Abstract Benthic life in the Southern Ocean (SO) features unique life history traits and species assemblages, but the origin and evolution of many of these taxonomic groups is still unclear. Sea stars (Asteroidea) are a diversified and abundant component of benthic ecosystems in the SO, in which they can play key ecological roles. Former studies suggest that the diversity of the entire class is still poorly known and underestimated, hampering the assessment of the origin and evolution of the class in the SO. In the present study, we analyse spatial patterns of SO sea star diversity using an occurrence database of ~14,000 entries. The biogeographic analysis is coupled with the exploration of an extensive molecular phylogeny based on over 4,400 specimen sequences to inform, support and/or question the observed diversity patterns. We show that the current taxonomy of SO asteroids needs revision and that their diversity has generally been overlooked and misinterpreted. Molecular results highlight the recent diversification of most studied taxa, at genus and species levels, which supports an evolutionary scenario referring to successive invasion and exchange events between the SO and adjacent regions, and clade diversification during periods of rapid environmental changes driven by the succession of glacial cycles. Our work advocates for employing, and endorsing the use of extensive genetic barcode libraries for biodiversity studies.

中文翻译：

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南大洋海星（Asteroidea）的高度多样性揭示了原始进化途径

摘要 南大洋 (SO) 底栖生物具有独特的生活史特征和物种组合，但其中许多分类群的起源和进化仍不清楚。海星 (Asteroidea) 是 SO 底栖生态系统中多样化和丰富的组成部分，它们可以在其中发挥关键的生态作用。以往的研究表明，整个类的多样性仍然知之甚少和被低估，阻碍了对SO中类的起源和演变的评估。在本研究中，我们使用约 14,000 个条目的发生数据库分析 SO 海星多样性的空间模式。生物地理学分析与基于 4,400 多个样本序列的广泛分子系统发育的探索相结合，以告知、支持和/或质疑观察到的多样性模式。我们表明当前的 SO 小行星分类需要修订，并且它们的多样性通常被忽视和误解。分子结果突出了最近研究的大多数分类群在属和种水平上的多样化，这支持了一种进化情景，指的是 SO 与相邻区域之间的连续入侵和交换事件，以及在由冰川周期。我们的工作提倡采用和支持使用广泛的遗传条形码库进行生物多样性研究。这支持进化情景，指的是 SO 与相邻区域之间的连续入侵和交换事件，以及在由冰川循环连续驱动的快速环境变化期间的进化枝多样化。我们的工作提倡采用和支持使用广泛的遗传条形码库进行生物多样性研究。这支持进化情景，指的是 SO 与相邻区域之间的连续入侵和交换事件，以及在由冰川循环连续驱动的快速环境变化期间的进化枝多样化。我们的工作提倡采用和支持使用广泛的遗传条形码库进行生物多样性研究。