RUI: Confidence Intervals for the Duration of a Mass Extinction

Swarthmore学院Steve Wang该奖项由《2009年美国复苏和再投资法案》(Public Law 111-5)资助。Signor-Lipps效应认为，由于化石保存不完整，一组分类群真正突然(同时)灭绝在化石记录中可能是渐进的。因此，在过去的二十年里，许多工作都致力于为地层剖面中所有类群的同时灭绝设计统计检验。然而，PI将开发与化石记录一致的方法来估计灭绝场景的范围，而不是局限于拒绝或未能拒绝这一单一的场景。换句话说，PI不会测试同时或渐进的过于简单化的区别，而是会问这样一个问题：渐进程度如何？PI将为大规模灭绝的持续时间建立一个数学可信区间，无论是根据第一个和最后一个灭绝分类群之间的时间或地层厚度。该项目提议实施一项统计测试，该测试将提供95%的置信度，证明物种灭绝发生在12至18米的地层厚度范围内。这并不否认真正同时灭绝的可能性；相反，在这个框架内，同时灭绝是一种可信区间包含可能的零米持续时间的灭绝。拟议的项目涉及广泛的跨学科，并将专门应用这一数学模型来估计二叠纪末大灭绝的持续时间，这可以说是显生宙最严重的生物危机。

Confidence Intervals for the Duration of a Mass ExtinctionSteve Wang, Swarthmore CollegeThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The Signor-Lipps effect holds that a truly sudden (simultaneous) extinction of a group of taxa may appear gradual in the fossil record due to incomplete fossil preservation. Therefore, much work in the last two decades has been devoted to devising statistical tests for a simultaneous extinction of all taxa in a stratigraphic section. Rather than being limited to rejecting or failing to reject this single scenario, however, the PI will develop methods to estimate the range of extinction scenarios that is consistent with the fossil record. In other words, rather than testing the oversimplified distinction of simultaneous or gradual, the PI will ask the question how gradual? The PI will develop a mathematical confidence interval for the duration of a mass extinction, either in terms of the time or stratigraphic thickness between the first and last taxon to go extinct. The project proposes to implement a statistical test that will provide 95% confidence that the extinction took place over a duration of 12 to 18 meters of stratigraphic thickness. This does not deny the possibility of a truly simultaneous extinction; rather, within this framework, a simultaneous extinction is one in which the confidence interval contains a possible duration of zero meters. The proposed project is broadly interdisciplinary and will specifically apply this mathematical model to estimate the duration of the end-Permian mass extinction, arguably the most severe biotic crisis of the Phanerozoic.