Paleoecologic gradient analysis of the Frasnian/Famennian extinction and recovery

该奖项是根据2009年美国恢复和再投资法案（公法111-5）资助的。摘要在生命的历史上，生物多样性曾多次因大规模灭绝而遭到毁灭，地球上大部分物种都因此而灭绝。史前世界的五次大规模灭绝被称为“大五”（恐龙在第五次也是最近的一次灭绝），而今天人类引起的灭绝被称为“第六次灭绝”。这种正在进行的灭绝，沿着导致它的环境变化，将在未来几十年对生物群落产生重要影响？例如，随着气候变化和竞争者或捕食者的灭绝，物种的地理和生态范围可能会发生变化，导致由意外的物种组合组成的新社区。我们想预测这些变化的性质？毕竟，这些群落为我们提供了栖息地和资源，而物种的转移具有重要的经济后果。预测生物对灭绝和环境变化的反应的一种方法是研究过去对类似变化的反应。也就是说，研究化石记录中的大规模灭绝。灭绝仅仅是产生了与以前类似的“稀疏化”群落，仅仅是一些物种被移除吗？或者，一旦捕食者和/或竞争对手被消灭，物种是否会扩展到新的栖息地和生态位？也许是环境的变化产生了由新的物种组合组成的群落。一些大规模的灭绝可能太大了，灾难性的，不能提供与现代世界相似的东西（例如，二叠纪-三叠纪灭绝）;一个不太严重的灭绝，其中更大比例的物种幸存下来，提供了一个更直接的模型。晚泥盆世灭绝（特别是弗拉斯期-法门期边界的事件）提供了一个合理的比较，本项目将对比灭绝前后形成的化石组合。在纽约和宾夕法尼亚州收集的这些组合是生活在泥盆纪覆盖该地区的浅海中的社区的化石遗迹。PI将结合联合收割机生态梯度分析和沉积学分析，以记录每个物种在灭绝之前和之后生活的环境，以及随时间的任何变化。他们还将研究物种之间共存模式的任何变化。这些结果不仅将揭示泥盆纪的生物变化，而且有望揭示未来世纪的生物变化。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Paleoecologic gradient analysis of the Frasnian/Famennian extinction and recoveryAndrew M. Bush and Christophe DuprazUniversity of ConnecticutEAR - 0922186ABSTRACT A number of times during life's history, biodiversity was decimated by mass extinctions that wiped out a large proportion of the Earth's species. The five largest mass extinctions of the prehistoric world are known as the "Big Five" (the dinosaurs died out in the fifth and most recent), and the present-day, human-induced extinction has been called the "Sixth Extinction". This ongoing extinction, along with the environmental changes that are causing it, will have important effects on biological communities in the coming decades?for example, as the climate changes and as competitors or predators go extinct, species' geographic and ecological ranges may shift, leading to new communities composed of unexpected combinations of species. We would like to predict the nature of these changes?after all, these communities provide us with habitat and resources, and the shifting of species has important economic consequences. One way to forecast biotic responses to extinction and environmental change is to study past responses to similar changes?that is, to study mass extinctions in the fossil record. Did extinctions simply produce "thinned out" communities that were similar to previous ones, merely with some species removed? Or did species expand into new habitats and ecological niches once predators and/or competitors were eliminated? Perhaps a changing environment produced communities composed of novel combinations of species.Some mass extinctions were probably too large and catastrophic to provide close analogues to the modern world (e.g., the Permian-Triassic extinction); a less severe extinction in which a greater proportion of species survived provides a more direct model. The Late Devonian extinction (specifically, the event at the Frasnian-Famennian boundary) provides a reasonable comparison, and this project will contrast fossil assemblages that formed before and after the extinction. Collected in New York and Pennsylvania, these assemblages are the fossilized remains of communities that lived in a shallow sea that covered the area in the Devonian. PIs will combine ecological gradient analysis with a sedimentological analysis to document the environments in which each species lived before and after the extinction, and any changes through time. They will also examine any changes in co-occurrence patterns among species. The results will cast light not just on biotic changes in the Devonian, but also, hopefully, on those in the coming century.