中的不确定性，可能会严重影响节点年龄的估计。在这里，我们比较并对比了东亚田螺科两个淡水蜗牛属（圆田螺属和玛琍螺属）的系统发育分歧估计与地质和化石历史。圆田螺物种通常是东亚广泛分布的物种，但现存的玛琍螺物种是中国云南古代湖泊特有的。根据一些先前的研究，该科多次发生壳形态的平行进化或趋同进化。这可能会影响使用化石记录进行的分歧时间估计。在本研究中，我们使用从ddRAD-seq位点获得的SNP数据来研究这两个属的种群历史。我们的结果显示，在中新世，湖泊特有谱系从广泛分布的谱系中分化出来，并且在更新世发生了多次向单个古代湖泊的殖民。我们的结果表明，估计的系统发育分歧时间、一些化石记录和古代湖泊的形成年龄之间存在很大的不一致。这些发现表明，这些类群中的一些化石记录可能被错误识别，并强调在使用这些记录进行分歧时间估计时，需要仔细评估地质证据和化石记录。
