The impact of Cenozoic cooling on assemblage diversity in planktonic foraminifera.
The impact of Cenozoic cooling on assemblage diversity in planktonic foraminifera.
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DOI：
10.1098/rstb.2015.0224
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发表时间：
2016-04-05
期刊：
影响因子：
--
通讯作者：
Purvis A
中科院分区：
文献类型：
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作者：
Fenton IS;Pearson PN;Dunkley Jones T;Farnsworth A;Lunt DJ;Markwick P;Purvis A
新生代浮游有孔虫(PF)(钙质浮游动物)可以说是所有类群中最详细的化石记录。这一记录的质量使得针对最近的组装开发的宏观生态环境控制模型可以在气候条件截然不同的情况下进行间隔测试。这些分析揭示了长期全球变冷在建立现代纬度多样性梯度(LDG)方面的作用--这是生物地理学和宏观生态学中最有力的概括之一。在这里，我们测试了为现代PF组合开发的环境多样性模型到始新世的可转移性(约。56-34 Ma)，这是一个全球明显变暖的时期。来自全球气候模型的环境变量与最新的环境多样性模型相结合来预测始新世丰富度梯度，然后将其与观测到的模式进行比较。结果表明，现代LDG--向两极较低的丰度--是在始新世发展起来的。统计模型预测与始新世早期数据之间的不匹配被认为是三个可能的原因：环境估计不准确，统计模型遗漏了相关变量，或者多样性各方面之间的相互关系--例如丰富度、均衡度、功能多样性--随着地质时间的推移而变化。到始新世晚期，环境与多样性的关系与今天发现的更加相似。
The Cenozoic planktonic foraminifera (PF) (calcareous zooplankton) have arguably the most detailed fossil record of any group. The quality of this record allows models of environmental controls on macroecology, developed for Recent assemblages, to be tested on intervals with profoundly different climatic conditions. These analyses shed light on the role of long-term global cooling in establishing the modern latitudinal diversity gradient (LDG)—one of the most powerful generalizations in biogeography and macroecology. Here, we test the transferability of environment-diversity models developed for modern PF assemblages to the Eocene epoch (approx. 56–34 Ma), a time of pronounced global warmth. Environmental variables from global climate models are combined with Recent environment–diversity models to predict Eocene richness gradients, which are then compared with observed patterns. The results indicate the modern LDG—lower richness towards the poles—developed through the Eocene. Three possible causes are suggested for the mismatch between statistical model predictions and data in the Early Eocene: the environmental estimates are inaccurate, the statistical model misses a relevant variable, or the intercorrelations among facets of diversity—e.g. richness, evenness, functional diversity—have changed over geological time. By the Late Eocene, environment–diversity relationships were much more similar to those found today.