School of Earth and Environment, University of Leeds, Leeds, UK.
School of Biology, University of Leeds, Leeds, UK.
Nat Commun. 2024 Oct 4;15(1):8599. doi: 10.1038/s41467-024-53000-2.
Mass extinctions are considered to be quintessential examples of Court Jester drivers of macroevolution, whereby abiotic pressures drive a suite of extinctions leading to huge ecosystem changes across geological timescales. Most research on mass extinctions ignores species interactions and community structure, limiting inference about which and why species go extinct, and how Red Queen processes that link speciation to extinction rates affect the subsequent recovery of biodiversity, structure and function. Here, we apply network reconstruction, secondary extinction modelling and community structure analysis to the Early Toarcian (Lower Jurassic; 183 Ma) Extinction Event and recovery. We find that primary extinctions targeted towards infaunal guilds, which caused secondary extinction cascades to higher trophic levels, reproduce the empirical post-extinction community most accurately. We find that the extinction event caused a switch from a diverse community with high levels of functional redundancy to a less diverse, more densely connected community of generalists. Recovery was characterised by a return to pre-extinction levels of some elements of community structure and function prior to the recovery of biodiversity. Full ecosystem recovery took ~7 million years at which point we see evidence of dramatically increased vertical structure linked to the Mesozoic Marine Revolution and modern marine ecosystem structure.
大规模灭绝被认为是宏观进化的法庭弄臣驱动的典型例子，在这种情况下，非生物压力会引发一系列灭绝事件，导致地质时间尺度上的巨大生态系统变化。大多数关于大规模灭绝的研究忽略了物种相互作用和群落结构，限制了关于哪些物种以及为什么会灭绝的推断，以及将物种形成与灭绝率联系起来的红皇后过程如何影响生物多样性、结构和功能的后续恢复。在这里，我们将网络重建、二级灭绝建模和群落结构分析应用于早托阿尔阶（下侏罗纪；183 Ma）灭绝事件及其恢复。我们发现，针对底栖生物群的初级灭绝导致了更高营养级别的二级灭绝级联，最准确地再现了经验后灭绝群落。我们发现，灭绝事件导致了一个从具有高度功能冗余的多样化群落向较少样性、更密集连接的普通物种群落的转变。恢复的特点是在生物多样性恢复之前，群落结构和功能的某些元素恢复到了灭绝前的水平。整个生态系统的恢复大约需要 700 万年，此时我们看到了与中生代海洋革命和现代海洋生态系统结构有关的垂直结构显著增加的证据。
