Genetic structure and demographic history of Indirana semipalmata, an endemic frog species of the Western Ghats, India

The evolutionary potential of a species mainly depends on the level of genetic variation in their populations. Maintenance of gene variation enables populations to adapt more quickly to environmental changes. The geographical gaps also influence the distribution and evolutionary history of many mountain frogs in the world. Hence, a sound knowledge in population genetic structure of a species will help understand its population dynamics and develop conservation strategies. In the context of facing threats to the amphibian fauna of Western Ghats due to habitat loss, we used both mitochondrial and nuclear DNA markers to investigate the genetic structure of an endemic frog species of the Western Ghats (Indirana semipalmata) with restricted distribution. The present study showed the importance of mountain gaps in shaping the species’ structuring in the Western Ghats. Though a high genetic diversity was observed for the species when considering a single unit in the southern Western Ghats, the restricted gene flow on/between either side of the Shencottah gap with genetic clustering of the sampled populations may warrant a unique management plan for the species. The habitat fragmentation of the Western Ghats through anthropogenic activities may result in severe setbacks to the survival of the species in the future.物种的进化潜力主要取决于其种群内的遗传变异水平。维持基因变异可使种群更快速地适应环境变化。地理间隙同样影响着全球诸多山地蛙类的分布与演化历史。因此，充分掌握某一物种的种群遗传结构，有助于明晰其种群动态并制定科学的保护策略。针对西高止山脉（Western Ghats）两栖动物群因栖息地丧失所面临的生存威胁，本研究采用线粒体DNA（mitochondrial DNA）与核DNA（nuclear DNA）分子标记，对西高止山脉特有、分布受限的蛙类物种半蹼印蟾（Indirana semipalmata）的遗传结构进行了调查。本研究证实了山地间隙在塑造西高止山脉该物种种群结构中的关键作用。尽管将南西高止山脉作为单一研究单元时，该物种呈现出较高的遗传多样性，但申科塔间隙（Shencottah gap）两侧的种群间基因交流受限，且采样种群存在遗传聚类现象，这表明该物种亟需制定专属的管理方案。人类活动引发的西高止山脉栖息地碎片化，或将对该物种的未来生存造成严重不利影响。