GEOGRAPHIC VARIATION IN ENVIRONMENTS AND EXTINCTION IN THE CARIBBEAN

该奖项由《2009年美国复苏和再投资法案》(公法111-5)资助。由于缺乏严格的环境和生物数据以及有限的地理覆盖面，理解重大灭绝事件的原因往往受到阻碍，这有助于确定一个地区的事件与其他地区的事件有多相似。国际和平研究所建议记录过去一千万年来北加勒比(北加勒比；牙买加和多米尼加共和国)的环境和进化变化模式，并将这些模式与已经从包括巴拿马和哥斯达黎加在内的西南加勒比地区(否则为西南加勒比)获得的类似数据进行比较。由于巴拿马地峡的崛起，西南太平洋经历了季节性上升流和生产力的急剧下降，对苔藓虫和扇贝的详细进化研究有力地支持了这样的假设，即生产力的下降是这些种群高度灭绝和物种形成的原因。以前的分类学研究表明，物种灭绝是相当强烈的，并且几乎在同一时间发生在北半球，但现有的非常有限的数据表明，生产力可能没有出现同等程度的下降。这项研究将提供第一个详细的环境和生物数据，以记录北卡罗来纳州的变化顺序。数据将与深港西部通道的数据完全可比，因为它们将使用相同的方法和标准进行收集和分析。研究结果将为生产率假说在更大范围内的检验提供确凿证据。如果北卡罗来纳州的生产率确实下降了，那么就不需要寻找其他解释了。但如果生产率没有下降，那么其他因素肯定也在加勒比海的灭绝中发挥了重要作用。可能的替代办法包括区域冷却引起的海洋变化，或在巴拿马门户关闭约一百万年后发生的与北半球冰川加剧有关的海平面上升和下降速度加快。该项目是非常可行的，因为在过去的25年里，广泛的地质和古生物调查已经提供了必要的地层框架，开始将故事的所有不同部分结合在一起。

Geographic Variation in Environments and Extinction in the CaribbeanJeremy B. JacksonUniversity of California, San Diego, Scripts Institute of OceanographyThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Understanding the causes of major extinction events is often hampered by a lack of rigorous environmental and biological data and limited geographic coverage, which can help determine how closely events in one region are mirrored in others. The PI proposes to document patterns of environmental and evolutionary change in the Northern Caribbean (NC; Jamaica and the Dominican Republic) over the past ten million years and compare these patterns with similar data already obtained from the southwestern Caribbean (otherwise the SWC), including Panama and Costa Rica. The SWC experienced a dramatic decrease in seasonal upwelling and productivity due to the rise of the Panamanian Isthmus, and detailed evolutionary studies of bryozoans and scallops strongly support the hypothesis that decline in productivity was responsible for the very high extinction and speciation in these groups. Previous taxonomic studies suggest that extinction was comparably strong and occurred at about the same time in the NC, but the very limited data available suggest that there may not have been an equivalent drop in productivity. This study will provide the first detailed environmental and biological data to document the sequence of changes in the NC. Data will be entirely comparable with those from the SWC because they will be collected and analyzed using the same methods and criteria. Results will provide a definitive test of the productivity hypothesis over a broad region. If productivity did decline in the NC there will be little need to look for alternative explanations. But if productivity did not decline, then other factors must also have played an important role in Caribbean extinction. Possible alternatives include oceanographic changes due to regional cooling or increased rates of rise and fall of sea level associated with the intensification of Northern Hemisphere glaciation that occurred about one million years after the closure of the Panamanian Portal. The project is highly feasible because extensive geological and paleontological investigations over the past 25 years have provided the necessary stratigraphic framework to begin to fit all the different pieces of the story together.