State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, 430074 Wuhan, China;
Senckenberg Biodiversity and Climate Research Center, 60325 Frankfurt am Main, Germany.
Proc Natl Acad Sci U S A. 2020 Jul 28;117(30):17578-17583. doi: 10.1073/pnas.1918953117. Epub 2020 Jul 6.
The latitudinal diversity gradient (LDG) is recognized as one of the most pervasive, global patterns of present-day biodiversity. However, the controlling mechanisms have proved difficult to identify because many potential drivers covary in space. The geological record presents a unique opportunity for understanding the mechanisms which drive the LDG by providing a direct window to deep-time biogeographic dynamics. Here we used a comprehensive database containing 52,318 occurrences of marine fossils to show that the shape of the LDG changed greatly during the Permian-Triassic mass extinction from showing a significant tropical peak to a flattened LDG. The flat LDG lasted for the entire Early Triassic (∼5 My) before reverting to a modern-like shape in the Middle Triassic. The environmental extremes that prevailed globally, especially the dramatic warming, likely induced selective extinction in low latitudes and accumulation of diversity in high latitudes through origination and poleward migration, which combined together account for the flat LDG of the Early Triassic.
纬度多样性梯度（LDG）被认为是当今生物多样性最普遍、最具全球性的模式之一。然而，由于许多潜在的驱动因素在空间上相互关联，因此证明很难确定控制机制。地质记录为理解驱动 LDG 的机制提供了一个独特的机会，因为它为深入了解过去的生物地理动态提供了一个直接的窗口。在这里，我们使用了一个包含 52318 个海洋化石出现的综合数据库，表明 LDG 的形状在二叠纪-三叠纪大灭绝期间发生了很大变化，从显示出显著的热带峰值到 LDG 变平。在整个早三叠世（约 500 万年），LDG 一直保持平坦，然后在中三叠世恢复到现代形状。全球普遍存在的极端环境，特别是剧烈的变暖，可能通过起源和向极地迁移导致低纬度选择性灭绝和高纬度多样性积累，这两者共同导致了早三叠世 LDG 的平坦。
