Investigation Into the Plio-Pleistocene Development of Pacific-Caribbean Environmental Differences Using Mollusc Stable Isotope Profiles

中美洲地峡的出现（大约 3.5马）提出了一个理想的自然实验，用于测试因果关系 海洋生物进化变化的速率和机制的基础 有机体 这一事件隔离了以前相邻的种群 在东太平洋和加勒比海，并启动了发展 在屏障的两侧有不同的选择机制。 软体动物的稳定同位素剖面可以提供一个极好的记录 周围环境条件。 特别是软体动物 同位素剖面记录了 温度、盐度和上升流的变化， 今天的东太平洋和加勒比海西南部。 稳定 将对选定的软体动物贝壳进行同位素分析 从广泛的和日期明确的上新世-更新世部分， 中美洲地峡一侧。 施行本 分析的目的是：1）跟踪之间的差异的发展 东太平洋和加勒比海环境，2）提供了一个 未来演化研究的古环境背景 海洋无脊椎动物分类群。

The emergence of the Central American isthmus (approximately 3.5 Ma) presents an ideal natural experiment for testing the causal basis of the rates and mechanisms of evolutionary change of marine organisms. This event isolated previously contiguous populations in the eastern Pacific and Caribbean, and initiated the development of different selective regimes on opposing sides of the barrier. Molluscan stable isotopic profiles can provide an excellent record of ambient environmental conditions. In particular, molluscan isotopic profiles record the contrasting patterns of seasonal change in temperature, salinity, and upwelling that characterize the eastern Pacific and southwestern Caribbean today. Stable isotopic analyses will be conducted for selected mollusc shells from extensive and well-dated Plio-Pleistocene sections on either side of the Central American isthmus. The purpose of these analyses is to: 1) track the development of the differences between eastern Pacific and Caribbean environments, and 2) provide a paleoenvironmental context for future evolutionary studies of marine invertebrate taxa.