Collaborative Research: Exploring the Links among Climate, Ecology, and Evolution in Paleogene Marine Faunas of the U.S. Gulf Coastal Plain

最近对人为影响的气候变化的预测强调了了解生物体和生物群落如何对长期和短期扰动作出反应的重要性。来自化石记录的数据可以在这类研究中发挥重要作用，为研究生态系统对长期气候变化的反应提供了可能，而人类在短短几年的时间尺度上是不可能观察到的。PIs计划评估气候对古近纪（约6500 - 2500万年前）美国墨西哥湾沿岸平原海洋软体动物群落生态和进化的影响。他们的方法使他们能够将年平均温度和季节性记录与多样性、群落组成和结构、形态（形状）和进化的变化结合起来。他们特别感兴趣的是了解气候变化的幅度和方向与进化或生态变化的数量和性质之间是否存在相关性，包括是否存在一个生态系统及其组成分类群不响应的容忍阈值。pi将从软体动物化石和鱼耳石（耳石）的化学成分中生成古气候记录，而古生态模式将从现有的博物馆藏品、已发表的文献和新的软体动物野外采样中产生。最后，他们将重建具有该地区和时间特征的两种主要软体动物群——双壳类和甲壳类腹足类的进化关系和趋势，并将这些信息与温度和生态记录相结合，以获得动物对气候变化的全面反应。他们的研究将大大有助于了解亚热带环境中的生物多样性如何对不同类型和程度的气候变化作出反应。

Recent projections of anthropogenically-influenced climate change have emphasized the importance of understanding how organisms and biotic communities respond to perturbations on both the long and short term. Data from the fossil record can be instrumental in such studies, offering the potential to study the response of ecosystems to protracted climate change impossible to observe on human time scales of only a few years. PIs plan to evaluate the influence of climate on the ecology and evolution of marine mollusk faunas from the U.S. Gulf Coastal Plain during the Paleogene (~65-25 million years ago). Their approach allows them to integrate records of mean annual temperature and seasonality with shifts in diversity, community composition and structure, morphology (shape), and evolution. They are particularly interested in learning whether there is a correlation between the magnitude and direction of climate change and the amount and nature of evolutionary or ecological change, including whether or not there are thresholds of tolerance below which an ecosystem and its component taxa do not respond. PIs will generate the paleoclimate record from the chemistry of fossil mollusks and fish otoliths (ear stones), and paleoecological patterns will arise from a combination of existing museum collections, published literature, and new field sampling of mollusk faunas. Lastly, they will reconstruct evolutionary relationships and trends within two dominant mollusk groups - venericard bivalves and turritelline gastropods - that are characteristic of this region and time, and overlay this information on the temperature and ecologic records for a comprehensive picture of faunal response to climate change. Their research will contribute substantially to knowledge of how biodiversity in sub-tropical settings responds to climate change of varying types and magnitudes.