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

晚奥陶世里士满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来评估动物动态。该奖项由2009年美国复苏和再投资法案（公法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征明显的强烈入侵活动，来评估入侵物种对物种形成、灭绝和群落重组的长期影响。本项目将采用生态位建模（ENM）技术，在入侵前、入侵中和入侵后的多个时间片上重建腕足类个体物种的地理分布范围。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居住的环境条件或生态位。然后预测物种的地理范围将扩展到研究区域内存在环境条件的地方。辛辛那提拱门晚奥陶世地层格架中丰富的化石将为实施和完善ENM方法来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）对重建的物种地理范围进行时空分析，通过入侵间隔考察生物地理格局。具体来说，该项目将分析辛辛那提地区原生物种在入侵期间灭绝与持续存在的生物地理差异。对于在入侵期存活下来的本地分类群，将评估它们是否通过(a)改变其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（=栖息地跟踪或生态位保守性），(b)适应变化的环境参数（=生态位进化），或(c)这些选项的某些组合来响应改变的环境。本文将对四个腕足动物属进行系统发育修正，以提供一个进化框架来评估Richmondian入侵期间的物种形成事件，并进一步表征入侵物种对物种形成的作用。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，以及在入侵环境中幸存下来的本地物种的特征（形态、系统发育、环境偏好等）。通过阐明古生代物种入侵过程中栖息地追踪、适应性变化和生物与非生物因素对动物动态的相对影响程度，可以更好地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、地层学野外工作、GIS和ENM技术方面的培训，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一个关于物种范围与环境之间关系以及物种入侵对化石记录的影响的永久性展览来丰富他们的收藏。收集的数据也将在同行评议的期刊上发表，并将以古生物学/地质学和生物学读者为目标，以便向对地球历史感兴趣的读者最好地传播有关入侵物种长期影响的数据，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.