Edie Stewart M, Huang Shan, Collins Katie S, Roy Kaustuv, Jablonski David
Department of the Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA.
Senckenberg Biodiversity and Climate Research Center (BiK-F), Senckenberganlage 25, Frankfurt (Main) 60325, Germany.
Integr Comp Biol. 2018 Dec 1;58(6):1179-1190. doi: 10.1093/icb/icy111.
Many aspects of climate affect the deployment of biodiversity in time and space, and so changes in climate might be expected to drive regional and global extinction of both taxa and their ecological functions. Here we examine the association of past climate changes with extinction in marine bivalves, which are increasingly used as a model system for macroecological and macroevolutionary analysis. Focusing on the Cenozoic Era (66 Myr ago to the present), we analyze extinction patterns in shallow-water marine bivalve genera relative to temperature dynamics as estimated from isotopic data in microfossils. When the entire Cenozoic timeseries is considered, extinction intensity is not significantly associated with the mean temperature or the detrended variance in temperature within a given time interval (stratigraphic stage). However, extinction increases significantly with both the rate of temperature change within the stage of extinction and the absolute change in mean temperature from the preceding stage to the stage of extinction. Thus, several extinction events, particularly the extinction pulse near the Pliocene-Pleistocene boundary, do appear to have climatic drivers. Further, the latitudinal diversity gradient today and the Cenozoic history of polar faunas suggest that long-term, regional extinctions associated with cooling removed not just taxa but a variety of ecological functions from high-latitude seas. These dynamics of biodiversity loss contrast with the two mass extinctions bracketing the Mesozoic Era, which had negligible effects on the diversity of ecological functions despite removing nearly as many taxa as the latitudinal gradient does today. Thus, the fossil record raises a key issue: whether the biotic consequences of present-day stresses will more closely resemble the long-term effects of past climate changes or those that cascaded from the mass extinctions.
气候的诸多方面会在时间和空间上影响生物多样性的分布，因此，气候的变化可能会导致生物分类群及其生态功能在区域和全球范围内灭绝。在此，我们研究过去气候变化与海洋双壳类动物灭绝之间的关联，海洋双壳类动物正日益成为宏观生态和宏观进化分析的模型系统。聚焦新生代（6600万年前至今），我们根据微化石同位素数据估算的温度动态，分析浅海海洋双壳类属的灭绝模式。当考虑整个新生代时间序列时，灭绝强度与给定时间间隔（地层阶段）内的平均温度或温度的去趋势化方差并无显著关联。然而，灭绝率会随着灭绝阶段内的温度变化率以及从前一阶段到灭绝阶段平均温度的绝对变化而显著增加。因此，一些灭绝事件，尤其是上新世 - 更新世边界附近的灭绝脉冲，似乎确实有气候驱动因素。此外，当今的纬度多样性梯度以及极地动物群的新生代历史表明，与变冷相关的长期区域灭绝不仅使生物分类群消失，还使高纬度海域的多种生态功能丧失。生物多样性丧失的这些动态与中生代的两次大灭绝形成对比，尽管中生代大灭绝所消除的生物分类群数量几乎与当今纬度梯度导致的灭绝数量相同，但对生态功能多样性的影响却微乎其微。因此，化石记录提出了一个关键问题：当今压力的生物后果会更类似于过去气候变化的长期影响，还是更类似于大灭绝引发的连锁反应。
