Cryptic species, taxonomic inflation, or a bit of both? New species phenomenon in Sri Lanka as suggested by a phylogeny of dwarf geckos (Reptilia, Squamata, Gekkonidae, <i>Cnemaspis</i>)

We evaluated the status of 16 of 22 recognized Sri Lankan <i>Cnemaspis</i> Strauch species, and flagged overlooked diversity with two mitochondrial (cyt <i>b</i> &amp; ND2) and two nuclear markers (RAG1 &amp; PDC) totalling 2829 base pairs. A fossil-calibrated timetree and sampling of other South Asian <i>Cnemaspis</i> provide insights into the diversification of the genus in peninsular India and Sri Lanka. Phylogenetic analyses consistently inferred two broad clades within South Asian <i>Cnemaspis</i>, with Sri Lankan species in two clades, which we call the <i>podihuna</i> and <i>kandiana</i> clades. Each Sri Lankan clade as a whole is sister to Indian taxa and nested within Indian lineages. <i>Cnemaspis modigliani</i> Das from Indonesia is a member of the <i>kandiana</i> clade. This suggests a minimum of two dispersal events between India and Sri Lanka and one between Sri Lanka/India and South-east Asia. South Asian <i>Cnemaspis</i> date back to at least the Eocene, in Sri Lanka to the early Miocene, with late Miocene diversification in the <i>kandiana</i> clade. All but one of the named species we sampled is likely to be valid, and 10 divergent unnamed lineages may warrant specific recognition. A resolution of Sri Lankan <i>Cnemaspis</i> taxonomy will require thorough sampling and the use of both morphological and molecular data.

本研究对22个已被确认的斯里兰卡溪虎属（Cnemaspis Strauch）物种中的16个类群开展分类学地位评估，通过总长度达2829个碱基对的2个线粒体基因标记（细胞色素b基因cyt b与烟酰胺腺嘌呤二核苷酸脱氢酶亚基2 ND2）、2个核基因标记（重组激活基因1 RAG1与PDC）开展分子分析，揭示了此前被忽视的物种多样性。基于化石校准的时间树以及对其他南亚溪虎属类群的采样分析，为该属在印度半岛与斯里兰卡的物种分化进程提供了关键认知。系统发育分析一致推断，南亚溪虎属可分为两大演化支系，斯里兰卡溪虎属物种分属其中两支，我们将其分别命名为podihuna演化支与kandiana演化支。两支斯里兰卡溪虎属演化支整体上均与印度类群构成姊妹群，且嵌套于印度演化支系内部。产自印度尼西亚的莫迪利亚尼溪虎（Cnemaspis modigliani Das）隶属于kandiana演化支。该结果表明，印度与斯里兰卡之间至少发生过两次物种扩散事件，而斯里兰卡/印度与东南亚之间则至少发生过一次物种扩散事件。南亚溪虎属的起源时间至少可追溯至始新世，斯里兰卡本土类群的起源时间则为早中新世，而kandiana演化支的物种分化发生于晚中新世。本研究采样的已命名物种中，除1个类群外其余均大概率为有效物种，另有10个分化显著的未命名演化支具备被认定为独立物种的潜力。要厘清斯里兰卡溪虎属的分类学问题，需开展全面的类群采样，并结合形态学与分子生物学数据开展综合研究。

搜集汇总

背景与挑战

背景概述

该数据集提供了斯里兰卡侏儒壁虎（Cnemaspis属）系统发育研究的分子数据，包括线粒体和核标记的序列信息，总长2829碱基对。研究揭示了物种形成和生物地理模式，识别出两个主要分支及潜在的未描述物种谱系，支持了印度与斯里兰卡之间多次扩散事件的假设。