Studies suggest that Pleistocene sea-level fluctuations have drastically affected shallow marine ecosystems such as coral reefs. In the Southwest Atlantic, a Seamounts chain near the Abrolhos Bank has been hypothesized as a stable climatic refugium during the Last Glacial Maximum (LGM). This refugium would have allowed recolonization of the present-day shoreline. Here, we integrated paleoclimatic simulations based on ecological niche modeling (ENM) and adopted a phylogeographic approach to assess this hypothesis for the endemic reef-building coral Mussismilia braziliensis. The niche modeling indicated that the potential distribution of M. braziliensis was smaller in the LGM than in the present; however, the predicted climatically stable regions were not located in the Victoria–Trindade seamount chain, but in regions to the north of this chain. Genetic data showed low structure for the three markers used: SRP-54, ITS, and MaSC-1. Our results suggest a scenario in which the M. braziliensis distribution probably followed the sea-level fluctuation, maintaining its latitudinal distribution range since the LGM, and that it was not confined to a reduced climatic refugium, as previously imagined. We highlight the pioneering nature of this study by combining phylogeography and paleoclimate modeling in order to clarify historical processes that resulted in the current scleractinian biodiversity of Brazilian reefs.

中文翻译：

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巴西特有珊瑚礁巴西Mussismilialia（Anthozoa，Scleractinia）的古气候分布和系统学

研究表明，更新世的海平面波动已经严重影响了浅海生态系统，例如珊瑚礁。在西南大西洋，Abrolhos银行附近的海山链被认为是在上次冰河最高期（LGM）期间稳定的气候避难所。这次避难将使今天的海岸线重新殖民化。在这里，我们基于生态位建模（ENM）整合了古气候模拟，并采用了一种系统地理学方法来评估该假设，以用于建立地方性珊瑚礁的巴西Mussismilia Braziliensis。生态位模型表明巴西分枝杆菌的潜在分布LGM中的LGM小于当前的LGM；但是，预计的气候稳定区域不在维多利亚-特林达德海山链中，而是在该链以北的区域中。遗传数据显示，所使用的三种标记物的结构较低：SRP-54，ITS和MaSC-1。我们的结果提出了一种场景，其中巴西分枝杆菌的分布可能跟随海平面波动，自LGM以来一直保持其纬度分布范围，并且不像以前想象的那样局限于减少的气候保护区。我们通过组合系统学和古气候模型来突出此研究的开创性，以阐明导致巴西珊瑚礁目前存在scleractinian生物多样性的历史过程。