The Biogeographic Impact of the Late Ordovician Richmondian Invasion: Assessing Faunal Dynamics by Combining Niche Modeling and Evolutionary History of Cincinnatian Brachiopods

晚奥陶世Richmondian入侵的生物地理影响：结合生态位模型和辛辛那提腕足动物的进化史评估动物群动态俄亥俄大学Alycia Stigall该奖项由2009年美国复苏和再投资法案(公共法律111-5)资助。该项目的目标是通过分析辛辛那提拱门晚奥陶世地层中保存的一段特别有特点的强烈入侵活动，来评估入侵物种对物种形成、灭绝和群落重组的长期影响。该项目将使用生态位模拟(ENM)技术来重建腕足类个体物种在入侵间隔之前、期间和之后的多个时间切片的地理范围。ENM方法利用从岩石记录中确定的沉积参数作为环境指标来估计单个物种所居住的一组环境条件或生态位。然后，物种地理范围被预测为延伸到研究区域内存在的一组环境条件。辛辛那提拱顶晚奥陶世地层中发育良好的地层格架内丰富的化石将为实施和完善ENM方法以模拟化石物种的地理范围提供良好的地质环境。利用地理信息系统(GIS)，将对重建的单个物种的地理范围进行空间和时间分析，以检查入侵间隔期间的生物地理模式。具体地说，这个项目将分析辛辛那提地区原产物种灭绝和入侵期间存活的物种之间的生物地理差异。对于在入侵间隔中幸存下来的本土分类群，它们是否通过(A)改变它们的生物地理范围以遵循一组首选的非生物环境条件而不表现出进化变化(=生境跟踪或生态位保守主义)，(B)适应改变环境参数(=生态位进化)，或(C)这些选择的某种组合，将被评估。将对四个腕足类属进行系统发育修订，以提供一个进化框架，以评估里士满入侵期间的物种形成事件，并进一步表征入侵物种在物种形成中的作用。该项目还将评估本地物种和移民物种对环境变化的反应是否不同，以及哪些特征(形态、系统发育、环境偏好等)。描述在入侵制度下幸存下来的本土物种的特征。通过阐明生境跟踪、适应性变化以及生物和非生物因素在古生代入侵事件过程中对动物群动态的相对程度，可以开发更好的约束来确定现代生态系统中物种入侵的预期长期(数千年)结果。至少三名研究生和最多四名本科生将接受系统古生物学、地层野外工作以及地理信息系统和ENM技术的培训，并将获得参加专业会议的经验。与辛辛那提博物馆中心的合作将通过捐赠新收集的材料和创建关于物种范围和环境之间的关系以及化石记录中物种入侵的影响的永久展览来丰富他们的藏品。收集的数据还将发表在同行评议的期刊上，并将面向古生物学/地质学和生物学受众，以便最好地向对地球历史感兴趣的受众传播关于入侵物种的长期影响的数据，以及入侵者在现代生物多样性危机中的潜在影响。

The biogeographic impact of the Late Ordovician Richmondian Invasion: Assessing faunal dynamics by combining niche modeling and evolutionary history of Cincinnatian brachiopodsAlycia Stigall, Ohio University This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The goal of this project is to assess the long-term impacts of invasive species on speciation, extinction, and community reorganization by analyzing a particularly well characterized interval of intense invasive activity preserved in the Late Ordovician strata of the Cincinnati Arch. This project will employ ecological niche modeling (ENM) techniques to reconstruct the geographic ranges of individual species of brachiopods at multiple time slices before, during, and after the invasion interval. ENM methods utilize sedimentary parameters determined from the rock record as environmental proxies to estimate the set of environmental condition, or niche, inhabited by individual species. The species geographic range is then predicted to extend to where the set of environmental conditions exists within the study area. The abundant fossils within a well-developed stratigraphic framework in Late Ordovician strata of the Cincinnati Arch will provide an excellent geologic setting to implement and refine ENM methods for modeling the geographic range of fossil species. Using Geographic Information Systems (GIS), the reconstructed geographic ranges of individual species will be analyzed spatially and temporally to examine biogeographic patterns through the invasion interval. Specifically, this project will analyze the biogeographic differences between species native to the Cincinnati region that become extinct versus persist through the invasion interval. For native taxa that survive the invasion interval, whether they respond to the altered environment by (a) shifting their biogeographic ranges to follow a preferred set of abiotic environmental conditions without exhibiting evolutionary change (=habitat tracking or niche conservatism), (b) adaptive change to shifting environmental parameters (=niche evolution), or (c) some combination of these options will be assessed. Phylogenetic revisions of the four brachiopod genera will be conducted to provide an evolutionary framework to assess speciation events during the Richmondian Invasion and further characterize the role of invasive species on speciation. This project will also assess whether native and immigrant species respond differently to environmental change and what features (morphological, phylogenetic, environmental preferences, etc.) characterize the native species that do survive the invasion regime. By elucidating the relative extent that habitat tracking, adaptive change, and biotic vs. abiotic factors have on faunal dynamics during the course of a Paleozoic invasion event, better constraints can be developed to determine the expected long-term (thousands of years) outcome of species invasions within the modern ecosystem. At least three graduate and up to four undergraduate students will be trained in systematic paleontology, stratigraphic field work, and GIS and ENM techniques and will gain experience participating in professional meetings. Collaboration with the Cincinnati Museum Center will result in enriching their collections through donating newly collected material and creation of a permanent exhibit on the relationship between species range and environments and the impact of species invasions in the fossil record. Data collected will also be published in peer-reviewed journals and will target both paleontological/geological and biological audiences in order to best disseminate data on the long term impacts of invasive species to audiences interested in Earth history as well as the potential effects of invaders in the modern biodiversity crisis.