Pinseel Eveline, Van de Vijver Bart, Wolfe Alexander P, Harper Margaret, Antoniades Dermot, Ashworth Allan C, Ector Luc, Lewis Adam R, Perren Bianca, Hodgson Dominic A, Sabbe Koen, Verleyen Elie, Vyverman Wim
Laboratory of Protistology and Aquatic Ecology, Department of Biology, Ghent University, Ghent, Belgium.
Meise Botanic Garden, Meise, Belgium.
Sci Adv. 2021 Sep 17;7(38):eabh3233. doi: 10.1126/sciadv.abh3233. Epub 2021 Sep 15.
Despite evidence for microbial endemism, an understanding of the impact of geological and paleoclimate events on the evolution of regional protist communities remains elusive. Here, we provide insights into the biogeographical history of Antarctic freshwater diatoms, using lacustrine fossils from mid-Miocene and Quaternary Antarctica, and dovetail this dataset with a global inventory of modern freshwater diatom communities. We reveal the existence of a diverse mid-Miocene diatom flora bearing similarities with several former Gondwanan landmasses. Miocene cooling and Plio-Pleistocene glaciations triggered multiple extinction waves, resulting in the selective depauperation of this flora. Although extinction dominated, in situ speciation and new colonizations ultimately shaped the species-poor, yet highly adapted and largely endemic, modern Antarctic diatom flora. Our results provide a more holistic view on the scale of biodiversity turnover in Neogene and Pleistocene Antarctica than the fragmentary perspective offered by macrofossils and underscore the sensitivity of lacustrine microbiota to large-scale climate perturbations.
尽管有证据表明微生物存在地方特有现象，但对于地质和古气候事件对区域原生生物群落演化的影响仍知之甚少。在此，我们利用来自中新世中期和第四纪南极洲的湖泊化石，深入了解南极淡水硅藻的生物地理历史，并将该数据集与全球现代淡水硅藻群落清单相结合。我们揭示了一个多样的中新世中期硅藻植物群的存在，它与几个前冈瓦纳大陆有相似之处。中新世冷却和上新世 - 更新世冰川作用引发了多次灭绝浪潮，导致该植物群选择性地减少。尽管灭绝占主导地位，但原地物种形成和新的定殖最终塑造了物种贫乏但高度适应且大多为地方特有的现代南极硅藻植物群。我们的结果提供了一个比大型化石所提供的零碎观点更全面的关于新近纪和更新世南极洲生物多样性更替规模的视角，并强调了湖泊微生物群对大规模气候扰动的敏感性。
